Pass the queried position as an argument to get_shadow_factor

[libs/gl.git] / shaderlib / shadow.glsl

diff --git a/shaderlib/shadow.glsl b/shaderlib/shadow.glsl
index 6f4acd2786a6319c242d9ff8300a00ecc535d0a7..52cd7c13ab767a4cb07b24e11b4be7bb1c898df4 100644 (file)
--- a/shaderlib/shadow.glsl
+++ b/shaderlib/shadow.glsl
@@ -1,20 +1,37 @@
 import msp_interface;
 
-layout(constant_id=auto) const bool use_shadow_map = false;
+struct ShadowParameters
+{
+       int enabled;
+       float darkness;
+       mat4 shd_world_matrix;
+       vec4 region;
+};
 
-#pragma MSP stage(vertex)
-void shadow_transform(vec4 eye_vertex)
+uniform ShadowMap
 {
-       out vec3 shadow_coord = (shd_eye_matrix*eye_vertex).xyz;
-}
+       ShadowParameters shadows[max_lights];
+};
+
+uniform sampler2DShadow shadow_map;
+
+layout(constant_id=auto) const bool use_shadow_map = false;
 
 #pragma MSP stage(fragment)
-virtual float get_shadow_factor(int index)
+virtual float get_shadow_factor(int index, vec4 world_pos)
 {
        if(use_shadow_map)
        {
-               float shadow_sample = texture(shadow_map, shadow_coord);
-               return mix(1.0, shadow_sample, shadow_darkness);
+               if(shadows[index].enabled==0)
+                       return 1.0;
+
+               vec3 shadow_coord = (shadows[index].shd_world_matrix*world_pos).xyz;
+               if(shadow_coord.x<0 || shadow_coord.x>1 || shadow_coord.y<0 || shadow_coord.y>1)
+                       return 1.0;
+
+               vec4 region = shadows[index].region;
+               float shadow_sample = texture(shadow_map, shadow_coord*vec3(region.zw, 1.0)+vec3(region.xy, 0.0));
+               return mix(1.0, shadow_sample, shadows[index].darkness);
        }
        else
                return 1.0;