/**
 * @file textures.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 "qbsp.h"

static int nummiptex = 0;
textureref_t textureref[MAX_MAP_TEXTURES];


/**
 * @brief
 */
extern int FindMiptex (char *name)
{
	int i;
	char path[1024];
	miptex_t *mt;

	for (i = 0; i < nummiptex; i++)
		if (!strcmp (name, textureref[i].name)) {
			return i;
		}
	if (nummiptex == MAX_MAP_TEXTURES)
		Error ("MAX_MAP_TEXTURES");
	strcpy (textureref[i].name, name);

	/* load the miptex to get the flags and values */
	sprintf (path, "%stextures/%s.wal", gamedir, name);
	if (TryLoadFile (path, (void **)&mt) != -1) {
		textureref[i].value = LittleLong (mt->value);
		textureref[i].flags = LittleLong (mt->flags);
		textureref[i].contents = LittleLong (mt->contents);
		strcpy (textureref[i].animname, mt->animname);
		free (mt);
	}
	nummiptex++;

	if (textureref[i].animname[0])
		FindMiptex (textureref[i].animname);

	return i;
}


/**
 * @brief
 */
static const vec3_t baseaxis[18] =
{
{0,0,1}, {1,0,0}, {0,-1,0},			/* floor */
{0,0,-1}, {1,0,0}, {0,-1,0},		/* ceiling */
{1,0,0}, {0,1,0}, {0,0,-1},			/* west wall */
{-1,0,0}, {0,1,0}, {0,0,-1},		/* east wall */
{0,1,0}, {1,0,0}, {0,0,-1},			/* south wall */
{0,-1,0}, {1,0,0}, {0,0,-1}			/* north wall */
};

/**
 * @brief
 */
static void TextureAxisFromPlane (plane_t *pln, vec3_t xv, vec3_t yv, qboolean isTerrain)
{
	int		bestaxis;
	vec_t	dot,best;
	int		i;
	int numaxis;

	/* Knightmare- terrain support, use floor/ceiling axis only */
	numaxis = (isTerrain) ? 2 : 6;

	best = 0;
	bestaxis = 0;

	for (i = 0; i < numaxis; i++) {
		dot = DotProduct(pln->normal, baseaxis[i*3]);
		if (dot > best) {
			best = dot;
			bestaxis = i;
		}
	}

	VectorCopy(baseaxis[bestaxis*3+1], xv);
	VectorCopy(baseaxis[bestaxis*3+2], yv);
}


/**
 * @brief
 */
extern int TexinfoForBrushTexture (plane_t *plane, brush_texture_t *bt, vec3_t origin, qboolean isTerrain)
{
	vec3_t vecs[2];
	int sv, tv;
	vec_t ang, sinv, cosv;
	vec_t ns, nt;
	texinfo_t tx, *tc;
	int i, j, k, mt;
	float shift[2];
	brush_texture_t anim;

	if (!bt->name[0])
		return 0;

	memset (&tx, 0, sizeof(tx));
	strcpy (tx.texture, bt->name);

	TextureAxisFromPlane(plane, vecs[0], vecs[1], isTerrain);

	shift[0] = DotProduct (origin, vecs[0]);
	shift[1] = DotProduct (origin, vecs[1]);

	if (!bt->scale[0])
		bt->scale[0] = 1;
	if (!bt->scale[1])
		bt->scale[1] = 1;

	/* rotate axis */
	if (bt->rotate == 0) {
		sinv = 0;
		cosv = 1;
	} else if (bt->rotate == 90) {
		sinv = 1;
		cosv = 0;
	} else if (bt->rotate == 180) {
		sinv = 0;
		cosv = -1;
	} else if (bt->rotate == 270) {
		sinv = -1;
		cosv = 0;
	} else {
		ang = bt->rotate / 180.0f * M_PI;
		sinv = sin(ang);
		cosv = cos(ang);
	}

	if (vecs[0][0])
		sv = 0;
	else if (vecs[0][1])
		sv = 1;
	else
		sv = 2;

	if (vecs[1][0])
		tv = 0;
	else if (vecs[1][1])
		tv = 1;
	else
		tv = 2;

	for (i = 0; i < 2; i++) {
		ns = cosv * vecs[i][sv] - sinv * vecs[i][tv];
		nt = sinv * vecs[i][sv] +  cosv * vecs[i][tv];
		vecs[i][sv] = ns;
		vecs[i][tv] = nt;
	}

	for (i = 0; i < 2; i++)
		for (j = 0; j < 3; j++)
			tx.vecs[i][j] = vecs[i][j] / bt->scale[i];

	tx.vecs[0][3] = bt->shift[0] + shift[0];
	tx.vecs[1][3] = bt->shift[1] + shift[1];
	tx.flags = bt->flags;
	tx.value = bt->value;

	/* find the texinfo */
	tc = texinfo;
	for (i = 0; i < numtexinfo; i++, tc++) {
		if (tc->flags != tx.flags)
			continue;
		if (tc->value != tx.value)
			continue;
		for (j = 0; j < 2; j++) {
			if (strcmp (tc->texture, tx.texture))
				goto skip;
			for (k = 0; k < 4; k++) {
				if (tc->vecs[j][k] != tx.vecs[j][k])
					goto skip;
			}
		}
		return i;
skip:;
	}
	*tc = tx;
	numtexinfo++;

	/* load the next animation */
	mt = FindMiptex (bt->name);
	if (textureref[mt].animname[0]) {
		anim = *bt;
		strcpy (anim.name, textureref[mt].animname);
		tc->nexttexinfo = TexinfoForBrushTexture (plane, &anim, origin, isTerrain);
	} else
		tc->nexttexinfo = -1;

	return i;
}