Add support for alpha to coverage

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

diff --git a/shaderlib/common.glsl b/shaderlib/common.glsl
index 44ef150acc314c746041ba1c74e5338c287e190f..695bce3b5da4ca0d8b06c5785a8bcea6f2c1da3a 100644 (file)
--- a/shaderlib/common.glsl
+++ b/shaderlib/common.glsl
@@ -1,16 +1,17 @@
 import msp_interface;
 import shadow;
 
-layout(set=0) uniform EnvMap
+struct AlphaCutoffParams
 {
-       mat3 env_world_matrix;
+       float cutoff;
+       float feather;
 };
 
 layout(set=1) uniform sampler2D normal_map;
-layout(set=0) uniform samplerCube environment_map;
-layout(set=0) uniform samplerCube irradiance_map;
 
+layout(constant_id=auto) const bool use_instancing = false;
 layout(constant_id=auto) const bool use_normal_map = false;
+layout(constant_id=auto) const bool use_alpha_cutoff = false;
 
 #pragma MSP stage(vertex)
 virtual vec4 get_vertex_position()
@@ -25,12 +26,18 @@ virtual vec3 get_vertex_normal()
 
 virtual mat4 get_vertex_transform()
 {
-       return world_obj_matrix;
+       if(use_instancing)
+               return transpose(mat4(instance_transform[0], instance_transform[1], instance_transform[2], vec4(0.0, 0.0, 0.0, 1.0)));
+       else
+               return world_obj_matrix;
 }
 
 virtual mat3 get_normal_transform()
 {
-       return world_obj_normal_matrix;
+       if(use_instancing)
+               return transpose(mat3(instance_transform[0].xyz, instance_transform[1].xyz, instance_transform[2].xyz));
+       else
+               return world_obj_normal_matrix;
 }
 
 void standard_transform()
@@ -95,21 +102,17 @@ virtual IncomingLight get_incoming_light(int index, vec3 world_pos)
        return IncomingLight(rel_pos/d, light_sources[index].color*attenuation);
 }
 
-virtual vec3 get_environment_sample(vec3 direction, float roughness)
-{
-       float lod = (2-roughness)*roughness*(textureQueryLevels(environment_map)-1);
-       return textureLod(environment_map, env_world_matrix*direction, lod).rgb;
-}
-
-virtual vec3 get_reflection(vec3 normal, vec3 look)
+float apply_alpha_cutoff(float alpha, AlphaCutoffParams params)
 {
-       vec3 reflect_dir = reflect(look, normal);
-       return get_environment_sample(reflect_dir, 0.0);
-}
-
-virtual vec3 get_irradiance_sample(vec3 normal)
-{
-       return texture(irradiance_map, env_world_matrix*normal).rgb;
+       if(use_alpha_cutoff)
+       {
+               if(alpha<params.cutoff)
+                       discard;
+               float limit = min(params.cutoff+params.feather*fwidth(alpha), 1.0);
+               return smoothstep(params.cutoff, limit, alpha);
+       }
+       else
+               return alpha;
 }
 
 vec3 apply_fog(vec3 color)