blender-archive/source/blender/modifiers/intern/MOD_screw.c

/*
 * ***** 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., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
 *
 * The Original Code is Copyright (C) 2005 by the Blender Foundation.
 * All rights reserved.
 *
 * Contributor(s): Daniel Dunbar
 *                 Ton Roosendaal,
 *                 Ben Batt,
 *                 Brecht Van Lommel,
 *                 Campbell Barton
 *
 * ***** END GPL LICENSE BLOCK *****
 *
 */

/** \file blender/modifiers/intern/MOD_screw.c
 *  \ingroup modifiers
 */


/* Screw modifier: revolves the edges about an axis */
#include <limits.h>

#include "DNA_meshdata_types.h"
#include "DNA_object_types.h"

#include "BLI_math.h"
#include "BLI_alloca.h"
#include "BLI_utildefines.h"

#include "BKE_cdderivedmesh.h"
#include "BKE_library_query.h"

#include "depsgraph_private.h"
#include "DEG_depsgraph_build.h"

#include "MOD_modifiertypes.h"
#include "MEM_guardedalloc.h"

#include "BLI_strict_flags.h"

/* used for gathering edge connectivity */
typedef struct ScrewVertConnect {
	float dist;  /* distance from the center axis */
	float co[3]; /* location relative to the transformed axis */
	float no[3]; /* calc normal of the vertex */
	unsigned int v[2]; /* 2  verts on either side of this one */
	MEdge *e[2]; /* edges on either side, a bit of a waste since each edge ref's 2 edges */
	char flag;
} ScrewVertConnect;

typedef struct ScrewVertIter {
	ScrewVertConnect *v_array;
	ScrewVertConnect *v_poin;
	unsigned int v, v_other;
	MEdge *e;
} ScrewVertIter;

#define SV_UNUSED (UINT_MAX)
#define SV_INVALID ((UINT_MAX) - 1)
#define SV_IS_VALID(v) ((v) < SV_INVALID)

static void screwvert_iter_init(ScrewVertIter *iter, ScrewVertConnect *array, unsigned int v_init, unsigned int dir)
{
	iter->v_array = array;
	iter->v = v_init;

	if (SV_IS_VALID(v_init)) {
		iter->v_poin = &array[v_init];
		iter->v_other = iter->v_poin->v[dir];
		iter->e = iter->v_poin->e[!dir];
	}
	else {
		iter->v_poin = NULL;
		iter->e = NULL;
	}
}


static void screwvert_iter_step(ScrewVertIter *iter)
{
	if (iter->v_poin->v[0] == iter->v_other) {
		iter->v_other = iter->v;
		iter->v = iter->v_poin->v[1];
	}
	else if (iter->v_poin->v[1] == iter->v_other) {
		iter->v_other = iter->v;
		iter->v = iter->v_poin->v[0];
	}
	if (SV_IS_VALID(iter->v)) {
		iter->v_poin = &iter->v_array[iter->v];
		iter->e = iter->v_poin->e[(iter->v_poin->e[0] == iter->e)];
	}
	else {
		iter->e = NULL;
		iter->v_poin = NULL;
	}
}

static DerivedMesh *dm_remove_doubles_on_axis(
        DerivedMesh *result, MVert *mvert_new, const uint totvert, const uint step_tot,
        const float axis_vec[3], const float axis_offset[3], const float merge_threshold)
{
	const float merge_threshold_sq = SQUARE(merge_threshold);
	const bool use_offset = axis_offset != NULL;
	uint tot_doubles = 0;
	for (uint i = 0; i < totvert; i += 1) {
		float axis_co[3];
		if (use_offset) {
			float offset_co[3];
			sub_v3_v3v3(offset_co, mvert_new[i].co, axis_offset);
			project_v3_v3v3_normalized(axis_co, offset_co, axis_vec);
			add_v3_v3(axis_co, axis_offset);
		}
		else {
			project_v3_v3v3_normalized(axis_co, mvert_new[i].co, axis_vec);
		}
		const float dist_sq = len_squared_v3v3(axis_co, mvert_new[i].co);
		if (dist_sq <= merge_threshold_sq) {
			mvert_new[i].flag |= ME_VERT_TMP_TAG;
			tot_doubles += 1;
			copy_v3_v3(mvert_new[i].co, axis_co);
		}
	}

	if (tot_doubles != 0) {
		uint tot = totvert * step_tot;
		int *full_doubles_map = MEM_malloc_arrayN(tot, sizeof(int), __func__);
		copy_vn_i(full_doubles_map, (int)tot, -1);

		uint tot_doubles_left = tot_doubles;
		for (uint i = 0; i < totvert; i += 1) {
			if (mvert_new[i].flag & ME_VERT_TMP_TAG) {
				int *doubles_map = &full_doubles_map[totvert + i] ;
				for (uint step = 1; step < step_tot; step += 1) {
					*doubles_map = (int)i;
					doubles_map += totvert;
				}
				tot_doubles_left -= 1;
				if (tot_doubles_left == 0) {
					break;
				}
			}
		}
		result = CDDM_merge_verts(result, full_doubles_map, (int)(tot_doubles * (step_tot - 1)), CDDM_MERGE_VERTS_DUMP_IF_MAPPED);
		MEM_freeN(full_doubles_map);
	}
	return result;
}

static void initData(ModifierData *md)
{
	ScrewModifierData *ltmd = (ScrewModifierData *) md;
	ltmd->ob_axis = NULL;
	ltmd->angle = (float)(M_PI * 2.0);
	ltmd->axis = 2;
	ltmd->flag = MOD_SCREW_SMOOTH_SHADING;
	ltmd->steps = 16;
	ltmd->render_steps = 16;
	ltmd->iter = 1;
	ltmd->merge_dist = 0.01f;
}

static DerivedMesh *applyModifier(
        ModifierData *md, Object *ob,
        DerivedMesh *derivedData,
        ModifierApplyFlag flag)
{
	DerivedMesh *dm = derivedData;
	DerivedMesh *result;
	ScrewModifierData *ltmd = (ScrewModifierData *) md;
	const bool use_render_params = (flag & MOD_APPLY_RENDER) != 0;

	int *origindex;
	int mpoly_index = 0;
	unsigned int step;
	unsigned int i, j;
	unsigned int i1, i2;
	unsigned int step_tot = use_render_params ? ltmd->render_steps : ltmd->steps;
	const bool do_flip = (ltmd->flag & MOD_SCREW_NORMAL_FLIP) != 0;

	const int quad_ord[4] = {
	    do_flip ? 3 : 0,
	    do_flip ? 2 : 1,
	    do_flip ? 1 : 2,
	    do_flip ? 0 : 3,
	};
	const int quad_ord_ofs[4] = {
	    do_flip ? 2 : 0,
	    1,
	    do_flip ? 0 : 2,
	    3,
	};

	unsigned int maxVerts = 0, maxEdges = 0, maxPolys = 0;
	const unsigned int totvert = (unsigned int)dm->getNumVerts(dm);
	const unsigned int totedge = (unsigned int)dm->getNumEdges(dm);
	const unsigned int totpoly = (unsigned int)dm->getNumPolys(dm);

	unsigned int *edge_poly_map = NULL;  /* orig edge to orig poly */
	unsigned int *vert_loop_map = NULL;  /* orig vert to orig loop */

	/* UV Coords */
	const unsigned int mloopuv_layers_tot = (unsigned int)CustomData_number_of_layers(&dm->loopData, CD_MLOOPUV);
	MLoopUV **mloopuv_layers = BLI_array_alloca(mloopuv_layers, mloopuv_layers_tot);
	float uv_u_scale;
	float uv_v_minmax[2] = {FLT_MAX, -FLT_MAX};
	float uv_v_range_inv;
	float uv_axis_plane[4];

	char axis_char = 'X';
	bool close;
	float angle = ltmd->angle;
	float screw_ofs = ltmd->screw_ofs;
	float axis_vec[3] = {0.0f, 0.0f, 0.0f};
	float tmp_vec1[3], tmp_vec2[3];
	float mat3[3][3];
	float mtx_tx[4][4]; /* transform the coords by an object relative to this objects transformation */
	float mtx_tx_inv[4][4]; /* inverted */
	float mtx_tmp_a[4][4];

	unsigned int vc_tot_linked = 0;
	short other_axis_1, other_axis_2;
	const float *tmpf1, *tmpf2;

	unsigned int edge_offset;

	MPoly *mpoly_orig, *mpoly_new, *mp_new;
	MLoop *mloop_orig, *mloop_new, *ml_new;
	MEdge *medge_orig, *med_orig, *med_new, *med_new_firstloop, *medge_new;
	MVert *mvert_new, *mvert_orig, *mv_orig, *mv_new, *mv_new_base;

	ScrewVertConnect *vc, *vc_tmp, *vert_connect = NULL;

	const char mpoly_flag = (ltmd->flag & MOD_SCREW_SMOOTH_SHADING) ? ME_SMOOTH : 0;

	/* don't do anything? */
	if (!totvert)
		return CDDM_from_template(dm, 0, 0, 0, 0, 0);

	switch (ltmd->axis) {
		case 0:
			other_axis_1 = 1;
			other_axis_2 = 2;
			break;
		case 1:
			other_axis_1 = 0;
			other_axis_2 = 2;
			break;
		default: /* 2, use default to quiet warnings */
			other_axis_1 = 0;
			other_axis_2 = 1;
			break;
	}

	axis_vec[ltmd->axis] = 1.0f;

	if (ltmd->ob_axis) {
		/* calc the matrix relative to the axis object */
		invert_m4_m4(mtx_tmp_a, ob->obmat);
		copy_m4_m4(mtx_tx_inv, ltmd->ob_axis->obmat);
		mul_m4_m4m4(mtx_tx, mtx_tmp_a, mtx_tx_inv);

		/* calc the axis vec */
		mul_mat3_m4_v3(mtx_tx, axis_vec); /* only rotation component */
		normalize_v3(axis_vec);

		/* screw */
		if (ltmd->flag & MOD_SCREW_OBJECT_OFFSET) {
			/* find the offset along this axis relative to this objects matrix */
			float totlen = len_v3(mtx_tx[3]);

			if (totlen != 0.0f) {
				float zero[3] = {0.0f, 0.0f, 0.0f};
				float cp[3];
				screw_ofs = closest_to_line_v3(cp, mtx_tx[3], zero, axis_vec);
			}
			else {
				screw_ofs = 0.0f;
			}
		}

		/* angle */

#if 0   /* can't include this, not predictable enough, though quite fun. */
		if (ltmd->flag & MOD_SCREW_OBJECT_ANGLE) {
			float mtx3_tx[3][3];
			copy_m3_m4(mtx3_tx, mtx_tx);

			float vec[3] = {0, 1, 0};
			float cross1[3];
			float cross2[3];
			cross_v3_v3v3(cross1, vec, axis_vec);

			mul_v3_m3v3(cross2, mtx3_tx, cross1);
			{
				float c1[3];
				float c2[3];
				float axis_tmp[3];

				cross_v3_v3v3(c1, cross2, axis_vec);
				cross_v3_v3v3(c2, axis_vec, c1);


				angle = angle_v3v3(cross1, c2);

				cross_v3_v3v3(axis_tmp, cross1, c2);
				normalize_v3(axis_tmp);

				if (len_v3v3(axis_tmp, axis_vec) > 1.0f)
					angle = -angle;

			}
		}
#endif
	}
	else {
		/* exis char is used by i_rotate*/
		axis_char = (char)(axis_char + ltmd->axis); /* 'X' + axis */

		/* useful to be able to use the axis vec in some cases still */
		zero_v3(axis_vec);
		axis_vec[ltmd->axis] = 1.0f;
	}

	/* apply the multiplier */
	angle *= (float)ltmd->iter;
	screw_ofs *= (float)ltmd->iter;
	uv_u_scale = 1.0f / (float)(step_tot);

	/* multiplying the steps is a bit tricky, this works best */
	step_tot = ((step_tot + 1) * ltmd->iter) - (ltmd->iter - 1);

	/* will the screw be closed?
	 * Note! smaller then FLT_EPSILON * 100 gives problems with float precision so its never closed. */
	if (fabsf(screw_ofs) <= (FLT_EPSILON * 100.0f) &&
	    fabsf(fabsf(angle) - ((float)M_PI * 2.0f)) <= (FLT_EPSILON * 100.0f))
	{
		close = 1;
		step_tot--;
		if (step_tot < 3) step_tot = 3;

		maxVerts = totvert  * step_tot;   /* -1 because we're joining back up */
		maxEdges = (totvert * step_tot) + /* these are the edges between new verts */
		           (totedge * step_tot);  /* -1 because vert edges join */
		maxPolys = totedge * step_tot;

		screw_ofs = 0.0f;
	}
	else {
		close = 0;
		if (step_tot < 3) step_tot = 3;

		maxVerts =  totvert  * step_tot; /* -1 because we're joining back up */
		maxEdges =  (totvert * (step_tot - 1)) + /* these are the edges between new verts */
		           (totedge * step_tot);  /* -1 because vert edges join */
		maxPolys =  totedge * (step_tot - 1);
	}

	if ((ltmd->flag & MOD_SCREW_UV_STRETCH_U) == 0) {
		uv_u_scale = (uv_u_scale / (float)ltmd->iter) * (angle / ((float)M_PI * 2.0f));
	}

	result = CDDM_from_template(dm, (int)maxVerts, (int)maxEdges, 0, (int)maxPolys * 4, (int)maxPolys);

	/* copy verts from mesh */
	mvert_orig =    dm->getVertArray(dm);
	medge_orig =    dm->getEdgeArray(dm);

	mvert_new =     result->getVertArray(result);
	mpoly_new =     result->getPolyArray(result);
	mloop_new =     result->getLoopArray(result);
	medge_new =     result->getEdgeArray(result);

	if (!CustomData_has_layer(&result->polyData, CD_ORIGINDEX)) {
		CustomData_add_layer(&result->polyData, CD_ORIGINDEX, CD_CALLOC, NULL, (int)maxPolys);
	}

	origindex = CustomData_get_layer(&result->polyData, CD_ORIGINDEX);

	DM_copy_vert_data(dm, result, 0, 0, (int)totvert); /* copy first otherwise this overwrites our own vertex normals */

	if (mloopuv_layers_tot) {
		float zero_co[3] = {0};
		plane_from_point_normal_v3(uv_axis_plane, zero_co, axis_vec);
	}

	if (mloopuv_layers_tot) {
		unsigned int uv_lay;
		for (uv_lay = 0; uv_lay < mloopuv_layers_tot; uv_lay++) {
			mloopuv_layers[uv_lay] = CustomData_get_layer_n(&result->loopData, CD_MLOOPUV, (int)uv_lay);
		}

		if (ltmd->flag & MOD_SCREW_UV_STRETCH_V) {
			for (i = 0, mv_orig = mvert_orig; i < totvert; i++, mv_orig++) {
				const float v = dist_signed_squared_to_plane_v3(mv_orig->co, uv_axis_plane);
				uv_v_minmax[0] = min_ff(v, uv_v_minmax[0]);
				uv_v_minmax[1] = max_ff(v, uv_v_minmax[1]);
			}
			uv_v_minmax[0] = sqrtf_signed(uv_v_minmax[0]);
			uv_v_minmax[1] = sqrtf_signed(uv_v_minmax[1]);
		}

		uv_v_range_inv = uv_v_minmax[1] - uv_v_minmax[0];
		uv_v_range_inv = uv_v_range_inv ? 1.0f / uv_v_range_inv : 0.0f;
	}

	/* Set the locations of the first set of verts */

	mv_new = mvert_new;
	mv_orig = mvert_orig;

	/* Copy the first set of edges */
	med_orig = medge_orig;
	med_new = medge_new;
	for (i = 0; i < totedge; i++, med_orig++, med_new++) {
		med_new->v1 = med_orig->v1;
		med_new->v2 = med_orig->v2;
		med_new->crease = med_orig->crease;
		med_new->flag = med_orig->flag &  ~ME_LOOSEEDGE;
	}

	/* build polygon -> edge map */
	if (totpoly) {
		MPoly *mp_orig;

		mpoly_orig = dm->getPolyArray(dm);
		mloop_orig = dm->getLoopArray(dm);
		edge_poly_map = MEM_malloc_arrayN(totedge, sizeof(*edge_poly_map), __func__);
		memset(edge_poly_map, 0xff, sizeof(*edge_poly_map) * totedge);

		vert_loop_map = MEM_malloc_arrayN(totvert, sizeof(*vert_loop_map), __func__);
		memset(vert_loop_map, 0xff, sizeof(*vert_loop_map) * totvert);

		for (i = 0, mp_orig = mpoly_orig; i < totpoly; i++, mp_orig++) {
			unsigned int loopstart = (unsigned int)mp_orig->loopstart;
			unsigned int loopend = loopstart + (unsigned int)mp_orig->totloop;

			MLoop *ml_orig = &mloop_orig[loopstart];
			unsigned int k;
			for (k = loopstart; k < loopend; k++, ml_orig++) {
				edge_poly_map[ml_orig->e] = i;
				vert_loop_map[ml_orig->v] = k;

				/* also order edges based on faces */
				if (medge_new[ml_orig->e].v1 != ml_orig->v) {
					SWAP(unsigned int, medge_new[ml_orig->e].v1, medge_new[ml_orig->e].v2);
				}
			}
		}
	}

	if (ltmd->flag & MOD_SCREW_NORMAL_CALC) {
		/*
		 * Normal Calculation (for face flipping)
		 * Sort edge verts for correct face flipping
		 * NOT REALLY NEEDED but face flipping is nice.
		 *
		 * */


		/* Notice!
		 *
		 * Since we are only ordering the edges here it can avoid mallocing the
		 * extra space by abusing the vert array before its filled with new verts.
		 * The new array for vert_connect must be at least sizeof(ScrewVertConnect) * totvert
		 * and the size of our resulting meshes array is sizeof(MVert) * totvert * 3
		 * so its safe to use the second 2 thrids of MVert the array for vert_connect,
		 * just make sure ScrewVertConnect struct is no more than twice as big as MVert,
		 * at the moment there is no chance of that being a problem,
		 * unless MVert becomes half its current size.
		 *
		 * once the edges are ordered, vert_connect is not needed and it can be used for verts
		 *
		 * This makes the modifier faster with one less alloc.
		 */

		vert_connect = MEM_malloc_arrayN(totvert, sizeof(ScrewVertConnect), "ScrewVertConnect");
		//vert_connect = (ScrewVertConnect *) &medge_new[totvert];  /* skip the first slice of verts */
		vc = vert_connect;

		/* Copy Vert Locations */
		/* - We can do this in a later loop - only do here if no normal calc */
		if (!totedge) {
			for (i = 0; i < totvert; i++, mv_orig++, mv_new++) {
				copy_v3_v3(mv_new->co, mv_orig->co);
				normalize_v3_v3(vc->no, mv_new->co); /* no edges- this is really a dummy normal */
			}
		}
		else {
			/*printf("\n\n\n\n\nStarting Modifier\n");*/
			/* set edge users */
			med_new = medge_new;
			mv_new = mvert_new;

			if (ltmd->ob_axis) {
				/*mtx_tx is initialized early on */
				for (i = 0; i < totvert; i++, mv_new++, mv_orig++, vc++) {
					vc->co[0] = mv_new->co[0] = mv_orig->co[0];
					vc->co[1] = mv_new->co[1] = mv_orig->co[1];
					vc->co[2] = mv_new->co[2] = mv_orig->co[2];

					vc->flag = 0;
					vc->e[0] = vc->e[1] = NULL;
					vc->v[0] = vc->v[1] = SV_UNUSED;

					mul_m4_v3(mtx_tx, vc->co);
					/* length in 2d, don't sqrt because this is only for comparison */
					vc->dist = vc->co[other_axis_1] * vc->co[other_axis_1] +
					           vc->co[other_axis_2] * vc->co[other_axis_2];

					/* printf("location %f %f %f -- %f\n", vc->co[0], vc->co[1], vc->co[2], vc->dist);*/
				}
			}
			else {
				for (i = 0; i < totvert; i++, mv_new++, mv_orig++, vc++) {
					vc->co[0] = mv_new->co[0] = mv_orig->co[0];
					vc->co[1] = mv_new->co[1] = mv_orig->co[1];
					vc->co[2] = mv_new->co[2] = mv_orig->co[2];

					vc->flag = 0;
					vc->e[0] = vc->e[1] = NULL;
					vc->v[0] = vc->v[1] = SV_UNUSED;

					/* length in 2d, don't sqrt because this is only for comparison */
					vc->dist = vc->co[other_axis_1] * vc->co[other_axis_1] +
					           vc->co[other_axis_2] * vc->co[other_axis_2];

					/* printf("location %f %f %f -- %f\n", vc->co[0], vc->co[1], vc->co[2], vc->dist);*/
				}
			}

			/* this loop builds connectivity info for verts */
			for (i = 0; i < totedge; i++, med_new++) {
				vc = &vert_connect[med_new->v1];

				if (vc->v[0] == SV_UNUSED) { /* unused */
					vc->v[0] = med_new->v2;
					vc->e[0] = med_new;
				}
				else if (vc->v[1] == SV_UNUSED) {
					vc->v[1] = med_new->v2;
					vc->e[1] = med_new;
				}
				else {
					vc->v[0] = vc->v[1] = SV_INVALID; /* error value  - don't use, 3 edges on vert */
				}

				vc = &vert_connect[med_new->v2];

				/* same as above but swap v1/2 */
				if (vc->v[0] == SV_UNUSED) { /* unused */
					vc->v[0] = med_new->v1;
					vc->e[0] = med_new;
				}
				else if (vc->v[1] == SV_UNUSED) {
					vc->v[1] = med_new->v1;
					vc->e[1] = med_new;
				}
				else {
					vc->v[0] = vc->v[1] = SV_INVALID; /* error value  - don't use, 3 edges on vert */
				}
			}

			/* find the first vert */
			vc = vert_connect;
			for (i = 0; i < totvert; i++, vc++) {
				/* Now do search for connected verts, order all edges and flip them
				 * so resulting faces are flipped the right way */
				vc_tot_linked = 0; /* count the number of linked verts for this loop */
				if (vc->flag == 0) {
					unsigned int v_best = SV_UNUSED, ed_loop_closed = 0; /* vert and vert new */
					ScrewVertIter lt_iter;
					float fl = -1.0f;

					/* compiler complains if not initialized, but it should be initialized below */
					bool ed_loop_flip = false;

					/*printf("Loop on connected vert: %i\n", i);*/

					for (j = 0; j < 2; j++) {
						/*printf("\tSide: %i\n", j);*/
						screwvert_iter_init(&lt_iter, vert_connect, i, j);
						if (j == 1) {
							screwvert_iter_step(&lt_iter);
						}
						while (lt_iter.v_poin) {
							/*printf("\t\tVERT: %i\n", lt_iter.v);*/
							if (lt_iter.v_poin->flag) {
								/*printf("\t\t\tBreaking Found end\n");*/
								//endpoints[0] = endpoints[1] = SV_UNUSED;
								ed_loop_closed = 1; /* circle */
								break;
							}
							lt_iter.v_poin->flag = 1;
							vc_tot_linked++;
							/*printf("Testing 2 floats %f : %f\n", fl, lt_iter.v_poin->dist);*/
							if (fl <= lt_iter.v_poin->dist) {
								fl = lt_iter.v_poin->dist;
								v_best = lt_iter.v;
								/*printf("\t\t\tVERT BEST: %i\n", v_best);*/
							}
							screwvert_iter_step(&lt_iter);
							if (!lt_iter.v_poin) {
								/*printf("\t\t\tFound End Also Num %i\n", j);*/
								/*endpoints[j] = lt_iter.v_other;*/ /* other is still valid */
								break;
							}
						}
					}

					/* now we have a collection of used edges. flip their edges the right way*/
					/*if (v_best != SV_UNUSED) - */

					/*printf("Done Looking - vc_tot_linked: %i\n", vc_tot_linked);*/

					if (vc_tot_linked > 1) {
						float vf_1, vf_2, vf_best;

						vc_tmp = &vert_connect[v_best];

						tmpf1 = vert_connect[vc_tmp->v[0]].co;
						tmpf2 = vert_connect[vc_tmp->v[1]].co;


						/* edge connects on each side! */
						if (SV_IS_VALID(vc_tmp->v[0]) && SV_IS_VALID(vc_tmp->v[1])) {
							/*printf("Verts on each side (%i %i)\n", vc_tmp->v[0], vc_tmp->v[1]);*/
							/* find out which is higher */

							vf_1 = tmpf1[ltmd->axis];
							vf_2 = tmpf2[ltmd->axis];
							vf_best = vc_tmp->co[ltmd->axis];

							if (vf_1 < vf_best && vf_best < vf_2) {
								ed_loop_flip = 0;
							}
							else if (vf_1 > vf_best && vf_best > vf_2) {
								ed_loop_flip = 1;
							}
							else {
								/* not so simple to work out which edge is higher */
								sub_v3_v3v3(tmp_vec1, tmpf1, vc_tmp->co);
								sub_v3_v3v3(tmp_vec2, tmpf2, vc_tmp->co);
								normalize_v3(tmp_vec1);
								normalize_v3(tmp_vec2);

								if (tmp_vec1[ltmd->axis] < tmp_vec2[ltmd->axis]) {
									ed_loop_flip = 1;
								}
								else {
									ed_loop_flip = 0;
								}
							}
						}
						else if (SV_IS_VALID(vc_tmp->v[0])) { /*vertex only connected on 1 side */
							/*printf("Verts on ONE side (%i %i)\n", vc_tmp->v[0], vc_tmp->v[1]);*/
							if (tmpf1[ltmd->axis] < vc_tmp->co[ltmd->axis]) { /* best is above */
								ed_loop_flip = 1;
							}
							else { /* best is below or even... in even case we can't know what to do. */
								ed_loop_flip = 0;
							}

						}
#if 0
						else {
							printf("No Connected ___\n");
						}
#endif

						/*printf("flip direction %i\n", ed_loop_flip);*/


						/* switch the flip option if set
						 * note: flip is now done at face level so copying vgroup slizes is easier */
#if 0
						if (do_flip)
							ed_loop_flip = !ed_loop_flip;
#endif

						if (angle < 0.0f)
							ed_loop_flip = !ed_loop_flip;

						/* if its closed, we only need 1 loop */
						for (j = ed_loop_closed; j < 2; j++) {
							/*printf("Ordering Side J %i\n", j);*/

							screwvert_iter_init(&lt_iter, vert_connect, v_best, j);
							/*printf("\n\nStarting - Loop\n");*/
							lt_iter.v_poin->flag = 1; /* so a non loop will traverse the other side */


							/* If this is the vert off the best vert and
							 * the best vert has 2 edges connected too it
							 * then swap the flip direction */
							if (j == 1 && SV_IS_VALID(vc_tmp->v[0]) && SV_IS_VALID(vc_tmp->v[1]))
								ed_loop_flip = !ed_loop_flip;

							while (lt_iter.v_poin && lt_iter.v_poin->flag != 2) {
								/*printf("\tOrdering Vert V %i\n", lt_iter.v);*/

								lt_iter.v_poin->flag = 2;
								if (lt_iter.e) {
									if (lt_iter.v == lt_iter.e->v1) {
										if (ed_loop_flip == 0) {
											/*printf("\t\t\tFlipping 0\n");*/
											SWAP(unsigned int, lt_iter.e->v1, lt_iter.e->v2);
										}
										/* else {
										    printf("\t\t\tFlipping Not 0\n");
										   }*/
									}
									else if (lt_iter.v == lt_iter.e->v2) {
										if (ed_loop_flip == 1) {
											/*printf("\t\t\tFlipping 1\n");*/
											SWAP(unsigned int, lt_iter.e->v1, lt_iter.e->v2);
										}
										/* else {
										    printf("\t\t\tFlipping Not 1\n");
										   }*/
									}
									/* else {
									    printf("\t\tIncorrect edge topology");
									   }*/
								}
								/* else {
								    printf("\t\tNo Edge at this point\n");
								   }*/
								screwvert_iter_step(&lt_iter);
							}
						}
					}
				}

				/* *VERTEX NORMALS*
				 * we know the surrounding edges are ordered correctly now
				 * so its safe to create vertex normals.
				 *
				 * calculate vertex normals that can be propagated on lathing
				 * use edge connectivity work this out */
				if (SV_IS_VALID(vc->v[0])) {
					if (SV_IS_VALID(vc->v[1])) {
						/* 2 edges connedted */
						/* make 2 connecting vert locations relative to the middle vert */
						sub_v3_v3v3(tmp_vec1, mvert_new[vc->v[0]].co, mvert_new[i].co);
						sub_v3_v3v3(tmp_vec2, mvert_new[vc->v[1]].co, mvert_new[i].co);
						/* normalize so both edges have the same influence, no matter their length */
						normalize_v3(tmp_vec1);
						normalize_v3(tmp_vec2);

						/* vc_no_tmp1 - this line is the average direction of both connecting edges
						 *
						 * Use the edge order to make the subtraction, flip the normal the right way
						 * edge should be there but check just in case... */
						if (vc->e[0]->v1 == i) {
							sub_v3_v3(tmp_vec1, tmp_vec2);
						}
						else {
							sub_v3_v3v3(tmp_vec1, tmp_vec2, tmp_vec1);
						}
					}
					else {
						/* only 1 edge connected - same as above except
						 * don't need to average edge direction */
						if (vc->e[0]->v2 == i) {
							sub_v3_v3v3(tmp_vec1, mvert_new[i].co, mvert_new[vc->v[0]].co);
						}
						else {
							sub_v3_v3v3(tmp_vec1, mvert_new[vc->v[0]].co, mvert_new[i].co);
						}
					}

					/* tmp_vec2 - is a line 90d from the pivot to the vec
					 * This is used so the resulting normal points directly away from the middle */
					cross_v3_v3v3(tmp_vec2, axis_vec, vc->co);

					if (UNLIKELY(is_zero_v3(tmp_vec2))) {
						/* we're _on_ the axis, so copy it based on our winding */
						if (vc->e[0]->v2 == i) {
							negate_v3_v3(vc->no, axis_vec);
						}
						else {
							copy_v3_v3(vc->no, axis_vec);
						}
					}
					else {
						/* edge average vector and right angle to the pivot make the normal */
						cross_v3_v3v3(vc->no, tmp_vec1, tmp_vec2);
					}

				}
				else {
					copy_v3_v3(vc->no, vc->co);
				}

				/* we won't be looping on this data again so copy normals here */
				if ((angle < 0.0f) != do_flip)
					negate_v3(vc->no);

				normalize_v3(vc->no);
				normal_float_to_short_v3(mvert_new[i].no, vc->no);

				/* Done with normals */
			}
		}
	}
	else {
		mv_orig = mvert_orig;
		mv_new = mvert_new;

		for (i = 0; i < totvert; i++, mv_new++, mv_orig++) {
			copy_v3_v3(mv_new->co, mv_orig->co);
		}
	}
	/* done with edge connectivity based normal flipping */

	/* Add Faces */
	for (step = 1; step < step_tot; step++) {
		const unsigned int varray_stride = totvert * step;
		float step_angle;
		float nor_tx[3];
		float mat[4][4];
		/* Rotation Matrix */
		step_angle = (angle / (float)(step_tot - (!close))) * (float)step;

		if (ltmd->ob_axis) {
			axis_angle_normalized_to_mat3(mat3, axis_vec, step_angle);
		}
		else {
			axis_angle_to_mat3_single(mat3, axis_char, step_angle);
		}
		copy_m4_m3(mat, mat3);

		if (screw_ofs)
			madd_v3_v3fl(mat[3], axis_vec, screw_ofs * ((float)step / (float)(step_tot - 1)));

		/* copy a slice */
		DM_copy_vert_data(dm, result, 0, (int)varray_stride, (int)totvert);

		mv_new_base = mvert_new;
		mv_new = &mvert_new[varray_stride]; /* advance to the next slice */

		for (j = 0; j < totvert; j++, mv_new_base++, mv_new++) {
			/* set normal */
			if (vert_connect) {
				mul_v3_m3v3(nor_tx, mat3, vert_connect[j].no);

				/* set the normal now its transformed */
				normal_float_to_short_v3(mv_new->no, nor_tx);
			}

			/* set location */
			copy_v3_v3(mv_new->co, mv_new_base->co);

			/* only need to set these if using non cleared memory */
			/*mv_new->mat_nr = mv_new->flag = 0;*/

			if (ltmd->ob_axis) {
				sub_v3_v3(mv_new->co, mtx_tx[3]);

				mul_m4_v3(mat, mv_new->co);

				add_v3_v3(mv_new->co, mtx_tx[3]);
			}
			else {
				mul_m4_v3(mat, mv_new->co);
			}

			/* add the new edge */
			med_new->v1 = varray_stride + j;
			med_new->v2 = med_new->v1 - totvert;
			med_new->flag = ME_EDGEDRAW | ME_EDGERENDER;
			med_new++;
		}
	}

	/* we can avoid if using vert alloc trick */
	if (vert_connect) {
		MEM_freeN(vert_connect);
		vert_connect = NULL;
	}

	if (close) {
		/* last loop of edges, previous loop doesn't account for the last set of edges */
		const unsigned int varray_stride = (step_tot - 1) * totvert;

		for (i = 0; i < totvert; i++) {
			med_new->v1 = i;
			med_new->v2 = varray_stride + i;
			med_new->flag = ME_EDGEDRAW | ME_EDGERENDER;
			med_new++;
		}
	}

	mp_new = mpoly_new;
	ml_new = mloop_new;
	med_new_firstloop = medge_new;

	/* more of an offset in this case */
	edge_offset = totedge + (totvert * (step_tot - (close ? 0 : 1)));

	for (i = 0; i < totedge; i++, med_new_firstloop++) {
		const unsigned int step_last = step_tot - (close ? 1 : 2);
		const unsigned int mpoly_index_orig = totpoly ? edge_poly_map[i] : UINT_MAX;
		const bool has_mpoly_orig = (mpoly_index_orig != UINT_MAX);
		float uv_v_offset_a, uv_v_offset_b;

		const unsigned int mloop_index_orig[2] = {
		    vert_loop_map ? vert_loop_map[medge_new[i].v1] : UINT_MAX,
		    vert_loop_map ? vert_loop_map[medge_new[i].v2] : UINT_MAX,
		};
		const bool has_mloop_orig = mloop_index_orig[0] != UINT_MAX;

		short mat_nr;

		/* for each edge, make a cylinder of quads */
		i1 = med_new_firstloop->v1;
		i2 = med_new_firstloop->v2;

		if (has_mpoly_orig) {
			mat_nr = mpoly_orig[mpoly_index_orig].mat_nr;
		}
		else {
			mat_nr = 0;
		}

		if (has_mloop_orig == false && mloopuv_layers_tot) {
			uv_v_offset_a = dist_signed_to_plane_v3(mvert_new[medge_new[i].v1].co, uv_axis_plane);
			uv_v_offset_b = dist_signed_to_plane_v3(mvert_new[medge_new[i].v2].co, uv_axis_plane);

			if (ltmd->flag & MOD_SCREW_UV_STRETCH_V) {
				uv_v_offset_a = (uv_v_offset_a - uv_v_minmax[0]) * uv_v_range_inv;
				uv_v_offset_b = (uv_v_offset_b - uv_v_minmax[0]) * uv_v_range_inv;
			}
		}

		for (step = 0; step <= step_last; step++) {

			/* Polygon */
			if (has_mpoly_orig) {
				DM_copy_poly_data(dm, result, (int)mpoly_index_orig, (int)mpoly_index, 1);
				origindex[mpoly_index] = (int)mpoly_index_orig;
			}
			else {
				origindex[mpoly_index] = ORIGINDEX_NONE;
				mp_new->flag = mpoly_flag;
				mp_new->mat_nr = mat_nr;
			}
			mp_new->loopstart = mpoly_index * 4;
			mp_new->totloop = 4;


			/* Loop-Custom-Data */
			if (has_mloop_orig) {
				int l_index = (int)(ml_new - mloop_new);
				DM_copy_loop_data(dm, result, (int)mloop_index_orig[0], l_index + 0, 1);
				DM_copy_loop_data(dm, result, (int)mloop_index_orig[1], l_index + 1, 1);
				DM_copy_loop_data(dm, result, (int)mloop_index_orig[1], l_index + 2, 1);
				DM_copy_loop_data(dm, result, (int)mloop_index_orig[0], l_index + 3, 1);

				if (mloopuv_layers_tot) {
					unsigned int uv_lay;
					const float uv_u_offset_a = (float)(step)     * uv_u_scale;
					const float uv_u_offset_b = (float)(step + 1) * uv_u_scale;
					for (uv_lay = 0; uv_lay < mloopuv_layers_tot; uv_lay++) {
						MLoopUV *mluv = &mloopuv_layers[uv_lay][l_index];

						mluv[quad_ord[0]].uv[0] += uv_u_offset_a;
						mluv[quad_ord[1]].uv[0] += uv_u_offset_a;
						mluv[quad_ord[2]].uv[0] += uv_u_offset_b;
						mluv[quad_ord[3]].uv[0] += uv_u_offset_b;
					}
				}
			}
			else {
				if (mloopuv_layers_tot) {
					int l_index = (int)(ml_new - mloop_new);

					unsigned int uv_lay;
					const float uv_u_offset_a = (float)(step)     * uv_u_scale;
					const float uv_u_offset_b = (float)(step + 1) * uv_u_scale;
					for (uv_lay = 0; uv_lay < mloopuv_layers_tot; uv_lay++) {
						MLoopUV *mluv = &mloopuv_layers[uv_lay][l_index];

						copy_v2_fl2(mluv[quad_ord[0]].uv, uv_u_offset_a, uv_v_offset_a);
						copy_v2_fl2(mluv[quad_ord[1]].uv, uv_u_offset_a, uv_v_offset_b);
						copy_v2_fl2(mluv[quad_ord[2]].uv, uv_u_offset_b, uv_v_offset_b);
						copy_v2_fl2(mluv[quad_ord[3]].uv, uv_u_offset_b, uv_v_offset_a);
					}
				}
			}

			/* Loop-Data */
			if (!(close && step == step_last)) {
				/* regular segments */
				ml_new[quad_ord[0]].v = i1;
				ml_new[quad_ord[1]].v = i2;
				ml_new[quad_ord[2]].v = i2 + totvert;
				ml_new[quad_ord[3]].v = i1 + totvert;

				ml_new[quad_ord_ofs[0]].e = step == 0 ? i : (edge_offset + step + (i * (step_tot - 1))) - 1;
				ml_new[quad_ord_ofs[1]].e = totedge + i2;
				ml_new[quad_ord_ofs[2]].e = edge_offset + step + (i * (step_tot - 1));
				ml_new[quad_ord_ofs[3]].e = totedge + i1;


				/* new vertical edge */
				if (step) { /* The first set is already done */
					med_new->v1 = i1;
					med_new->v2 = i2;
					med_new->flag = med_new_firstloop->flag;
					med_new->crease = med_new_firstloop->crease;
					med_new++;
				}
				i1 += totvert;
				i2 += totvert;
			}
			else {
				/* last segment */
				ml_new[quad_ord[0]].v = i1;
				ml_new[quad_ord[1]].v = i2;
				ml_new[quad_ord[2]].v = med_new_firstloop->v2;
				ml_new[quad_ord[3]].v = med_new_firstloop->v1;

				ml_new[quad_ord_ofs[0]].e = (edge_offset + step + (i * (step_tot - 1))) - 1;
				ml_new[quad_ord_ofs[1]].e = totedge + i2;
				ml_new[quad_ord_ofs[2]].e = i;
				ml_new[quad_ord_ofs[3]].e = totedge + i1;
			}

			mp_new++;
			ml_new += 4;
			mpoly_index++;
		}

		/* new vertical edge */
		med_new->v1 = i1;
		med_new->v2 = i2;
		med_new->flag = med_new_firstloop->flag & ~ME_LOOSEEDGE;
		med_new->crease = med_new_firstloop->crease;
		med_new++;
	}

	/* validate loop edges */
#if 0
	{
		unsigned i = 0;
		printf("\n");
		for (; i < maxPolys * 4; i += 4) {
			unsigned int ii;
			ml_new = mloop_new + i;
			ii = findEd(medge_new, maxEdges, ml_new[0].v, ml_new[1].v);
			printf("%d %d -- ", ii, ml_new[0].e);
			ml_new[0].e = ii;

			ii = findEd(medge_new, maxEdges, ml_new[1].v, ml_new[2].v);
			printf("%d %d -- ", ii, ml_new[1].e);
			ml_new[1].e = ii;

			ii = findEd(medge_new, maxEdges, ml_new[2].v, ml_new[3].v);
			printf("%d %d -- ", ii, ml_new[2].e);
			ml_new[2].e = ii;

			ii = findEd(medge_new, maxEdges, ml_new[3].v, ml_new[0].v);
			printf("%d %d\n", ii, ml_new[3].e);
			ml_new[3].e = ii;

		}
	}
#endif

	if (edge_poly_map) {
		MEM_freeN(edge_poly_map);
	}

	if (vert_loop_map) {
		MEM_freeN(vert_loop_map);
	}

	if ((ltmd->flag & MOD_SCREW_MERGE) && (screw_ofs == 0.0f)) {
		DerivedMesh *result_prev = result;
		result = dm_remove_doubles_on_axis(
		        result, mvert_new, totvert, step_tot,
		        axis_vec, ltmd->ob_axis ? mtx_tx[3] : NULL, ltmd->merge_dist);
		if (result != result_prev) {
			result->dirty |= DM_DIRTY_NORMALS;
		}
	}

	if ((ltmd->flag & MOD_SCREW_NORMAL_CALC) == 0) {
		result->dirty |= DM_DIRTY_NORMALS;
	}

	return result;
}


static void updateDepgraph(ModifierData *md, const ModifierUpdateDepsgraphContext *ctx)
{
	ScrewModifierData *ltmd = (ScrewModifierData *) md;

	if (ltmd->ob_axis) {
		DagNode *curNode = dag_get_node(ctx->forest, ltmd->ob_axis);

		dag_add_relation(ctx->forest, curNode, ctx->obNode,
		                 DAG_RL_DATA_DATA | DAG_RL_OB_DATA,
		                 "Screw Modifier");
	}
}

static void updateDepsgraph(ModifierData *md, const ModifierUpdateDepsgraphContext *ctx)
{
	ScrewModifierData *ltmd = (ScrewModifierData *)md;
	if (ltmd->ob_axis != NULL) {
		DEG_add_object_relation(ctx->node, ltmd->ob_axis, DEG_OB_COMP_TRANSFORM, "Screw Modifier");
	}
}

static void foreachObjectLink(
        ModifierData *md, Object *ob,
        ObjectWalkFunc walk, void *userData)
{
	ScrewModifierData *ltmd = (ScrewModifierData *) md;

	walk(userData, ob, &ltmd->ob_axis, IDWALK_CB_NOP);
}

ModifierTypeInfo modifierType_Screw = {
	/* name */              "Screw",
	/* structName */        "ScrewModifierData",
	/* structSize */        sizeof(ScrewModifierData),
	/* type */              eModifierTypeType_Constructive,

	/* flags */             eModifierTypeFlag_AcceptsMesh |
	                        eModifierTypeFlag_AcceptsCVs |
	                        eModifierTypeFlag_SupportsEditmode |
	                        eModifierTypeFlag_EnableInEditmode,

	/* copyData */          modifier_copyData_generic,
	/* deformVerts */       NULL,
	/* deformMatrices */    NULL,
	/* deformVertsEM */     NULL,
	/* deformMatricesEM */  NULL,
	/* applyModifier */     applyModifier,
	/* applyModifierEM */   NULL,
	/* initData */          initData,
	/* requiredDataMask */  NULL,
	/* freeData */          NULL,
	/* isDisabled */        NULL,
	/* updateDepgraph */    updateDepgraph,
	/* updateDepsgraph */   updateDepsgraph,
	/* dependsOnTime */     NULL,
	/* dependsOnNormals */	NULL,
	/* foreachObjectLink */ foreachObjectLink,
	/* foreachIDLink */     NULL,
	/* foreachTexLink */    NULL,
};