| Brian | edf24e6 | 2007-02-03 11:36:16 -0700 | [diff] [blame] | 1 | // Fragment shader for 2D texture with shadow attenuation |
| 2 | // Brian Paul |
| 3 | |
| 4 | |
| 5 | uniform sampler2D tex2d; |
| 6 | uniform vec3 lightPos; |
| 7 | |
| 8 | void main() |
| 9 | { |
| 10 | // XXX should compute this from lightPos |
| 11 | vec2 shadowCenter = vec2(-0.25, -0.25); |
| 12 | |
| 13 | // d = distance from center |
| 14 | float d = distance(gl_TexCoord[0].xy, shadowCenter); |
| 15 | |
| 16 | // attenuate and clamp |
| 17 | d = clamp(d * d * d, 0.0, 2.0); |
| 18 | |
| 19 | // modulate texture by d for shadow effect |
| 20 | gl_FragColor = d * texture2D(tex2d, gl_TexCoord[0].xy, 0.0); |
| 21 | } |