shaderlib/shadow.glsl

   1 import lighting;
   2
   3 struct ShadowParameters
   4 {
   5         int type;
   6         float darkness;
   7         int matrix_index;
   8         vec4 region;
   9         vec2 bias;
  10 };
  11
  12 layout(set=0) uniform ShadowMap
  13 {
  14         ShadowParameters shadows[max_lights];
  15         mat4 shd_world_matrix[max_lights*4];
  16 };
  17
  18 layout(set=0) uniform sampler2DShadow shadow_map;
  19
  20 layout(constant_id=auto) const bool use_shadow_map = false;
  21
  22 #pragma MSP stage(fragment)
  23 virtual float get_shadow_factor(int index, vec4 world_pos)
  24 {
  25         if(use_shadow_map)
  26         {
  27                 int type = shadows[index].type;
  28                 vec3 shadow_coord;
  29                 if(type==1)
  30                 {
  31                         shadow_coord = (shd_world_matrix[shadows[index].matrix_index]*world_pos).xyz;
  32                         shadow_coord.z -= shadows[index].bias.x;
  33                 }
  34                 else if(type==2)
  35                 {
  36                         int base = shadows[index].matrix_index;
  37                         vec4 clip_coord = shd_world_matrix[base]*world_pos;
  38                         for(int i=1; i<4; ++i)
  39                         {
  40                                 vec4 c = shd_world_matrix[base+i]*world_pos;
  41                                 if(c.w>clip_coord.w)
  42                                         clip_coord = c;
  43                         }
  44                         shadow_coord = clip_coord.xyz/clip_coord.w;
  45                         vec2 bias = shadows[index].bias;
  46                         shadow_coord.z = (shadow_coord.z+bias.x)/bias.y-bias.x;
  47                 }
  48                 else
  49                         return 1.0;
  50
  51                 if(shadow_coord.x<0 || shadow_coord.x>1 || shadow_coord.y<0 || shadow_coord.y>1)
  52                         return 1.0;
  53
  54                 vec4 region = shadows[index].region;
  55                 float shadow_sample = texture(shadow_map, vec3(shadow_coord.xy*region.zw+region.xy, min(shadow_coord.z, 1.0)));
  56                 return mix(1.0, shadow_sample, shadows[index].darkness);
  57         }
  58         else
  59                 return 1.0;
  60 }