quakeforge/libs/video/renderer/gl/gl_warp.c
Bill Currie 12776e487a [gl] Implement screen warping for liquids
It's not the most efficient code (uses sin() directly), but at least it
works (and with about 75% cpu headroom at 72fps on my machine).
2022-03-26 18:13:37 +09:00

140 lines
3.4 KiB
C

/*
gl_warp.c
water polygons
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
*/
#ifdef HAVE_CONFIG_H
# include "config.h"
#endif
#include "QF/cvar.h"
#include "QF/sys.h"
#include "QF/GL/defines.h"
#include "QF/GL/funcs.h"
#include "QF/GL/qf_rsurf.h"
#include "r_internal.h"
#include "vid_gl.h"
// speed up sin calculations - Ed
static float turbsin[] = {
# include "gl_warp_sin.h"
};
#define TURBSCALE (256.0 / (2 * M_PI))
#define TURBFRAC (32.0 / (2 * M_PI)) // an 8th of TURBSCALE
/*
GL_EmitWaterPolys
Does a water warp on the pre-fragmented glpoly_t chain
*/
void
GL_EmitWaterPolys (msurface_t *surf)
{
float os, ot, s, t, timetemp;
float *v;
int i;
glpoly_t *p;
timetemp = vr_data.realtime * TURBSCALE;
for (p = surf->polys; p; p = p->next) {
qfglBegin (GL_POLYGON);
for (i = 0, v = p->verts[0]; i < p->numverts; i++, v += VERTEXSIZE) {
os = turbsin[(int) (v[3] * TURBFRAC + timetemp) & 255];
ot = turbsin[(int) (v[4] * TURBFRAC + timetemp) & 255];
s = (v[3] + ot) * (1.0 / 64.0);
t = (v[4] + os) * (1.0 / 64.0);
qfglTexCoord2f (s, t);
if (r_waterripple->value != 0) {
vec3_t nv;
VectorCopy (v, nv);
nv[2] += r_waterripple->value * os * ot * (1.0 / 64.0);
qfglVertex3fv (nv);
} else
qfglVertex3fv (v);
}
qfglEnd ();
}
}
const float S = 0.15625;
const float F = 2.5;
const float A = 0.01;
static void
warp_uv (float *uv, float time)
{
float p1 = (time * S + F * uv[1]) * 2 * M_PI;
float p2 = (time * S + F * uv[0]) * 2 * M_PI;
uv[0] = uv[0] * (1 - 2 * A) + A * (1 + sin (p1));
uv[1] = uv[1] * (1 - 2 * A) + A * (1 + sin (p2));
}
void
gl_WarpScreen (framebuffer_t *fb)
{
gl_framebuffer_t *buffer = fb->buffer;
qfglMatrixMode (GL_PROJECTION);
qfglLoadIdentity ();
qfglOrtho (0, r_refdef.vrect.width, r_refdef.vrect.height, 0, -9999, 9999);
qfglMatrixMode (GL_MODELVIEW);
qfglLoadIdentity ();
qfglColor3ubv (color_white);
qfglDisable (GL_DEPTH_TEST);
qfglFrontFace (GL_CCW);
qfglBindTexture (GL_TEXTURE_2D, buffer->color);
int base_x = r_refdef.vrect.x;
int base_y = r_refdef.vrect.y;
int width = r_refdef.vrect.width;
int height = r_refdef.vrect.height;
float time = vr_data.realtime;
for (int y = 0; y < height; y += 40) {
qfglBegin (GL_QUAD_STRIP);
for (int x = 0; x <= width; x+= 40) {
int y2 = y + 40;
int xy1[] = { base_x + x, base_y + y };
int xy2[] = { base_x + x, base_y + y2};
float uv1[] = { (float) x / width, 1 - (float) y / height };
float uv2[] = { (float) x / width, 1 - (float) y2 / height };
warp_uv (uv1, time);
warp_uv (uv2, time);
qfglTexCoord2fv (uv2);
qfglVertex2iv (xy2);
qfglTexCoord2fv (uv1);
qfglVertex2iv (xy1);
}
qfglEnd ();
}
}