quakeforge/libs/video/renderer/gl/gl_dyn_fires.c
2001-09-28 06:26:31 +00:00

151 lines
3.1 KiB
C

/*
gl_dyn_fires.c
dynamic fires
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
#ifdef HAVE_STRING_H
# include <string.h>
#endif
#ifdef HAVE_STRINGS_H
# include <strings.h>
#endif
#include <stdlib.h>
#include "QF/cmd.h"
#include "QF/console.h"
#include "QF/cvar.h"
#include "QF/render.h"
#include "QF/GL/defines.h"
#include "QF/GL/funcs.h"
#include "QF/GL/qf_rlight.h"
#include "r_cvar.h"
#include "r_dynamic.h"
#include "r_shared.h"
extern float v_blend[4];
void
AddLightBlend (float r, float g, float b, float a2)
{
float a;
v_blend[3] = a = v_blend[3] + a2 * (1 - v_blend[3]);
a2 = a2 / a;
v_blend[0] = v_blend[0] * (1 - a2) + r * a2;
v_blend[1] = v_blend[1] * (1 - a2) + g * a2;
v_blend[2] = v_blend[2] * (1 - a2) + b * a2;
}
/*
R_DrawFire
draws one fireball - probably never need to call this directly
*/
void
R_DrawFire (fire_t *f)
{
float radius;
float *b_sin, *b_cos;
int i, j;
vec3_t vec, vec2;
b_sin = bubble_sintable;
b_cos = bubble_costable;
radius = f->size - 0.5;
// figure out if we're inside the area of effect
VectorSubtract (f->origin, r_origin, vec);
if (Length (vec) < radius) {
AddLightBlend (f->color[0], f->color[1], f->color[2],
f->size * 0.0003); // we are
return;
}
// we're not - draw it
qfglBegin (GL_TRIANGLE_FAN);
qfglColor3fv (f->color);
for (i = 0; i < 3; i++)
vec[i] = f->origin[i] - vpn[i] * radius;
qfglVertex3fv (vec);
qfglColor3ubv (color_black);
// don't panic, this just draws a bubble...
for (i = 16; i >= 0; i--) {
for (j = 0; j < 3; j++) {
vec[j] = f->origin[j] + (*b_cos * vright[j]
+ vup[j] * (*b_sin)) * radius;
vec2[j] = f->owner[j] + (*b_cos * vright[j]
+ vup[j] * (*b_sin)) * radius;
}
qfglVertex3fv (vec);
qfglVertex3fv (vec2);
b_sin += 2;
b_cos += 2;
}
qfglEnd ();
}
/*
R_UpdateFires
Draws each fireball in sequence
*/
void
R_UpdateFires (void)
{
int i;
fire_t *f;
if (!gl_fires->int_val)
return;
qfglDepthMask (GL_FALSE);
qfglDisable (GL_TEXTURE_2D);
qfglBlendFunc (GL_ONE, GL_ONE);
f = r_fires;
for (i = 0; i < MAX_FIRES; i++, f++) {
if (f->die < r_realtime || !f->size)
continue;
f->size += f->decay;
R_DrawFire (f);
}
qfglColor3ubv (color_white);
qfglEnable (GL_TEXTURE_2D);
qfglBlendFunc (GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
qfglDepthMask (GL_TRUE);
}