/*
	gl_dyn_textures.c

	Dynamic texture generation.

	Copyright (C) 1996-1997  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:

		Free Software Foundation, Inc.
		59 Temple Place - Suite 330
		Boston, MA  02111-1307, USA

*/
static const char rcsid[] = 
	"$Id$";

#ifdef HAVE_CONFIG_H
# include "config.h"
#endif

#include <stdlib.h>

#include "QF/qtypes.h"
#include "QF/GL/defines.h"
#include "QF/GL/funcs.h"
#include "QF/GL/qf_noisetextures.h"
#include "QF/GL/qf_vid.h"

int         part_tex_dot;
int         part_tex_smoke;
int         part_tex_spark;


static void
GDT_InitDotParticleTexture (void)
{
	byte        data[16][16][2];
	int         x, y, dx2, dy, d;

	for (x = 0; x < 16; x++) {
		dx2 = x - 8;
		dx2 *= dx2;
		for (y = 0; y < 16; y++) {
			dy = y - 8;
			d = 255 - 4 * (dx2 + (dy * dy));
			if (d <= 0) {
				d = 0;
				data[y][x][0] = 0;
			} else
				data[y][x][0] = 255;

			data[y][x][1] = (byte) d;
		}
	}
	part_tex_dot = texture_extension_number++;
	qfglBindTexture (GL_TEXTURE_2D, part_tex_dot);
	qfglTexParameterf (GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
	qfglTexParameterf (GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
	qfglTexImage2D (GL_TEXTURE_2D, 0, 2, 16, 16, 0, GL_LUMINANCE_ALPHA,
		      GL_UNSIGNED_BYTE, data);
}

static void
GDT_InitSparkParticleTexture (void)
{
	byte        data[16][16][2];
	int         x, y, dx2, dy, d;

	for (x = 0; x < 16; x++) {
		dx2 = 8 - abs (x - 8);
		dx2 *= dx2;
		for (y = 0; y < 16; y++) {
			dy = 8 - abs (y - 8);
			d = 3 * (dx2 + dy * dy) - 100;
			if (d > 255)
				d = 255;
			if (d < 1) {
				d = 0;
				data[y][x][0] = 0;
			} else
				data[y][x][0] = 255;

			data[y][x][1] = (byte) d;
		}
	}
	part_tex_spark = texture_extension_number++;
	qfglBindTexture (GL_TEXTURE_2D, part_tex_spark);
	qfglTexParameterf (GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
	qfglTexParameterf (GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
	qfglTexImage2D (GL_TEXTURE_2D, 0, 2, 16, 16, 0, GL_LUMINANCE_ALPHA,
		      GL_UNSIGNED_BYTE, data);
}

static void
GDT_InitSmokeParticleTexture (void)
{
	byte        d;
	byte        data[32][32][2], noise1[32][32], noise2[32][32];
	float       dx, dy2;
	int         x, y, c;

	noise_plasma (&noise1[0][0], 32);
	noise_diamondsquare (&noise2[0][0], 32, 4);
	for (y = 0; y < 32; y++)
	{
		dy2 = y - 16;
		dy2 *= dy2;
		for (x = 0; x < 32; x++) {
			dx = x - 16;
			c = 255 - (dx * dx + dy2);
			if (c < 1)
				c = 0;
			d = (noise1[y][x] + noise2[y][x]) / 2;
			if (d > 0) {
				data[y][x][0] = 255;
				data[y][x][1] = (d * c) / 255;
			} else {
				data[y][x][0] = 255;
				data[y][x][1] = 0;
			}
		}
	}
	part_tex_smoke = texture_extension_number++;
	qfglBindTexture (GL_TEXTURE_2D, part_tex_smoke);
	qfglTexParameterf (GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
	qfglTexParameterf (GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
	qfglTexImage2D (GL_TEXTURE_2D, 0, 2, 32, 32, 0, GL_LUMINANCE_ALPHA,
					GL_UNSIGNED_BYTE, data);
}

void
GDT_Init (void)
{
	GDT_InitDotParticleTexture ();
	GDT_InitSparkParticleTexture ();
	GDT_InitSmokeParticleTexture ();
}