/**
 * @file patches.c
 * @brief
 */

/*
Copyright (C) 1997-2001 Id Software, Inc.

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.

*/

#include "qrad.h"

static vec3_t texture_reflectivity[MAX_MAP_TEXINFO];

/*
===================================================================
TEXTURE LIGHT VALUES
===================================================================
*/

/**
 *	@brief
 */
extern void CalcTextureReflectivity (void)
{
	int i, j;

	byte *palette = NULL;
	char path[1024];

	sprintf(path, "%spics/colormap.pcx", gamedir);

	/* get the game palette */
	Load256Image(path, NULL, &palette, NULL, NULL);

	/* allways set index 0 even if no textures */
	texture_reflectivity[0][0] = 0.5;
	texture_reflectivity[0][1] = 0.5;
	texture_reflectivity[0][2] = 0.5;

	for (i = 0; i < numtexinfo; i++) {
		/* see if an earlier texinfo allready got the value */
		for (j = 0; j < i; j++)
			if (!strcmp(texinfo[i].texture, texinfo[j].texture)) {
				VectorCopy(texture_reflectivity[j], texture_reflectivity[i]);
				break;
			}
		if (j != i)
			continue;

		texture_reflectivity[i][0] = 0.5;
		texture_reflectivity[i][1] = 0.5;
		texture_reflectivity[i][2] = 0.5;
	}
	if (palette)
		free(palette);
}

/*
=======================================================================
MAKE FACES
=======================================================================
*/

/**
 *	@brief
 */
static winding_t *WindingFromFace (dface_t *f)
{
	int			i;
	int			se;
	dvertex_t	*dv;
	int			v;
	winding_t	*w;

	w = AllocWinding(f->numedges);
	w->numpoints = f->numedges;

	for (i = 0; i < f->numedges; i++) {
		se = dsurfedges[f->firstedge + i];
		if (se < 0)
			v = dedges[-se].v[1];
		else
			v = dedges[se].v[0];

		dv = &dvertexes[v];
		VectorCopy(dv->point, w->p[i]);
	}

	RemoveColinearPoints(w);

	return w;
}

/**
 *	@brief
 */
static void BaseLightForFace (dface_t *f, vec3_t color)
{
	texinfo_t	*tx;

	/* check for light emited by texture */
	tx = &texinfo[f->texinfo];
	if (!(tx->flags & SURF_LIGHT) || tx->value == 0) {
		VectorClear(color);
		return;
	}

	VectorScale(texture_reflectivity[f->texinfo], tx->value, color);
}

static float totalarea;
/**
 *	@brief
 */
static void MakePatchForFace (int fn, winding_t *w)
{
	dface_t *f;
	float	area;
	patch_t		*patch;
	dplane_t	*pl;
	int			i;
	vec3_t		color;
	dleaf_t		*leaf;

	f = &dfaces[fn];

	area = WindingArea (w);
	totalarea += area;

	patch = &patches[num_patches];
	if (num_patches == MAX_PATCHES)
		Error ("num_patches == MAX_PATCHES");
	patch->next = face_patches[fn];
	face_patches[fn] = patch;

	patch->winding = w;

	if (f->side)
		patch->plane = &backplanes[f->planenum];
	else
		patch->plane = &dplanes[f->planenum];
	/* origin offset faces must create new planes */
	if (face_offset[fn][0] || face_offset[fn][1] || face_offset[fn][2] ) {
		if (numplanes + fakeplanes >= MAX_MAP_PLANES)
			Error("numplanes + fakeplanes >= MAX_MAP_PLANES");
		pl = &dplanes[numplanes + fakeplanes];
		fakeplanes++;

		*pl = *(patch->plane);
		pl->dist += DotProduct(face_offset[fn], pl->normal);
		patch->plane = pl;
	}

	WindingCenter(w, patch->origin);
	VectorAdd(patch->origin, patch->plane->normal, patch->origin);
	leaf = Rad_PointInLeaf(patch->origin);
	patch->cluster = leaf->cluster;
	if (patch->cluster == -1)
		Sys_FPrintf(SYS_VRB, "patch->cluster == -1\n");

	patch->area = area;
	if (patch->area <= 1)
		patch->area = 1;

	VectorCopy (texture_reflectivity[f->texinfo], patch->reflectivity);

	/* non-bmodel patches can emit light */
	if (fn < dmodels[0].numfaces) {
		BaseLightForFace(f, patch->baselight);

		ColorNormalize(patch->reflectivity, color);

		for (i = 0; i < 3; i++)
			patch->baselight[i] *= color[i];

		VectorCopy(patch->baselight, patch->totallight);
	}
	num_patches++;
}

#if 0
/**
 *	@brief
 */
static entity_t *EntityForModel (int modnum)
{
	int		i;
	char	*s;
	char	name[16];

	sprintf (name, "*%i", modnum);
	/* search the entities for one using modnum */
	for (i = 0; i < num_entities; i++) {
		s = ValueForKey (&entities[i], "model");
		if (!strcmp (s, name))
			return &entities[i];
	}

	return &entities[0];
}
#endif

/**
 *	@brief
 */
extern void MakePatches (void)
{
	int		i, j, k;
	dface_t	*f;
	int		fn;
	winding_t	*w;
	dmodel_t	*mod;
	vec3_t		origin;
#if 0
	entity_t	*ent;
#endif

	Sys_FPrintf( SYS_VRB, "%i faces\n", numfaces);

	for (i = 0; i < nummodels; i++) {
		mod = &dmodels[i];
#if 0
		ent = EntityForModel(i);
		/* bmodels with origin brushes need to be offset into their
		 * in-use position */
		GetVectorForKey(ent, "origin", origin);
#else
		VectorCopy(vec3_origin, origin);
#endif

		for (j = 0; j < mod->numfaces; j++) {
			fn = mod->firstface + j;
			VectorCopy(origin, face_offset[fn]);
			f = &dfaces[fn];
			w = WindingFromFace(f);
			for (k = 0; k < w->numpoints; k++)
				VectorAdd(w->p[k], origin, w->p[k]);
			MakePatchForFace(fn, w);
		}
	}

	Sys_FPrintf(SYS_VRB, "%i square feet\n", (int)(totalarea/64));
}

/*
=======================================================================
SUBDIVIDE
=======================================================================
*/

/**
 *	@brief
 */
static void FinishSplit (patch_t *patch, patch_t *newp)
{
	dleaf_t		*leaf;

	VectorCopy(patch->baselight, newp->baselight);
	VectorCopy(patch->totallight, newp->totallight);
	VectorCopy(patch->reflectivity, newp->reflectivity);
	newp->plane = patch->plane;

	patch->area = WindingArea(patch->winding);
	newp->area = WindingArea(newp->winding);

	if (patch->area <= 1)
		patch->area = 1;
	if (newp->area <= 1)
		newp->area = 1;

	WindingCenter(patch->winding, patch->origin);
	VectorAdd(patch->origin, patch->plane->normal, patch->origin);
	leaf = Rad_PointInLeaf(patch->origin);
	patch->cluster = leaf->cluster;
	if (patch->cluster == -1)
		Sys_FPrintf(SYS_VRB, "patch->cluster == -1\n");

	WindingCenter(newp->winding, newp->origin);
	VectorAdd(newp->origin, newp->plane->normal, newp->origin);
	leaf = Rad_PointInLeaf(newp->origin);
	newp->cluster = leaf->cluster;
	if (newp->cluster == -1)
		Sys_FPrintf(SYS_VRB, "patch->cluster == -1\n");
}

/**
 *	@brief Chops the patch only if its local bounds exceed the max size
 */
static void SubdividePatch (patch_t *patch)
{
	winding_t *w, *o1, *o2;
	vec3_t	mins, maxs, total;
	vec3_t	split;
	vec_t	dist;
	int		i, j;
	vec_t	v;
	patch_t	*newp;

	w = patch->winding;
	mins[0] = mins[1] = mins[2] = 99999;
	maxs[0] = maxs[1] = maxs[2] = -99999;
	for (i = 0; i < w->numpoints; i++)
		for (j = 0; j < 3; j++) {
			v = w->p[i][j];
			if (v < mins[j])
				mins[j] = v;
			if (v > maxs[j])
				maxs[j] = v;
		}
	VectorSubtract (maxs, mins, total);
	for (i = 0; i < 3; i++)
		if (total[i] > (subdiv+1) )
			break;
	/* no splitting needed */
	if (i == 3)
		return;

	/* split the winding */
	VectorCopy(vec3_origin, split);
	split[i] = 1;
	dist = (mins[i] + maxs[i])*0.5;
	ClipWindingEpsilon(w, split, dist, ON_EPSILON, &o1, &o2);

	/* create a new patch */
	if (num_patches == MAX_PATCHES)
		Error("MAX_PATCHES (%i)", num_patches);
	newp = &patches[num_patches];
	num_patches++;

	newp->next = patch->next;
	patch->next = newp;

	patch->winding = o1;
	newp->winding = o2;

	FinishSplit(patch, newp);

	SubdividePatch(patch);
	SubdividePatch(newp);
}


/**
 *	@brief Chops the patch by a global grid
 */
static void DicePatch (patch_t *patch)
{
	winding_t *w, *o1, *o2;
	vec3_t	mins, maxs;
	vec3_t	split;
	vec_t	dist;
	int		i;
	patch_t	*newp;

	w = patch->winding;
	WindingBounds(w, mins, maxs);
	for (i = 0; i < 3; i++)
		if (floor((mins[i] + 1) / subdiv) < floor((maxs[i] - 1) / subdiv))
			break;
	/* no splitting needed */
	if (i == 3)
		return;

	/* split the winding */
	VectorCopy(vec3_origin, split);
	split[i] = 1;
	dist = subdiv * (1 + floor((mins[i] + 1) / subdiv));
	ClipWindingEpsilon(w, split, dist, ON_EPSILON, &o1, &o2);

	/* create a new patch */
	if (num_patches == MAX_PATCHES)
		Error("MAX_PATCHES (%i)", num_patches);
	newp = &patches[num_patches];
	num_patches++;

	newp->next = patch->next;
	patch->next = newp;

	patch->winding = o1;
	newp->winding = o2;

	FinishSplit(patch, newp);

	DicePatch(patch);
	DicePatch(newp);
}


/**
 *	@brief
 */
extern void SubdividePatches (void)
{
	int i, num;

	if (subdiv < 1)
		return;

	/* because the list will grow */
	num = num_patches;
	for (i = 0; i < num ; i++)
		DicePatch(&patches[i]);
	Sys_FPrintf(SYS_VRB, "%i patches after subdivision\n", num_patches);
}