Implement alpha cutoff for materials

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

diff --git a/shaderlib/phong.glsl b/shaderlib/phong.glsl
index 080c904895668f1e985a893ef959fb467ee0a91d..234897116183a4997c625687447b65172ef8036d 100644 (file)
--- a/shaderlib/phong.glsl
+++ b/shaderlib/phong.glsl
@@ -14,6 +14,7 @@ struct BasicMaterialParameters
 uniform BasicMaterial
 {
        BasicMaterialParameters basic_material;
+       float alpha_cutoff;
 };
 
 uniform sampler2D diffuse_map;
@@ -30,6 +31,7 @@ layout(constant_id=auto) const bool use_emission = false;
 layout(constant_id=auto) const bool use_emission_map = false;
 layout(constant_id=auto) const bool use_reflectivity = false;
 layout(constant_id=auto) const bool use_reflectivity_map = false;
+layout(constant_id=auto) const bool use_alpha_cutoff = false;
 
 #pragma MSP stage(fragment)
 virtual vec4 get_diffuse_color()
@@ -112,10 +114,13 @@ vec3 phong_lighting(vec3 normal, vec3 look, vec3 surface_diffuse, vec3 surface_s
 
 void main()
 {
+       vec4 surface_diffuse = get_diffuse_color();
+       if(use_alpha_cutoff && surface_diffuse.a<alpha_cutoff)
+               discard;
+
        vec3 normal = get_fragment_normal();
        vec3 look = normalize(world_look_dir);
 
-       vec4 surface_diffuse = get_diffuse_color();
        vec3 surface_specular = get_specular_color();
        float shininess = get_shininess_value();