Examples/Advanced/DeferredShading/DSPointLight.fp.glsl

   1 #version 120
   2
   3 #extension GL_ARB_texture_rectangle : require
   4 #extension GL_ARB_texture_rectangle : enable
   5
   6 // compute point light INDEX for fragment at POS with normal NORM
   7 // and diffuse material color MDIFF
   8 vec4 computePointLight(int index, vec3 pos, vec3 norm, vec4 mDiff)
   9 {
  10     vec4  color      = vec4(0., 0., 0., 0.);
  11
  12     vec3  lightDirUN = gl_LightSource[index].position.xyz - pos;
  13     vec3  lightDir   = normalize(lightDirUN);
  14     float NdotL      = max(dot(norm, lightDir), 0.);
  15
  16     if(NdotL > 0.)
  17     {
  18         float lightDist = length   (lightDirUN);
  19         float distAtt   = dot(vec3(gl_LightSource[index].constantAttenuation,
  20                                    gl_LightSource[index].linearAttenuation,
  21                                    gl_LightSource[index].quadraticAttenuation),
  22                               vec3(1., lightDist, lightDist * lightDist));
  23         distAtt = 1. / distAtt;
  24
  25         color = distAtt * NdotL * mDiff * gl_LightSource[index].diffuse;
  26     }
  27
  28     return color;
  29 }
  30
  31 // DS input buffers
  32 uniform sampler2DRect texBufPos;
  33 uniform sampler2DRect texBufNorm;
  34 uniform sampler2DRect texBufDiff;
  35 uniform vec2          vpOffset;
  36
  37 // DS pass
  38 void main(void)
  39 {
  40     vec2 lookup = gl_FragCoord.xy - vpOffset;
  41     vec3 norm   = texture2DRect(texBufNorm, lookup).xyz;
  42
  43     if(dot(norm, norm) < 0.95)
  44     {
  45         discard;
  46     }
  47     else
  48     {
  49         vec4  posAmb = texture2DRect(texBufPos,  lookup);
  50         vec3  pos    = posAmb.xyz;
  51         float amb    = posAmb.w;
  52         vec4  mDiff  = texture2DRect(texBufDiff, lookup);
  53
  54         gl_FragColor = computePointLight(0, pos, norm, mDiff);
  55     }
  56 }