builtin_data/_ambientocclusion_occlude.glsl

   1 import flat_effect;
   2 import _ambientocclusion;
   3
   4 #pragma MSP stage(fragment)
   5 layout(location=0) out float frag_out;
   6 void main()
   7 {
   8         vec3 tex_scale = vec3(1.0/vec2(textureSize(depth, 0)), 0.0);
   9
  10         vec3 center = get_fragment_position(texcoord);
  11         vec3 left = get_fragment_position(texcoord-tex_scale.xz);
  12         vec3 right = get_fragment_position(texcoord+tex_scale.xz);
  13         vec3 bottom = get_fragment_position(texcoord-tex_scale.zy);
  14         vec3 top = get_fragment_position(texcoord+tex_scale.zy);
  15
  16         vec3 normal = normalize(cross(get_slope(left, center, right), get_slope(bottom, center, top)));
  17         vec3 tangent = (abs(normal.x)>abs(normal.y) ? vec3(-normal.z, 0.0, normal.x) : vec3(0.0, -normal.z, normal.y));
  18         vec3 binormal = cross(normal, tangent);
  19
  20         vec4 rv = texture(rotate, gl_FragCoord.xy/4.0)*2.0-1.0;
  21         mat3 transform = mat3(tangent, binormal, normal)*mat3(rv.xy, 0.0, rv.zx, 0.0, 0.0, 0.0, 1.0)*occlusion_radius;
  22
  23         float min_depth = project(vec3(center.xy, center.z+occlusion_radius)).z;
  24         float occlusion_sum = 0.0;
  25         float count = 0.0;
  26         for(int i=0; i<n_samples; ++i)
  27         {
  28                 vec3 psp = project(center+transform*sample_points[i]);
  29                 float sample_depth = texture(depth, psp.xy*0.5+0.5).r;
  30                 if(sample_depth>=min_depth)
  31                 {
  32                         if(sample_depth<psp.z)
  33                                 occlusion_sum += 1.0;
  34                         count += 1.0;
  35                 }
  36         }
  37         frag_out = 1.0-occlusion_sum/count;
  38 }