Flip normal if a surface faces away from the camera

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

diff --git a/shaderlib/common.glsl b/shaderlib/common.glsl
index 5c10d06fbcac31a5fd9c06f5e37293ea406c2203..557d4d76a17cff24ef538946d8d95e531d5c099d 100644 (file)
--- a/shaderlib/common.glsl
+++ b/shaderlib/common.glsl
@@ -1,59 +1,62 @@
 import msp_interface;
 import shadow;
 
+uniform EnvMap
+{
+       mat3 env_world_matrix;
+};
+
+uniform sampler2D normal_map;
+uniform samplerCube environment_map;
+uniform samplerCube irradiance_map;
+
 layout(constant_id=auto) const bool use_normal_map = false;
 
 #pragma MSP stage(vertex)
-vec4 get_vertex_position()
+virtual vec4 get_vertex_position()
 {
        return vertex;
 }
 
-vec3 get_vertex_normal()
+virtual vec3 get_vertex_normal()
 {
        return normal;
 }
 
-vec4 transform_position(vec4 pos)
+virtual mat4 get_vertex_transform()
 {
-       return eye_obj_matrix*pos;
+       return world_obj_matrix;
 }
 
-vec3 transform_normal(vec3 nor)
+virtual mat3 get_normal_transform()
 {
-       return eye_obj_normal_matrix*nor;
+       return world_obj_normal_matrix;
 }
 
 void standard_transform()
 {
-       out vec4 eye_vertex = transform_position(get_vertex_position());
-       gl_Position = projection_matrix*eye_vertex;
-
-       out vec3 eye_normal = transform_normal(get_vertex_normal());
-       vec3 eye_tangent = transform_normal(tangent);
-       vec3 eye_binormal = transform_normal(binormal);
-       out mat3 eye_tbn_matrix = mat3(eye_tangent, eye_binormal, eye_normal);
+       mat4 vertex_tf = get_vertex_transform();
+       mat3 normal_tf = get_normal_transform();
 
-       out vec3 eye_look_dir = normalize(eye_vertex.xyz);
-       out vec3 tbn_look_dir = eye_look_dir*eye_tbn_matrix;
+       out vec4 world_vertex = vertex_tf*get_vertex_position();
+       vec4 eye_vertex = eye_world_matrix*world_vertex;
+       gl_Position = clip_eye_matrix*eye_vertex;
 
-       out vec3 eye_light_dir = normalize(light_sources[0].position.xyz-eye_vertex.xyz*light_sources[0].position.w);
-       out vec3 tbn_light_dir = eye_light_dir*eye_tbn_matrix;
+       out vec3 world_normal = normalize(normal_tf*get_vertex_normal());
+       if(use_normal_map)
+       {
+               vec3 world_tangent = normalize(normal_tf*tangent);
+               vec3 world_binormal = normalize(cross(world_normal, world_tangent));
+               out mat3 world_tbn_matrix = mat3(world_tangent, world_binormal, world_normal);
+       }
 
-       out vec3 eye_halfway_dir = normalize(eye_light_dir-eye_look_dir);
-       out vec3 tbn_halfway_dir = eye_halfway_dir*eye_tbn_matrix;
+       vec3 eye_pos = world_eye_matrix[3].xyz;
+       out vec3 world_look_dir = normalize(world_vertex.xyz-eye_pos);
 
-       out vec3 tbn_zenith_dir = eye_zenith_dir*eye_tbn_matrix;
-       out vec3 shadow_coord = (shd_eye_matrix*eye_vertex).xyz;
        out float fog_coord = eye_vertex.z;
-
-       for(int i=0; i<max_clip_planes; ++i)
-               gl_ClipDistance[i] = dot(eye_vertex, clip_planes[i].equation);
-
-       shadow_transform(eye_vertex);
 }
 
-void custom_transform()
+virtual void custom_transform()
 {
 }
 
@@ -65,30 +68,52 @@ void main()
 }
 
 #pragma MSP stage(fragment)
-vec3 get_fragment_normal()
+struct IncomingLight
+{
+       vec3 direction;
+       vec3 color;
+};
+
+layout(location=0) out vec4 frag_color;
+
+virtual vec3 get_fragment_normal()
 {
+       vec3 normal;
+       float sgn = (gl_FrontFacing ? 1.0 : -1.0);
        if(use_normal_map)
-               return normalize(texture(normal_map, texcoord.xy).xyz*2.0-1.0);
+               return sgn*normalize(world_tbn_matrix*(texture(normal_map, texcoord.xy).xyz*2.0-1.0));
        else
-               return vec3(0.0, 0.0, 1.0);
+               return sgn*normalize(world_normal);
+}
+
+virtual IncomingLight get_incoming_light(int index, vec3 world_pos)
+{
+       vec4 light_pos = light_sources[index].position;
+       vec3 rel_pos = light_pos.xyz-world_pos*light_pos.w;
+       float d = length(rel_pos);
+       float attenuation = 1.0/dot(vec3(1.0, d, d*d), light_sources[index].attenuation);
+       return IncomingLight(rel_pos/d, light_sources[index].color*attenuation);
 }
 
-vec4 get_environment_sample(vec3 direction)
+virtual vec3 get_environment_sample(vec3 direction, float roughness)
 {
-       return texture(environment_map, direction);
+       float lod = (2-roughness)*roughness*(textureQueryLevels(environment_map)-1);
+       return textureLod(environment_map, env_world_matrix*direction, lod).rgb;
 }
 
-vec3 get_reflection(vec3 normal, vec3 look)
+virtual vec3 get_reflection(vec3 normal, vec3 look)
 {
        vec3 reflect_dir = reflect(look, normal);
-       if(use_normal_map)
-               reflect_dir = eye_tbn_matrix*reflect_dir;
+       return get_environment_sample(reflect_dir, 0.0);
+}
 
-       return get_environment_sample(env_eye_matrix*reflect_dir).rgb;
+virtual vec3 get_irradiance_sample(vec3 normal)
+{
+       return texture(irradiance_map, env_world_matrix*normal).rgb;
 }
 
 vec3 apply_fog(vec3 color)
 {
        float fog_value = exp(fog_coord*fog_density);
-       return mix(fog_color, color, fog_value);
+       return mix(fog_color.rgb, color, fog_value);
 }