fteqw/engine/shaders/glsl/crepuscular_rays.glsl
Spoike 5b4756f3d9 Lazy GLSL loading, for faster load times.
Fixed some xim issues, for proper keyboard input under x11.
Cmake project can now work for cross compiling win32 targets.
Some other fun-but-pointless stuff.



git-svn-id: https://svn.code.sf.net/p/fteqw/code/trunk@5344 fc73d0e0-1445-4013-8a0c-d673dee63da5
2018-11-27 16:48:19 +00:00

44 lines
1.3 KiB
GLSL

!!cvarf crep_decay
!!cvarf crep_density
!!cvarf crep_weight
!!samps 1
//this is a post-processing shader, drawn in 2d
//there will be a render target containing sky surfaces drawn with crepuscular_sky, and everything else drawn with crepuscular_opaque (to mask out the sky)
//this shader then just smudges the sky out a bit as though its coming from the sun or whatever through the clouds.
//yoinked from http://fabiensanglard.net/lightScattering/index.php
varying vec2 tc;
#ifdef VERTEX_SHADER
attribute vec2 v_texcoord;
void main ()
{
tc = v_texcoord;
gl_Position = vec4(v_position, 1.0);
}
#endif
#ifdef FRAGMENT_SHADER
const float crep_decay = 0.94;
const float crep_density = 0.5;
const float crep_weight = 0.2;
uniform vec3 l_lightcolour;
uniform vec3 l_lightscreen;
const int NUM_SAMPLES = 100;
void main()
{
vec2 deltaTextCoord = vec2(tc.st - l_lightscreen.xy);
vec2 textCoo = tc.st;
deltaTextCoord *= 1.0 / float(NUM_SAMPLES) * crep_density;
float illuminationDecay = 1.0;
gl_FragColor = vec4(0.0,0.0,0.0,0.0);
for(int i=0; i < NUM_SAMPLES ; i++)
{
textCoo -= deltaTextCoord;
vec4 sample = texture2D(s_t0, textCoo);
sample *= illuminationDecay * crep_weight;
gl_FragColor += sample;
illuminationDecay *= crep_decay;
}
gl_FragColor *= vec4(l_lightcolour, 1.0);
}
#endif