/*
 * ***** 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 Blender Foundation.
 * All rights reserved.
 *
 * The Original Code is: all of this file.
 *
 * Contributor(s): none yet.
 *
 * ***** END GPL LICENSE BLOCK *****
 */

/** \file blender/nodes/texture/node_texture_util.c
 *  \ingroup nodes
 */

 
/*
	HOW TEXTURE NODES WORK

	In contrast to Shader nodes, which place a color into the output
	stack when executed, Texture nodes place a TexDelegate* there. To
	obtain a color value from this, a node further up the chain reads
	the TexDelegate* from its input stack, and uses tex_call_delegate to
	retrieve the color from the delegate.
 
	comments: (ton)

	This system needs recode, a node system should rely on the stack, and 
	callbacks for nodes only should evaluate own node, not recursively go
	over other previous ones.
*/

#include <assert.h>
#include "node_texture_util.h"

#define PREV_RES 128 /* default preview resolution */

static void tex_call_delegate(TexDelegate *dg, float *out, TexParams *params, short thread)
{
	if(dg->node->need_exec) {
		dg->fn(out, params, dg->node, dg->in, thread);

		if(dg->cdata->do_preview)
			tex_do_preview(dg->node, params->previewco, out);
	}
}

static void tex_input(float *out, int sz, bNodeStack *in, TexParams *params, short thread)
{
	TexDelegate *dg = in->data;
	if(dg) {
		tex_call_delegate(dg, in->vec, params, thread);
	
		if(in->hasoutput && in->sockettype == SOCK_FLOAT)
			in->vec[1] = in->vec[2] = in->vec[0];
	}
	memcpy(out, in->vec, sz * sizeof(float));
}

void tex_input_vec(float *out, bNodeStack *in, TexParams *params, short thread)
{
	tex_input(out, 3, in, params, thread);
}

void tex_input_rgba(float *out, bNodeStack *in, TexParams *params, short thread)
{
	tex_input(out, 4, in, params, thread);
	
	if(in->hasoutput && in->sockettype == SOCK_FLOAT)
	{
		out[1] = out[2] = out[0];
		out[3] = 1;
	}
	
	if(in->hasoutput && in->sockettype == SOCK_VECTOR) {
		out[0] = out[0] * .5f + .5f;
		out[1] = out[1] * .5f + .5f;
		out[2] = out[2] * .5f + .5f;
		out[3] = 1;
	}
}

float tex_input_value(bNodeStack *in, TexParams *params, short thread)
{
	float out[4];
	tex_input_vec(out, in, params, thread);
	return out[0];
}

void params_from_cdata(TexParams *out, TexCallData *in)
{
	out->co = in->co;
	out->dxt = in->dxt;
	out->dyt = in->dyt;
	out->previewco = in->co;
	out->osatex = in->osatex;
	out->cfra = in->cfra;
	out->shi = in->shi;
	out->mtex = in->mtex;
}

void tex_do_preview(bNode *node, float *co, float *col)
{
	bNodePreview *preview= node->preview;

	if(preview) {
		int xs= ((co[0] + 1.0f)*0.5f)*preview->xsize;
		int ys= ((co[1] + 1.0f)*0.5f)*preview->ysize;

		nodeAddToPreview(node, col, xs, ys, 0); /* 0 = no color management */
	}
}

void tex_output(bNode *node, bNodeStack **in, bNodeStack *out, TexFn texfn, TexCallData *cdata)
{
	TexDelegate *dg;
	if(!out->data)
		/* Freed in tex_end_exec (node.c) */
		dg = out->data = MEM_mallocN(sizeof(TexDelegate), "tex delegate");
	else
		dg = out->data;
	
	dg->cdata= cdata;
	dg->fn = texfn;
	dg->node = node;
	memcpy(dg->in, in, MAX_SOCKET * sizeof(bNodeStack*));
	dg->type = out->sockettype;
}

/* Used for muted nodes, just pass the TexDelegate data from input to output…
 * XXX That *%!?¿§ callback TextureDelegate system is a nightmare here!
 *     So I have to use an ugly hack (checking inputs twice!)… Yuk!
 *     I’d be very happy if someone can imagine a better solution
 *     (without changing the whole stuff).
 * WARNING: These are only suitable for default muting behavior. If you want a custom
 *          one for your texnode, you must not use them!
 */
static void passonvalfn(float *out, TexParams *p, bNode *node, bNodeStack **in, short thread)
{
	bNodeSocket *sock;
	int i;

	/* test the inputs */
	for(i=0, sock = node->inputs.first; sock; sock = sock->next, i++) {
		if(sock->link && sock->type==SOCK_FLOAT && in) {
			out[0] = tex_input_value(in[i], p, thread);
			break;
		}
	}
}

static void passonvecfn(float *out, TexParams *p, bNode *node, bNodeStack **in, short thread)
{
	bNodeSocket *sock;
	int i;

	/* test the inputs */
	for(i=0, sock = node->inputs.first; sock; sock = sock->next, i++) {
		if(sock->link && sock->type==SOCK_VECTOR && in) {
			tex_input_vec(out, in[i], p, thread);
			break;
		}
	}
}

static void passoncolfn(float *out, TexParams *p, bNode *node, bNodeStack **in, short thread)
{
	bNodeSocket *sock;
	int i;

	/* test the inputs */
	for(i=0, sock = node->inputs.first; sock; sock = sock->next, i++) {
		if(sock->link && sock->type==SOCK_RGBA && in) {
			tex_input_rgba(out, in[i], p, thread);
			break;
		}
	}
}

void node_tex_pass_on(void *data, int UNUSED(thread), struct bNode *node, void *UNUSED(nodedata),
                      struct bNodeStack **in, struct bNodeStack **out)
{
	ListBase links;
	LinkInOutsMuteNode *lnk;
	int i;

	if(node->typeinfo->mutelinksfunc == NULL)
		return;

	/* Get default muting links (as bNodeStack pointers). */
	links = node->typeinfo->mutelinksfunc(NULL, node, in, out, NULL, NULL);

	for(lnk = links.first; lnk; lnk = lnk->next) {
		/* XXX This breaks the generality of the system.
		 *     Again, unfortunately, I see no other way to do due to tex nodes behavior...
		 */
		void (*passonfn)(float *out, TexParams *p, bNode *node, bNodeStack **in, short thread);
		switch(((bNodeStack*)(lnk->in))->sockettype) {
		case SOCK_FLOAT:
			passonfn = passonvalfn;
			break;
		case SOCK_VECTOR:
			passonfn = passonvecfn;
			break;
		case SOCK_RGBA:
			passonfn = passoncolfn;
			break;
		default:
			passonfn = NULL;
		}
		for(i = 0; i < lnk->num_outs; i++) {
			if(((bNodeStack*)(lnk->in))->data && passonfn)
				tex_output(node, in, ((bNodeStack*)(lnk->outs))+i, passonfn, data);
		}
		/* If num_outs > 1, lnk->outs was an allocated table of pointers... */
		if(i > 1)
			MEM_freeN(lnk->outs);
	}
	BLI_freelistN(&links);
}

void ntreeTexCheckCyclics(struct bNodeTree *ntree)
{
	bNode *node;
	for(node= ntree->nodes.first; node; node= node->next) {
		
		if(node->type == TEX_NODE_TEXTURE && node->id)
		{
			/* custom2 stops the node from rendering */
			if(node->custom1) {
				node->custom2 = 1;
				node->custom1 = 0;
			} else {
				Tex *tex = (Tex *)node->id;
				
				node->custom2 = 0;
			
				node->custom1 = 1;
				if(tex->use_nodes && tex->nodetree) {
					ntreeTexCheckCyclics(tex->nodetree);
				}
				node->custom1 = 0;
			}
		}

	}
}