quakeforge/libs/video/renderer/gl/gl_dyn_textures.c

/*
	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

	$Id$
*/

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

#include <stdlib.h>

#include "glquake.h"

extern void noise_diamondsquare(unsigned char *noise, int size);
extern void noise_plasma(unsigned char *noise, int size);

static void GDT_InitDotParticleTexture (void);
static void GDT_InitSparkParticleTexture (void);
static void GDT_InitSmokeParticleTexture (void);
static void GDT_InitSmokeRingParticleTexture (void);

int         part_tex_dot;
int         part_tex_spark;
int         part_tex_smoke[8];
int         part_tex_smoke_ring[8];


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


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

	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++;
	glBindTexture (GL_TEXTURE_2D, part_tex_dot);
	glTexParameterf (GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
	glTexParameterf (GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
	glTexImage2D (GL_TEXTURE_2D, 0, 2, 16, 16, 0, GL_LUMINANCE_ALPHA,
		      GL_UNSIGNED_BYTE, data);
}


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

	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++;
	glBindTexture (GL_TEXTURE_2D, part_tex_spark);
	glTexParameterf (GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
	glTexParameterf (GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
	glTexImage2D (GL_TEXTURE_2D, 0, 2, 16, 16, 0, GL_LUMINANCE_ALPHA,
		      GL_UNSIGNED_BYTE, data);
}


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

	for (i = 0; i < 8; i++) {
		noise_plasma (&noise1[0][0], 32);
		noise_diamondsquare (&noise2[0][0], 32);
		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[i] = texture_extension_number++;
		glBindTexture (GL_TEXTURE_2D, part_tex_smoke[i]);
		glTexParameterf (GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
		glTexParameterf (GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
		glTexImage2D (GL_TEXTURE_2D, 0, 2, 32, 32, 0, GL_LUMINANCE_ALPHA,
			      GL_UNSIGNED_BYTE, data);
	}
}


static void
GDT_InitSmokeRingParticleTexture (void)
{
	int         i, x, y, b;
	float       dx, dy, c, c2;
	byte        d, data[32][32][2], noise1[32][32], noise2[32][32];

	for (i = 0; i < 8; i++) {
		noise_diamondsquare (&noise1[0][0], 32);
		noise_plasma (&noise2[0][0], 32);
		for (y = 0; y < 32; y++)
		{
			dy = y - 16;
			dy *= dy;
			for (x = 0; x < 32; x++) {
				dx = x - 16;
				dx *= dx;
				c = 255 - (dx + dy);
				c2 = (dx + dy);
				if (c < 1) c = 0;
				if (c2 < 1) c2 = 0;
				//b = ((c / 255) * (c2 / 255)) * 512;
				b = (c * c2) * 512 / (255*255);
				if (b < 1) b = 0;
				d = (noise1[y][x] + noise2[y][x]) / 2;
				if (d > 0) {
					data[y][x][0] = 255;
					data[y][x][1] = (d * b)/255;
				} else {
					data[y][x][0] = 255;
					data[y][x][1] = 0;
				}
			}
		}
		part_tex_smoke_ring[i] = texture_extension_number++;
		glBindTexture (GL_TEXTURE_2D, part_tex_smoke_ring[i]);
		glTexParameterf (GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
		glTexParameterf (GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
		glTexImage2D (GL_TEXTURE_2D, 0, 2, 32, 32, 0, GL_LUMINANCE_ALPHA,
			      GL_UNSIGNED_BYTE, data);
	}
}