quakeforge/libs/video/renderer/glsl/quaketrb.frag

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uniform sampler2D palette;
uniform sampler2D texture;
uniform float realtime;
uniform vec4 fog;
varying vec2 tst;
2012-01-28 12:20:34 +00:00
varying vec4 color;
const float SPEED = 20.0;
const float CYCLE = 128.0;
const float PI = 3.14159;
const float FACTOR = PI * 2.0 / CYCLE;
const vec2 BIAS = vec2 (1.0, 1.0);
const float SCALE = 8.0;
float
sqr (float x)
{
return x * x;
}
vec4
fogBlend (vec4 color)
{
float f;
vec4 fog_color = vec4 (fog.rgb, 1.0);
f = exp (-sqr (fog.a / gl_FragCoord.w));
return mix (fog_color, color, f);
}
vec2
turb_st (vec2 st, float time)
{
vec2 angle = st.ts * CYCLE / 2.0;
vec2 phase = vec2 (time, time) * SPEED;
return st + (sin ((angle + phase) * FACTOR) + BIAS) / SCALE;
}
void
main (void)
{
float pix;
vec2 st;
st = turb_st (tst, realtime);
pix = texture2D (texture, st).r;
gl_FragColor = fogBlend (texture2D (palette, vec2 (pix, 0.0)) * color);
}