blender-archive/source/blender/editors/sculpt_paint/paint_image.c

/**
 * $Id$
 * imagepaint.c
 *
 * Functions to paint images in 2D and 3D.
 * 
 * ***** BEGIN GPL LICENSE BLOCK *****
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; either version 2
 * of the License, or (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software Foundation,
 * Inc., 59 Temple Place - Suite 330, Boston, MA	02111-1307, USA.
 *
 * The Original Code is Copyright (C) 2001-2002 by NaN Holding BV.
 * All rights reserved.
 *
 * The Original Code is: some of this file.
 *
 * Contributor(s): Jens Ole Wund (bjornmose), Campbell Barton (ideasman42)
 *
 * ***** END GPL LICENSE BLOCK *****
 */

#include <float.h>
#include <string.h>
#include <stdio.h>
#include <math.h>

#include "MEM_guardedalloc.h"

#ifdef WIN32
#include "BLI_winstuff.h"
#endif
#include "BLI_arithb.h"
#include "BLI_blenlib.h"
#include "BLI_dynstr.h"
#include "BLI_linklist.h"
#include "BLI_memarena.h"
#include "PIL_time.h"
#include "BLI_threads.h"

#include "IMB_imbuf.h"
#include "IMB_imbuf_types.h"

#include "DNA_brush_types.h"
#include "DNA_image_types.h"
#include "DNA_mesh_types.h"
#include "DNA_meshdata_types.h"
#include "DNA_node_types.h"
#include "DNA_object_types.h"
#include "DNA_scene_types.h"
#include "DNA_screen_types.h"
#include "DNA_space_types.h"
#include "DNA_userdef_types.h"
#include "DNA_view3d_types.h"
#include "DNA_windowmanager_types.h"

#include "BKE_context.h"
#include "BKE_brush.h"
#include "BKE_global.h"
#include "BKE_image.h"
#include "BKE_main.h"
#include "BKE_mesh.h"
#include "BKE_node.h"
#include "BKE_paint.h"
#include "BKE_utildefines.h"
#include "BKE_DerivedMesh.h"
#include "BKE_report.h"
#include "BKE_depsgraph.h"

#include "BIF_gl.h"
#include "BIF_glutil.h"

#include "UI_interface.h"
#include "UI_view2d.h"

#include "ED_image.h"
#include "ED_object.h"
#include "ED_screen.h"
#include "ED_view3d.h"

#include "WM_api.h"
#include "WM_types.h"

#include "RNA_access.h"
#include "RNA_define.h"

#include "GPU_draw.h"

#include "paint_intern.h"

/* Defines and Structs */

#define IMAPAINT_CHAR_TO_FLOAT(c) ((c)/255.0f)

#define IMAPAINT_FLOAT_RGB_TO_CHAR(c, f) { (c)[0]=FTOCHAR((f)[0]); (c)[1]=FTOCHAR((f)[1]); (c)[2]=FTOCHAR((f)[2]); }
#define IMAPAINT_FLOAT_RGBA_TO_CHAR(c, f) { (c)[0]=FTOCHAR((f)[0]); (c)[1]=FTOCHAR((f)[1]); (c)[2]=FTOCHAR((f)[2]); (c)[3]=FTOCHAR((f)[3]); }

#define IMAPAINT_CHAR_RGB_TO_FLOAT(f, c) { (f)[0]=IMAPAINT_CHAR_TO_FLOAT((c)[0]); (f)[1]=IMAPAINT_CHAR_TO_FLOAT((c)[1]); (f)[2]=IMAPAINT_CHAR_TO_FLOAT((c)[2]); }
#define IMAPAINT_CHAR_RGBA_TO_FLOAT(f, c) { (f)[0]=IMAPAINT_CHAR_TO_FLOAT((c)[0]); (f)[1]=IMAPAINT_CHAR_TO_FLOAT((c)[1]); (f)[2]=IMAPAINT_CHAR_TO_FLOAT((c)[2]); (f)[3]=IMAPAINT_CHAR_TO_FLOAT((c)[3]); }
#define IMAPAINT_FLOAT_RGB_COPY(a, b) VECCOPY(a, b)

#define IMAPAINT_TILE_BITS			6
#define IMAPAINT_TILE_SIZE			(1 << IMAPAINT_TILE_BITS)
#define IMAPAINT_TILE_NUMBER(size)	(((size)+IMAPAINT_TILE_SIZE-1) >> IMAPAINT_TILE_BITS)

#define MAXUNDONAME	64

static void imapaint_image_update(SpaceImage *sima, Image *image, ImBuf *ibuf, short texpaint);


typedef struct ImagePaintState {
	SpaceImage *sima;
	View2D *v2d;
	Scene *scene;
	bScreen *screen;

	Brush *brush;
	short tool, blend;
	Image *image;
	ImBuf *canvas;
	ImBuf *clonecanvas;
	short clonefreefloat;
	char *warnpackedfile;
	char *warnmultifile;

	/* texture paint only */
	Object *ob;
	Mesh *me;
	int faceindex;
	float uv[2];
} ImagePaintState;

typedef struct ImagePaintPartialRedraw {
	int x1, y1, x2, y2;
	int enabled;
} ImagePaintPartialRedraw;


/* ProjectionPaint defines */

/* approx the number of buckets to have under the brush,
 * used with the brush size to set the ps->buckets_x and ps->buckets_y value.
 * 
 * When 3 - a brush should have ~9 buckets under it at once
 * ...this helps for threading while painting as well as
 * avoiding initializing pixels that wont touch the brush */
#define PROJ_BUCKET_BRUSH_DIV 4

#define PROJ_BUCKET_RECT_MIN 4
#define PROJ_BUCKET_RECT_MAX 256

#define PROJ_BOUNDBOX_DIV 8
#define PROJ_BOUNDBOX_SQUARED  (PROJ_BOUNDBOX_DIV * PROJ_BOUNDBOX_DIV)

//#define PROJ_DEBUG_PAINT 1
//#define PROJ_DEBUG_NOSEAMBLEED 1
//#define PROJ_DEBUG_PRINT_CLIP 1
#define PROJ_DEBUG_WINCLIP 1

/* projectFaceSeamFlags options */
//#define PROJ_FACE_IGNORE	1<<0	/* When the face is hidden, backfacing or occluded */
//#define PROJ_FACE_INIT	1<<1	/* When we have initialized the faces data */
#define PROJ_FACE_SEAM1	1<<0	/* If this face has a seam on any of its edges */
#define PROJ_FACE_SEAM2	1<<1
#define PROJ_FACE_SEAM3	1<<2
#define PROJ_FACE_SEAM4	1<<3

#define PROJ_FACE_NOSEAM1	1<<4
#define PROJ_FACE_NOSEAM2	1<<5
#define PROJ_FACE_NOSEAM3	1<<6
#define PROJ_FACE_NOSEAM4	1<<7

/* a slightly scaled down face is used to get fake 3D location for edge pixels in the seams
 * as this number approaches  1.0f the likelihood increases of float precision errors where
 * it is occluded by an adjacent face */
#define PROJ_FACE_SCALE_SEAM	0.99f

#define PROJ_BUCKET_NULL		0
#define PROJ_BUCKET_INIT		1<<0
// #define PROJ_BUCKET_CLONE_INIT	1<<1

/* used for testing doubles, if a point is on a line etc */
#define PROJ_GEOM_TOLERANCE 0.00075f

/* vert flags */
#define PROJ_VERT_CULL 1

#define PI_80_DEG ((M_PI_2 / 9) * 8)

/* This is mainly a convenience struct used so we can keep an array of images we use
 * Thir imbufs, etc, in 1 array, When using threads this array is copied for each thread
 * because 'partRedrawRect' and 'touch' values would not be thread safe */
typedef struct ProjPaintImage {
	Image *ima;
	ImBuf *ibuf;
	ImagePaintPartialRedraw *partRedrawRect;
	struct UndoTile **undoRect; /* only used to build undo tiles after painting */
	int touch;
} ProjPaintImage;

/* Main projection painting struct passed to all projection painting functions */
typedef struct ProjPaintState {
	View3D *v3d;
	RegionView3D *rv3d;
	ARegion *ar;
	Scene *scene;

	Brush *brush;
	short tool, blend;
	Object *ob;
	/* end similarities with ImagePaintState */
	
	DerivedMesh    *dm;
	int 			dm_totface;
	int 			dm_totvert;
	
	MVert 		   *dm_mvert;
	MFace 		   *dm_mface;
	MTFace 		   *dm_mtface;
	MTFace 		   *dm_mtface_clone;	/* other UV layer, use for cloning between layers */
	MTFace 		   *dm_mtface_mask;
	
	/* projection painting only */
	MemArena *arena_mt[BLENDER_MAX_THREADS];/* for multithreading, the first item is sometimes used for non threaded cases too */
	LinkNode **bucketRect;				/* screen sized 2D array, each pixel has a linked list of ProjPixel's */
	LinkNode **bucketFaces;				/* bucketRect aligned array linkList of faces overlapping each bucket */
	unsigned char *bucketFlags;					/* store if the bucks have been initialized  */
#ifndef PROJ_DEBUG_NOSEAMBLEED
	char *faceSeamFlags;				/* store info about faces, if they are initialized etc*/
	float (*faceSeamUVs)[4][2];			/* expanded UVs for faces to use as seams */
	LinkNode **vertFaces;				/* Only needed for when seam_bleed_px is enabled, use to find UV seams */
#endif
	char *vertFlags;					/* store options per vert, now only store if the vert is pointing away from the view */
	int buckets_x;						/* The size of the bucket grid, the grid span's screenMin/screenMax so you can paint outsize the screen or with 2 brushes at once */
	int buckets_y;
	
	ProjPaintImage *projImages;
	
	int image_tot;				/* size of projectImages array */
	
	float (*screenCoords)[4];	/* verts projected into floating point screen space */
	
	float screenMin[2];			/* 2D bounds for mesh verts on the screen's plane (screenspace) */
	float screenMax[2]; 
	float screen_width;			/* Calculated from screenMin & screenMax */
	float screen_height;
	
	/* options for projection painting */
	int do_layer_clone;
	int do_layer_mask;
	int do_layer_mask_inv;
	
	short do_occlude;			/* Use raytraced occlusion? - ortherwise will paint right through to the back*/
	short do_backfacecull;	/* ignore faces with normals pointing away, skips a lot of raycasts if your normals are correctly flipped */
	short do_mask_normal;			/* mask out pixels based on their normals */
	float normal_angle;				/* what angle to mask at*/
	float normal_angle_inner;
	float normal_angle_range;		/* difference between normal_angle and normal_angle_inner, for easy access */
	
	short is_ortho;
	short is_airbrush;					/* only to avoid using (ps.brush->flag & BRUSH_AIRBRUSH) */
	short is_texbrush;					/* only to avoid running  */
#ifndef PROJ_DEBUG_NOSEAMBLEED
	float seam_bleed_px;
#endif
	/* clone vars */
	float cloneOffset[2];
	
	float projectMat[4][4];		/* Projection matrix, use for getting screen coords */
	float viewDir[3];			/* View vector, use for do_backfacecull and for ray casting with an ortho viewport  */
	float viewPos[3];			/* View location in object relative 3D space, so can compare to verts  */
	float clipsta, clipend;
	
	/* threads */
	int thread_tot;
	int bucketMin[2];
	int bucketMax[2];
	int context_bucket_x, context_bucket_y; /* must lock threads while accessing these */
} ProjPaintState;

typedef union pixelPointer
{
	float *f_pt;			/* float buffer */
	unsigned int *uint_pt; /* 2 ways to access a char buffer */
	unsigned char *ch_pt;
} PixelPointer;

typedef union pixelStore
{
	unsigned char ch[4];
	unsigned int uint;
	float f[4];
} PixelStore;

typedef struct ProjPixel {
	float projCoSS[2]; /* the floating point screen projection of this pixel */
	
	/* Only used when the airbrush is disabled.
	 * Store the max mask value to avoid painting over an area with a lower opacity
	 * with an advantage that we can avoid touching the pixel at all, if the 
	 * new mask value is lower then mask_max */
	unsigned short mask_max;
	
	/* for various reasons we may want to mask out painting onto this pixel */
	unsigned short mask;
	
	short x_px, y_px;
	
	PixelStore origColor;
	PixelStore newColor;
	PixelPointer pixel;
	
	short image_index; /* if anyone wants to paint onto more then 32768 images they can bite me */
	unsigned char bb_cell_index;
} ProjPixel;

typedef struct ProjPixelClone {
	struct ProjPixel __pp;
	PixelStore clonepx;
} ProjPixelClone;

/* Finish projection painting structs */


typedef struct UndoTile {
	struct UndoTile *next, *prev;
	ID id;
	void *rect;
	int x, y;
} UndoTile;

typedef struct UndoElem {
	struct UndoElem *next, *prev;
	char name[MAXUNDONAME];
	uintptr_t undosize;

	ImBuf *ibuf;
	ListBase tiles;
} UndoElem;

static ListBase undobase = {NULL, NULL};
static UndoElem *curundo = NULL;
static ImagePaintPartialRedraw imapaintpartial = {0, 0, 0, 0, 0};

/* UNDO */

/* internal functions */

static void undo_copy_tile(UndoTile *tile, ImBuf *tmpibuf, ImBuf *ibuf, int restore)
{
	/* copy or swap contents of tile->rect and region in ibuf->rect */
	IMB_rectcpy(tmpibuf, ibuf, 0, 0, tile->x*IMAPAINT_TILE_SIZE,
		tile->y*IMAPAINT_TILE_SIZE, IMAPAINT_TILE_SIZE, IMAPAINT_TILE_SIZE);

	if(ibuf->rect_float) {
		SWAP(void*, tmpibuf->rect_float, tile->rect);
	} else {
		SWAP(void*, tmpibuf->rect, tile->rect);
	}
	
	if(restore)
		IMB_rectcpy(ibuf, tmpibuf, tile->x*IMAPAINT_TILE_SIZE,
			tile->y*IMAPAINT_TILE_SIZE, 0, 0, IMAPAINT_TILE_SIZE, IMAPAINT_TILE_SIZE);
}

static UndoTile *undo_init_tile(ID *id, ImBuf *ibuf, ImBuf **tmpibuf, int x_tile, int y_tile)
{
	UndoTile *tile;
	int allocsize;
	
	if (*tmpibuf==NULL)
		*tmpibuf = IMB_allocImBuf(IMAPAINT_TILE_SIZE, IMAPAINT_TILE_SIZE, 32, IB_rectfloat|IB_rect, 0);
	
	tile= MEM_callocN(sizeof(UndoTile), "ImaUndoTile");
	tile->id= *id;
	tile->x= x_tile;
	tile->y= y_tile;

	allocsize= IMAPAINT_TILE_SIZE*IMAPAINT_TILE_SIZE*4;
	allocsize *= (ibuf->rect_float)? sizeof(float): sizeof(char);
	tile->rect= MEM_mapallocN(allocsize, "ImaUndoRect");

	undo_copy_tile(tile, *tmpibuf, ibuf, 0);
	curundo->undosize += allocsize;

	BLI_addtail(&curundo->tiles, tile);
	
	return tile;
}

static void undo_restore(UndoElem *undo)
{
	Image *ima = NULL;
	ImBuf *ibuf, *tmpibuf;
	UndoTile *tile;

	if(!undo)
		return;

	tmpibuf= IMB_allocImBuf(IMAPAINT_TILE_SIZE, IMAPAINT_TILE_SIZE, 32,
	                        IB_rectfloat|IB_rect, 0);
	
	for(tile=undo->tiles.first; tile; tile=tile->next) {
		/* find image based on name, pointer becomes invalid with global undo */
		if(ima && strcmp(tile->id.name, ima->id.name)==0);
		else {
			for(ima=G.main->image.first; ima; ima=ima->id.next)
				if(strcmp(tile->id.name, ima->id.name)==0)
					break;
		}

		ibuf= BKE_image_get_ibuf(ima, NULL);

		if (!ima || !ibuf || !(ibuf->rect || ibuf->rect_float))
			continue;

		undo_copy_tile(tile, tmpibuf, ibuf, 1);

		GPU_free_image(ima); /* force OpenGL reload */
		if(ibuf->rect_float)
			imb_freerectImBuf(ibuf); /* force recreate of char rect */
	}

	IMB_freeImBuf(tmpibuf);
}

static void undo_free(UndoElem *undo)
{
	UndoTile *tile;

	for(tile=undo->tiles.first; tile; tile=tile->next)
		MEM_freeN(tile->rect);
	BLI_freelistN(&undo->tiles);
}

static void undo_imagepaint_push_begin(char *name)
{
	UndoElem *uel;
	int nr;
	
	/* Undo push is split up in begin and end, the reason is that as painting
	 * happens more tiles are added to the list, and at the very end we know
	 * how much memory the undo used to remove old undo elements */

	/* remove all undos after (also when curundo==NULL) */
	while(undobase.last != curundo) {
		uel= undobase.last;
		undo_free(uel);
		BLI_freelinkN(&undobase, uel);
	}
	
	/* make new */
	curundo= uel= MEM_callocN(sizeof(UndoElem), "undo file");
	BLI_addtail(&undobase, uel);

	/* name can be a dynamic string */
	strncpy(uel->name, name, MAXUNDONAME-1);
	
	/* limit amount to the maximum amount*/
	nr= 0;
	uel= undobase.last;
	while(uel) {
		nr++;
		if(nr==U.undosteps) break;
		uel= uel->prev;
	}
	if(uel) {
		while(undobase.first!=uel) {
			UndoElem *first= undobase.first;
			undo_free(first);
			BLI_freelinkN(&undobase, first);
		}
	}
}

static void undo_imagepaint_push_end()
{
	UndoElem *uel;
	uintptr_t totmem, maxmem;

	if(U.undomemory != 0) {
		/* limit to maximum memory (afterwards, we can't know in advance) */
		totmem= 0;
		maxmem= ((uintptr_t)U.undomemory)*1024*1024;

		uel= undobase.last;
		while(uel) {
			totmem+= uel->undosize;
			if(totmem>maxmem) break;
			uel= uel->prev;
		}

		if(uel) {
			while(undobase.first!=uel) {
				UndoElem *first= undobase.first;
				undo_free(first);
				BLI_freelinkN(&undobase, first);
			}
		}
	}
}

void undo_imagepaint_step(int step)
{
	UndoElem *undo;

	if(step==1) {
		if(curundo==NULL);
		else {
			if(G.f & G_DEBUG) printf("undo %s\n", curundo->name);
			undo_restore(curundo);
			curundo= curundo->prev;
		}
	}
	else if(step==-1) {
		if((curundo!=NULL && curundo->next==NULL) || undobase.first==NULL);
		else {
			undo= (curundo && curundo->next)? curundo->next: undobase.first;
			undo_restore(undo);
			curundo= undo;
			if(G.f & G_DEBUG) printf("redo %s\n", undo->name);
		}
	}
}

void undo_imagepaint_clear(void)
{
	UndoElem *uel;
	
	uel= undobase.first;
	while(uel) {
		undo_free(uel);
		uel= uel->next;
	}

	BLI_freelistN(&undobase);
	curundo= NULL;
}

/* fast projection bucket array lookup, use the safe version for bound checking  */
static int project_bucket_offset(const ProjPaintState *ps, const float projCoSS[2])
{
	/* If we were not dealing with screenspace 2D coords we could simple do...
	 * ps->bucketRect[x + (y*ps->buckets_y)] */
	
	/* please explain?
	 * projCoSS[0] - ps->screenMin[0]	: zero origin
	 * ... / ps->screen_width				: range from 0.0 to 1.0
	 * ... * ps->buckets_x		: use as a bucket index
	 *
	 * Second multiplication does similar but for vertical offset
	 */
	return	(	(int)(((projCoSS[0] - ps->screenMin[0]) / ps->screen_width)  * ps->buckets_x)) + 
		(	(	(int)(((projCoSS[1] - ps->screenMin[1])  / ps->screen_height) * ps->buckets_y)) * ps->buckets_x);
}

static int project_bucket_offset_safe(const ProjPaintState *ps, const float projCoSS[2])
{
	int bucket_index = project_bucket_offset(ps, projCoSS);
	
	if (bucket_index < 0 || bucket_index >= ps->buckets_x*ps->buckets_y) {	
		return -1;
	}
	else {
		return bucket_index;
	}
}

#define SIDE_OF_LINE(pa, pb, pp)	((pa[0]-pp[0])*(pb[1]-pp[1]))-((pb[0]-pp[0])*(pa[1]-pp[1]))

static float AreaSignedF2Dfl(float *v1, float *v2, float *v3)
{
   return (float)(0.5f*((v1[0]-v2[0])*(v2[1]-v3[1]) +
(v1[1]-v2[1])*(v3[0]-v2[0])));
}

static void BarycentricWeights2f(float pt[2], float v1[2], float v2[2], float v3[2], float w[3])
{
   float wtot_inv, wtot;

   w[0] = AreaSignedF2Dfl(v2, v3, pt);
   w[1] = AreaSignedF2Dfl(v3, v1, pt);
   w[2] = AreaSignedF2Dfl(v1, v2, pt);
   wtot = w[0]+w[1]+w[2];

   if (wtot != 0.0f) {
       wtot_inv = 1.0f/wtot;

       w[0] = w[0]*wtot_inv;
       w[1] = w[1]*wtot_inv;
       w[2] = w[2]*wtot_inv;
   }
   else /* dummy values for zero area face */
       w[0] = w[1] = w[2] = 1.0f/3.0f;
}

/* still use 2D X,Y space but this works for verts transformed by a perspective matrix, using their 4th component as a weight */
static void BarycentricWeightsPersp2f(float pt[2], float v1[4], float v2[4], float v3[4], float w[3])
{
   float wtot_inv, wtot;

   w[0] = AreaSignedF2Dfl(v2, v3, pt) / v1[3];
   w[1] = AreaSignedF2Dfl(v3, v1, pt) / v2[3];
   w[2] = AreaSignedF2Dfl(v1, v2, pt) / v3[3];
   wtot = w[0]+w[1]+w[2];

   if (wtot != 0.0f) {
       wtot_inv = 1.0f/wtot;

       w[0] = w[0]*wtot_inv;
       w[1] = w[1]*wtot_inv;
       w[2] = w[2]*wtot_inv;
   }
   else /* dummy values for zero area face */
       w[0] = w[1] = w[2] = 1.0f/3.0f;
}

static float VecZDepthOrtho(float pt[2], float v1[3], float v2[3], float v3[3], float w[3])
{
	BarycentricWeights2f(pt, v1, v2, v3, w);
	return (v1[2]*w[0]) + (v2[2]*w[1]) + (v3[2]*w[2]);
}

static float VecZDepthPersp(float pt[2], float v1[3], float v2[3], float v3[3], float w[3])
{
	BarycentricWeightsPersp2f(pt, v1, v2, v3, w);
	return (v1[2]*w[0]) + (v2[2]*w[1]) + (v3[2]*w[2]);
}


/* Return the top-most face index that the screen space coord 'pt' touches (or -1) */
static int project_paint_PickFace(const ProjPaintState *ps, float pt[2], float w[3], int *side)
{
	LinkNode *node;
	float w_tmp[3];
	float *v1, *v2, *v3, *v4;
	int bucket_index;
	int face_index;
	int best_side = -1;
	int best_face_index = -1;
	float z_depth_best = FLT_MAX, z_depth;
	MFace *mf;
	
	bucket_index = project_bucket_offset_safe(ps, pt);
	if (bucket_index==-1)
		return -1;
	
	
	
	/* we could return 0 for 1 face buckets, as long as this function assumes
	 * that the point its testing is only every originated from an existing face */
	
	for (node= ps->bucketFaces[bucket_index]; node; node= node->next) {
		face_index = GET_INT_FROM_POINTER(node->link);
		mf= ps->dm_mface + face_index;
		
		v1= ps->screenCoords[mf->v1];
		v2= ps->screenCoords[mf->v2];
		v3= ps->screenCoords[mf->v3];
		
		if (IsectPT2Df(pt, v1, v2, v3)) {
			if (ps->is_ortho)	z_depth= VecZDepthOrtho(pt, v1, v2, v3, w_tmp);
			else				z_depth= VecZDepthPersp(pt, v1, v2, v3, w_tmp);
			
			if (z_depth < z_depth_best) {
				best_face_index = face_index;
				best_side = 0;
				z_depth_best = z_depth;
				VECCOPY(w, w_tmp);
			}
		}
		else if (mf->v4) {
			v4= ps->screenCoords[mf->v4];
			
			if (IsectPT2Df(pt, v1, v3, v4)) {
				if (ps->is_ortho)	z_depth= VecZDepthOrtho(pt, v1, v3, v4, w_tmp);
				else				z_depth= VecZDepthPersp(pt, v1, v3, v4, w_tmp);

				if (z_depth < z_depth_best) {
					best_face_index = face_index;
					best_side= 1;
					z_depth_best = z_depth;
					VECCOPY(w, w_tmp);
				}
			}
		}
	}
	
	*side = best_side;
	return best_face_index; /* will be -1 or a valid face */
}

/* Converts a uv coord into a pixel location wrapping if the uv is outside 0-1 range */
static void uvco_to_wrapped_pxco(float uv[2], int ibuf_x, int ibuf_y, float *x, float *y)
{
	/* use */
	*x = (float)fmodf(uv[0], 1.0f);
	*y = (float)fmodf(uv[1], 1.0f);
	
	if (*x < 0.0f) *x += 1.0f;
	if (*y < 0.0f) *y += 1.0f;
	
	*x = *x * ibuf_x - 0.5f;
	*y = *y * ibuf_y - 0.5f;
}

/* Set the top-most face color that the screen space coord 'pt' touches (or return 0 if none touch) */
static int project_paint_PickColor(const ProjPaintState *ps, float pt[2], float *rgba_fp, unsigned char *rgba, const int interp)
{
	float w[3], uv[2];
	int side;
	int face_index;
	MTFace *tf;
	ImBuf *ibuf;
	int xi, yi;
	
	
	face_index = project_paint_PickFace(ps, pt, w, &side);
	
	if (face_index == -1)
		return 0;
	
	tf = ps->dm_mtface + face_index;
	
	if (side == 0) {
		Vec2Lerp3f(uv, tf->uv[0], tf->uv[1], tf->uv[2], w);
	}
	else { /* QUAD */
		Vec2Lerp3f(uv, tf->uv[0], tf->uv[2], tf->uv[3], w);
	}
	
	ibuf = tf->tpage->ibufs.first; /* we must have got the imbuf before getting here */
	if (!ibuf) return 0;
	
	if (interp) {
		float x, y;
		uvco_to_wrapped_pxco(uv, ibuf->x, ibuf->y, &x, &y);
		
		if (ibuf->rect_float) {
			if (rgba_fp) {
				bilinear_interpolation_color_wrap(ibuf, NULL, rgba_fp, x, y);
			}
			else {
				float rgba_tmp_f[4];
				bilinear_interpolation_color_wrap(ibuf, NULL, rgba_tmp_f, x, y);
				IMAPAINT_FLOAT_RGBA_TO_CHAR(rgba, rgba_tmp_f);
			}
		}
		else {
			if (rgba) {
				bilinear_interpolation_color_wrap(ibuf, rgba, NULL, x, y);
			}
			else {
				unsigned char rgba_tmp[4];
				bilinear_interpolation_color_wrap(ibuf, rgba_tmp, NULL, x, y);
				IMAPAINT_CHAR_RGBA_TO_FLOAT(rgba_fp, rgba_tmp);
			}
		}
	}
	else {
		xi = (uv[0]*ibuf->x) + 0.5f;
		yi = (uv[1]*ibuf->y) + 0.5f;
		
		//if (xi<0 || xi>=ibuf->x  ||  yi<0 || yi>=ibuf->y) return 0;
		
		/* wrap */
		xi = ((int)(uv[0]*ibuf->x)) % ibuf->x;
		if (xi<0) xi += ibuf->x;
		yi = ((int)(uv[1]*ibuf->y)) % ibuf->y;
		if (yi<0) yi += ibuf->y;
		
		
		if (rgba) {
			if (ibuf->rect_float) {
				float *rgba_tmp_fp = ibuf->rect_float + (xi + yi * ibuf->x * 4);
				IMAPAINT_FLOAT_RGBA_TO_CHAR(rgba, rgba_tmp_fp);
			}
			else {
				*((unsigned int *)rgba) = *(unsigned int *)(((char *)ibuf->rect) + ((xi + yi * ibuf->x) * 4));
			}
		}
		
		if (rgba_fp) {
			if (ibuf->rect_float) {
				QUATCOPY(rgba_fp, ((float *)ibuf->rect_float + ((xi + yi * ibuf->x) * 4)));
			}
			else {
				char *tmp_ch= ((char *)ibuf->rect) + ((xi + yi * ibuf->x) * 4);
				IMAPAINT_CHAR_RGBA_TO_FLOAT(rgba_fp, tmp_ch);
			}
		}
	}
	return 1;
}

/* Check if 'pt' is infront of the 3 verts on the Z axis (used for screenspace occlusuion test)
 * return...
 *  0	: no occlusion
 * -1	: no occlusion but 2D intersection is true (avoid testing the other half of a quad)
 *  1	: occluded
    2	: occluded with w[3] weights set (need to know in some cases) */

static int project_paint_occlude_ptv(float pt[3], float v1[3], float v2[3], float v3[3], float w[3], int is_ortho)
{
	/* if all are behind us, return false */
	if(v1[2] > pt[2] && v2[2] > pt[2] && v3[2] > pt[2])
		return 0;
		
	/* do a 2D point in try intersection */
	if (!IsectPT2Df(pt, v1, v2, v3))
		return 0; /* we know there is  */
	

	/* From here on we know there IS an intersection */
	/* if ALL of the verts are infront of us then we know it intersects ? */
	if(v1[2] < pt[2] && v2[2] < pt[2] && v3[2] < pt[2]) {
		return 1;
	}
	else {
		/* we intersect? - find the exact depth at the point of intersection */
		/* Is this point is occluded by another face? */
		if (is_ortho) {
			if (VecZDepthOrtho(pt, v1, v2, v3, w) < pt[2]) return 2;
		}
		else {
			if (VecZDepthPersp(pt, v1, v2, v3, w) < pt[2]) return 2;
		}
	}
	return -1;
}


static int project_paint_occlude_ptv_clip(
		const ProjPaintState *ps, const MFace *mf,
		float pt[3], float v1[3], float v2[3], float v3[3],
		const int side )
{
	float w[3], wco[3];
	int ret = project_paint_occlude_ptv(pt, v1, v2, v3, w, ps->is_ortho);

	if (ret <= 0)
		return ret;

	if (ret==1) { /* weights not calculated */
		if (ps->is_ortho)	BarycentricWeights2f(pt, v1, v2, v3, w);
		else				BarycentricWeightsPersp2f(pt, v1, v2, v3, w);
	}

	/* Test if we're in the clipped area, */
	if (side)	VecLerp3f(wco, ps->dm_mvert[mf->v1].co, ps->dm_mvert[mf->v3].co, ps->dm_mvert[mf->v4].co, w);
	else		VecLerp3f(wco, ps->dm_mvert[mf->v1].co, ps->dm_mvert[mf->v2].co, ps->dm_mvert[mf->v3].co, w);
	
	Mat4MulVecfl(ps->ob->obmat, wco);
	if(!view3d_test_clipping(ps->rv3d, wco)) {
		return 1;
	}
	
	return -1;
}


/* Check if a screenspace location is occluded by any other faces
 * check, pixelScreenCo must be in screenspace, its Z-Depth only needs to be used for comparison
 * and dosn't need to be correct in relation to X and Y coords (this is the case in perspective view) */
static int project_bucket_point_occluded(const ProjPaintState *ps, LinkNode *bucketFace, const int orig_face, float pixelScreenCo[4])
{
	MFace *mf;
	int face_index;
	int isect_ret;
	float w[3]; /* not needed when clipping */
	
	/* we could return 0 for 1 face buckets, as long as this function assumes
	 * that the point its testing is only every originated from an existing face */

	for (; bucketFace; bucketFace = bucketFace->next) {
		face_index = GET_INT_FROM_POINTER(bucketFace->link);

		if (orig_face != face_index) {
			mf = ps->dm_mface + face_index;
			if(ps->rv3d->rflag & RV3D_CLIPPING)
				isect_ret = project_paint_occlude_ptv_clip(ps, mf, pixelScreenCo, ps->screenCoords[mf->v1], ps->screenCoords[mf->v2], ps->screenCoords[mf->v3], 0);
			else
				isect_ret = project_paint_occlude_ptv(pixelScreenCo, ps->screenCoords[mf->v1], ps->screenCoords[mf->v2], ps->screenCoords[mf->v3], w, ps->is_ortho);

			/* Note, if isect_ret==-1 then we dont want to test the other side of the quad */
			if (isect_ret==0 && mf->v4) {
				if(ps->rv3d->rflag & RV3D_CLIPPING)
					isect_ret = project_paint_occlude_ptv_clip(ps, mf, pixelScreenCo, ps->screenCoords[mf->v1], ps->screenCoords[mf->v3], ps->screenCoords[mf->v4], 1);
				else
					isect_ret = project_paint_occlude_ptv(pixelScreenCo, ps->screenCoords[mf->v1], ps->screenCoords[mf->v3], ps->screenCoords[mf->v4], w, ps->is_ortho);
			}
			if (isect_ret>=1) {
				/* TODO - we may want to cache the first hit,
				 * it is not possible to swap the face order in the list anymore */
				return 1;
			}
		}
	}
	return 0;
}

/* basic line intersection, could move to arithb.c, 2 points with a horiz line
 * 1 for an intersection, 2 if the first point is aligned, 3 if the second point is aligned */
#define ISECT_TRUE 1
#define ISECT_TRUE_P1 2
#define ISECT_TRUE_P2 3
static int line_isect_y(const float p1[2], const float p2[2], const float y_level, float *x_isect)
{
	float y_diff;
	
	if (y_level==p1[1]) { /* are we touching the first point? - no interpolation needed */
		*x_isect = p1[0];
		return ISECT_TRUE_P1;
	}
	if (y_level==p2[1]) { /* are we touching the second point? - no interpolation needed */
		*x_isect = p2[0];
		return ISECT_TRUE_P2;
	}
	
	y_diff= fabsf(p1[1]-p2[1]); /* yuck, horizontal line, we cant do much here */
	
	if (y_diff < 0.000001f) {
		*x_isect = (p1[0]+p2[0]) * 0.5f;
		return ISECT_TRUE;		
	}
	
	if (p1[1] > y_level && p2[1] < y_level) {
		*x_isect = (p2[0]*(p1[1]-y_level) + p1[0]*(y_level-p2[1])) / y_diff;  /*(p1[1]-p2[1]);*/
		return ISECT_TRUE;
	}
	else if (p1[1] < y_level && p2[1] > y_level) {
		*x_isect = (p2[0]*(y_level-p1[1]) + p1[0]*(p2[1]-y_level)) / y_diff;  /*(p2[1]-p1[1]);*/
		return ISECT_TRUE;
	}
	else {
		return 0;
	}
}

static int line_isect_x(const float p1[2], const float p2[2], const float x_level, float *y_isect)
{
	float x_diff;
	
	if (x_level==p1[0]) { /* are we touching the first point? - no interpolation needed */
		*y_isect = p1[1];
		return ISECT_TRUE_P1;
	}
	if (x_level==p2[0]) { /* are we touching the second point? - no interpolation needed */
		*y_isect = p2[1];
		return ISECT_TRUE_P2;
	}
	
	x_diff= fabsf(p1[0]-p2[0]); /* yuck, horizontal line, we cant do much here */
	
	if (x_diff < 0.000001) { /* yuck, vertical line, we cant do much here */
		*y_isect = (p1[0]+p2[0]) * 0.5f;
		return ISECT_TRUE;		
	}
	
	if (p1[0] > x_level && p2[0] < x_level) {
		*y_isect = (p2[1]*(p1[0]-x_level) + p1[1]*(x_level-p2[0])) / x_diff; /*(p1[0]-p2[0]);*/
		return ISECT_TRUE;
	}
	else if (p1[0] < x_level && p2[0] > x_level) {
		*y_isect = (p2[1]*(x_level-p1[0]) + p1[1]*(p2[0]-x_level)) / x_diff; /*(p2[0]-p1[0]);*/
		return ISECT_TRUE;
	}
	else {
		return 0;
	}
}

/* simple func use for comparing UV locations to check if there are seams.
 * Its possible this gives incorrect results, when the UVs for 1 face go into the next 
 * tile, but do not do this for the adjacent face, it could return a false positive.
 * This is so unlikely that Id not worry about it. */
#ifndef PROJ_DEBUG_NOSEAMBLEED
static int cmp_uv(const float vec2a[2], const float vec2b[2])
{
	/* if the UV's are not between 0.0 and 1.0 */
	float xa = (float)fmodf(vec2a[0], 1.0f);
	float ya = (float)fmodf(vec2a[1], 1.0f);
	
	float xb = (float)fmodf(vec2b[0], 1.0f);
	float yb = (float)fmodf(vec2b[1], 1.0f);	
	
	if (xa < 0.0f) xa += 1.0f;
	if (ya < 0.0f) ya += 1.0f;
	
	if (xb < 0.0f) xb += 1.0f;
	if (yb < 0.0f) yb += 1.0f;
	
	return ((fabsf(xa-xb) < PROJ_GEOM_TOLERANCE) && (fabsf(ya-yb) < PROJ_GEOM_TOLERANCE)) ? 1:0;
}
#endif

/* set min_px and max_px to the image space bounds of the UV coords 
 * return zero if there is no area in the returned rectangle */
#ifndef PROJ_DEBUG_NOSEAMBLEED
static int pixel_bounds_uv(
		const float uv1[2], const float uv2[2], const float uv3[2], const float uv4[2],
		rcti *bounds_px,
		const int ibuf_x, const int ibuf_y,
		int is_quad
) {
	float min_uv[2], max_uv[2]; /* UV bounds */
	
	INIT_MINMAX2(min_uv, max_uv);
	
	DO_MINMAX2(uv1, min_uv, max_uv);
	DO_MINMAX2(uv2, min_uv, max_uv);
	DO_MINMAX2(uv3, min_uv, max_uv);
	if (is_quad)
		DO_MINMAX2(uv4, min_uv, max_uv);
	
	bounds_px->xmin = (int)(ibuf_x * min_uv[0]);
	bounds_px->ymin = (int)(ibuf_y * min_uv[1]);
	
	bounds_px->xmax = (int)(ibuf_x * max_uv[0]) +1;
	bounds_px->ymax = (int)(ibuf_y * max_uv[1]) +1;
	
	/*printf("%d %d %d %d \n", min_px[0], min_px[1], max_px[0], max_px[1]);*/
	
	/* face uses no UV area when quantized to pixels? */
	return (bounds_px->xmin == bounds_px->xmax || bounds_px->ymin == bounds_px->ymax) ? 0 : 1;
}
#endif

static int pixel_bounds_array(float (* uv)[2], rcti *bounds_px, const int ibuf_x, const int ibuf_y, int tot)
{
	float min_uv[2], max_uv[2]; /* UV bounds */
	
	if (tot==0) {
		return 0;
	}
	
	INIT_MINMAX2(min_uv, max_uv);
	
	while (tot--) {
		DO_MINMAX2((*uv), min_uv, max_uv);
		uv++;
	}
	
	bounds_px->xmin = (int)(ibuf_x * min_uv[0]);
	bounds_px->ymin = (int)(ibuf_y * min_uv[1]);
	
	bounds_px->xmax = (int)(ibuf_x * max_uv[0]) +1;
	bounds_px->ymax = (int)(ibuf_y * max_uv[1]) +1;
	
	/*printf("%d %d %d %d \n", min_px[0], min_px[1], max_px[0], max_px[1]);*/
	
	/* face uses no UV area when quantized to pixels? */
	return (bounds_px->xmin == bounds_px->xmax || bounds_px->ymin == bounds_px->ymax) ? 0 : 1;
}

#ifndef PROJ_DEBUG_NOSEAMBLEED

/* This function returns 1 if this face has a seam along the 2 face-vert indicies
 * 'orig_i1_fidx' and 'orig_i2_fidx' */
static int check_seam(const ProjPaintState *ps, const int orig_face, const int orig_i1_fidx, const int orig_i2_fidx, int *other_face, int *orig_fidx)
{
	LinkNode *node;
	int face_index;
	int i1, i2;
	int i1_fidx = -1, i2_fidx = -1; /* index in face */
	MFace *mf;
	MTFace *tf;
	const MFace *orig_mf = ps->dm_mface + orig_face;  
	const MTFace *orig_tf = ps->dm_mtface + orig_face;
	
	/* vert indicies from face vert order indicies */
	i1 = (*(&orig_mf->v1 + orig_i1_fidx));
	i2 = (*(&orig_mf->v1 + orig_i2_fidx));
	
	for (node = ps->vertFaces[i1]; node; node = node->next) {
		face_index = GET_INT_FROM_POINTER(node->link);

		if (face_index != orig_face) {
			mf = ps->dm_mface + face_index;
			/* could check if the 2 faces images match here,
			 * but then there wouldn't be a way to return the opposite face's info */
			
			
			/* We need to know the order of the verts in the adjacent face 
			 * set the i1_fidx and i2_fidx to (0,1,2,3) */
			if		(mf->v1==i1)			i1_fidx = 0;
			else if	(mf->v2==i1)			i1_fidx = 1;
			else if	(mf->v3==i1)			i1_fidx = 2;
			else if	(mf->v4 && mf->v4==i1)	i1_fidx = 3;
			
			if		(mf->v1==i2)			i2_fidx = 0;
			else if	(mf->v2==i2)			i2_fidx = 1;
			else if	(mf->v3==i2)			i2_fidx = 2;
			else if	(mf->v4 && mf->v4==i2)	i2_fidx = 3;
			
			/* Only need to check if 'i2_fidx' is valid because we know i1_fidx is the same vert on both faces */
			if (i2_fidx != -1) {
				/* This IS an adjacent face!, now lets check if the UVs are ok */
				tf = ps->dm_mtface + face_index;
				
				/* set up the other face */
				*other_face = face_index;
				*orig_fidx = (i1_fidx < i2_fidx) ? i1_fidx : i2_fidx;
				
				/* first test if they have the same image */
				if (	(orig_tf->tpage == tf->tpage) &&
						cmp_uv(orig_tf->uv[orig_i1_fidx], tf->uv[i1_fidx]) &&
						cmp_uv(orig_tf->uv[orig_i2_fidx], tf->uv[i2_fidx]) )
				{
					// printf("SEAM (NONE)\n");
					return 0;
					
				}
				else {
					// printf("SEAM (UV GAP)\n");
					return 1;
				}
			}
		}
	}
	// printf("SEAM (NO FACE)\n");
	*other_face = -1;
	return 1;
}

/* Calculate outset UV's, this is not the same as simply scaling the UVs,
 * since the outset coords are a margin that keep an even distance from the original UV's,
 * note that the image aspect is taken into account */
static void uv_image_outset(float (*orig_uv)[2], float (*outset_uv)[2], const float scaler, const int ibuf_x, const int ibuf_y, const int is_quad)
{
	float a1, a2, a3, a4=0.0f;
	float puv[4][2]; /* pixelspace uv's */
	float no1[2], no2[2], no3[2], no4[2]; /* normals */
	float dir1[2], dir2[2], dir3[2], dir4[2];
	float ibuf_x_inv = 1.0f / (float)ibuf_x; 
	float ibuf_y_inv = 1.0f / (float)ibuf_y; 
	
	/* make UV's in pixel space so we can */
	puv[0][0] = orig_uv[0][0] * ibuf_x;
	puv[0][1] = orig_uv[0][1] * ibuf_y;
	
	puv[1][0] = orig_uv[1][0] * ibuf_x;
	puv[1][1] = orig_uv[1][1] * ibuf_y;
	
	puv[2][0] = orig_uv[2][0] * ibuf_x;
	puv[2][1] = orig_uv[2][1] * ibuf_y;
	
	if (is_quad) {
		puv[3][0] = orig_uv[3][0] * ibuf_x;
		puv[3][1] = orig_uv[3][1] * ibuf_y;
	}
	
	/* face edge directions */
	Vec2Subf(dir1, puv[1], puv[0]);
	Vec2Subf(dir2, puv[2], puv[1]);
	Normalize2(dir1);
	Normalize2(dir2);
	
	if (is_quad) {
		Vec2Subf(dir3, puv[3], puv[2]);
		Vec2Subf(dir4, puv[0], puv[3]);
		Normalize2(dir3);
		Normalize2(dir4);
	}
	else {
		Vec2Subf(dir3, puv[0], puv[2]);
		Normalize2(dir3);
	}
	
	if (is_quad) {
		a1 = AngleToLength(NormalizedVecAngle2_2D(dir4, dir1));
		a2 = AngleToLength(NormalizedVecAngle2_2D(dir1, dir2));
		a3 = AngleToLength(NormalizedVecAngle2_2D(dir2, dir3));
		a4 = AngleToLength(NormalizedVecAngle2_2D(dir3, dir4));
	}
	else {
		a1 = AngleToLength(NormalizedVecAngle2_2D(dir3, dir1));
		a2 = AngleToLength(NormalizedVecAngle2_2D(dir1, dir2));
		a3 = AngleToLength(NormalizedVecAngle2_2D(dir2, dir3));
	}
	
	if (is_quad) {
		Vec2Subf(no1, dir4, dir1);
		Vec2Subf(no2, dir1, dir2);
		Vec2Subf(no3, dir2, dir3);
		Vec2Subf(no4, dir3, dir4);
		Normalize2(no1);
		Normalize2(no2);
		Normalize2(no3);
		Normalize2(no4);
		Vec2Mulf(no1, a1*scaler);
		Vec2Mulf(no2, a2*scaler);
		Vec2Mulf(no3, a3*scaler);
		Vec2Mulf(no4, a4*scaler);
		Vec2Addf(outset_uv[0], puv[0], no1);
		Vec2Addf(outset_uv[1], puv[1], no2);
		Vec2Addf(outset_uv[2], puv[2], no3);
		Vec2Addf(outset_uv[3], puv[3], no4);
		outset_uv[0][0] *= ibuf_x_inv;
		outset_uv[0][1] *= ibuf_y_inv;
		
		outset_uv[1][0] *= ibuf_x_inv;
		outset_uv[1][1] *= ibuf_y_inv;
		
		outset_uv[2][0] *= ibuf_x_inv;
		outset_uv[2][1] *= ibuf_y_inv;
		
		outset_uv[3][0] *= ibuf_x_inv;
		outset_uv[3][1] *= ibuf_y_inv;
	}
	else {
		Vec2Subf(no1, dir3, dir1);
		Vec2Subf(no2, dir1, dir2);
		Vec2Subf(no3, dir2, dir3);
		Normalize2(no1);
		Normalize2(no2);
		Normalize2(no3);
		Vec2Mulf(no1, a1*scaler);
		Vec2Mulf(no2, a2*scaler);
		Vec2Mulf(no3, a3*scaler);
		Vec2Addf(outset_uv[0], puv[0], no1);
		Vec2Addf(outset_uv[1], puv[1], no2);
		Vec2Addf(outset_uv[2], puv[2], no3);
		outset_uv[0][0] *= ibuf_x_inv;
		outset_uv[0][1] *= ibuf_y_inv;
		
		outset_uv[1][0] *= ibuf_x_inv;
		outset_uv[1][1] *= ibuf_y_inv;
		
		outset_uv[2][0] *= ibuf_x_inv;
		outset_uv[2][1] *= ibuf_y_inv;
	}
}

/* 
 * Be tricky with flags, first 4 bits are PROJ_FACE_SEAM1 to 4, last 4 bits are PROJ_FACE_NOSEAM1 to 4
 * 1<<i - where i is (0-3) 
 * 
 * If we're multithreadng, make sure threads are locked when this is called
 */
static void project_face_seams_init(const ProjPaintState *ps, const int face_index, const int is_quad)
{
	int other_face, other_fidx; /* vars for the other face, we also set its flag */
	int fidx1 = is_quad ? 3 : 2;
	int fidx2 = 0; /* next fidx in the face (0,1,2,3) -> (1,2,3,0) or (0,1,2) -> (1,2,0) for a tri */
	
	do {
		if ((ps->faceSeamFlags[face_index] & (1<<fidx1|16<<fidx1)) == 0) {
			if (check_seam(ps, face_index, fidx1, fidx2, &other_face, &other_fidx)) {
				ps->faceSeamFlags[face_index] |= 1<<fidx1;
				if (other_face != -1)
					ps->faceSeamFlags[other_face] |= 1<<other_fidx;
			}
			else {
				ps->faceSeamFlags[face_index] |= 16<<fidx1;
				if (other_face != -1)
					ps->faceSeamFlags[other_face] |= 16<<other_fidx; /* second 4 bits for disabled */
			}
		}
		
		fidx2 = fidx1;
	} while (fidx1--);
}
#endif // PROJ_DEBUG_NOSEAMBLEED


/* TODO - move to arithb.c */

/* little sister we only need to know lambda */
static float lambda_cp_line2(const float p[2], const float l1[2], const float l2[2])
{
	float h[2], u[2];
	
	u[0] = l2[0] - l1[0];
	u[1] = l2[1] - l1[1];

	h[0] = p[0] - l1[0];
	h[1] = p[1] - l1[1];
	
	return(Inp2f(u, h)/Inp2f(u, u));
}


/* Converts a UV location to a 3D screenspace location
 * Takes a 'uv' and 3 UV coords, and sets the values of pixelScreenCo
 * 
 * This is used for finding a pixels location in screenspace for painting */
static void screen_px_from_ortho(
		float uv[2],
		float v1co[3], float v2co[3], float v3co[3], /* Screenspace coords */
		float uv1co[2], float uv2co[2], float uv3co[2],
		float pixelScreenCo[4],
		float w[3])
{
	BarycentricWeights2f(uv, uv1co, uv2co, uv3co, w);
	VecLerp3f(pixelScreenCo, v1co, v2co, v3co, w);
}

/* same as screen_px_from_ortho except we need to take into account
 * the perspective W coord for each vert */
static void screen_px_from_persp(
		float uv[2],
		float v1co[3], float v2co[3], float v3co[3], /* screenspace coords */
		float uv1co[2], float uv2co[2], float uv3co[2],
		float pixelScreenCo[4],
		float w[3])
{

	float wtot_inv, wtot;
	BarycentricWeights2f(uv, uv1co, uv2co, uv3co, w);
	
	/* re-weight from the 4th coord of each screen vert */
	w[0] *= v1co[3];
	w[1] *= v2co[3];
	w[2] *= v3co[3];
	
	wtot = w[0]+w[1]+w[2];
	
	if (wtot > 0.0f) {
		wtot_inv = 1.0f / wtot;
		w[0] *= wtot_inv;
		w[1] *= wtot_inv;
		w[2] *= wtot_inv;
	}
	else {
		w[0] = w[1] = w[2] = 1.0/3.0; /* dummy values for zero area face */
	}
	/* done re-weighting */
	
	VecLerp3f(pixelScreenCo, v1co, v2co, v3co, w);
}

static void project_face_pixel(const MTFace *tf_other, ImBuf *ibuf_other, const float w[3], int side, unsigned char rgba_ub[4], float rgba_f[4])
{
	float *uvCo1, *uvCo2, *uvCo3;
	float uv_other[2], x, y;
	
	uvCo1 =  (float *)tf_other->uv[0];
	if (side==1) {
		uvCo2 =  (float *)tf_other->uv[2];
		uvCo3 =  (float *)tf_other->uv[3];
	}
	else {
		uvCo2 =  (float *)tf_other->uv[1];
		uvCo3 =  (float *)tf_other->uv[2];
	}
	
	Vec2Lerp3f(uv_other, uvCo1, uvCo2, uvCo3, w);
	
	/* use */
	uvco_to_wrapped_pxco(uv_other, ibuf_other->x, ibuf_other->y, &x, &y);
	
	
	if (ibuf_other->rect_float) { /* from float to float */
		bilinear_interpolation_color_wrap(ibuf_other, NULL, rgba_f, x, y);
	}
	else { /* from char to float */
		bilinear_interpolation_color_wrap(ibuf_other, rgba_ub, NULL, x, y);
	}
		
}

/* run this outside project_paint_uvpixel_init since pixels with mask 0 dont need init */
float project_paint_uvpixel_mask(
		const ProjPaintState *ps,
		const int face_index,
		const int side,
		const float w[3])
{
	float mask;
	
	/* Image Mask */
	if (ps->do_layer_mask) {
		/* another UV layers image is masking this one's */
		ImBuf *ibuf_other;
		const MTFace *tf_other = ps->dm_mtface_mask + face_index;
		
		if (tf_other->tpage && (ibuf_other = BKE_image_get_ibuf(tf_other->tpage, NULL))) {
			/* BKE_image_get_ibuf - TODO - this may be slow */
			unsigned char rgba_ub[4];
			float rgba_f[4];
			
			project_face_pixel(tf_other, ibuf_other, w, side, rgba_ub, rgba_f);
			
			if (ibuf_other->rect_float) { /* from float to float */
				mask = ((rgba_f[0]+rgba_f[1]+rgba_f[2])/3.0f) * rgba_f[3];
			}
			else { /* from char to float */
				mask = ((rgba_ub[0]+rgba_ub[1]+rgba_ub[2])/(256*3.0f)) * (rgba_ub[3]/256.0f);
			}
			
			if (!ps->do_layer_mask_inv) /* matching the gimps layer mask black/white rules, white==full opacity */
				mask = (1.0f - mask);

			if (mask == 0.0f) {
				return 0.0f;
			}
		}
		else {
			return 0.0f;
		}
	} else {
		mask = 1.0f;
	}
	
	/* calculate mask */
	if (ps->do_mask_normal) {
		MFace *mf = ps->dm_mface + face_index;
		short *no1, *no2, *no3;
		float no[3], angle;
		no1 = ps->dm_mvert[mf->v1].no;
		if (side==1) {
			no2 = ps->dm_mvert[mf->v3].no;
			no3 = ps->dm_mvert[mf->v4].no;
		}
		else {
			no2 = ps->dm_mvert[mf->v2].no;
			no3 = ps->dm_mvert[mf->v3].no;
		}
		
		no[0] = w[0]*no1[0] + w[1]*no2[0] + w[2]*no3[0];
		no[1] = w[0]*no1[1] + w[1]*no2[1] + w[2]*no3[1];
		no[2] = w[0]*no1[2] + w[1]*no2[2] + w[2]*no3[2];
		Normalize(no);
		
		/* now we can use the normal as a mask */
		if (ps->is_ortho) {
			angle = NormalizedVecAngle2((float *)ps->viewDir, no);
		}
		else {
			/* Annoying but for the perspective view we need to get the pixels location in 3D space :/ */
			float viewDirPersp[3];
			float *co1, *co2, *co3;
			co1 = ps->dm_mvert[mf->v1].co;
			if (side==1) {
				co2 = ps->dm_mvert[mf->v3].co;
				co3 = ps->dm_mvert[mf->v4].co;
			}
			else {
				co2 = ps->dm_mvert[mf->v2].co;
				co3 = ps->dm_mvert[mf->v3].co;
			}

			/* Get the direction from the viewPoint to the pixel and normalize */
			viewDirPersp[0] = (ps->viewPos[0] - (w[0]*co1[0] + w[1]*co2[0] + w[2]*co3[0]));
			viewDirPersp[1] = (ps->viewPos[1] - (w[0]*co1[1] + w[1]*co2[1] + w[2]*co3[1]));
			viewDirPersp[2] = (ps->viewPos[2] - (w[0]*co1[2] + w[1]*co2[2] + w[2]*co3[2]));
			Normalize(viewDirPersp);
			
			angle = NormalizedVecAngle2(viewDirPersp, no);
		}
		
		if (angle >= ps->normal_angle) {
			return 0.0f; /* outsize the normal limit*/
		}
		else if (angle > ps->normal_angle_inner) {
			mask *= (ps->normal_angle - angle) / ps->normal_angle_range;
		} /* otherwise no mask normal is needed, were within the limit */
	}
	
	// This only works when the opacity dosnt change while painting, stylus pressure messes with this
	// so dont use it.
	// if (ps->is_airbrush==0) mask *= ps->brush->alpha;
	
	return mask;
}

/* run this function when we know a bucket's, face's pixel can be initialized,
 * return the ProjPixel which is added to 'ps->bucketRect[bucket_index]' */
static ProjPixel *project_paint_uvpixel_init(
		const ProjPaintState *ps,
		MemArena *arena,
		const ImBuf *ibuf,
		short x_px, short y_px,
		const float mask,
		const int face_index,
		const int image_index,
		const float pixelScreenCo[4],
		const int side,
		const float w[3])
{
	ProjPixel *projPixel;
	short size;
	
	/* wrap pixel location */
	x_px = x_px % ibuf->x;
	if (x_px<0) x_px += ibuf->x;
	y_px = y_px % ibuf->y;
	if (y_px<0) y_px += ibuf->y;
	
	if (ps->tool==PAINT_TOOL_CLONE) {
		size = sizeof(ProjPixelClone);
	}
	else if (ps->tool==PAINT_TOOL_SMEAR) {
		size = sizeof(ProjPixelClone);
	}
	else {
		size = sizeof(ProjPixel);
	}
	
	projPixel = (ProjPixel *)BLI_memarena_alloc(arena, size);
	//memset(projPixel, 0, size);
	
	if (ibuf->rect_float) {
		projPixel->pixel.f_pt = (float *)ibuf->rect_float + ((x_px + y_px * ibuf->x) * 4);
		projPixel->origColor.f[0] = projPixel->newColor.f[0] = projPixel->pixel.f_pt[0];  
		projPixel->origColor.f[1] = projPixel->newColor.f[1] = projPixel->pixel.f_pt[1];  
		projPixel->origColor.f[2] = projPixel->newColor.f[2] = projPixel->pixel.f_pt[2];  
		projPixel->origColor.f[3] = projPixel->newColor.f[3] = projPixel->pixel.f_pt[3];  
	}
	else {
		projPixel->pixel.ch_pt = ((unsigned char *)ibuf->rect + ((x_px + y_px * ibuf->x) * 4));
		projPixel->origColor.uint = projPixel->newColor.uint = *projPixel->pixel.uint_pt;
	}
	
	/* screenspace unclamped, we could keep its z and w values but dont need them at the moment */
	VECCOPY2D(projPixel->projCoSS, pixelScreenCo);
	
	projPixel->x_px = x_px;
	projPixel->y_px = y_px;
	
	projPixel->mask = (unsigned short)(mask * 65535);
	projPixel->mask_max = 0;
	
	/* which bounding box cell are we in?, needed for undo */
	projPixel->bb_cell_index = ((int)(((float)x_px/(float)ibuf->x) * PROJ_BOUNDBOX_DIV)) + ((int)(((float)y_px/(float)ibuf->y) * PROJ_BOUNDBOX_DIV)) * PROJ_BOUNDBOX_DIV ;
	
	/* done with view3d_project_float inline */
	if (ps->tool==PAINT_TOOL_CLONE) {
		if (ps->dm_mtface_clone) {
			ImBuf *ibuf_other;
			const MTFace *tf_other = ps->dm_mtface_clone + face_index;
			
			if (tf_other->tpage && (ibuf_other = BKE_image_get_ibuf(tf_other->tpage, NULL))) {
				/* BKE_image_get_ibuf - TODO - this may be slow */
				
				if (ibuf->rect_float) {
					if (ibuf_other->rect_float) { /* from float to float */
						project_face_pixel(tf_other, ibuf_other, w, side, NULL, ((ProjPixelClone *)projPixel)->clonepx.f);
					}
					else { /* from char to float */
						unsigned char rgba_ub[4];
						project_face_pixel(tf_other, ibuf_other, w, side, rgba_ub, NULL);
						IMAPAINT_CHAR_RGBA_TO_FLOAT(((ProjPixelClone *)projPixel)->clonepx.f, rgba_ub);
					}
				}
				else {
					if (ibuf_other->rect_float) { /* float to char */
						float rgba[4];
						project_face_pixel(tf_other, ibuf_other, w, side, NULL, rgba);
						IMAPAINT_FLOAT_RGBA_TO_CHAR(((ProjPixelClone *)projPixel)->clonepx.ch, rgba)
					}
					else { /* char to char */
						project_face_pixel(tf_other, ibuf_other, w, side, ((ProjPixelClone *)projPixel)->clonepx.ch, NULL);
					}
				}
			}
			else {
				if (ibuf->rect_float) {
					((ProjPixelClone *)projPixel)->clonepx.f[3] = 0;
				}
				else {
					((ProjPixelClone *)projPixel)->clonepx.ch[3] = 0;
				}
			}
			
		}
		else {
			float co[2];
			Vec2Subf(co, projPixel->projCoSS, (float *)ps->cloneOffset);
			
			/* no need to initialize the bucket, we're only checking buckets faces and for this
			 * the faces are alredy initialized in project_paint_delayed_face_init(...) */
			if (ibuf->rect_float) {
				if (!project_paint_PickColor(ps, co, ((ProjPixelClone *)projPixel)->clonepx.f, NULL, 1)) {
					((ProjPixelClone *)projPixel)->clonepx.f[3] = 0; /* zero alpha - ignore */
				}
			}
			else {
				if (!project_paint_PickColor(ps, co, NULL, ((ProjPixelClone *)projPixel)->clonepx.ch, 1)) {
					((ProjPixelClone *)projPixel)->clonepx.ch[3] = 0; /* zero alpha - ignore */
				}
			}
		}
	}
	
#ifdef PROJ_DEBUG_PAINT
	if (ibuf->rect_float)	projPixel->pixel.f_pt[0] = 0;
	else					projPixel->pixel.ch_pt[0] = 0;
#endif
	projPixel->image_index = image_index;
	
	return projPixel;
}

static int line_clip_rect2f(
		rctf *rect,
		const float l1[2], const float l2[2],
		float l1_clip[2], float l2_clip[2])
{
	/* first account for horizontal, then vertical lines */
	/* horiz */
	if (fabsf(l1[1]-l2[1]) < PROJ_GEOM_TOLERANCE) {
		/* is the line out of range on its Y axis? */
		if (l1[1] < rect->ymin || l1[1] > rect->ymax) {
			return 0;
		}
		/* line is out of range on its X axis */
		if ((l1[0] < rect->xmin && l2[0] < rect->xmin) || (l1[0] > rect->xmax && l2[0] > rect->xmax)) {
			return 0;
		}
		
		
		if (fabsf(l1[0]-l2[0]) < PROJ_GEOM_TOLERANCE) { /* this is a single point  (or close to)*/
			if (BLI_in_rctf(rect, l1[0], l1[1])) {
				VECCOPY2D(l1_clip, l1);
				VECCOPY2D(l2_clip, l2);
				return 1;
			}
			else {
				return 0;
			}
		}
		
		VECCOPY2D(l1_clip, l1);
		VECCOPY2D(l2_clip, l2);
		CLAMP(l1_clip[0], rect->xmin, rect->xmax);
		CLAMP(l2_clip[0], rect->xmin, rect->xmax);
		return 1;
	}
	else if (fabsf(l1[0]-l2[0]) < PROJ_GEOM_TOLERANCE) {
		/* is the line out of range on its X axis? */
		if (l1[0] < rect->xmin || l1[0] > rect->xmax) {
			return 0;
		}
		
		/* line is out of range on its Y axis */
		if ((l1[1] < rect->ymin && l2[1] < rect->ymin) || (l1[1] > rect->ymax && l2[1] > rect->ymax)) {
			return 0;
		}
		
		if (fabsf(l1[1]-l2[1]) < PROJ_GEOM_TOLERANCE) { /* this is a single point  (or close to)*/
			if (BLI_in_rctf(rect, l1[0], l1[1])) {
				VECCOPY2D(l1_clip, l1);
				VECCOPY2D(l2_clip, l2);
				return 1;
			}
			else {
				return 0;
			}
		}
		
		VECCOPY2D(l1_clip, l1);
		VECCOPY2D(l2_clip, l2);
		CLAMP(l1_clip[1], rect->ymin, rect->ymax);
		CLAMP(l2_clip[1], rect->ymin, rect->ymax);
		return 1;
	}
	else {
		float isect;
		short ok1 = 0;
		short ok2 = 0;
		
		/* Done with vertical lines */
		
		/* are either of the points inside the rectangle ? */
		if (BLI_in_rctf(rect, l1[0], l1[1])) {
			VECCOPY2D(l1_clip, l1);
			ok1 = 1;
		}
		
		if (BLI_in_rctf(rect, l2[0], l2[1])) {
			VECCOPY2D(l2_clip, l2);
			ok2 = 1;
		}
		
		/* line inside rect */
		if (ok1 && ok2) return 1;
		
		/* top/bottom */
		if (line_isect_y(l1, l2, rect->ymin, &isect) && (isect >= rect->xmin) && (isect <= rect->xmax)) {
			if (l1[1] < l2[1]) { /* line 1 is outside */
				l1_clip[0] = isect;
				l1_clip[1] = rect->ymin;
				ok1 = 1;
			}
			else {
				l2_clip[0] = isect;
				l2_clip[1] = rect->ymin;
				ok2 = 2;
			}
		}
		
		if (ok1 && ok2) return 1;
		
		if (line_isect_y(l1, l2, rect->ymax, &isect) && (isect >= rect->xmin) && (isect <= rect->xmax)) {
			if (l1[1] > l2[1]) { /* line 1 is outside */
				l1_clip[0] = isect;
				l1_clip[1] = rect->ymax;
				ok1 = 1;
			}
			else {
				l2_clip[0] = isect;
				l2_clip[1] = rect->ymax;
				ok2 = 2;
			}
		}
		
		if (ok1 && ok2) return 1;
		
		/* left/right */
		if (line_isect_x(l1, l2, rect->xmin, &isect) && (isect >= rect->ymin) && (isect <= rect->ymax)) {
			if (l1[0] < l2[0]) { /* line 1 is outside */
				l1_clip[0] = rect->xmin;
				l1_clip[1] = isect;
				ok1 = 1;
			}
			else {
				l2_clip[0] = rect->xmin;
				l2_clip[1] = isect;
				ok2 = 2;
			}
		}
	
		if (ok1 && ok2) return 1;
		
		if (line_isect_x(l1, l2, rect->xmax, &isect) && (isect >= rect->ymin) && (isect <= rect->ymax)) {
			if (l1[0] > l2[0]) { /* line 1 is outside */
				l1_clip[0] = rect->xmax;
				l1_clip[1] = isect;
				ok1 = 1;
			}
			else {
				l2_clip[0] = rect->xmax;
				l2_clip[1] = isect;
				ok2 = 2;
			}
		}
		
		if (ok1 && ok2) {
			return 1;
		}
		else {
			return 0;
		}
	}
}



/* scale the quad & tri about its center
 * scaling by PROJ_FACE_SCALE_SEAM (0.99x) is used for getting fake UV pixel coords that are on the
 * edge of the face but slightly inside it occlusion tests dont return hits on adjacent faces */
static void scale_quad(float insetCos[4][3], float *origCos[4], const float inset)
{
	float cent[3];
	cent[0] = (origCos[0][0] + origCos[1][0] + origCos[2][0] + origCos[3][0]) / 4.0f;
	cent[1] = (origCos[0][1] + origCos[1][1] + origCos[2][1] + origCos[3][1]) / 4.0f;
	cent[2] = (origCos[0][2] + origCos[1][2] + origCos[2][2] + origCos[3][2]) / 4.0f;
	
	VecSubf(insetCos[0], origCos[0], cent);
	VecSubf(insetCos[1], origCos[1], cent);
	VecSubf(insetCos[2], origCos[2], cent);
	VecSubf(insetCos[3], origCos[3], cent);
	
	VecMulf(insetCos[0], inset);
	VecMulf(insetCos[1], inset);
	VecMulf(insetCos[2], inset);
	VecMulf(insetCos[3], inset);
	
	VecAddf(insetCos[0], insetCos[0], cent);
	VecAddf(insetCos[1], insetCos[1], cent);
	VecAddf(insetCos[2], insetCos[2], cent);
	VecAddf(insetCos[3], insetCos[3], cent);
}


static void scale_tri(float insetCos[4][3], float *origCos[4], const float inset)
{
	float cent[3];
	cent[0] = (origCos[0][0] + origCos[1][0] + origCos[2][0]) / 3.0f;
	cent[1] = (origCos[0][1] + origCos[1][1] + origCos[2][1]) / 3.0f;
	cent[2] = (origCos[0][2] + origCos[1][2] + origCos[2][2]) / 3.0f;
	
	VecSubf(insetCos[0], origCos[0], cent);
	VecSubf(insetCos[1], origCos[1], cent);
	VecSubf(insetCos[2], origCos[2], cent);
	
	VecMulf(insetCos[0], inset);
	VecMulf(insetCos[1], inset);
	VecMulf(insetCos[2], inset);
	
	VecAddf(insetCos[0], insetCos[0], cent);
	VecAddf(insetCos[1], insetCos[1], cent);
	VecAddf(insetCos[2], insetCos[2], cent);
}


static float Vec2Lenf_nosqrt(const float *v1, const float *v2)
{
	float x, y;

	x = v1[0]-v2[0];
	y = v1[1]-v2[1];
	return x*x+y*y;
}

static float Vec2Lenf_nosqrt_other(const float *v1, const float v2_1, const float v2_2)
{
	float x, y;

	x = v1[0]-v2_1;
	y = v1[1]-v2_2;
	return x*x+y*y;
}

/* note, use a squared value so we can use Vec2Lenf_nosqrt
 * be sure that you have done a bounds check first or this may fail */
/* only give bucket_bounds as an arg because we need it elsewhere */
static int project_bucket_isect_circle(const int bucket_x, const int bucket_y, const float cent[2], const float radius_squared, rctf *bucket_bounds)
{
	 
	/* Would normally to a simple intersection test, however we know the bounds of these 2 alredy intersect 
	 * so we only need to test if the center is inside the vertical or horizontal bounds on either axis,
	 * this is even less work then an intersection test
	 * 
	if (BLI_in_rctf(bucket_bounds, cent[0], cent[1]))
		return 1;
	 */
	
	if((bucket_bounds->xmin <= cent[0] && bucket_bounds->xmax >= cent[0]) || (bucket_bounds->ymin <= cent[1] && bucket_bounds->ymax >= cent[1]) ) {
	   return 1;
	}
	
	/* out of bounds left */
	if (cent[0] < bucket_bounds->xmin) {
		/* lower left out of radius test */
		if (cent[1] < bucket_bounds->ymin) {
			return (Vec2Lenf_nosqrt_other(cent, bucket_bounds->xmin, bucket_bounds->ymin) < radius_squared) ? 1 : 0;
		} 
		/* top left test */
		else if (cent[1] > bucket_bounds->ymax) {
			return (Vec2Lenf_nosqrt_other(cent, bucket_bounds->xmin, bucket_bounds->ymax) < radius_squared) ? 1 : 0;
		}
	}
	else if (cent[0] > bucket_bounds->xmax) {
		/* lower right out of radius test */
		if (cent[1] < bucket_bounds->ymin) {
			return (Vec2Lenf_nosqrt_other(cent, bucket_bounds->xmax, bucket_bounds->ymin) < radius_squared) ? 1 : 0;
		} 
		/* top right test */
		else if (cent[1] > bucket_bounds->ymax) {
			return (Vec2Lenf_nosqrt_other(cent, bucket_bounds->xmax, bucket_bounds->ymax) < radius_squared) ? 1 : 0;
		}
	}
	
	return 0;
}



/* Note for rect_to_uvspace_ortho() and rect_to_uvspace_persp()
 * in ortho view this function gives good results when bucket_bounds are outside the triangle
 * however in some cases, perspective view will mess up with faces that have minimal screenspace area (viewed from the side)
 * 
 * for this reason its not relyable in this case so we'll use the Simple Barycentric' funcs that only account for points inside the triangle.
 * however switching back to this for ortho is always an option */

static void rect_to_uvspace_ortho(
		rctf *bucket_bounds,
		float *v1coSS, float *v2coSS, float *v3coSS,
		float *uv1co, float *uv2co, float *uv3co,
		float bucket_bounds_uv[4][2],
		const int flip)
{
	float uv[2];
	float w[3];
	
	/* get the UV space bounding box */
	uv[0] = bucket_bounds->xmax;
	uv[1] = bucket_bounds->ymin;
	BarycentricWeights2f(uv, v1coSS, v2coSS, v3coSS, w);
	Vec2Lerp3f(bucket_bounds_uv[flip?3:0], uv1co, uv2co, uv3co, w);

	//uv[0] = bucket_bounds->xmax; // set above
	uv[1] = bucket_bounds->ymax;
	BarycentricWeights2f(uv, v1coSS, v2coSS, v3coSS, w);
	Vec2Lerp3f(bucket_bounds_uv[flip?2:1], uv1co, uv2co, uv3co, w);

	uv[0] = bucket_bounds->xmin;
	//uv[1] = bucket_bounds->ymax; // set above
	BarycentricWeights2f(uv, v1coSS, v2coSS, v3coSS, w);
	Vec2Lerp3f(bucket_bounds_uv[flip?1:2], uv1co, uv2co, uv3co, w);

	//uv[0] = bucket_bounds->xmin; // set above
	uv[1] = bucket_bounds->ymin;
	BarycentricWeights2f(uv, v1coSS, v2coSS, v3coSS, w);
	Vec2Lerp3f(bucket_bounds_uv[flip?0:3], uv1co, uv2co, uv3co, w);
}

/* same as above but use BarycentricWeightsPersp2f */
static void rect_to_uvspace_persp(
		rctf *bucket_bounds,
		float *v1coSS, float *v2coSS, float *v3coSS,
		float *uv1co, float *uv2co, float *uv3co,
		float bucket_bounds_uv[4][2],
		const int flip
	)
{
	float uv[2];
	float w[3];
	
	/* get the UV space bounding box */
	uv[0] = bucket_bounds->xmax;
	uv[1] = bucket_bounds->ymin;
	BarycentricWeightsPersp2f(uv, v1coSS, v2coSS, v3coSS, w);
	Vec2Lerp3f(bucket_bounds_uv[flip?3:0], uv1co, uv2co, uv3co, w);

	//uv[0] = bucket_bounds->xmax; // set above
	uv[1] = bucket_bounds->ymax;
	BarycentricWeightsPersp2f(uv, v1coSS, v2coSS, v3coSS, w);
	Vec2Lerp3f(bucket_bounds_uv[flip?2:1], uv1co, uv2co, uv3co, w);

	uv[0] = bucket_bounds->xmin;
	//uv[1] = bucket_bounds->ymax; // set above
	BarycentricWeightsPersp2f(uv, v1coSS, v2coSS, v3coSS, w);
	Vec2Lerp3f(bucket_bounds_uv[flip?1:2], uv1co, uv2co, uv3co, w);

	//uv[0] = bucket_bounds->xmin; // set above
	uv[1] = bucket_bounds->ymin;
	BarycentricWeightsPersp2f(uv, v1coSS, v2coSS, v3coSS, w);
	Vec2Lerp3f(bucket_bounds_uv[flip?0:3], uv1co, uv2co, uv3co, w);
}

/* This works as we need it to but we can save a few steps and not use it */

#if 0
static float angle_2d_clockwise(const float p1[2], const float p2[2], const float p3[2])
{
	float v1[2], v2[2];
	
	v1[0] = p1[0]-p2[0];	v1[1] = p1[1]-p2[1];
	v2[0] = p3[0]-p2[0];	v2[1] = p3[1]-p2[1];
	
	return -atan2(v1[0]*v2[1] - v1[1]*v2[0], v1[0]*v2[0]+v1[1]*v2[1]);
}
#endif

#define ISECT_1 (1)
#define ISECT_2 (1<<1)
#define ISECT_3 (1<<2)
#define ISECT_4 (1<<3)
#define ISECT_ALL3 ((1<<3)-1)
#define ISECT_ALL4 ((1<<4)-1)

/* limit must be a fraction over 1.0f */
static int IsectPT2Df_limit(float pt[2], float v1[2], float v2[2], float v3[2], float limit)
{
	return ((AreaF2Dfl(pt,v1,v2) + AreaF2Dfl(pt,v2,v3) + AreaF2Dfl(pt,v3,v1)) / (AreaF2Dfl(v1,v2,v3))) < limit;
}

/* Clip the face by a bucket and set the uv-space bucket_bounds_uv
 * so we have the clipped UV's to do pixel intersection tests with 
 * */
static int float_z_sort_flip(const void *p1, const void *p2) {
	return (((float *)p1)[2] < ((float *)p2)[2] ? 1:-1);
}

static int float_z_sort(const void *p1, const void *p2) {
	return (((float *)p1)[2] < ((float *)p2)[2] ?-1:1);
}

static void project_bucket_clip_face(
		const int is_ortho,
		rctf *bucket_bounds,
		float *v1coSS, float *v2coSS, float *v3coSS,
		float *uv1co, float *uv2co, float *uv3co,
		float bucket_bounds_uv[8][2],
		int *tot)
{
	int inside_bucket_flag = 0;
	int inside_face_flag = 0;
	const int flip = ((SIDE_OF_LINE(v1coSS, v2coSS, v3coSS) > 0.0f) != (SIDE_OF_LINE(uv1co, uv2co, uv3co) > 0.0f));
	
	float bucket_bounds_ss[4][2];

	/* get the UV space bounding box */
	inside_bucket_flag |= BLI_in_rctf(bucket_bounds, v1coSS[0], v1coSS[1]);
	inside_bucket_flag |= BLI_in_rctf(bucket_bounds, v2coSS[0], v2coSS[1])		<< 1;
	inside_bucket_flag |= BLI_in_rctf(bucket_bounds, v3coSS[0], v3coSS[1])		<< 2;
	
	if (inside_bucket_flag == ISECT_ALL3) {
		/* all screenspace points are inside the bucket bounding box, this means we dont need to clip and can simply return the UVs */
		if (flip) { /* facing the back? */
			VECCOPY2D(bucket_bounds_uv[0], uv3co);
			VECCOPY2D(bucket_bounds_uv[1], uv2co);
			VECCOPY2D(bucket_bounds_uv[2], uv1co);
		}
		else {
			VECCOPY2D(bucket_bounds_uv[0], uv1co);
			VECCOPY2D(bucket_bounds_uv[1], uv2co);
			VECCOPY2D(bucket_bounds_uv[2], uv3co);
		}
		
		*tot = 3; 
		return;
	}
	
	/* get the UV space bounding box */
	/* use IsectPT2Df_limit here so we catch points are are touching the tri edge (or a small fraction over) */
	bucket_bounds_ss[0][0] = bucket_bounds->xmax;
	bucket_bounds_ss[0][1] = bucket_bounds->ymin;
	inside_face_flag |= (IsectPT2Df_limit(bucket_bounds_ss[0], v1coSS, v2coSS, v3coSS, 1+PROJ_GEOM_TOLERANCE) ? ISECT_1 : 0);
	
	bucket_bounds_ss[1][0] = bucket_bounds->xmax;
	bucket_bounds_ss[1][1] = bucket_bounds->ymax;
	inside_face_flag |= (IsectPT2Df_limit(bucket_bounds_ss[1], v1coSS, v2coSS, v3coSS, 1+PROJ_GEOM_TOLERANCE) ? ISECT_2 : 0);

	bucket_bounds_ss[2][0] = bucket_bounds->xmin;
	bucket_bounds_ss[2][1] = bucket_bounds->ymax;
	inside_face_flag |= (IsectPT2Df_limit(bucket_bounds_ss[2], v1coSS, v2coSS, v3coSS, 1+PROJ_GEOM_TOLERANCE) ? ISECT_3 : 0);

	bucket_bounds_ss[3][0] = bucket_bounds->xmin;
	bucket_bounds_ss[3][1] = bucket_bounds->ymin;
	inside_face_flag |= (IsectPT2Df_limit(bucket_bounds_ss[3], v1coSS, v2coSS, v3coSS, 1+PROJ_GEOM_TOLERANCE) ? ISECT_4 : 0);
	
	if (inside_face_flag == ISECT_ALL4) {
		/* bucket is totally inside the screenspace face, we can safely use weights */
		
		if (is_ortho)	rect_to_uvspace_ortho(bucket_bounds, v1coSS, v2coSS, v3coSS, uv1co, uv2co, uv3co, bucket_bounds_uv, flip);
		else			rect_to_uvspace_persp(bucket_bounds, v1coSS, v2coSS, v3coSS, uv1co, uv2co, uv3co, bucket_bounds_uv, flip);
		
		*tot = 4;
		return;
	}
	else {
		/* The Complicated Case! 
		 * 
		 * The 2 cases above are where the face is inside the bucket or the bucket is inside the face.
		 * 
		 * we need to make a convex polyline from the intersection between the screenspace face
		 * and the bucket bounds.
		 * 
		 * There are a number of ways this could be done, currently it just collects all intersecting verts,
		 * and line intersections,  then sorts them clockwise, this is a lot easier then evaluating the geometry to
		 * do a correct clipping on both shapes. */
		
		
		/* add a bunch of points, we know must make up the convex hull which is the clipped rect and triangle */
		
		
		
		/* Maximum possible 6 intersections when using a rectangle and triangle */
		float isectVCosSS[8][3]; /* The 3rd float is used to store angle for qsort(), NOT as a Z location */
		float v1_clipSS[2], v2_clipSS[2];
		float w[3];
		
		/* calc center*/
		float cent[2] = {0.0f, 0.0f};
		/*float up[2] = {0.0f, 1.0f};*/
		int i;
		short doubles;
		
		(*tot) = 0;
		
		if (inside_face_flag & ISECT_1)	{ VECCOPY2D(isectVCosSS[*tot], bucket_bounds_ss[0]); (*tot)++; }
		if (inside_face_flag & ISECT_2)	{ VECCOPY2D(isectVCosSS[*tot], bucket_bounds_ss[1]); (*tot)++; }
		if (inside_face_flag & ISECT_3)	{ VECCOPY2D(isectVCosSS[*tot], bucket_bounds_ss[2]); (*tot)++; }
		if (inside_face_flag & ISECT_4)	{ VECCOPY2D(isectVCosSS[*tot], bucket_bounds_ss[3]); (*tot)++; }
		
		if (inside_bucket_flag & ISECT_1) {	VECCOPY2D(isectVCosSS[*tot], v1coSS); (*tot)++; }
		if (inside_bucket_flag & ISECT_2) {	VECCOPY2D(isectVCosSS[*tot], v2coSS); (*tot)++; }
		if (inside_bucket_flag & ISECT_3) {	VECCOPY2D(isectVCosSS[*tot], v3coSS); (*tot)++; }
		
		if ((inside_bucket_flag & (ISECT_1|ISECT_2)) != (ISECT_1|ISECT_2)) {
			if (line_clip_rect2f(bucket_bounds, v1coSS, v2coSS, v1_clipSS, v2_clipSS)) {
				if ((inside_bucket_flag & ISECT_1)==0) { VECCOPY2D(isectVCosSS[*tot], v1_clipSS); (*tot)++; }
				if ((inside_bucket_flag & ISECT_2)==0) { VECCOPY2D(isectVCosSS[*tot], v2_clipSS); (*tot)++; }
			}
		}
		
		if ((inside_bucket_flag & (ISECT_2|ISECT_3)) != (ISECT_2|ISECT_3)) {
			if (line_clip_rect2f(bucket_bounds, v2coSS, v3coSS, v1_clipSS, v2_clipSS)) {
				if ((inside_bucket_flag & ISECT_2)==0) { VECCOPY2D(isectVCosSS[*tot], v1_clipSS); (*tot)++; }
				if ((inside_bucket_flag & ISECT_3)==0) { VECCOPY2D(isectVCosSS[*tot], v2_clipSS); (*tot)++; }
			}
		}	
		
		if ((inside_bucket_flag & (ISECT_3|ISECT_1)) != (ISECT_3|ISECT_1)) {
			if (line_clip_rect2f(bucket_bounds, v3coSS, v1coSS, v1_clipSS, v2_clipSS)) {
				if ((inside_bucket_flag & ISECT_3)==0) { VECCOPY2D(isectVCosSS[*tot], v1_clipSS); (*tot)++; }
				if ((inside_bucket_flag & ISECT_1)==0) { VECCOPY2D(isectVCosSS[*tot], v2_clipSS); (*tot)++; }
			}
		}
		
		
		if ((*tot) < 3) { /* no intersections to speak of */
			*tot = 0;
			return;
		}
	
		/* now we have all points we need, collect their angles and sort them clockwise */
		
		for(i=0; i<(*tot); i++) {
			cent[0] += isectVCosSS[i][0];
			cent[1] += isectVCosSS[i][1];
		}
		cent[0] = cent[0] / (float)(*tot);
		cent[1] = cent[1] / (float)(*tot);
		
		
		
		/* Collect angles for every point around the center point */

		
#if 0	/* uses a few more cycles then the above loop */
		for(i=0; i<(*tot); i++) {
			isectVCosSS[i][2] = angle_2d_clockwise(up, cent, isectVCosSS[i]);
		}
#endif

		v1_clipSS[0] = cent[0]; /* Abuse this var for the loop below */
		v1_clipSS[1] = cent[1] + 1.0f;
		
		for(i=0; i<(*tot); i++) {
			v2_clipSS[0] = isectVCosSS[i][0] - cent[0];
			v2_clipSS[1] = isectVCosSS[i][1] - cent[1];
			isectVCosSS[i][2] = atan2f(v1_clipSS[0]*v2_clipSS[1] - v1_clipSS[1]*v2_clipSS[0], v1_clipSS[0]*v2_clipSS[0]+v1_clipSS[1]*v2_clipSS[1]); 
		}
		
		if (flip)	qsort(isectVCosSS, *tot, sizeof(float)*3, float_z_sort_flip);
		else		qsort(isectVCosSS, *tot, sizeof(float)*3, float_z_sort);
		
		/* remove doubles */
		/* first/last check */
		if (fabsf(isectVCosSS[0][0]-isectVCosSS[(*tot)-1][0]) < PROJ_GEOM_TOLERANCE &&  fabsf(isectVCosSS[0][1]-isectVCosSS[(*tot)-1][1]) < PROJ_GEOM_TOLERANCE) {
			(*tot)--;
		}
		
		/* its possible there is only a few left after remove doubles */
		if ((*tot) < 3) {
			// printf("removed too many doubles A\n");
			*tot = 0;
			return;
		}
		
		doubles = TRUE;
		while (doubles==TRUE) {
			doubles = FALSE;
			for(i=1; i<(*tot); i++) {
				if (fabsf(isectVCosSS[i-1][0]-isectVCosSS[i][0]) < PROJ_GEOM_TOLERANCE &&
					fabsf(isectVCosSS[i-1][1]-isectVCosSS[i][1]) < PROJ_GEOM_TOLERANCE)
				{
					int j;
					for(j=i+1; j<(*tot); j++) {
						isectVCosSS[j-1][0] = isectVCosSS[j][0]; 
						isectVCosSS[j-1][1] = isectVCosSS[j][1]; 
					}
					doubles = TRUE; /* keep looking for more doubles */
					(*tot)--;
				}
			}
		}
		
		/* its possible there is only a few left after remove doubles */
		if ((*tot) < 3) {
			// printf("removed too many doubles B\n");
			*tot = 0;
			return;
		}
		
		
		if (is_ortho) {
			for(i=0; i<(*tot); i++) {
				BarycentricWeights2f(isectVCosSS[i], v1coSS, v2coSS, v3coSS, w);
				Vec2Lerp3f(bucket_bounds_uv[i], uv1co, uv2co, uv3co, w);
			}
		}
		else {
			for(i=0; i<(*tot); i++) {
				BarycentricWeightsPersp2f(isectVCosSS[i], v1coSS, v2coSS, v3coSS, w);
				Vec2Lerp3f(bucket_bounds_uv[i], uv1co, uv2co, uv3co, w);
			}
		}
	}

#ifdef PROJ_DEBUG_PRINT_CLIP
	/* include this at the bottom of the above function to debug the output */

	{
		/* If there are ever any problems, */
		float test_uv[4][2];
		int i;
		if (is_ortho)	rect_to_uvspace_ortho(bucket_bounds, v1coSS, v2coSS, v3coSS, uv1co, uv2co, uv3co, test_uv, flip);
		else				rect_to_uvspace_persp(bucket_bounds, v1coSS, v2coSS, v3coSS, uv1co, uv2co, uv3co, test_uv, flip);
		printf("(  [(%f,%f), (%f,%f), (%f,%f), (%f,%f)], ", test_uv[0][0], test_uv[0][1],   test_uv[1][0], test_uv[1][1],    test_uv[2][0], test_uv[2][1],    test_uv[3][0], test_uv[3][1]);
		
		printf("  [(%f,%f), (%f,%f), (%f,%f)], ", uv1co[0], uv1co[1],   uv2co[0], uv2co[1],    uv3co[0], uv3co[1]);
		
		printf("[");
		for (i=0; i < (*tot); i++) {
			printf("(%f, %f),", bucket_bounds_uv[i][0], bucket_bounds_uv[i][1]);
		}
		printf("]),\\\n");
	}
#endif
}

	/*
# This script creates faces in a blender scene from printed data above.

project_ls = [
...(output from above block)...
]
 
from Blender import Scene, Mesh, Window, sys, Mathutils

import bpy

V = Mathutils.Vector

def main():
	sce = bpy.data.scenes.active
	
	for item in project_ls:
		bb = item[0]
		uv = item[1]
		poly = item[2]
		
		me = bpy.data.meshes.new()
		ob = sce.objects.new(me)
		
		me.verts.extend([V(bb[0]).resize3D(), V(bb[1]).resize3D(), V(bb[2]).resize3D(), V(bb[3]).resize3D()])
		me.faces.extend([(0,1,2,3),])
		me.verts.extend([V(uv[0]).resize3D(), V(uv[1]).resize3D(), V(uv[2]).resize3D()])
		me.faces.extend([(4,5,6),])
		
		vs = [V(p).resize3D() for p in poly]
		print len(vs)
		l = len(me.verts)
		me.verts.extend(vs)
		
		i = l
		while i < len(me.verts):
			ii = i+1
			if ii==len(me.verts):
				ii = l
			me.edges.extend([i, ii])
			i+=1

if __name__ == '__main__':
	main()
 */	


#undef ISECT_1
#undef ISECT_2
#undef ISECT_3
#undef ISECT_4
#undef ISECT_ALL3
#undef ISECT_ALL4

	
/* checks if pt is inside a convex 2D polyline, the polyline must be ordered rotating clockwise
 * otherwise it would have to test for mixed (SIDE_OF_LINE > 0.0f) cases */
int IsectPoly2Df(const float pt[2], float uv[][2], const int tot)
{
	int i;
	if (SIDE_OF_LINE(uv[tot-1], uv[0], pt) < 0.0f)
		return 0;
	
	for (i=1; i<tot; i++) {
		if (SIDE_OF_LINE(uv[i-1], uv[i], pt) < 0.0f)
			return 0;
		
	}
	
	return 1;
}
static int IsectPoly2Df_twoside(const float pt[2], float uv[][2], const int tot)
{
	int i;
	int side = (SIDE_OF_LINE(uv[tot-1], uv[0], pt) > 0.0f);
	
	for (i=1; i<tot; i++) {
		if ((SIDE_OF_LINE(uv[i-1], uv[i], pt) > 0.0f) != side)
			return 0;
		
	}
	
	return 1;
}

/* One of the most important function for projectiopn painting, since it selects the pixels to be added into each bucket.
 * initialize pixels from this face where it intersects with the bucket_index, optionally initialize pixels for removing seams */
static void project_paint_face_init(const ProjPaintState *ps, const int thread_index, const int bucket_index, const int face_index, const int image_index, rctf *bucket_bounds, const ImBuf *ibuf)
{
	/* Projection vars, to get the 3D locations into screen space  */
	MemArena *arena = ps->arena_mt[thread_index];
	LinkNode **bucketPixelNodes = ps->bucketRect + bucket_index;
	LinkNode *bucketFaceNodes = ps->bucketFaces[bucket_index];
	
	const MFace *mf = ps->dm_mface + face_index;
	const MTFace *tf = ps->dm_mtface + face_index;
	
	/* UV/pixel seeking data */
	int x; /* Image X-Pixel */
	int y;/* Image Y-Pixel */
	float mask;
	float uv[2]; /* Image floating point UV - same as x, y but from 0.0-1.0 */
	
	int side;
	float *v1coSS, *v2coSS, *v3coSS; /* vert co screen-space, these will be assigned to mf->v1,2,3 or mf->v1,3,4 */
	
	float *vCo[4]; /* vertex screenspace coords */
	
	float w[3], wco[3];
	
	float *uv1co, *uv2co, *uv3co; /* for convenience only, these will be assigned to tf->uv[0],1,2 or tf->uv[0],2,3 */
	float pixelScreenCo[4];
	
	rcti bounds_px; /* ispace bounds */
	/* vars for getting uvspace bounds */
	
	float tf_uv_pxoffset[4][2]; /* bucket bounds in UV space so we can init pixels only for this face,  */
	float xhalfpx, yhalfpx;
	const float ibuf_xf = ibuf->x, ibuf_yf = ibuf->y;
	
	int has_x_isect = 0, has_isect = 0; /* for early loop exit */
	
	int i1, i2, i3;
	
	float uv_clip[8][2];
	int uv_clip_tot;
	const short is_ortho = ps->is_ortho;
	const short do_backfacecull = ps->do_backfacecull;
	
	vCo[0] = ps->dm_mvert[mf->v1].co;
	vCo[1] = ps->dm_mvert[mf->v2].co;
	vCo[2] = ps->dm_mvert[mf->v3].co;
	
	
	/* Use tf_uv_pxoffset instead of tf->uv so we can offset the UV half a pixel
	 * this is done so we can avoid offseting all the pixels by 0.5 which causes
	 * problems when wrapping negative coords */
	xhalfpx = (0.5f+   (PROJ_GEOM_TOLERANCE/3.0f)   ) / ibuf_xf;
	yhalfpx = (0.5f+   (PROJ_GEOM_TOLERANCE/4.0f)   ) / ibuf_yf;
	
	/* Note about (PROJ_GEOM_TOLERANCE/x) above...
	  Needed to add this offset since UV coords are often quads aligned to pixels.
	  In this case pixels can be exactly between 2 triangles causing nasty
	  artifacts.
	  
	  This workaround can be removed and painting will still work on most cases
	  but since the first thing most people try is painting onto a quad- better make it work.
	 */



	tf_uv_pxoffset[0][0] = tf->uv[0][0] - xhalfpx;
	tf_uv_pxoffset[0][1] = tf->uv[0][1] - yhalfpx;

	tf_uv_pxoffset[1][0] = tf->uv[1][0] - xhalfpx;
	tf_uv_pxoffset[1][1] = tf->uv[1][1] - yhalfpx;
	
	tf_uv_pxoffset[2][0] = tf->uv[2][0] - xhalfpx;
	tf_uv_pxoffset[2][1] = tf->uv[2][1] - yhalfpx;	
	
	if (mf->v4) {
		vCo[3] = ps->dm_mvert[ mf->v4 ].co;
		
		tf_uv_pxoffset[3][0] = tf->uv[3][0] - xhalfpx;
		tf_uv_pxoffset[3][1] = tf->uv[3][1] - yhalfpx;
		side = 1;
	}
	else {
		side = 0;
	}
	
	do {
		if (side==1) {
			i1=0; i2=2; i3=3;
		}
		else {
			i1=0; i2=1; i3=2;
		}
		
		uv1co = tf_uv_pxoffset[i1]; // was tf->uv[i1];
		uv2co = tf_uv_pxoffset[i2]; // was tf->uv[i2];
		uv3co = tf_uv_pxoffset[i3]; // was tf->uv[i3];

		v1coSS = ps->screenCoords[ (*(&mf->v1 + i1)) ];
		v2coSS = ps->screenCoords[ (*(&mf->v1 + i2)) ];
		v3coSS = ps->screenCoords[ (*(&mf->v1 + i3)) ];
		
		/* This funtion gives is a concave polyline in UV space from the clipped quad and tri*/
		project_bucket_clip_face(
				is_ortho, bucket_bounds,
				v1coSS, v2coSS, v3coSS,
				uv1co, uv2co, uv3co,
				uv_clip, &uv_clip_tot
		);

		/* sometimes this happens, better just allow for 8 intersectiosn even though there should be max 6 */
		/*
		if (uv_clip_tot>6) {
			printf("this should never happen! %d\n", uv_clip_tot);
		}*/
		

		if (pixel_bounds_array(uv_clip, &bounds_px, ibuf->x, ibuf->y, uv_clip_tot)) {
			
			/* clip face and */
			
			has_isect = 0;
			for (y = bounds_px.ymin; y < bounds_px.ymax; y++) {
				//uv[1] = (((float)y) + 0.5f) / (float)ibuf->y;
				uv[1] = (float)y / ibuf_yf; /* use pixel offset UV coords instead */
				
				has_x_isect = 0;
				for (x = bounds_px.xmin; x < bounds_px.xmax; x++) {
					//uv[0] = (((float)x) + 0.5f) / ibuf->x;
					uv[0] = (float)x / ibuf_xf; /* use pixel offset UV coords instead */
					
					/* Note about IsectPoly2Df_twoside, checking the face or uv flipping doesnt work,
					 * could check the poly direction but better to do this */
					if(	(do_backfacecull		&& IsectPoly2Df(uv, uv_clip, uv_clip_tot)) ||
						(do_backfacecull==0		&& IsectPoly2Df_twoside(uv, uv_clip, uv_clip_tot))) {
						
						has_x_isect = has_isect = 1;
						
						if (is_ortho)	screen_px_from_ortho(uv, v1coSS, v2coSS, v3coSS, uv1co, uv2co, uv3co, pixelScreenCo, w);
						else			screen_px_from_persp(uv, v1coSS, v2coSS, v3coSS, uv1co, uv2co, uv3co, pixelScreenCo, w);
						
						/* a pitty we need to get the worldspace pixel location here */
						if(ps->rv3d->rflag & RV3D_CLIPPING) {
							VecLerp3f(wco, ps->dm_mvert[ (*(&mf->v1 + i1)) ].co, ps->dm_mvert[ (*(&mf->v1 + i2)) ].co, ps->dm_mvert[ (*(&mf->v1 + i3)) ].co, w);
							Mat4MulVecfl(ps->ob->obmat, wco);
							if(view3d_test_clipping(ps->rv3d, wco)) {
								continue; /* Watch out that no code below this needs to run */
							}
						}
						
						/* Is this UV visible from the view? - raytrace */
						/* project_paint_PickFace is less complex, use for testing */
						//if (project_paint_PickFace(ps, pixelScreenCo, w, &side) == face_index) {
						if (ps->do_occlude==0 || !project_bucket_point_occluded(ps, bucketFaceNodes, face_index, pixelScreenCo)) {
							
							mask = project_paint_uvpixel_mask(ps, face_index, side, w);
							
							if (mask > 0.0f) {
								BLI_linklist_prepend_arena(
									bucketPixelNodes,
									project_paint_uvpixel_init(ps, arena, ibuf, x, y, mask, face_index, image_index, pixelScreenCo, side, w),
									arena
								);
							}
						}
						
					}
//#if 0
					else if (has_x_isect) {
						/* assuming the face is not a bow-tie - we know we cant intersect again on the X */
						break;
					}
//#endif
				}
				
				
#if 0			/* TODO - investigate why this dosnt work sometimes! it should! */
				/* no intersection for this entire row, after some intersection above means we can quit now */
				if (has_x_isect==0 && has_isect) { 
					break;
				}
#endif
			}
		}
	} while(side--);

	
	
#ifndef PROJ_DEBUG_NOSEAMBLEED
	if (ps->seam_bleed_px > 0.0f) {
		int face_seam_flag;
		
		if (ps->thread_tot > 1)
			BLI_lock_thread(LOCK_CUSTOM1); /* Other threads could be modifying these vars */
		
		face_seam_flag = ps->faceSeamFlags[face_index];
		
		/* are any of our edges un-initialized? */
		if ((face_seam_flag & (PROJ_FACE_SEAM1|PROJ_FACE_NOSEAM1))==0 || 
			(face_seam_flag & (PROJ_FACE_SEAM2|PROJ_FACE_NOSEAM2))==0 || 
			(face_seam_flag & (PROJ_FACE_SEAM3|PROJ_FACE_NOSEAM3))==0 || 
			(face_seam_flag & (PROJ_FACE_SEAM4|PROJ_FACE_NOSEAM4))==0
		) {
			project_face_seams_init(ps, face_index, mf->v4);
			face_seam_flag = ps->faceSeamFlags[face_index];
			//printf("seams - %d %d %d %d\n", flag&PROJ_FACE_SEAM1, flag&PROJ_FACE_SEAM2, flag&PROJ_FACE_SEAM3, flag&PROJ_FACE_SEAM4);
		}
		
		if ((face_seam_flag & (PROJ_FACE_SEAM1|PROJ_FACE_SEAM2|PROJ_FACE_SEAM3|PROJ_FACE_SEAM4))==0) {
			
			if (ps->thread_tot > 1)
				BLI_unlock_thread(LOCK_CUSTOM1); /* Other threads could be modifying these vars */
			
		}
		else {
			/* we have a seam - deal with it! */
			
			/* Now create new UV's for the seam face */
			float (*outset_uv)[2] = ps->faceSeamUVs[face_index];
			float insetCos[4][3]; /* inset face coords.  NOTE!!! ScreenSace for ortho, Worldspace in prespective view */

			float fac;
			float *vCoSS[4]; /* vertex screenspace coords */
			
			float bucket_clip_edges[2][2]; /* store the screenspace coords of the face, clipped by the bucket's screen aligned rectangle */
			float edge_verts_inset_clip[2][3];
			int fidx1, fidx2; /* face edge pairs - loop throuh these ((0,1), (1,2), (2,3), (3,0)) or ((0,1), (1,2), (2,0)) for a tri */
			
			float seam_subsection[4][2];
			float fac1, fac2, ftot;
			
			
			if (outset_uv[0][0]==FLT_MAX) /* first time initialize */
				uv_image_outset(tf_uv_pxoffset, outset_uv, ps->seam_bleed_px, ibuf->x, ibuf->y, mf->v4);
			
			/* ps->faceSeamUVs cant be modified when threading, now this is done we can unlock */
			if (ps->thread_tot > 1)
				BLI_unlock_thread(LOCK_CUSTOM1); /* Other threads could be modifying these vars */
			
			vCoSS[0] = ps->screenCoords[mf->v1];
			vCoSS[1] = ps->screenCoords[mf->v2];
			vCoSS[2] = ps->screenCoords[mf->v3];
			if (mf->v4)
				vCoSS[3] = ps->screenCoords[ mf->v4 ];
			
			/* PROJ_FACE_SCALE_SEAM must be slightly less then 1.0f */
			if (is_ortho) {
				if (mf->v4)	scale_quad(insetCos, vCoSS, PROJ_FACE_SCALE_SEAM);
				else		scale_tri(insetCos, vCoSS, PROJ_FACE_SCALE_SEAM);
			}
			else {
				if (mf->v4)	scale_quad(insetCos, vCo, PROJ_FACE_SCALE_SEAM);
				else		scale_tri(insetCos, vCo, PROJ_FACE_SCALE_SEAM);
			}
			
			side = 0; /* for triangles this wont need to change */
			
			for (fidx1 = 0; fidx1 < (mf->v4 ? 4 : 3); fidx1++) {
				if (mf->v4)		fidx2 = (fidx1==3) ? 0 : fidx1+1; /* next fidx in the face (0,1,2,3) -> (1,2,3,0) */
				else			fidx2 = (fidx1==2) ? 0 : fidx1+1; /* next fidx in the face (0,1,2) -> (1,2,0) */
				
				if (	(face_seam_flag & (1<<fidx1)) && /* 1<<fidx1 -> PROJ_FACE_SEAM# */
						line_clip_rect2f(bucket_bounds, vCoSS[fidx1], vCoSS[fidx2], bucket_clip_edges[0], bucket_clip_edges[1])
				) {

					ftot = Vec2Lenf(vCoSS[fidx1], vCoSS[fidx2]); /* screenspace edge length */
					
					if (ftot > 0.0f) { /* avoid div by zero */
						if (mf->v4) {
							if (fidx1==2 || fidx2==2)	side= 1;
							else						side= 0;
						}
						
						fac1 = Vec2Lenf(vCoSS[fidx1], bucket_clip_edges[0]) / ftot;
						fac2 = Vec2Lenf(vCoSS[fidx1], bucket_clip_edges[1]) / ftot;
						
						Vec2Lerpf(seam_subsection[0], tf_uv_pxoffset[fidx1], tf_uv_pxoffset[fidx2], fac1);
						Vec2Lerpf(seam_subsection[1], tf_uv_pxoffset[fidx1], tf_uv_pxoffset[fidx2], fac2);

						Vec2Lerpf(seam_subsection[2], outset_uv[fidx1], outset_uv[fidx2], fac2);
						Vec2Lerpf(seam_subsection[3], outset_uv[fidx1], outset_uv[fidx2], fac1);
						
						/* if the bucket_clip_edges values Z values was kept we could avoid this
						 * Inset needs to be added so occlusion tests wont hit adjacent faces */
						VecLerpf(edge_verts_inset_clip[0], insetCos[fidx1], insetCos[fidx2], fac1);
						VecLerpf(edge_verts_inset_clip[1], insetCos[fidx1], insetCos[fidx2], fac2);
						

						if (pixel_bounds_uv(seam_subsection[0], seam_subsection[1], seam_subsection[2], seam_subsection[3], &bounds_px, ibuf->x, ibuf->y, 1)) {
							/* bounds between the seam rect and the uvspace bucket pixels */
							
							has_isect = 0;
							for (y = bounds_px.ymin; y < bounds_px.ymax; y++) {
								// uv[1] = (((float)y) + 0.5f) / (float)ibuf->y;
								uv[1] = (float)y / ibuf_yf; /* use offset uvs instead */
								
								has_x_isect = 0;
								for (x = bounds_px.xmin; x < bounds_px.xmax; x++) {
									//uv[0] = (((float)x) + 0.5f) / (float)ibuf->x;
									uv[0] = (float)x / ibuf_xf; /* use offset uvs instead */
									
									/* test we're inside uvspace bucket and triangle bounds */
									if (IsectPQ2Df(uv, seam_subsection[0], seam_subsection[1], seam_subsection[2], seam_subsection[3])) {
										
										/* We need to find the closest point along the face edge,
										 * getting the screen_px_from_*** wont work because our actual location
										 * is not relevent, since we are outside the face, Use VecLerpf to find
										 * our location on the side of the face's UV */
										/*
										if (is_ortho)	screen_px_from_ortho(ps, uv, v1co, v2co, v3co, uv1co, uv2co, uv3co, pixelScreenCo);
										else					screen_px_from_persp(ps, uv, v1co, v2co, v3co, uv1co, uv2co, uv3co, pixelScreenCo);
										*/
										
										/* Since this is a seam we need to work out where on the line this pixel is */
										//fac = lambda_cp_line2(uv, uv_seam_quad[0], uv_seam_quad[1]);
										
										fac = lambda_cp_line2(uv, seam_subsection[0], seam_subsection[1]);
										if (fac < 0.0f)		{ VECCOPY(pixelScreenCo, edge_verts_inset_clip[0]); }
										else if (fac > 1.0f)	{ VECCOPY(pixelScreenCo, edge_verts_inset_clip[1]); }
										else				{ VecLerpf(pixelScreenCo, edge_verts_inset_clip[0], edge_verts_inset_clip[1], fac); }
										
										if (!is_ortho) {
											pixelScreenCo[3] = 1.0f;
											Mat4MulVec4fl((float(*)[4])ps->projectMat, pixelScreenCo); /* cast because of const */
											pixelScreenCo[0] = (float)(ps->ar->winx/2.0f)+(ps->ar->winx/2.0f)*pixelScreenCo[0]/pixelScreenCo[3];	
											pixelScreenCo[1] = (float)(ps->ar->winy/2.0f)+(ps->ar->winy/2.0f)*pixelScreenCo[1]/pixelScreenCo[3];
											pixelScreenCo[2] = pixelScreenCo[2]/pixelScreenCo[3]; /* Use the depth for bucket point occlusion */
										}
										
										if (ps->do_occlude==0 || !project_bucket_point_occluded(ps, bucketFaceNodes, face_index, pixelScreenCo)) {
											
											/* Only bother calculating the weights if we intersect */
											if (ps->do_mask_normal || ps->dm_mtface_clone) {
#if 0
												/* This is not QUITE correct since UV is not inside the UV's but good enough for seams */
												if (side) {
													BarycentricWeights2f(uv, tf_uv_pxoffset[0], tf_uv_pxoffset[2], tf_uv_pxoffset[3], w);
												}
												else {
													BarycentricWeights2f(uv, tf_uv_pxoffset[0], tf_uv_pxoffset[1], tf_uv_pxoffset[2], w);
												}
#endif
#if 1
												/* Cheat, we know where we are along the edge so work out the weights from that */
												fac = fac1 + (fac * (fac2-fac1));
												w[0]=w[1]=w[2]= 0.0;
												if (side) {
													w[fidx1?fidx1-1:0] = fac;
													w[fidx2?fidx2-1:0] = 1.0-fac;
												}
												else {
													w[fidx1] = fac;
													w[fidx2] = 1.0-fac;
												}
#endif
											}
											
											/* a pitty we need to get the worldspace pixel location here */
											if(ps->rv3d->rflag & RV3D_CLIPPING) {
												if (side)	VecLerp3f(wco, ps->dm_mvert[mf->v1].co, ps->dm_mvert[mf->v3].co, ps->dm_mvert[mf->v4].co, w);
												else		VecLerp3f(wco, ps->dm_mvert[mf->v1].co, ps->dm_mvert[mf->v2].co, ps->dm_mvert[mf->v3].co, w);
												
												Mat4MulVecfl(ps->ob->obmat, wco);
												if(view3d_test_clipping(ps->rv3d, wco)) {
													continue; /* Watch out that no code below this needs to run */
												}
											}
											
											mask = project_paint_uvpixel_mask(ps, face_index, side, w);
											
											if (mask > 0.0f) {
												BLI_linklist_prepend_arena(
													bucketPixelNodes,
													project_paint_uvpixel_init(ps, arena, ibuf, x, y, mask, face_index, image_index, pixelScreenCo, side, w),
													arena
												);
											}
											
										}
									}
									else if (has_x_isect) {
										/* assuming the face is not a bow-tie - we know we cant intersect again on the X */
										break;
									}
								}
								
#if 0							/* TODO - investigate why this dosnt work sometimes! it should! */
								/* no intersection for this entire row, after some intersection above means we can quit now */
								if (has_x_isect==0 && has_isect) { 
									break;
								}
#endif
							}
						}
					}
				}
			}
		}
	}
#endif // PROJ_DEBUG_NOSEAMBLEED
}


/* takes floating point screenspace min/max and returns int min/max to be used as indicies for ps->bucketRect, ps->bucketFlags */
static void project_paint_bucket_bounds(const ProjPaintState *ps, const float min[2], const float max[2], int bucketMin[2], int bucketMax[2])
{
	/* divide by bucketWidth & bucketHeight so the bounds are offset in bucket grid units */
	bucketMin[0] = (int)(((float)(min[0] - ps->screenMin[0]) / ps->screen_width) * ps->buckets_x) + 0.5f; /* these offsets of 0.5 and 1.5 seem odd but they are correct */
	bucketMin[1] = (int)(((float)(min[1] - ps->screenMin[1]) / ps->screen_height) * ps->buckets_y) + 0.5f;
	
	bucketMax[0] = (int)(((float)(max[0] - ps->screenMin[0]) / ps->screen_width) * ps->buckets_x) + 1.5f;
	bucketMax[1] = (int)(((float)(max[1] - ps->screenMin[1]) / ps->screen_height) * ps->buckets_y) + 1.5f;	
	
	/* incase the rect is outside the mesh 2d bounds */
	CLAMP(bucketMin[0], 0, ps->buckets_x);
	CLAMP(bucketMin[1], 0, ps->buckets_y);
	
	CLAMP(bucketMax[0], 0, ps->buckets_x);
	CLAMP(bucketMax[1], 0, ps->buckets_y);
}

/* set bucket_bounds to a screen space-aligned floating point bound-box */
static void project_bucket_bounds(const ProjPaintState *ps, const int bucket_x, const int bucket_y, rctf *bucket_bounds)
{
	bucket_bounds->xmin =	ps->screenMin[0]+((bucket_x)*(ps->screen_width / ps->buckets_x));		/* left */
	bucket_bounds->xmax =	ps->screenMin[0]+((bucket_x+1)*(ps->screen_width / ps->buckets_x));	/* right */
	
	bucket_bounds->ymin =	ps->screenMin[1]+((bucket_y)*(ps->screen_height / ps->buckets_y));		/* bottom */
	bucket_bounds->ymax =	ps->screenMin[1]+((bucket_y+1)*(ps->screen_height  / ps->buckets_y));	/* top */
}

/* Fill this bucket with pixels from the faces that intersect it.
 * 
 * have bucket_bounds as an argument so we don;t need to give bucket_x/y the rect function needs */
static void project_bucket_init(const ProjPaintState *ps, const int thread_index, const int bucket_index, rctf *bucket_bounds)
{
	LinkNode *node;
	int face_index, image_index=0;
	ImBuf *ibuf = NULL;
	MTFace *tf;
	
	Image *tpage_last = NULL;
	

	if (ps->image_tot==1) {
		/* Simple loop, no context switching */
		ibuf = ps->projImages[0].ibuf;
		
		for (node = ps->bucketFaces[bucket_index]; node; node= node->next) { 
			project_paint_face_init(ps, thread_index, bucket_index, GET_INT_FROM_POINTER(node->link), 0, bucket_bounds, ibuf);
		}
	}
	else {
		
		/* More complicated loop, switch between images */
		for (node = ps->bucketFaces[bucket_index]; node; node= node->next) {
			face_index = GET_INT_FROM_POINTER(node->link);
				
			/* Image context switching */
			tf = ps->dm_mtface+face_index;
			if (tpage_last != tf->tpage) {
				tpage_last = tf->tpage;
				
				image_index = -1; /* sanity check */
				
				for (image_index=0; image_index < ps->image_tot; image_index++) {
					if (ps->projImages[image_index].ima == tpage_last) {
						ibuf = ps->projImages[image_index].ibuf;
						break;
					}
				}
			}
			/* context switching done */
			
			project_paint_face_init(ps, thread_index, bucket_index, face_index, image_index, bucket_bounds, ibuf);
			
		}
	}
	
	ps->bucketFlags[bucket_index] |= PROJ_BUCKET_INIT;
}


/* We want to know if a bucket and a face overlap in screen-space
 * 
 * Note, if this ever returns false positives its not that bad, since a face in the bounding area will have its pixels
 * calculated when it might not be needed later, (at the moment at least)
 * obviously it shouldn't have bugs though */

static int project_bucket_face_isect(ProjPaintState *ps, float min[2], float max[2], int bucket_x, int bucket_y, int bucket_index, const MFace *mf)
{
	/* TODO - replace this with a tricker method that uses sideofline for all screenCoords's edges against the closest bucket corner */
	rctf bucket_bounds;
	float p1[2], p2[2], p3[2], p4[2];
	float *v, *v1,*v2,*v3,*v4=NULL;
	int fidx;
	
	project_bucket_bounds(ps, bucket_x, bucket_y, &bucket_bounds);
	
	/* Is one of the faces verts in the bucket bounds? */
	
	fidx = mf->v4 ? 3:2;
	do {
		v = ps->screenCoords[ (*(&mf->v1 + fidx)) ];
		if (BLI_in_rctf(&bucket_bounds, v[0], v[1])) {
			return 1;
		}
	} while (fidx--);
	
	v1 = ps->screenCoords[mf->v1];
	v2 = ps->screenCoords[mf->v2];
	v3 = ps->screenCoords[mf->v3];
	if (mf->v4) {
		v4 = ps->screenCoords[mf->v4];
	}
	
	p1[0] = bucket_bounds.xmin; p1[1] = bucket_bounds.ymin;
	p2[0] = bucket_bounds.xmin;	p2[1] = bucket_bounds.ymax;
	p3[0] = bucket_bounds.xmax;	p3[1] = bucket_bounds.ymax;
	p4[0] = bucket_bounds.xmax;	p4[1] = bucket_bounds.ymin;
		
	if (mf->v4) {
		if(	IsectPQ2Df(p1, v1, v2, v3, v4) || IsectPQ2Df(p2, v1, v2, v3, v4) || IsectPQ2Df(p3, v1, v2, v3, v4) || IsectPQ2Df(p4, v1, v2, v3, v4) ||
			/* we can avoid testing v3,v1 because another intersection MUST exist if this intersects */
			(IsectLL2Df(p1, p2, v1, v2) || IsectLL2Df(p1, p2, v2, v3) || IsectLL2Df(p1, p2, v3, v4)) ||
			(IsectLL2Df(p2, p3, v1, v2) || IsectLL2Df(p2, p3, v2, v3) || IsectLL2Df(p2, p3, v3, v4)) ||
			(IsectLL2Df(p3, p4, v1, v2) || IsectLL2Df(p3, p4, v2, v3) || IsectLL2Df(p3, p4, v3, v4)) ||
			(IsectLL2Df(p4, p1, v1, v2) || IsectLL2Df(p4, p1, v2, v3) || IsectLL2Df(p4, p1, v3, v4))
		) {
			return 1;
		}
	}
	else {
		if(	IsectPT2Df(p1, v1, v2, v3) || IsectPT2Df(p2, v1, v2, v3) || IsectPT2Df(p3, v1, v2, v3) || IsectPT2Df(p4, v1, v2, v3) ||
			/* we can avoid testing v3,v1 because another intersection MUST exist if this intersects */
			(IsectLL2Df(p1, p2, v1, v2) || IsectLL2Df(p1, p2, v2, v3)) ||
			(IsectLL2Df(p2, p3, v1, v2) || IsectLL2Df(p2, p3, v2, v3)) ||
			(IsectLL2Df(p3, p4, v1, v2) || IsectLL2Df(p3, p4, v2, v3)) ||
			(IsectLL2Df(p4, p1, v1, v2) || IsectLL2Df(p4, p1, v2, v3))
		) {
			return 1;
		}
	}

	return 0;
}

/* Add faces to the bucket but dont initialize its pixels
 * TODO - when painting occluded, sort the faces on their min-Z and only add faces that faces that are not occluded */
static void project_paint_delayed_face_init(ProjPaintState *ps, const MFace *mf, const MTFace *tf, const int face_index)
{
	float min[2], max[2], *vCoSS;
	int bucketMin[2], bucketMax[2]; /* for  ps->bucketRect indexing */
	int fidx, bucket_x, bucket_y, bucket_index;
	int has_x_isect = -1, has_isect = 0; /* for early loop exit */
	MemArena *arena = ps->arena_mt[0]; /* just use the first thread arena since threading has not started yet */
	
	INIT_MINMAX2(min, max);
	
	fidx = mf->v4 ? 3:2;
	do {
		vCoSS = ps->screenCoords[ *(&mf->v1 + fidx) ];
		DO_MINMAX2(vCoSS, min, max);
	} while (fidx--);
	
	project_paint_bucket_bounds(ps, min, max, bucketMin, bucketMax);
	
	for (bucket_y = bucketMin[1]; bucket_y < bucketMax[1]; bucket_y++) {
		has_x_isect = 0;
		for (bucket_x = bucketMin[0]; bucket_x < bucketMax[0]; bucket_x++) {
			
			bucket_index = bucket_x + (bucket_y * ps->buckets_x);
			
			if (project_bucket_face_isect(ps, min, max, bucket_x, bucket_y, bucket_index, mf)) {
				BLI_linklist_prepend_arena(
					&ps->bucketFaces[ bucket_index ],
					SET_INT_IN_POINTER(face_index), /* cast to a pointer to shut up the compiler */
					arena
				);
				
				has_x_isect = has_isect = 1;
			}
			else if (has_x_isect) {
				/* assuming the face is not a bow-tie - we know we cant intersect again on the X */
				break;
			}
		}
		
		/* no intersection for this entire row, after some intersection above means we can quit now */
		if (has_x_isect==0 && has_isect) { 
			break;
		}
	}
	
#ifndef PROJ_DEBUG_NOSEAMBLEED
	if (ps->seam_bleed_px > 0.0f) {
		if (!mf->v4) {
			ps->faceSeamFlags[face_index] |= PROJ_FACE_NOSEAM4; /* so this wont show up as an untagged edge */
		}
		**ps->faceSeamUVs[face_index] = FLT_MAX; /* set as uninitialized */
	}
#endif
}

/* run once per stroke before projection painting */
static void project_paint_begin(ProjPaintState *ps)
{	
	/* Viewport vars */
	float mat[3][3];
	
	float no[3];
	
	float (*projScreenCo)[4]; /* Note, we could have 4D vectors are only needed for */
	float projMargin;
	/* Image Vars - keep track of images we have used */
	LinkNode *image_LinkList = NULL;
	LinkNode *node;
	
	ProjPaintImage *projIma;
	Image *tpage_last = NULL;
	
	/* Face vars */
	MFace *mf;
	MTFace *tf;
	
	int a, i; /* generic looping vars */
	int image_index = -1, face_index;
	
	MemArena *arena; /* at the moment this is just ps->arena_mt[0], but use this to show were not multithreading */
	
	/* ---- end defines ---- */
	
	/* paint onto the derived mesh */
	ps->dm = mesh_get_derived_final(ps->scene, ps->ob, ps->v3d->customdata_mask);
	
	if ( !CustomData_has_layer( &ps->dm->faceData, CD_MTFACE) ) {
		ps->dm = NULL;
		return; 
	}
	ps->dm_mvert = ps->dm->getVertArray(ps->dm);
	ps->dm_mface = ps->dm->getFaceArray(ps->dm);
	ps->dm_mtface= ps->dm->getFaceDataArray(ps->dm, CD_MTFACE);
	
	ps->dm_totvert = ps->dm->getNumVerts(ps->dm);
	ps->dm_totface = ps->dm->getNumFaces(ps->dm);
	
	/* use clone mtface? */
	
	
	/* Note, use the original mesh for getting the clone and mask layer index
	 * this avoids re-generating the derived mesh just to get the new index */
	if (ps->do_layer_clone) {
		//int layer_num = CustomData_get_clone_layer(&ps->dm->faceData, CD_MTFACE);
		int layer_num = CustomData_get_clone_layer(&((Mesh *)ps->ob->data)->fdata, CD_MTFACE);
		if (layer_num != -1)
			ps->dm_mtface_clone = CustomData_get_layer_n(&ps->dm->faceData, CD_MTFACE, layer_num);
		
		if (ps->dm_mtface_clone==NULL || ps->dm_mtface_clone==ps->dm_mtface) {
			ps->do_layer_clone = 0;
			ps->dm_mtface_clone= NULL;
		}
	}
	
	if (ps->do_layer_mask) {
		//int layer_num = CustomData_get_mask_layer(&ps->dm->faceData, CD_MTFACE);
		int layer_num = CustomData_get_mask_layer(&((Mesh *)ps->ob->data)->fdata, CD_MTFACE);
		if (layer_num != -1)
			ps->dm_mtface_mask = CustomData_get_layer_n(&ps->dm->faceData, CD_MTFACE, layer_num);
		
		if (ps->dm_mtface_mask==NULL || ps->dm_mtface_mask==ps->dm_mtface) {
			ps->do_layer_mask = 0;
			ps->dm_mtface_mask = NULL;
		}
	}
	

	
	ps->viewDir[0] = 0.0f;
	ps->viewDir[1] = 0.0f;
	ps->viewDir[2] = 1.0f;
	
	view3d_get_object_project_mat(ps->rv3d, ps->ob, ps->projectMat);
	
	/* viewDir - object relative */
	Mat4Invert(ps->ob->imat, ps->ob->obmat);
	Mat3CpyMat4(mat, ps->rv3d->viewinv);
	Mat3MulVecfl(mat, ps->viewDir);
	Mat3CpyMat4(mat, ps->ob->imat);
	Mat3MulVecfl(mat, ps->viewDir);
	Normalize(ps->viewDir);
	
	/* viewPos - object relative */
	VECCOPY(ps->viewPos, ps->rv3d->viewinv[3]);
	Mat3CpyMat4(mat, ps->ob->imat);
	Mat3MulVecfl(mat, ps->viewPos);
	VecAddf(ps->viewPos, ps->viewPos, ps->ob->imat[3]);
	
	{	/* only use these for running 'get_view3d_viewplane' */
		rctf viewplane;
		
		ps->is_ortho = get_view3d_viewplane(ps->v3d, ps->rv3d, ps->ar->winx, ps->ar->winy, &viewplane, &ps->clipsta, &ps->clipend, NULL);
		
		//printf("%f %f\n", ps->clipsta, ps->clipend);
		if (ps->is_ortho) { /* only needed for ortho */
			float fac = 2.0f / (ps->clipend - ps->clipsta);  
			ps->clipsta *= fac;
			ps->clipend *= fac;
		}
		else {
			/* TODO - can we even adjust for clip start/end? */
		}
		
	}
	
	ps->is_airbrush = (ps->brush->flag & BRUSH_AIRBRUSH) ? 1 : 0;
	
	ps->is_texbrush = (ps->brush->mtex[ps->brush->texact] && ps->brush->mtex[ps->brush->texact]->tex) ? 1 : 0;

	
	/* calculate vert screen coords
	 * run this early so we can calculate the x/y resolution of our bucket rect */
	INIT_MINMAX2(ps->screenMin, ps->screenMax);
	
	ps->screenCoords = MEM_mallocN(sizeof(float) * ps->dm_totvert * 4, "ProjectPaint ScreenVerts");
	projScreenCo = ps->screenCoords;
	
	if (ps->is_ortho) {
		for(a=0; a < ps->dm_totvert; a++, projScreenCo++) {
			VECCOPY((*projScreenCo), ps->dm_mvert[a].co);
			Mat4MulVecfl(ps->projectMat, (*projScreenCo));
			
			/* screen space, not clamped */
			(*projScreenCo)[0] = (float)(ps->ar->winx/2.0f)+(ps->ar->winx/2.0f)*(*projScreenCo)[0];
			(*projScreenCo)[1] = (float)(ps->ar->winy/2.0f)+(ps->ar->winy/2.0f)*(*projScreenCo)[1];
			DO_MINMAX2((*projScreenCo), ps->screenMin, ps->screenMax);
		}
	}
	else {
		for(a=0; a < ps->dm_totvert; a++, projScreenCo++) {
			VECCOPY((*projScreenCo), ps->dm_mvert[a].co);
			(*projScreenCo)[3] = 1.0f;

			Mat4MulVec4fl(ps->projectMat, (*projScreenCo));

			
			if ((*projScreenCo)[3] > ps->clipsta) {
				/* screen space, not clamped */
				(*projScreenCo)[0] = (float)(ps->ar->winx/2.0f)+(ps->ar->winx/2.0f)*(*projScreenCo)[0]/(*projScreenCo)[3];
				(*projScreenCo)[1] = (float)(ps->ar->winy/2.0f)+(ps->ar->winy/2.0f)*(*projScreenCo)[1]/(*projScreenCo)[3];
				(*projScreenCo)[2] = (*projScreenCo)[2]/(*projScreenCo)[3]; /* Use the depth for bucket point occlusion */
				DO_MINMAX2((*projScreenCo), ps->screenMin, ps->screenMax);
			}
			else {
				/* TODO - deal with cases where 1 side of a face goes behind the view ?
				 * 
				 * After some research this is actually very tricky, only option is to
				 * clip the derived mesh before painting, which is a Pain */
				(*projScreenCo)[0] = FLT_MAX;
			}
		}
	}
	
	/* If this border is not added we get artifacts for faces that
	 * have a parallel edge and at the bounds of the the 2D projected verts eg
	 * - a single screen aligned quad */
	projMargin = (ps->screenMax[0] - ps->screenMin[0]) * 0.000001f;
	ps->screenMax[0] += projMargin;
	ps->screenMin[0] -= projMargin;
	projMargin = (ps->screenMax[1] - ps->screenMin[1]) * 0.000001f;
	ps->screenMax[1] += projMargin;
	ps->screenMin[1] -= projMargin;
	
#ifdef PROJ_DEBUG_WINCLIP
	CLAMP(ps->screenMin[0], -ps->brush->size, ps->ar->winx + ps->brush->size);
	CLAMP(ps->screenMax[0], -ps->brush->size, ps->ar->winx + ps->brush->size);

	CLAMP(ps->screenMin[1], -ps->brush->size, ps->ar->winy + ps->brush->size);
	CLAMP(ps->screenMax[1], -ps->brush->size, ps->ar->winy + ps->brush->size);
#endif
	
	/* only for convenience */
	ps->screen_width  = ps->screenMax[0] - ps->screenMin[0];
	ps->screen_height = ps->screenMax[1] - ps->screenMin[1];
	
	ps->buckets_x = (int)(ps->screen_width / (((float)ps->brush->size) / PROJ_BUCKET_BRUSH_DIV));
	ps->buckets_y = (int)(ps->screen_height / (((float)ps->brush->size) / PROJ_BUCKET_BRUSH_DIV));
	
	/* printf("\tscreenspace bucket division x:%d y:%d\n", ps->buckets_x, ps->buckets_y); */
	
	/* really high values could cause problems since it has to allocate a few
	 * (ps->buckets_x*ps->buckets_y) sized arrays  */
	CLAMP(ps->buckets_x, PROJ_BUCKET_RECT_MIN, PROJ_BUCKET_RECT_MAX);
	CLAMP(ps->buckets_y, PROJ_BUCKET_RECT_MIN, PROJ_BUCKET_RECT_MAX);
	
	ps->bucketRect = (LinkNode **)MEM_callocN(sizeof(LinkNode *) * ps->buckets_x * ps->buckets_y, "paint-bucketRect");
	ps->bucketFaces= (LinkNode **)MEM_callocN(sizeof(LinkNode *) * ps->buckets_x * ps->buckets_y, "paint-bucketFaces");
	
	ps->bucketFlags= (unsigned char *)MEM_callocN(sizeof(char) * ps->buckets_x * ps->buckets_y, "paint-bucketFaces");
#ifndef PROJ_DEBUG_NOSEAMBLEED
	if (ps->seam_bleed_px > 0.0f) {
		ps->vertFaces= (LinkNode **)MEM_callocN(sizeof(LinkNode *) * ps->dm_totvert, "paint-vertFaces");
		ps->faceSeamFlags = (char *)MEM_callocN(sizeof(char) * ps->dm_totface, "paint-faceSeamFlags");
		ps->faceSeamUVs= MEM_mallocN(sizeof(float) * ps->dm_totface * 8, "paint-faceSeamUVs");
	}
#endif
	
	/* Thread stuff
	 * 
	 * very small brushes run a lot slower multithreaded since the advantage with
	 * threads is being able to fill in multiple buckets at once.
	 * Only use threads for bigger brushes. */
	
	if (ps->scene->r.mode & R_FIXED_THREADS) {
		ps->thread_tot = ps->scene->r.threads;
	}
	else {
		ps->thread_tot = BLI_system_thread_count();
	}
	for (a=0; a<ps->thread_tot; a++) {
		ps->arena_mt[a] = BLI_memarena_new(1<<16);
	}
	
	arena = ps->arena_mt[0]; 
	
	if (ps->do_backfacecull && ps->do_mask_normal) {
		MVert *v = ps->dm_mvert;
		float viewDirPersp[3];
		
		ps->vertFlags = MEM_callocN(sizeof(char) * ps->dm_totvert, "paint-vertFlags");
		
		for(a=0; a < ps->dm_totvert; a++, v++) {
			no[0] = (float)(v->no[0] / 32767.0f);
			no[1] = (float)(v->no[1] / 32767.0f);
			no[2] = (float)(v->no[2] / 32767.0f);
			
			if (ps->is_ortho) {
				if (NormalizedVecAngle2(ps->viewDir, no) >= ps->normal_angle) { /* 1 vert of this face is towards us */
					ps->vertFlags[a] |= PROJ_VERT_CULL;
				}
			}
			else {
				VecSubf(viewDirPersp, ps->viewPos, v->co);
				Normalize(viewDirPersp);
				if (NormalizedVecAngle2(viewDirPersp, no) >= ps->normal_angle) { /* 1 vert of this face is towards us */
					ps->vertFlags[a] |= PROJ_VERT_CULL;
				}
			}
		}
	}
	

	for(face_index = 0, tf = ps->dm_mtface, mf = ps->dm_mface; face_index < ps->dm_totface; mf++, tf++, face_index++) {
		
#ifndef PROJ_DEBUG_NOSEAMBLEED
		/* add face user if we have bleed enabled, set the UV seam flags later */
		/* annoying but we need to add all faces even ones we never use elsewhere */
		if (ps->seam_bleed_px > 0.0f) {
			BLI_linklist_prepend_arena(&ps->vertFaces[mf->v1], SET_INT_IN_POINTER(face_index), arena);
			BLI_linklist_prepend_arena(&ps->vertFaces[mf->v2], SET_INT_IN_POINTER(face_index), arena);
			BLI_linklist_prepend_arena(&ps->vertFaces[mf->v3], SET_INT_IN_POINTER(face_index), arena);
			if (mf->v4) {
				BLI_linklist_prepend_arena(&ps->vertFaces[ mf->v4 ], SET_INT_IN_POINTER(face_index), arena);
			}
		}
#endif
		
		if (tf->tpage && ((G.f & G_FACESELECT)==0 || mf->flag & ME_FACE_SEL)) {
			
			float *v1coSS, *v2coSS, *v3coSS, *v4coSS=NULL;
			
			v1coSS = ps->screenCoords[mf->v1]; 
			v2coSS = ps->screenCoords[mf->v2]; 
			v3coSS = ps->screenCoords[mf->v3];
			if (mf->v4) {
				v4coSS = ps->screenCoords[mf->v4]; 
			}
			
			
			if (!ps->is_ortho) {
				if (	v1coSS[0]==FLT_MAX ||
						v2coSS[0]==FLT_MAX ||
						v3coSS[0]==FLT_MAX ||
						(mf->v4 && v4coSS[0]==FLT_MAX)
				) {
					continue;
				}
			}
			
#ifdef PROJ_DEBUG_WINCLIP
			/* ignore faces outside the view */
			if (
				   (v1coSS[0] < ps->screenMin[0] &&
					v2coSS[0] < ps->screenMin[0] &&
					v3coSS[0] < ps->screenMin[0] &&
					(mf->v4 && v4coSS[0] < ps->screenMin[0])) ||
					
				   (v1coSS[0] > ps->screenMax[0] &&
					v2coSS[0] > ps->screenMax[0] &&
					v3coSS[0] > ps->screenMax[0] &&
					(mf->v4 && v4coSS[0] > ps->screenMax[0])) ||
					
				   (v1coSS[1] < ps->screenMin[1] &&
					v2coSS[1] < ps->screenMin[1] &&
					v3coSS[1] < ps->screenMin[1] &&
					(mf->v4 && v4coSS[1] < ps->screenMin[1])) ||
					
				   (v1coSS[1] > ps->screenMax[1] &&
					v2coSS[1] > ps->screenMax[1] &&
					v3coSS[1] > ps->screenMax[1] &&
					(mf->v4 && v4coSS[1] > ps->screenMax[1]))
			) {
				continue;
			}
			
#endif //PROJ_DEBUG_WINCLIP
	
			
			if (ps->do_backfacecull) {
				if (ps->do_mask_normal) {
					/* Since we are interpolating the normals of faces, we want to make 
					 * sure all the verts are pointing away from the view,
					 * not just the face */
					if (	(ps->vertFlags[mf->v1] & PROJ_VERT_CULL) &&
							(ps->vertFlags[mf->v2] & PROJ_VERT_CULL) &&
							(ps->vertFlags[mf->v3] & PROJ_VERT_CULL) &&
							(mf->v4==0 || ps->vertFlags[mf->v4] & PROJ_VERT_CULL)
							
					) {
						continue;
					}
				}
				else {
					if (SIDE_OF_LINE(v1coSS, v2coSS, v3coSS) < 0.0f) {
						continue;
					}
					
				}
			}
			
			if (tpage_last != tf->tpage) {
				
				image_index = BLI_linklist_index(image_LinkList, tf->tpage);
				
				if (image_index==-1 && BKE_image_get_ibuf(tf->tpage, NULL)) { /* MemArena dosnt have an append func */
					BLI_linklist_append(&image_LinkList, tf->tpage);
					image_index = ps->image_tot;
					ps->image_tot++;
				}
				
				tpage_last = tf->tpage;
			}
			
			if (image_index != -1) {
				/* Initialize the faces screen pixels */
				/* Add this to a list to initialize later */
				project_paint_delayed_face_init(ps, mf, tf, face_index);
			}
		}
	}
	
	/* build an array of images we use*/
	projIma = ps->projImages = (ProjPaintImage *)BLI_memarena_alloc(arena, sizeof(ProjPaintImage) * ps->image_tot);
	
	for (node= image_LinkList, i=0; node; node= node->next, i++, projIma++) {
		projIma->ima = node->link;
		projIma->touch = 0;
		projIma->ibuf = BKE_image_get_ibuf(projIma->ima, NULL);
		projIma->partRedrawRect =  BLI_memarena_alloc(arena, sizeof(ImagePaintPartialRedraw) * PROJ_BOUNDBOX_SQUARED);
		memset(projIma->partRedrawRect, 0, sizeof(ImagePaintPartialRedraw) * PROJ_BOUNDBOX_SQUARED);
	}
	
	/* we have built the array, discard the linked list */
	BLI_linklist_free(image_LinkList, NULL);
}

static void project_paint_begin_clone(ProjPaintState *ps, int mouse[2])
{
	/* setup clone offset */
	if (ps->tool == PAINT_TOOL_CLONE) {
		float projCo[4];
		float *curs= give_cursor(ps->scene, ps->v3d);
		VECCOPY(projCo, curs);
		Mat4MulVecfl(ps->ob->imat, projCo);
		
		projCo[3] = 1.0f;
		Mat4MulVec4fl(ps->projectMat, projCo);
		ps->cloneOffset[0] = mouse[0] - ((float)(ps->ar->winx/2.0f)+(ps->ar->winx/2.0f)*projCo[0]/projCo[3]);
		ps->cloneOffset[1] = mouse[1] - ((float)(ps->ar->winy/2.0f)+(ps->ar->winy/2.0f)*projCo[1]/projCo[3]);
	}	
}	

static void project_paint_end(ProjPaintState *ps)
{
	int a;
	
	/* build undo data from original pixel colors */
	if(U.uiflag & USER_GLOBALUNDO) {
		ProjPixel *projPixel;
		ImBuf *tmpibuf = NULL, *tmpibuf_float = NULL;
		LinkNode *pixel_node;
		UndoTile *tile;
		MemArena *arena = ps->arena_mt[0]; /* threaded arena re-used for non threaded case */
				
		int bucket_tot = (ps->buckets_x * ps->buckets_y); /* we could get an X/Y but easier to loop through all possible buckets */
		int bucket_index; 
		int tile_index;
		int x_round, y_round;
		int x_tile, y_tile;
		int is_float = -1;
		
		/* context */
		ProjPaintImage *last_projIma;
		int last_image_index = -1;
		int last_tile_width=0;
		
		for(a=0, last_projIma=ps->projImages; a < ps->image_tot; a++, last_projIma++) {
			int size = sizeof(UndoTile **) * IMAPAINT_TILE_NUMBER(last_projIma->ibuf->x) * IMAPAINT_TILE_NUMBER(last_projIma->ibuf->y);
			last_projIma->undoRect = (UndoTile **) BLI_memarena_alloc(arena, size);
			memset(last_projIma->undoRect, 0, size);
			last_projIma->ibuf->userflags |= IB_BITMAPDIRTY;
		}
		
		for (bucket_index = 0; bucket_index < bucket_tot; bucket_index++) {
			/* loop through all pixels */
			for(pixel_node= ps->bucketRect[bucket_index]; pixel_node; pixel_node= pixel_node->next) {
			
				/* ok we have a pixel, was it modified? */
				projPixel = (ProjPixel *)pixel_node->link;
				
				if (last_image_index != projPixel->image_index) {
					/* set the context */
					last_image_index =	projPixel->image_index;
					last_projIma =		ps->projImages + last_image_index;
					last_tile_width =	IMAPAINT_TILE_NUMBER(last_projIma->ibuf->x);
					is_float =			last_projIma->ibuf->rect_float ? 1 : 0;
				}
				
				
				if (	(is_float == 0 && projPixel->origColor.uint != *projPixel->pixel.uint_pt) || 
								
						(is_float == 1 && 
						(	projPixel->origColor.f[0] != projPixel->pixel.f_pt[0] || 
							projPixel->origColor.f[1] != projPixel->pixel.f_pt[1] ||
							projPixel->origColor.f[2] != projPixel->pixel.f_pt[2] ||
							projPixel->origColor.f[3] != projPixel->pixel.f_pt[3] ))
				) {
					
					x_tile =  projPixel->x_px >> IMAPAINT_TILE_BITS;
					y_tile =  projPixel->y_px >> IMAPAINT_TILE_BITS;
					
					x_round = x_tile * IMAPAINT_TILE_SIZE;
					y_round = y_tile * IMAPAINT_TILE_SIZE;
					
					tile_index = x_tile + y_tile * last_tile_width;
					
					if (last_projIma->undoRect[tile_index]==NULL) {
						/* add the undo tile from the modified image, then write the original colors back into it */
						tile = last_projIma->undoRect[tile_index] = undo_init_tile(&last_projIma->ima->id, last_projIma->ibuf, is_float ? (&tmpibuf_float):(&tmpibuf) , x_tile, y_tile);
					}
					else {
						tile = last_projIma->undoRect[tile_index];
					}
					
					/* This is a BIT ODD, but overwrite the undo tiles image info with this pixels original color
					 * because allocating the tiles allong the way slows down painting */
					
					if (is_float) {
						float *rgba_fp = (float *)tile->rect + (((projPixel->x_px - x_round) + (projPixel->y_px - y_round) * IMAPAINT_TILE_SIZE)) * 4;
						QUATCOPY(rgba_fp, projPixel->origColor.f);
					}
					else {
						((unsigned int *)tile->rect)[ (projPixel->x_px - x_round) + (projPixel->y_px - y_round) * IMAPAINT_TILE_SIZE ] = projPixel->origColor.uint;
					}
				}
			}
		}
		
		if (tmpibuf)		IMB_freeImBuf(tmpibuf);
		if (tmpibuf_float)	IMB_freeImBuf(tmpibuf_float);
	}
	/* done calculating undo data */
	
	MEM_freeN(ps->screenCoords);
	MEM_freeN(ps->bucketRect);
	MEM_freeN(ps->bucketFaces);
	MEM_freeN(ps->bucketFlags);
	
#ifndef PROJ_DEBUG_NOSEAMBLEED
	if (ps->seam_bleed_px > 0.0f) {
		MEM_freeN(ps->vertFaces);
		MEM_freeN(ps->faceSeamFlags);
		MEM_freeN(ps->faceSeamUVs);
	}
#endif
	
	if (ps->vertFlags) MEM_freeN(ps->vertFlags);
	
	for (a=0; a<ps->thread_tot; a++) {
		BLI_memarena_free(ps->arena_mt[a]);
	}
	
	ps->dm->release(ps->dm);
}

/* 1= an undo, -1 is a redo. */
static void partial_redraw_array_init(ImagePaintPartialRedraw *pr)
{
	int tot = PROJ_BOUNDBOX_SQUARED;
	while (tot--) {
		pr->x1 = 10000000;
		pr->y1 = 10000000;
		
		pr->x2 = -1;
		pr->y2 = -1;
		
		pr->enabled = 1;
		
		pr++;
	}
}


static int partial_redraw_array_merge(ImagePaintPartialRedraw *pr, ImagePaintPartialRedraw *pr_other, int tot)
{
	int touch= 0;
	while (tot--) {
		pr->x1 = MIN2(pr->x1, pr_other->x1);
		pr->y1 = MIN2(pr->y1, pr_other->y1);
		
		pr->x2 = MAX2(pr->x2, pr_other->x2);
		pr->y2 = MAX2(pr->y2, pr_other->y2);
		
		if (pr->x2 != -1)
			touch = 1;
		
		pr++; pr_other++;
	}
	
	return touch;
}

/* Loop over all images on this mesh and update any we have touched */
static int project_image_refresh_tagged(ProjPaintState *ps)
{
	ImagePaintPartialRedraw *pr;
	ProjPaintImage *projIma;
	int a,i;
	int redraw = 0;
	
	
	for (a=0, projIma=ps->projImages; a < ps->image_tot; a++, projIma++) {
		if (projIma->touch) {
			/* look over each bound cell */
			for (i=0; i<PROJ_BOUNDBOX_SQUARED; i++) {
				pr = &(projIma->partRedrawRect[i]);
				if (pr->x2 != -1) { /* TODO - use 'enabled' ? */
					imapaintpartial = *pr;
					imapaint_image_update(NULL, projIma->ima, projIma->ibuf, 1); /*last 1 is for texpaint*/
					redraw = 1;
				}
			}
			
			projIma->touch = 0; /* clear for reuse */
		}
	}
	
	return redraw;
}

/* run this per painting onto each mouse location */
static int project_bucket_iter_init(ProjPaintState *ps, const float mval_f[2])
{
	float min_brush[2], max_brush[2];
	float size_half = ((float)ps->brush->size) * 0.5f;
	
	/* so we dont have a bucket bounds that is way too small to paint into */
	// if (size_half < 1.0f) size_half = 1.0f; // this dosnt work yet :/
	
	min_brush[0] = mval_f[0] - size_half;
	min_brush[1] = mval_f[1] - size_half;
	
	max_brush[0] = mval_f[0] + size_half;
	max_brush[1] = mval_f[1] + size_half;
	
	/* offset to make this a valid bucket index */
	project_paint_bucket_bounds(ps, min_brush, max_brush, ps->bucketMin, ps->bucketMax);
	
	/* mouse outside the model areas? */
	if (ps->bucketMin[0]==ps->bucketMax[0] || ps->bucketMin[1]==ps->bucketMax[1]) {
		return 0;
	}
	
	ps->context_bucket_x = ps->bucketMin[0];
	ps->context_bucket_y = ps->bucketMin[1];
	return 1;
}

static int project_bucket_iter_next(ProjPaintState *ps, int *bucket_index, rctf *bucket_bounds, const float mval[2])
{
	if (ps->thread_tot > 1)
		BLI_lock_thread(LOCK_CUSTOM1);
	
	//printf("%d %d \n", ps->context_bucket_x, ps->context_bucket_y);
	
	for ( ; ps->context_bucket_y < ps->bucketMax[1]; ps->context_bucket_y++) {
		for ( ; ps->context_bucket_x < ps->bucketMax[0]; ps->context_bucket_x++) {
			
			/* use bucket_bounds for project_bucket_isect_circle and project_bucket_init*/
			project_bucket_bounds(ps, ps->context_bucket_x, ps->context_bucket_y, bucket_bounds);
			
			if (project_bucket_isect_circle(ps->context_bucket_x, ps->context_bucket_y, mval, ps->brush->size * ps->brush->size, bucket_bounds)) {
				*bucket_index = ps->context_bucket_x + (ps->context_bucket_y * ps->buckets_x);
				ps->context_bucket_x++;
				
				if (ps->thread_tot > 1)
					BLI_unlock_thread(LOCK_CUSTOM1);
				
				return 1;
			}
		}
		ps->context_bucket_x = ps->bucketMin[0];
	}
	
	if (ps->thread_tot > 1)
		BLI_unlock_thread(LOCK_CUSTOM1);
	return 0;
}

/* Each thread gets one of these, also used as an argument to pass to project_paint_op */
typedef struct ProjectHandle {
	/* args */
	ProjPaintState *ps;
	float prevmval[2];
	float mval[2];
	
	/* annoying but we need to have image bounds per thread, then merge into ps->projectPartialRedraws */
	ProjPaintImage *projImages;	/* array of partial redraws */
	
	/* thread settings */
	int thread_index;
} ProjectHandle;

static void blend_color_mix(unsigned char *cp, const unsigned char *cp1, const unsigned char *cp2, const int fac)
{
	/* this and other blending modes previously used >>8 instead of /255. both
	   are not equivalent (>>8 is /256), and the former results in rounding
	   errors that can turn colors black fast after repeated blending */
	const int mfac= 255-fac;

	cp[0]= (mfac*cp1[0]+fac*cp2[0])/255;
	cp[1]= (mfac*cp1[1]+fac*cp2[1])/255;
	cp[2]= (mfac*cp1[2]+fac*cp2[2])/255;
	cp[3]= (mfac*cp1[3]+fac*cp2[3])/255;
}

static void blend_color_mix_float(float *cp, const float *cp1, const float *cp2, const float fac)
{
	const float mfac= 1.0-fac;
	cp[0]= mfac*cp1[0] + fac*cp2[0];
	cp[1]= mfac*cp1[1] + fac*cp2[1];
	cp[2]= mfac*cp1[2] + fac*cp2[2];
	cp[3]= mfac*cp1[3] + fac*cp2[3];
}

static void do_projectpaint_clone(ProjPaintState *ps, ProjPixel *projPixel, float *rgba, float alpha, float mask)
{
	if (ps->is_airbrush==0 && mask < 1.0f) {
		projPixel->newColor.uint = IMB_blend_color(projPixel->newColor.uint, ((ProjPixelClone*)projPixel)->clonepx.uint, (int)(alpha*255), ps->blend);
		blend_color_mix(projPixel->pixel.ch_pt,  projPixel->origColor.ch, projPixel->newColor.ch, (int)(mask*255));
	}
	else {
		*projPixel->pixel.uint_pt = IMB_blend_color(*projPixel->pixel.uint_pt, ((ProjPixelClone*)projPixel)->clonepx.uint, (int)(alpha*mask*255), ps->blend);
	}
}

static void do_projectpaint_clone_f(ProjPaintState *ps, ProjPixel *projPixel, float *rgba, float alpha, float mask)
{
	if (ps->is_airbrush==0 && mask < 1.0f) {
		IMB_blend_color_float(projPixel->newColor.f, projPixel->newColor.f, ((ProjPixelClone *)projPixel)->clonepx.f, alpha, ps->blend);
		blend_color_mix_float(projPixel->pixel.f_pt,  projPixel->origColor.f, projPixel->newColor.f, mask);
	}
	else {
		IMB_blend_color_float(projPixel->pixel.f_pt, projPixel->pixel.f_pt, ((ProjPixelClone *)projPixel)->clonepx.f, alpha*mask, ps->blend);
	}
}

/* do_projectpaint_smear*
 * 
 * note, mask is used to modify the alpha here, this is not correct since it allows
 * accumulation of color greater then 'projPixel->mask' however in the case of smear its not 
 * really that important to be correct as it is with clone and painting 
 */
static void do_projectpaint_smear(ProjPaintState *ps, ProjPixel *projPixel, float *rgba, float alpha, float mask, MemArena *smearArena, LinkNode **smearPixels, float co[2])
{
	unsigned char rgba_ub[4];
	
	if (project_paint_PickColor(ps, co, NULL, rgba_ub, 1)==0)
		return; 
	/* ((ProjPixelClone *)projPixel)->clonepx.uint = IMB_blend_color(*projPixel->pixel.uint_pt, *((unsigned int *)rgba_ub), (int)(alpha*mask*255), ps->blend); */
	blend_color_mix(((ProjPixelClone *)projPixel)->clonepx.ch, projPixel->pixel.ch_pt, rgba_ub, (int)(alpha*mask*255));
	BLI_linklist_prepend_arena(smearPixels, (void *)projPixel, smearArena);
} 

static void do_projectpaint_smear_f(ProjPaintState *ps, ProjPixel *projPixel, float *rgba, float alpha, float mask, MemArena *smearArena, LinkNode **smearPixels_f, float co[2])
{
	unsigned char rgba_ub[4];
	unsigned char rgba_smear[4];
	
	if (project_paint_PickColor(ps, co, NULL, rgba_ub, 1)==0)
		return;
	
	IMAPAINT_FLOAT_RGBA_TO_CHAR(rgba_smear, projPixel->pixel.f_pt);
	/* (ProjPixelClone *)projPixel)->clonepx.uint = IMB_blend_color(*((unsigned int *)rgba_smear), *((unsigned int *)rgba_ub), (int)(alpha*mask*255), ps->blend); */
	blend_color_mix(((ProjPixelClone *)projPixel)->clonepx.ch, rgba_smear, (rgba_ub), (int)(alpha*mask*255)); 
	BLI_linklist_prepend_arena(smearPixels_f, (void *)projPixel, smearArena);
}

static void do_projectpaint_draw(ProjPaintState *ps, ProjPixel *projPixel, float *rgba, float alpha, float mask)
{
	unsigned char rgba_ub[4];
	
	if (ps->is_texbrush) {
		rgba_ub[0] = FTOCHAR(rgba[0] * ps->brush->rgb[0]);
		rgba_ub[1] = FTOCHAR(rgba[1] * ps->brush->rgb[1]);
		rgba_ub[2] = FTOCHAR(rgba[2] * ps->brush->rgb[2]);
		rgba_ub[3] = FTOCHAR(rgba[3]);
	}
	else {
		IMAPAINT_FLOAT_RGB_TO_CHAR(rgba_ub, ps->brush->rgb);
		rgba_ub[3] = 255;
	}
	
	if (ps->is_airbrush==0 && mask < 1.0f) {
		projPixel->newColor.uint = IMB_blend_color(projPixel->newColor.uint, *((unsigned int *)rgba_ub), (int)(alpha*255), ps->blend);
		blend_color_mix(projPixel->pixel.ch_pt,  projPixel->origColor.ch, projPixel->newColor.ch, (int)(mask*255));
	}
	else {
		*projPixel->pixel.uint_pt = IMB_blend_color(*projPixel->pixel.uint_pt, *((unsigned int *)rgba_ub), (int)(alpha*mask*255), ps->blend);
	}
}

static void do_projectpaint_draw_f(ProjPaintState *ps, ProjPixel *projPixel, float *rgba, float alpha, float mask) {
	if (ps->is_texbrush) {
		rgba[0] *= ps->brush->rgb[0];
		rgba[1] *= ps->brush->rgb[1];
		rgba[2] *= ps->brush->rgb[2];
	}
	else {
		VECCOPY(rgba, ps->brush->rgb);
	}
	
	if (ps->is_airbrush==0 && mask < 1.0f) {
		IMB_blend_color_float(projPixel->newColor.f, projPixel->newColor.f, rgba, alpha, ps->blend);
		blend_color_mix_float(projPixel->pixel.f_pt,  projPixel->origColor.f, projPixel->newColor.f, mask);
	}
	else {
		IMB_blend_color_float(projPixel->pixel.f_pt, projPixel->pixel.f_pt, rgba, alpha*mask, ps->blend);
	}
}



/* run this for single and multithreaded painting */
static void *do_projectpaint_thread(void *ph_v)
{
	/* First unpack args from the struct */
	ProjPaintState *ps =			((ProjectHandle *)ph_v)->ps;
	ProjPaintImage *projImages =	((ProjectHandle *)ph_v)->projImages;
	const float *lastpos =			((ProjectHandle *)ph_v)->prevmval;
	const float *pos =				((ProjectHandle *)ph_v)->mval;
	const int thread_index =		((ProjectHandle *)ph_v)->thread_index;
	/* Done with args from ProjectHandle */

	LinkNode *node;
	ProjPixel *projPixel;
	
	int last_index = -1;
	ProjPaintImage *last_projIma= NULL;
	ImagePaintPartialRedraw *last_partial_redraw_cell;
	
	float rgba[4], alpha, dist_nosqrt, dist;
	
	float brush_size_sqared;
	float falloff;
	int bucket_index;
	int is_floatbuf = 0;
	const short tool =  ps->tool;
	rctf bucket_bounds;
	
	/* for smear only */
	float pos_ofs[2];
	float co[2];
	float mask = 1.0f; /* airbrush wont use mask */
	unsigned short mask_short;
	float size_half = ((float)ps->brush->size) * 0.5f;
	
	LinkNode *smearPixels = NULL;
	LinkNode *smearPixels_f = NULL;
	MemArena *smearArena = NULL; /* mem arena for this brush projection only */
	
	
	if (tool==PAINT_TOOL_SMEAR) {
		pos_ofs[0] = pos[0] - lastpos[0];
		pos_ofs[1] = pos[1] - lastpos[1];
		
		smearArena = BLI_memarena_new(1<<16);
	}
	
	/* avoid a square root with every dist comparison */
	brush_size_sqared = ps->brush->size * ps->brush->size; 
	
	/* printf("brush bounds %d %d %d %d\n", bucketMin[0], bucketMin[1], bucketMax[0], bucketMax[1]); */
	
	while (project_bucket_iter_next(ps, &bucket_index, &bucket_bounds, pos)) {				
		
		/* Check this bucket and its faces are initialized */
		if (ps->bucketFlags[bucket_index] == PROJ_BUCKET_NULL) {
			/* No pixels initialized */
			project_bucket_init(ps, thread_index, bucket_index, &bucket_bounds);
		}

		for (node = ps->bucketRect[bucket_index]; node; node = node->next) {
			
			projPixel = (ProjPixel *)node->link;
			
			/*dist = Vec2Lenf(projPixel->projCoSS, pos);*/ /* correct but uses a sqrtf */
			dist_nosqrt = Vec2Lenf_nosqrt(projPixel->projCoSS, pos);
			
			/*if (dist < s->brush->size) {*/ /* correct but uses a sqrtf */
			if (dist_nosqrt < brush_size_sqared && (dist=sqrtf(dist_nosqrt)) < size_half) {
				falloff = brush_curve_strength_clamp(ps->brush, dist, size_half);
				if (falloff > 0.0f) {
					if (ps->is_texbrush) {
						brush_sample_tex(ps->brush, projPixel->projCoSS, rgba);
						alpha = rgba[3];
					} else {
						alpha = 1.0f;
					}
					
					if (ps->is_airbrush) {
						/* for an aurbrush there is no real mask, so just multiply the alpha by it */
						alpha *= falloff * ps->brush->alpha;
						mask = ((float)projPixel->mask)/65535.0f;
					}
					else {
						/* This brush dosnt accumulate so add some curve to the brushes falloff */
						falloff = 1.0f - falloff;
						falloff = 1.0f - (falloff * falloff);
						
						mask_short = projPixel->mask * (ps->brush->alpha * falloff);
						if (mask_short > projPixel->mask_max) {
							mask = ((float)mask_short)/65535.0f;
							projPixel->mask_max = mask_short;
						}
						else {
							/*mask = ((float)projPixel->mask_max)/65535.0f;*/
							
							/* Go onto the next pixel */
							continue;
						}
					}
					
					if (alpha > 0.0f) {
						
						if (last_index != projPixel->image_index) {
							last_index = projPixel->image_index;
							last_projIma = projImages + last_index;
							
							last_projIma->touch = 1;
							is_floatbuf = last_projIma->ibuf->rect_float ? 1 : 0;
						}
						
						last_partial_redraw_cell = last_projIma->partRedrawRect + projPixel->bb_cell_index;
						last_partial_redraw_cell->x1 = MIN2(last_partial_redraw_cell->x1, projPixel->x_px);
						last_partial_redraw_cell->y1 = MIN2(last_partial_redraw_cell->y1, projPixel->y_px);
						
						last_partial_redraw_cell->x2 = MAX2(last_partial_redraw_cell->x2, projPixel->x_px+1);
						last_partial_redraw_cell->y2 = MAX2(last_partial_redraw_cell->y2, projPixel->y_px+1);
						
						
						switch(tool) {
						case PAINT_TOOL_CLONE:
							if (is_floatbuf) {
								if (((ProjPixelClone *)projPixel)->clonepx.f[3]) {
									do_projectpaint_clone_f(ps, projPixel, rgba, alpha, mask);
								}
							}
							else {
								if (((ProjPixelClone*)projPixel)->clonepx.ch[3]) { 
									do_projectpaint_clone(ps, projPixel, rgba, alpha, mask);
								}
							}
							break;
						case PAINT_TOOL_SMEAR:
							Vec2Subf(co, projPixel->projCoSS, pos_ofs);
							
							if (is_floatbuf)	do_projectpaint_smear_f(ps, projPixel, rgba, alpha, mask, smearArena, &smearPixels_f, co);
							else				do_projectpaint_smear(ps, projPixel, rgba, alpha, mask, smearArena, &smearPixels, co);
							break;
						default:
							if (is_floatbuf)	do_projectpaint_draw_f(ps, projPixel, rgba, alpha, mask);
							else				do_projectpaint_draw(ps, projPixel, rgba, alpha, mask);
							break;
						}
					}
					/* done painting */
				}
			}
		}
	}

	
	if (tool==PAINT_TOOL_SMEAR) {
		
		for (node= smearPixels; node; node= node->next) { /* this wont run for a float image */
			projPixel = node->link;
			*projPixel->pixel.uint_pt = ((ProjPixelClone *)projPixel)->clonepx.uint;
		}
		
		for (node= smearPixels_f; node; node= node->next) {
			projPixel = node->link;
			IMAPAINT_CHAR_RGBA_TO_FLOAT(projPixel->pixel.f_pt,  ((ProjPixelClone *)projPixel)->clonepx.ch);
		}
		
		BLI_memarena_free(smearArena);
	}
	
	return NULL;
}

static int project_paint_op(void *state, ImBuf *ibufb, float *lastpos, float *pos)
{
	/* First unpack args from the struct */
	ProjPaintState *ps = (ProjPaintState *)state;
	int touch_any = 0;	
	
	ProjectHandle handles[BLENDER_MAX_THREADS];
	ListBase threads;
	int a,i;
	
	if (!project_bucket_iter_init(ps, pos)) {
		return 0;
	}
	
	if (ps->thread_tot > 1)
		BLI_init_threads(&threads, do_projectpaint_thread, ps->thread_tot);
	
	/* get the threads running */
	for(a=0; a < ps->thread_tot; a++) {
		
		/* set defaults in handles */
		//memset(&handles[a], 0, sizeof(BakeShade));
		
		handles[a].ps = ps;
		VECCOPY2D(handles[a].mval, pos);
		VECCOPY2D(handles[a].prevmval, lastpos);
		
		/* thread spesific */
		handles[a].thread_index = a;
		
		handles[a].projImages = (ProjPaintImage *)BLI_memarena_alloc(ps->arena_mt[a], ps->image_tot * sizeof(ProjPaintImage));
		
		memcpy(handles[a].projImages, ps->projImages, ps->image_tot * sizeof(ProjPaintImage));
		
		/* image bounds */
		for (i=0; i< ps->image_tot; i++) {
			handles[a].projImages[i].partRedrawRect = (ImagePaintPartialRedraw *)BLI_memarena_alloc(ps->arena_mt[a], sizeof(ImagePaintPartialRedraw) * PROJ_BOUNDBOX_SQUARED);
			memcpy(handles[a].projImages[i].partRedrawRect, ps->projImages[i].partRedrawRect, sizeof(ImagePaintPartialRedraw) * PROJ_BOUNDBOX_SQUARED);			
		}

		if (ps->thread_tot > 1)
			BLI_insert_thread(&threads, &handles[a]);
	}
	
	if (ps->thread_tot > 1) /* wait for everything to be done */
		BLI_end_threads(&threads);
	else
		do_projectpaint_thread(&handles[0]);
		
	
	/* move threaded bounds back into ps->projectPartialRedraws */
	for(i=0; i < ps->image_tot; i++) {
		int touch = 0;
		for(a=0; a < ps->thread_tot; a++) {
			touch |= partial_redraw_array_merge(ps->projImages[i].partRedrawRect, handles[a].projImages[i].partRedrawRect, PROJ_BOUNDBOX_SQUARED);
		}
		
		if (touch) {
			ps->projImages[i].touch = 1;
			touch_any = 1;
		}
	}
	
	return touch_any;
}


static int project_paint_sub_stroke(ProjPaintState *ps, BrushPainter *painter, int *prevmval_i, int *mval_i, double time, float pressure)
{
	
	/* Use mouse coords as floats for projection painting */
	float pos[2];
	
	pos[0] = mval_i[0];
	pos[1] = mval_i[1];
	
	// we may want to use this later 
	// brush_painter_require_imbuf(painter, ((ibuf->rect_float)? 1: 0), 0, 0);
	
	if (brush_painter_paint(painter, project_paint_op, pos, time, pressure, ps)) {
		return 1;
	}
	else return 0;
}


static int project_paint_stroke(ProjPaintState *ps, BrushPainter *painter, int *prevmval_i, int *mval_i, double time, float pressure)
{
	int a, redraw;
	
	for (a=0; a < ps->image_tot; a++)
		partial_redraw_array_init(ps->projImages[a].partRedrawRect);
	
	redraw= project_paint_sub_stroke(ps, painter, prevmval_i, mval_i, time, pressure);
	
	if(project_image_refresh_tagged(ps))
		return redraw;
	
	return 0;
}

/* Imagepaint Partial Redraw & Dirty Region */

static void imapaint_clear_partial_redraw()
{
	memset(&imapaintpartial, 0, sizeof(imapaintpartial));
}

static void imapaint_dirty_region(Image *ima, ImBuf *ibuf, int x, int y, int w, int h)
{
	ImBuf *tmpibuf = NULL;
	UndoTile *tile;
	int srcx= 0, srcy= 0, origx;

	IMB_rectclip(ibuf, NULL, &x, &y, &srcx, &srcy, &w, &h);

	if (w == 0 || h == 0)
		return;
	
	if (!imapaintpartial.enabled) {
		imapaintpartial.x1 = x;
		imapaintpartial.y1 = y;
		imapaintpartial.x2 = x+w;
		imapaintpartial.y2 = y+h;
		imapaintpartial.enabled = 1;
	}
	else {
		imapaintpartial.x1 = MIN2(imapaintpartial.x1, x);
		imapaintpartial.y1 = MIN2(imapaintpartial.y1, y);
		imapaintpartial.x2 = MAX2(imapaintpartial.x2, x+w);
		imapaintpartial.y2 = MAX2(imapaintpartial.y2, y+h);
	}

	w = ((x + w - 1) >> IMAPAINT_TILE_BITS);
	h = ((y + h - 1) >> IMAPAINT_TILE_BITS);
	origx = (x >> IMAPAINT_TILE_BITS);
	y = (y >> IMAPAINT_TILE_BITS);
	
	for (; y <= h; y++) {
		for (x=origx; x <= w; x++) {
			for(tile=curundo->tiles.first; tile; tile=tile->next)
				if(tile->x == x && tile->y == y && strcmp(tile->id.name, ima->id.name)==0)
					break;

			if(!tile) {
				undo_init_tile(&ima->id, ibuf, &tmpibuf, x, y);
			}
		}
	}

	ibuf->userflags |= IB_BITMAPDIRTY;
	
	if (tmpibuf)
		IMB_freeImBuf(tmpibuf);
}

static void imapaint_image_update(SpaceImage *sima, Image *image, ImBuf *ibuf, short texpaint)
{
	if(ibuf->rect_float)
		/* TODO - should just update a portion from imapaintpartial! */
		imb_freerectImBuf(ibuf); /* force recreate of char rect */
	if(ibuf->mipmap[0])
		imb_freemipmapImBuf(ibuf);

	/* todo: should set_tpage create ->rect? */
	if(texpaint || (sima && sima->lock)) {
		int w = imapaintpartial.x2 - imapaintpartial.x1;
		int h = imapaintpartial.y2 - imapaintpartial.y1;
		GPU_paint_update_image(image, imapaintpartial.x1, imapaintpartial.y1, w, h, !texpaint);
	}
}

/* Image Paint Operations */

static void imapaint_ibuf_get_set_rgb(ImBuf *ibuf, int x, int y, short torus, short set, float *rgb)
{
	if (torus) {
		x %= ibuf->x;
		if (x < 0) x += ibuf->x;
		y %= ibuf->y;
		if (y < 0) y += ibuf->y;
	}

	if (ibuf->rect_float) {
		float *rrgbf = ibuf->rect_float + (ibuf->x*y + x)*4;

		if (set) {
			IMAPAINT_FLOAT_RGB_COPY(rrgbf, rgb);
		} else {
			IMAPAINT_FLOAT_RGB_COPY(rgb, rrgbf);
		}
	}
	else {
		char *rrgb = (char*)ibuf->rect + (ibuf->x*y + x)*4;

		if (set) {
			IMAPAINT_FLOAT_RGB_TO_CHAR(rrgb, rgb)
		} else {
			IMAPAINT_CHAR_RGB_TO_FLOAT(rgb, rrgb)
		}
	}
}

static int imapaint_ibuf_add_if(ImBuf *ibuf, unsigned int x, unsigned int y, float *outrgb, short torus)
{
	float inrgb[3];

	if ((x >= ibuf->x) || (y >= ibuf->y)) {
		if (torus) imapaint_ibuf_get_set_rgb(ibuf, x, y, 1, 0, inrgb);
		else return 0;
	}
	else imapaint_ibuf_get_set_rgb(ibuf, x, y, 0, 0, inrgb);

	outrgb[0] += inrgb[0];
	outrgb[1] += inrgb[1];
	outrgb[2] += inrgb[2];

	return 1;
}

static void imapaint_lift_soften(ImBuf *ibuf, ImBuf *ibufb, int *pos, short torus)
{
	int x, y, count, xi, yi, xo, yo;
	int out_off[2], in_off[2], dim[2];
	float outrgb[3];

	dim[0] = ibufb->x;
	dim[1] = ibufb->y;
	in_off[0] = pos[0];
	in_off[1] = pos[1];
	out_off[0] = out_off[1] = 0;

	if (!torus) {
		IMB_rectclip(ibuf, ibufb, &in_off[0], &in_off[1], &out_off[0],
			&out_off[1], &dim[0], &dim[1]);

		if ((dim[0] == 0) || (dim[1] == 0))
			return;
	}

	for (y=0; y < dim[1]; y++) {
		for (x=0; x < dim[0]; x++) {
			/* get input pixel */
			xi = in_off[0] + x;
			yi = in_off[1] + y;

			count = 1;
			imapaint_ibuf_get_set_rgb(ibuf, xi, yi, torus, 0, outrgb);

			count += imapaint_ibuf_add_if(ibuf, xi-1, yi-1, outrgb, torus);
			count += imapaint_ibuf_add_if(ibuf, xi-1, yi  , outrgb, torus);
			count += imapaint_ibuf_add_if(ibuf, xi-1, yi+1, outrgb, torus);

			count += imapaint_ibuf_add_if(ibuf, xi  , yi-1, outrgb, torus);
			count += imapaint_ibuf_add_if(ibuf, xi  , yi+1, outrgb, torus);

			count += imapaint_ibuf_add_if(ibuf, xi+1, yi-1, outrgb, torus);
			count += imapaint_ibuf_add_if(ibuf, xi+1, yi  , outrgb, torus);
			count += imapaint_ibuf_add_if(ibuf, xi+1, yi+1, outrgb, torus);

			outrgb[0] /= count;
			outrgb[1] /= count;
			outrgb[2] /= count;

			/* write into brush buffer */
			xo = out_off[0] + x;
			yo = out_off[1] + y;
			imapaint_ibuf_get_set_rgb(ibufb, xo, yo, 0, 1, outrgb);
		}
	}
}

static void imapaint_lift_smear(ImBuf *ibuf, ImBuf *ibufb, int *pos)
{
	IMB_rectblend_torus(ibufb, ibuf, 0, 0, pos[0], pos[1],
		ibufb->x, ibufb->y, IMB_BLEND_COPY_RGB);
}

static ImBuf *imapaint_lift_clone(ImBuf *ibuf, ImBuf *ibufb, int *pos)
{
	/* note: allocImbuf returns zero'd memory, so regions outside image will
	   have zero alpha, and hence not be blended onto the image */
	int w=ibufb->x, h=ibufb->y, destx=0, desty=0, srcx=pos[0], srcy=pos[1];
	ImBuf *clonebuf= IMB_allocImBuf(w, h, ibufb->depth, ibufb->flags, 0);

	IMB_rectclip(clonebuf, ibuf, &destx, &desty, &srcx, &srcy, &w, &h);
	IMB_rectblend(clonebuf, ibuf, destx, desty, srcx, srcy, w, h,
		IMB_BLEND_COPY_RGB);
	IMB_rectblend(clonebuf, ibufb, destx, desty, destx, desty, w, h,
		IMB_BLEND_COPY_ALPHA);

	return clonebuf;
}

static void imapaint_convert_brushco(ImBuf *ibufb, float *pos, int *ipos)
{
	ipos[0]= (int)(pos[0] - ibufb->x/2);
	ipos[1]= (int)(pos[1] - ibufb->y/2);
}

/* dosnt run for projection painting
 * only the old style painting in the 3d view */
static int imapaint_paint_op(void *state, ImBuf *ibufb, float *lastpos, float *pos)
{
	ImagePaintState *s= ((ImagePaintState*)state);
	ImBuf *clonebuf= NULL;
	short torus= s->brush->flag & BRUSH_TORUS;
	short blend= s->blend;
	float *offset= s->brush->clone.offset;
	float liftpos[2];
	int bpos[2], blastpos[2], bliftpos[2];

	imapaint_convert_brushco(ibufb, pos, bpos);

	/* lift from canvas */
	if(s->tool == PAINT_TOOL_SOFTEN) {
		imapaint_lift_soften(s->canvas, ibufb, bpos, torus);
	}
	else if(s->tool == PAINT_TOOL_SMEAR) {
		if (lastpos[0]==pos[0] && lastpos[1]==pos[1])
			return 0;

		imapaint_convert_brushco(ibufb, lastpos, blastpos);
		imapaint_lift_smear(s->canvas, ibufb, blastpos);
	}
	else if(s->tool == PAINT_TOOL_CLONE && s->clonecanvas) {
		liftpos[0]= pos[0] - offset[0]*s->canvas->x;
		liftpos[1]= pos[1] - offset[1]*s->canvas->y;

		imapaint_convert_brushco(ibufb, liftpos, bliftpos);
		clonebuf= imapaint_lift_clone(s->clonecanvas, ibufb, bliftpos);
	}

	imapaint_dirty_region(s->image, s->canvas, bpos[0], bpos[1], ibufb->x, ibufb->y);

	/* blend into canvas */
	if(torus)
		IMB_rectblend_torus(s->canvas, (clonebuf)? clonebuf: ibufb,
			bpos[0], bpos[1], 0, 0, ibufb->x, ibufb->y, blend);
	else
		IMB_rectblend(s->canvas, (clonebuf)? clonebuf: ibufb,
			bpos[0], bpos[1], 0, 0, ibufb->x, ibufb->y, blend);
			
	if(clonebuf) IMB_freeImBuf(clonebuf);

	return 1;
}

/* 3D TexturePaint */

static int texpaint_break_stroke(float *prevuv, float *fwuv, float *bkuv, float *uv)
{
	float d1[2], d2[2];
	float mismatch = Vec2Lenf(fwuv, uv);
	float len1 = Vec2Lenf(prevuv, fwuv);
	float len2 = Vec2Lenf(bkuv, uv);

	Vec2Subf(d1, fwuv, prevuv);
	Vec2Subf(d2, uv, bkuv);

	return ((Inp2f(d1, d2) < 0.0f) || (mismatch > MAX2(len1, len2)*2));
}

/* ImagePaint Common */

static int imapaint_canvas_set(ImagePaintState *s, Image *ima)
{
	ImBuf *ibuf= BKE_image_get_ibuf(ima, s->sima? &s->sima->iuser: NULL);
	
	/* verify that we can paint and set canvas */
	if(ima->packedfile && ima->rr) {
		s->warnpackedfile = ima->id.name + 2;
		return 0;
	}	
	else if(ibuf && ibuf->channels!=4) {
		s->warnmultifile = ima->id.name + 2;
		return 0;
	}
	else if(!ima || !ibuf || !(ibuf->rect || ibuf->rect_float))
		return 0;

	s->image= ima;
	s->canvas= ibuf;

	/* set clone canvas */
	if(s->tool == PAINT_TOOL_CLONE) {
		ima= s->brush->clone.image;
		ibuf= BKE_image_get_ibuf(ima, s->sima? &s->sima->iuser: NULL);
		
		if(!ima || !ibuf || !(ibuf->rect || ibuf->rect_float))
			return 0;

		s->clonecanvas= ibuf;

		if(s->canvas->rect_float && !s->clonecanvas->rect_float) {
			/* temporarily add float rect for cloning */
			IMB_float_from_rect(s->clonecanvas);
			s->clonefreefloat= 1;
		}
		else if(!s->canvas->rect_float && !s->clonecanvas->rect)
			IMB_rect_from_float(s->clonecanvas);
	}

	return 1;
}

static void imapaint_canvas_free(ImagePaintState *s)
{
	if (s->clonefreefloat)
		imb_freerectfloatImBuf(s->clonecanvas);
}

static int imapaint_paint_sub_stroke(ImagePaintState *s, BrushPainter *painter, Image *image, short texpaint, float *uv, double time, int update, float pressure)
{
	ImBuf *ibuf= BKE_image_get_ibuf(image, s->sima? &s->sima->iuser: NULL);
	float pos[2];

	if(!ibuf)
		return 0;

	pos[0] = uv[0]*ibuf->x;
	pos[1] = uv[1]*ibuf->y;

	brush_painter_require_imbuf(painter, ((ibuf->rect_float)? 1: 0), 0, 0);

	if (brush_painter_paint(painter, imapaint_paint_op, pos, time, pressure, s)) {
		if (update)
			imapaint_image_update(s->sima, image, ibuf, texpaint);
		return 1;
	}
	else return 0;
}

static int imapaint_paint_stroke(ViewContext *vc, ImagePaintState *s, BrushPainter *painter, short texpaint, int *prevmval, int *mval, double time, float pressure)
{
	Image *newimage = NULL;
	float fwuv[2], bkuv[2], newuv[2];
	unsigned int newfaceindex;
	int breakstroke = 0, redraw = 0;

	if (texpaint) {
		/* pick new face and image */
		if (	imapaint_pick_face(vc, s->me, mval, &newfaceindex) &&
				((G.f & G_FACESELECT)==0 || (s->me->mface+newfaceindex)->flag & ME_FACE_SEL)
		) {
			ImBuf *ibuf;
			
			newimage = (s->me->mtface+newfaceindex)->tpage;
			ibuf= BKE_image_get_ibuf(newimage, s->sima? &s->sima->iuser: NULL);

			if(ibuf && ibuf->rect)
				imapaint_pick_uv(s->scene, s->ob, s->me, newfaceindex, mval, newuv);
			else {
				newimage = NULL;
				newuv[0] = newuv[1] = 0.0f;
			}
		}
		else
			newuv[0] = newuv[1] = 0.0f;

		/* see if stroke is broken, and if so finish painting in old position */
		if (s->image) {
			imapaint_pick_uv(s->scene, s->ob, s->me, s->faceindex, mval, fwuv);
			imapaint_pick_uv(s->scene, s->ob, s->me, newfaceindex, prevmval, bkuv);

			if (newimage == s->image)
				breakstroke= texpaint_break_stroke(s->uv, fwuv, bkuv, newuv);
			else
				breakstroke= 1;
		}
		else
			fwuv[0]= fwuv[1]= 0.0f;

		if (breakstroke) {
			imapaint_pick_uv(s->scene, s->ob, s->me, s->faceindex, mval, fwuv);
			redraw |= imapaint_paint_sub_stroke(s, painter, s->image, texpaint,
				fwuv, time, 1, pressure);
			imapaint_clear_partial_redraw();
			brush_painter_break_stroke(painter);
		}

		/* set new canvas */
		if (newimage && (newimage != s->image))
			if (!imapaint_canvas_set(s, newimage))
				newimage = NULL;

		/* paint in new image */
		if (newimage) {
			if (breakstroke)
				redraw|= imapaint_paint_sub_stroke(s, painter, newimage,
					texpaint, bkuv, time, 0, pressure);
			redraw|= imapaint_paint_sub_stroke(s, painter, newimage, texpaint,
				newuv, time, 1, pressure);
		}

		/* update state */
		s->image = newimage;
		s->faceindex = newfaceindex;
		s->uv[0] = newuv[0];
		s->uv[1] = newuv[1];
	}
	else {
		UI_view2d_region_to_view(s->v2d, mval[0], mval[1], &newuv[0], &newuv[1]);
		redraw |= imapaint_paint_sub_stroke(s, painter, s->image, texpaint, newuv,
			time, 1, pressure);
	}

	if (redraw)
		imapaint_clear_partial_redraw();

	return redraw;
}

/************************ image paint poll ************************/

static Brush *image_paint_brush(bContext *C)
{
	Scene *scene= CTX_data_scene(C);
	ToolSettings *settings= scene->toolsettings;

	return paint_brush(&settings->imapaint.paint);
}

static int image_paint_poll(bContext *C)
{
	Object *obact = CTX_data_active_object(C);

	if(!image_paint_brush(C))
		return 0;

	if((obact && obact->mode & OB_MODE_TEXTURE_PAINT) && CTX_wm_region_view3d(C)) {
		return 1;
	}
	else {
		SpaceImage *sima= CTX_wm_space_image(C);

		if(sima) {
			ARegion *ar= CTX_wm_region(C);

			if((sima->flag & SI_DRAWTOOL) && ar->regiontype==RGN_TYPE_WINDOW)
				return 1;
		}
	}

	return 0;
}

static int image_paint_3d_poll(bContext *C)
{
	if(CTX_wm_region_view3d(C))
		return image_paint_poll(C);
	
	return 0;
}

static int image_paint_2d_clone_poll(bContext *C)
{
	Scene *scene= CTX_data_scene(C);
	ToolSettings *settings= scene->toolsettings;
	Brush *brush= image_paint_brush(C);

	if(!CTX_wm_region_view3d(C) && image_paint_poll(C))
		if(brush && (settings->imapaint.tool == PAINT_TOOL_CLONE))
			if(brush->clone.image)
				return 1;
	
	return 0;
}

/************************ paint operator ************************/

typedef enum PaintMode {
	PAINT_MODE_2D,
	PAINT_MODE_3D,
	PAINT_MODE_3D_PROJECT
} PaintMode;

typedef struct PaintOperation {
	PaintMode mode;

	BrushPainter *painter;
	ImagePaintState s;
	ProjPaintState ps;

	int first;
	int prevmouse[2];
	float prev_pressure; /* need this since we dont get tablet events for pressure change */
	int brush_size_orig;
	double starttime;

	ViewContext vc;
	wmTimer *timer;
} PaintOperation;

static void paint_redraw(bContext *C, ImagePaintState *s, int final)
{
	if(final) {
		if(s->image)
			GPU_free_image(s->image);

		WM_event_add_notifier(C, NC_IMAGE|NA_EDITED, s->image);

		// XXX node update
#if 0
		if(!s->sima && s->image) {
			/* after paint, tag Image or RenderResult nodes changed */
			if(s->scene->nodetree) {
				imagepaint_composite_tags(s->scene->nodetree, image, &s->sima->iuser);
			}
			/* signal composite (hurmf, need an allqueue?) */
			if(s->sima->lock) {
				ScrArea *sa;
				for(sa=s->screen->areabase.first; sa; sa= sa->next) {
					if(sa->spacetype==SPACE_NODE) {
						if(((SpaceNode *)sa->spacedata.first)->treetype==NTREE_COMPOSIT) {
							addqueue(sa->win, UI_BUT_EVENT, B_NODE_TREE_EXEC);
							break;
						}
					}
				}
			}
		}		
#endif
	}
	else {
		if(!s->sima || !s->sima->lock)
			ED_region_tag_redraw(CTX_wm_region(C));
		else
			WM_event_add_notifier(C, NC_IMAGE|NA_EDITED, s->image);
	}
}

static int texture_paint_init(bContext *C, wmOperator *op)
{
	Scene *scene= CTX_data_scene(C);
	ToolSettings *settings= scene->toolsettings;
	PaintOperation *pop;
	Brush *brush;

	pop= MEM_callocN(sizeof(PaintOperation), "PaintOperation");
	pop->first= 1;
	op->customdata= pop;
	
	/* initialize from context */
	if(CTX_wm_region_view3d(C)) {
		pop->ps.v3d= CTX_wm_view3d(C);
		pop->ps.rv3d= CTX_wm_region_view3d(C);
		pop->mode= PAINT_MODE_3D;

		if(!(settings->imapaint.flag & IMAGEPAINT_PROJECT_DISABLE))
			pop->mode= PAINT_MODE_3D_PROJECT;
		else
			view3d_set_viewcontext(C, &pop->vc);
	}
	else {
		pop->s.sima= CTX_wm_space_image(C);
		pop->s.v2d= &CTX_wm_region(C)->v2d;
	}

	pop->s.scene= scene;
	pop->ps.scene= scene;
	pop->s.screen= CTX_wm_screen(C);
	pop->ps.ar= CTX_wm_region(C);

	/* intialize brush */
	brush= paint_brush(&settings->imapaint.paint);
	if(!brush)
		return 0;

	pop->s.brush = brush;
	pop->s.tool = settings->imapaint.tool;
	if(pop->mode == PAINT_MODE_3D && (pop->s.tool == PAINT_TOOL_CLONE))
		pop->s.tool = PAINT_TOOL_DRAW;
	pop->s.blend = pop->s.brush->blend;
	
	if(pop->mode == PAINT_MODE_3D_PROJECT) {
		pop->ps.brush = pop->s.brush;
		pop->ps.tool = pop->s.tool;
		pop->ps.blend = pop->s.blend;

		pop->brush_size_orig = pop->ps.brush->size; /* not nice hack because 1 size brushes always fail with projection paint */
	}

	if(pop->mode != PAINT_MODE_2D) {
		pop->ps.ob = pop->s.ob = OBACT;
		if (!pop->s.ob || !(pop->s.ob->lay & pop->ps.v3d->lay)) return 0;
		pop->s.me = get_mesh(pop->s.ob);
		if (!pop->s.me) return 0;

		/* Dont allow brush size below 2 */
		if (pop->ps.brush && pop->ps.brush->size<=1)
			pop->ps.brush->size = 2;
	}
	else {
		pop->s.image = pop->s.sima->image;

		if(!imapaint_canvas_set(&pop->s, pop->s.sima->image)) {
			if(pop->s.warnmultifile)
				BKE_report(op->reports, RPT_WARNING, "Image requires 4 color channels to paint");
			if(pop->s.warnpackedfile)
				BKE_report(op->reports, RPT_WARNING, "Packed MultiLayer files cannot be painted");

			return 0;
		}
	}
	
	/* note, if we have no UVs on the derived mesh, then we must return here */
	if(pop->mode == PAINT_MODE_3D_PROJECT) {
		/* setup projection painting data */
		pop->ps.do_backfacecull = (settings->imapaint.flag & IMAGEPAINT_PROJECT_BACKFACE) ? 0 : 1;
		pop->ps.do_occlude = (settings->imapaint.flag & IMAGEPAINT_PROJECT_XRAY) ? 0 : 1;
		pop->ps.do_mask_normal = (settings->imapaint.flag & IMAGEPAINT_PROJECT_FLAT) ? 0 : 1;;
		
		if (pop->ps.tool == PAINT_TOOL_CLONE)
			pop->ps.do_layer_clone = (settings->imapaint.flag & IMAGEPAINT_PROJECT_LAYER_CLONE);
		
		pop->ps.do_layer_mask = (settings->imapaint.flag & IMAGEPAINT_PROJECT_LAYER_MASK) ? 1 : 0;
		pop->ps.do_layer_mask_inv = (settings->imapaint.flag & IMAGEPAINT_PROJECT_LAYER_MASK_INV) ? 1 : 0;
		
		
#ifndef PROJ_DEBUG_NOSEAMBLEED
		pop->ps.seam_bleed_px = settings->imapaint.seam_bleed; /* pixel num to bleed */
#endif

		if(pop->ps.do_mask_normal) {
			pop->ps.normal_angle_inner = settings->imapaint.normal_angle;
			pop->ps.normal_angle = (pop->ps.normal_angle_inner + 90.0f) * 0.5f;
		}
		else {
			pop->ps.normal_angle_inner= pop->ps.normal_angle= settings->imapaint.normal_angle;
		}

		pop->ps.normal_angle_inner *=	M_PI_2 / 90;
		pop->ps.normal_angle *=			M_PI_2 / 90;
		pop->ps.normal_angle_range = pop->ps.normal_angle - pop->ps.normal_angle_inner;
		
		if(pop->ps.normal_angle_range <= 0.0f)
			pop->ps.do_mask_normal = 0; /* no need to do blending */

		project_paint_begin(&pop->ps);
		
		if(pop->ps.dm==NULL)
			return 0;
	}
	
	settings->imapaint.flag |= IMAGEPAINT_DRAWING;
	undo_imagepaint_push_begin("Image Paint");

	/* create painter */
	pop->painter= brush_painter_new(pop->s.brush);

	return 1;
}

static void paint_apply(bContext *C, wmOperator *op, PointerRNA *itemptr)
{
	PaintOperation *pop= op->customdata;
	float time, mousef[2];
	float pressure;
	int mouse[2], redraw;

	RNA_float_get_array(itemptr, "mouse", mousef);
	mouse[0] = mousef[0];
	mouse[1] = mousef[1];
	time= RNA_float_get(itemptr, "time");
	pressure= RNA_float_get(itemptr, "pressure");

	if(pop->first)
		project_paint_begin_clone(&pop->ps, mouse);

	if(pop->mode == PAINT_MODE_3D)
		view3d_operator_needs_opengl(C);

	if(pop->mode == PAINT_MODE_3D_PROJECT) {
		redraw= project_paint_stroke(&pop->ps, pop->painter, pop->prevmouse, mouse, time, pressure);
		pop->prevmouse[0]= mouse[0];
		pop->prevmouse[1]= mouse[1];

	}
	else { 
		redraw= imapaint_paint_stroke(&pop->vc, &pop->s, pop->painter, pop->mode == PAINT_MODE_3D, pop->prevmouse, mouse, time, pressure);
		pop->prevmouse[0]= mouse[0];
		pop->prevmouse[1]= mouse[1];
	}

	if(redraw)
		paint_redraw(C, &pop->s, 0);

	pop->first= 0;
}

static void paint_exit(bContext *C, wmOperator *op)
{
	Scene *scene= CTX_data_scene(C);
	ToolSettings *settings= scene->toolsettings;
	PaintOperation *pop= op->customdata;

	if(pop->timer)
		WM_event_remove_window_timer(CTX_wm_window(C), pop->timer);

	settings->imapaint.flag &= ~IMAGEPAINT_DRAWING;
	imapaint_canvas_free(&pop->s);
	brush_painter_free(pop->painter);

	if(pop->mode == PAINT_MODE_3D_PROJECT) {
		pop->ps.brush->size = pop->brush_size_orig;
		project_paint_end(&pop->ps);
	}
	
	paint_redraw(C, &pop->s, 1);
	undo_imagepaint_push_end();
	
	if(pop->s.warnmultifile)
		BKE_reportf(op->reports, RPT_WARNING, "Image requires 4 color channels to paint: %s", pop->s.warnmultifile);
	if(pop->s.warnpackedfile)
		BKE_reportf(op->reports, RPT_WARNING, "Packed MultiLayer files cannot be painted: %s", pop->s.warnpackedfile);

	MEM_freeN(pop);
}

static int paint_exec(bContext *C, wmOperator *op)
{
	if(!texture_paint_init(C, op)) {
		MEM_freeN(op->customdata);
		return OPERATOR_CANCELLED;
	}

	RNA_BEGIN(op->ptr, itemptr, "stroke") {
		paint_apply(C, op, &itemptr);
	}
	RNA_END;

	paint_exit(C, op);

	return OPERATOR_FINISHED;
}

static void paint_apply_event(bContext *C, wmOperator *op, wmEvent *event)
{
	ARegion *ar= CTX_wm_region(C);
	PaintOperation *pop= op->customdata;
	wmTabletData *wmtab;
	PointerRNA itemptr;
	float pressure, mousef[2];
	double time;
	int tablet, mouse[2];

	// XXX +1 matches brush location better but
	// still not exact, find out why and fix ..
	mouse[0]= event->x - ar->winrct.xmin + 1;
	mouse[1]= event->y - ar->winrct.ymin + 1;

	time= PIL_check_seconds_timer();

	tablet= 0;
	pressure= 0;
	pop->s.blend= pop->s.brush->blend;

	if(event->custom == EVT_DATA_TABLET) {
		wmtab= event->customdata;

		tablet= (wmtab->Active != EVT_TABLET_NONE);
		pressure= wmtab->Pressure;
		if(wmtab->Active == EVT_TABLET_ERASER)
			pop->s.blend= IMB_BLEND_ERASE_ALPHA;
	}
	else /* otherwise airbrush becomes 1.0 pressure instantly */
		pressure= pop->prev_pressure ? pop->prev_pressure : 1.0f;

	if(pop->first) {
		pop->prevmouse[0]= mouse[0];
		pop->prevmouse[1]= mouse[1];
		pop->starttime= time;

		/* special exception here for too high pressure values on first touch in
		   windows for some tablets, then we just skip first touch ..  */
		if ((pop->s.brush->flag & (BRUSH_ALPHA_PRESSURE|BRUSH_SIZE_PRESSURE|BRUSH_SPACING_PRESSURE)) && tablet && (pressure >= 0.99f))
			return;
	}

	/* fill in stroke */
	RNA_collection_add(op->ptr, "stroke", &itemptr);

	mousef[0] = mouse[0];
	mousef[1] = mouse[1];
	RNA_float_set_array(&itemptr, "mouse", mousef);
	RNA_float_set(&itemptr, "time", (float)(time - pop->starttime));
	RNA_float_set(&itemptr, "pressure", pressure);

	/* apply */
	paint_apply(C, op, &itemptr);

	pop->prev_pressure= pressure;
}

static int paint_invoke(bContext *C, wmOperator *op, wmEvent *event)
{
	PaintOperation *pop;

	if(!texture_paint_init(C, op)) {
		MEM_freeN(op->customdata);
		return OPERATOR_CANCELLED;
	}
	
	paint_apply_event(C, op, event);

	pop= op->customdata;
	WM_event_add_modal_handler(C, op);

	if(pop->s.brush->flag & BRUSH_AIRBRUSH)
		pop->timer= WM_event_add_window_timer(CTX_wm_window(C), TIMER, 0.01f);

	return OPERATOR_RUNNING_MODAL;
}

static int paint_modal(bContext *C, wmOperator *op, wmEvent *event)
{
	PaintOperation *pop= op->customdata;

	switch(event->type) {
		case LEFTMOUSE:
		case MIDDLEMOUSE:
		case RIGHTMOUSE: // XXX hardcoded
			paint_exit(C, op);
			return OPERATOR_FINISHED;
		case MOUSEMOVE:
			paint_apply_event(C, op, event);
			break;
		case TIMER:
			if(event->customdata == pop->timer)
				paint_apply_event(C, op, event);
			break;
	}

	return OPERATOR_RUNNING_MODAL;
}

static int paint_cancel(bContext *C, wmOperator *op)
{
	paint_exit(C, op);

	return OPERATOR_CANCELLED;
}

void PAINT_OT_image_paint(wmOperatorType *ot)
{
	/* identifiers */
	ot->name= "Image Paint";
	ot->idname= "PAINT_OT_image_paint";
	
	/* api callbacks */
	ot->exec= paint_exec;
	ot->invoke= paint_invoke;
	ot->modal= paint_modal;
	ot->cancel= paint_cancel;
	ot->poll= image_paint_poll;

	/* flags */
	ot->flag= OPTYPE_REGISTER|OPTYPE_UNDO|OPTYPE_BLOCKING;

	/* properties */
	RNA_def_collection_runtime(ot->srna, "stroke", &RNA_OperatorStrokeElement, "Stroke", "");
}

static int get_imapaint_zoom(bContext *C, float *zoomx, float *zoomy)
{
	RegionView3D *rv3d= CTX_wm_region_view3d(C);

	if(!rv3d) {
		SpaceImage *sima= CTX_wm_space_image(C);
		ARegion *ar= CTX_wm_region(C);
		
		ED_space_image_zoom(sima, ar, zoomx, zoomy);

		return 1;
	}

	*zoomx = *zoomy = 1;

	return 0;
}

/************************ cursor drawing *******************************/

static void brush_drawcursor(bContext *C, int x, int y, void *customdata)
{
	Brush *brush= image_paint_brush(C);

	if(brush) {
		float zoomx, zoomy;
		glPushMatrix();

		glTranslatef((float)x, (float)y, 0.0f);

		if(get_imapaint_zoom(C, &zoomx, &zoomy))
			glScalef(zoomx, zoomy, 1.0f);

		glColor4ub(255, 255, 255, 128);
		glEnable( GL_LINE_SMOOTH );
		glEnable(GL_BLEND);
		glutil_draw_lined_arc(0.0, M_PI*2.0, brush->size*0.5f, 40);
		glDisable(GL_BLEND);
		glDisable( GL_LINE_SMOOTH );
		
		glPopMatrix();
	}
}

static void toggle_paint_cursor(bContext *C, int enable)
{
	ToolSettings *settings= CTX_data_scene(C)->toolsettings;

	if(settings->imapaint.paintcursor && !enable) {
		WM_paint_cursor_end(CTX_wm_manager(C), settings->imapaint.paintcursor);
		settings->imapaint.paintcursor = NULL;
	}
	else if(enable)
		settings->imapaint.paintcursor= WM_paint_cursor_activate(CTX_wm_manager(C), image_paint_poll, brush_drawcursor, NULL);
}

/* ************ image paint radial control *************/
static int paint_radial_control_invoke(bContext *C, wmOperator *op, wmEvent *event)
{
	float zoom;
	ToolSettings *ts = CTX_data_scene(C)->toolsettings;
	get_imapaint_zoom(C, &zoom, &zoom);
	toggle_paint_cursor(C, !ts->imapaint.paintcursor);
	brush_radial_control_invoke(op, paint_brush(&ts->imapaint.paint), 0.5 * zoom);
	return WM_radial_control_invoke(C, op, event);
}

static int paint_radial_control_modal(bContext *C, wmOperator *op, wmEvent *event)
{
	ToolSettings *ts = CTX_data_scene(C)->toolsettings;
	int ret = WM_radial_control_modal(C, op, event);
	if(ret != OPERATOR_RUNNING_MODAL)
	        toggle_paint_cursor(C, !ts->imapaint.paintcursor);
	return ret;
}

static int paint_radial_control_exec(bContext *C, wmOperator *op)
{
	Brush *brush = paint_brush(&CTX_data_scene(C)->toolsettings->imapaint.paint);
	float zoom;
	int ret;
	char str[256];
	get_imapaint_zoom(C, &zoom, &zoom);
	ret = brush_radial_control_exec(op, brush, 2.0 / zoom);
	WM_radial_control_string(op, str, 256);
	
	WM_event_add_notifier(C, NC_BRUSH|NA_EDITED, brush);

	return ret;
}

void PAINT_OT_image_paint_radial_control(wmOperatorType *ot)
{
	WM_OT_radial_control_partial(ot);

	ot->name= "Image Paint Radial Control";
	ot->idname= "PAINT_OT_image_paint_radial_control";

	ot->invoke= paint_radial_control_invoke;
	ot->modal= paint_radial_control_modal;
	ot->exec= paint_radial_control_exec;
	ot->poll= image_paint_poll;
	
	/* flags */
	ot->flag= OPTYPE_REGISTER|OPTYPE_UNDO|OPTYPE_BLOCKING;
}

/************************ grab clone operator ************************/

typedef struct GrabClone {
	float startoffset[2];
	int startx, starty;
} GrabClone;

static void grab_clone_apply(bContext *C, wmOperator *op)
{
	Brush *brush= image_paint_brush(C);
	float delta[2];

	RNA_float_get_array(op->ptr, "delta", delta);
	brush->clone.offset[0] += delta[0];
	brush->clone.offset[1] += delta[1];

	ED_region_tag_redraw(CTX_wm_region(C));
}

static int grab_clone_exec(bContext *C, wmOperator *op)
{
	grab_clone_apply(C, op);

	return OPERATOR_FINISHED;
}

static int grab_clone_invoke(bContext *C, wmOperator *op, wmEvent *event)
{
	Brush *brush= image_paint_brush(C);
	GrabClone *cmv;

	cmv= MEM_callocN(sizeof(GrabClone), "GrabClone");
	cmv->startoffset[0]= brush->clone.offset[0];
	cmv->startoffset[1]= brush->clone.offset[1];
	cmv->startx= event->x;
	cmv->starty= event->y;
	op->customdata= cmv;

	WM_event_add_modal_handler(C, op);

	return OPERATOR_RUNNING_MODAL;
}

static int grab_clone_modal(bContext *C, wmOperator *op, wmEvent *event)
{
	Brush *brush= image_paint_brush(C);
	ARegion *ar= CTX_wm_region(C);
	GrabClone *cmv= op->customdata;
	float startfx, startfy, fx, fy, delta[2];
	int xmin= ar->winrct.xmin, ymin= ar->winrct.ymin;

	switch(event->type) {
		case LEFTMOUSE:
		case MIDDLEMOUSE:
		case RIGHTMOUSE: // XXX hardcoded
			MEM_freeN(op->customdata);
			return OPERATOR_FINISHED;
		case MOUSEMOVE:
			/* mouse moved, so move the clone image */
			UI_view2d_region_to_view(&ar->v2d, cmv->startx - xmin, cmv->starty - ymin, &startfx, &startfy);
			UI_view2d_region_to_view(&ar->v2d, event->x - xmin, event->y - ymin, &fx, &fy);

			delta[0]= fx - startfx;
			delta[1]= fy - startfy;
			RNA_float_set_array(op->ptr, "delta", delta);

			brush->clone.offset[0]= cmv->startoffset[0];
			brush->clone.offset[1]= cmv->startoffset[1];

			grab_clone_apply(C, op);
			break;
	}

	return OPERATOR_RUNNING_MODAL;
}

static int grab_clone_cancel(bContext *C, wmOperator *op)
{
	MEM_freeN(op->customdata);
	return OPERATOR_CANCELLED;
}

void PAINT_OT_grab_clone(wmOperatorType *ot)
{
	/* identifiers */
	ot->name= "Grab Clone";
	ot->idname= "PAINT_OT_grab_clone";
	
	/* api callbacks */
	ot->exec= grab_clone_exec;
	ot->invoke= grab_clone_invoke;
	ot->modal= grab_clone_modal;
	ot->cancel= grab_clone_cancel;
	ot->poll= image_paint_2d_clone_poll;

	/* flags */
	ot->flag= OPTYPE_REGISTER|OPTYPE_UNDO|OPTYPE_BLOCKING;

	/* properties */
	RNA_def_float_vector(ot->srna, "delta", 2, NULL, -FLT_MAX, FLT_MAX, "Delta", "Delta offset of clone image in 0.0..1.0 coordinates.", -1.0f, 1.0f);
}

/******************** sample color operator ********************/

static int sample_color_exec(bContext *C, wmOperator *op)
{
	Scene *scene= CTX_data_scene(C);
	Brush *brush= image_paint_brush(C);
	ARegion *ar= CTX_wm_region(C);
	int location[2];

	RNA_int_get_array(op->ptr, "location", location);
	paint_sample_color(scene, ar, location[0], location[1]);

	WM_event_add_notifier(C, NC_BRUSH|NA_EDITED, brush);
	
	return OPERATOR_FINISHED;
}

static int sample_color_invoke(bContext *C, wmOperator *op, wmEvent *event)
{
	ARegion *ar= CTX_wm_region(C);
	int location[2];

	location[0]= event->x - ar->winrct.xmin;
	location[1]= event->y - ar->winrct.ymin;
	RNA_int_set_array(op->ptr, "location", location);

	return sample_color_exec(C, op);
}

void PAINT_OT_sample_color(wmOperatorType *ot)
{
	/* identifiers */
	ot->name= "Sample Color";
	ot->idname= "PAINT_OT_sample_color";
	
	/* api callbacks */
	ot->exec= sample_color_exec;
	ot->invoke= sample_color_invoke;
	ot->poll= image_paint_poll;

	/* flags */
	ot->flag= OPTYPE_REGISTER|OPTYPE_UNDO;

	/* properties */
	RNA_def_int_vector(ot->srna, "location", 2, NULL, 0, INT_MAX, "Location", "Cursor location in region coordinates.", 0, 16384);
}

/******************** set clone cursor operator ********************/

static int set_clone_cursor_exec(bContext *C, wmOperator *op)
{
	Scene *scene= CTX_data_scene(C);
	View3D *v3d= CTX_wm_view3d(C);
	float *cursor= give_cursor(scene, v3d);

	RNA_float_get_array(op->ptr, "location", cursor);
	
	ED_area_tag_redraw(CTX_wm_area(C));
	
	return OPERATOR_FINISHED;
}

static int set_clone_cursor_invoke(bContext *C, wmOperator *op, wmEvent *event)
{
	Scene *scene= CTX_data_scene(C);
	View3D *v3d= CTX_wm_view3d(C);
	ARegion *ar= CTX_wm_region(C);
	float location[3];
	short mval[2];

	mval[0]= event->x - ar->winrct.xmin;
	mval[1]= event->y - ar->winrct.ymin;

	view3d_operator_needs_opengl(C);

	if(!view_autodist(scene, ar, v3d, mval, location))
		return OPERATOR_CANCELLED;

	RNA_float_set_array(op->ptr, "location", location);

	return set_clone_cursor_exec(C, op);
}

void PAINT_OT_clone_cursor_set(wmOperatorType *ot)
{
	/* identifiers */
	ot->name= "Set Clone Cursor";
	ot->idname= "PAINT_OT_clone_cursor_set";
	
	/* api callbacks */
	ot->exec= set_clone_cursor_exec;
	ot->invoke= set_clone_cursor_invoke;
	ot->poll= image_paint_3d_poll;

	/* flags */
	ot->flag= OPTYPE_REGISTER|OPTYPE_UNDO;

	/* properties */
	RNA_def_float_vector(ot->srna, "location", 3, NULL, -FLT_MAX, FLT_MAX, "Location", "Cursor location in world space coordinates.", -10000.0f, 10000.0f);
}

/******************** texture paint toggle operator ********************/

static int texture_paint_toggle_poll(bContext *C)
{
	if(CTX_data_edit_object(C))
		return 0;
	if(CTX_data_active_object(C)==NULL)
		return 0;

	return 1;
}

static int texture_paint_toggle_exec(bContext *C, wmOperator *op)
{
	Scene *scene= CTX_data_scene(C);
	Object *ob= CTX_data_active_object(C);
	Mesh *me= 0;
	
	if(ob==NULL)
		return OPERATOR_CANCELLED;
	
	if (object_data_is_libdata(ob)) {
		BKE_report(op->reports, RPT_ERROR, "Can't edit external libdata.");
		return OPERATOR_CANCELLED;
	}

	me= get_mesh(ob);

	if(!(ob->mode & OB_MODE_TEXTURE_PAINT) && !me) {
		BKE_report(op->reports, RPT_ERROR, "Can only enter texture paint mode for mesh objects.");
		return OPERATOR_CANCELLED;
	}

	if(ob->mode & OB_MODE_TEXTURE_PAINT) {
		ob->mode &= ~OB_MODE_TEXTURE_PAINT;

		if(U.glreslimit != 0)
			GPU_free_images();
		GPU_paint_set_mipmap(1);

		toggle_paint_cursor(C, 0);
	}
	else {
		ob->mode |= OB_MODE_TEXTURE_PAINT;

		if(me->mtface==NULL)
			me->mtface= CustomData_add_layer(&me->fdata, CD_MTFACE, CD_DEFAULT,
							 NULL, me->totface);

		paint_init(&scene->toolsettings->imapaint.paint, PAINT_CURSOR_TEXTURE_PAINT);

		if(U.glreslimit != 0)
			GPU_free_images();
		GPU_paint_set_mipmap(0);

		toggle_paint_cursor(C, 1);
	}

	DAG_id_flush_update(&ob->id, OB_RECALC_DATA);
	WM_event_add_notifier(C, NC_SCENE|ND_MODE, scene);

	return OPERATOR_FINISHED;
}

void PAINT_OT_texture_paint_toggle(wmOperatorType *ot)
{
	/* identifiers */
	ot->name= "Texture Paint Toggle";
	ot->idname= "PAINT_OT_texture_paint_toggle";
	
	/* api callbacks */
	ot->exec= texture_paint_toggle_exec;
	ot->poll= texture_paint_toggle_poll;

	/* flags */
	ot->flag= OPTYPE_REGISTER|OPTYPE_UNDO;
}

/************* texture paint radial control *************/

static int texture_paint_radial_control_invoke(bContext *C, wmOperator *op, wmEvent *event)
{
	ToolSettings *ts = CTX_data_scene(C)->toolsettings;
	toggle_paint_cursor(C, !ts->imapaint.paintcursor);
	brush_radial_control_invoke(op, paint_brush(&ts->imapaint.paint), 0.5);
	return WM_radial_control_invoke(C, op, event);
}

static int texture_paint_radial_control_exec(bContext *C, wmOperator *op)
{
	Brush *brush = paint_brush(&CTX_data_scene(C)->toolsettings->imapaint.paint);
	int ret = brush_radial_control_exec(op, brush, 2);
	char str[256];
	WM_radial_control_string(op, str, 256);

	WM_event_add_notifier(C, NC_BRUSH|NA_EDITED, brush);

	return ret;
}

static int texture_paint_poll(bContext *C)
{
	if(texture_paint_toggle_poll(C))
		if(CTX_data_active_object(C)->mode & OB_MODE_TEXTURE_PAINT)
			return 1;
	
	return 0;
}

int image_texture_paint_poll(bContext *C)
{
	return (texture_paint_poll(C) || image_paint_poll(C));
}

void PAINT_OT_texture_paint_radial_control(wmOperatorType *ot)
{
	WM_OT_radial_control_partial(ot);

	ot->name= "Texture Paint Radial Control";
	ot->idname= "PAINT_OT_texture_paint_radial_control";

	ot->invoke= texture_paint_radial_control_invoke;
	ot->modal= paint_radial_control_modal;
	ot->exec= texture_paint_radial_control_exec;
	ot->poll= texture_paint_poll;
	
	/* flags */
	ot->flag= OPTYPE_REGISTER|OPTYPE_UNDO;
}