Move lighting calculations to world space

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

diff --git a/shaderlib/cooktorrance.glsl b/shaderlib/cooktorrance.glsl
index e23f12190b5f77da6a425842a15986a44801b876..8e95752f7d6dc71b6e8e8fcc942ff2b3da518743 100644 (file)
--- a/shaderlib/cooktorrance.glsl
+++ b/shaderlib/cooktorrance.glsl
@@ -2,17 +2,36 @@ import msp_interface;
 import common;
 import shadow;
 
-const bool use_base_color_map = false;
-const bool use_metalness_map = false;
-const bool use_roughness_map = false;
-const bool use_occlusion_map = false;
-const bool use_emission = false;
-const bool use_emission_map = false;
+struct PbrMaterialParameters
+{
+       vec4 base_color;
+       vec4 emission;
+       float metalness;
+       float roughness;
+};
+
+uniform PbrMaterial
+{
+       PbrMaterialParameters pbr_material;
+};
+
+uniform sampler2D base_color_map;
+uniform sampler2D metalness_map;
+uniform sampler2D roughness_map;
+uniform sampler2D occlusion_map;
+uniform sampler2D emission_map;
+
+layout(constant_id=auto) const bool use_base_color_map = false;
+layout(constant_id=auto) const bool use_metalness_map = false;
+layout(constant_id=auto) const bool use_roughness_map = false;
+layout(constant_id=auto) const bool use_occlusion_map = false;
+layout(constant_id=auto) const bool use_emission = false;
+layout(constant_id=auto) const bool use_emission_map = false;
 
 const float PI = 3.1415926535;
 
 #pragma MSP stage(fragment)
-vec4 get_base_color()
+virtual vec4 get_base_color()
 {
        if(use_base_color_map)
                return texture(base_color_map, texcoord.xy);
@@ -20,7 +39,7 @@ vec4 get_base_color()
                return pbr_material.base_color;
 }
 
-float get_metalness_value()
+virtual float get_metalness_value()
 {
        if(use_metalness_map)
                return texture(metalness_map, texcoord.xy).r;
@@ -28,7 +47,7 @@ float get_metalness_value()
                return pbr_material.metalness;
 }
 
-float get_roughness_value()
+virtual float get_roughness_value()
 {
        if(use_roughness_map)
                return texture(roughness_map, texcoord.xy).r;
@@ -36,7 +55,7 @@ float get_roughness_value()
                return pbr_material.roughness;
 }
 
-float get_occlusion_value()
+virtual float get_occlusion_value()
 {
        if(use_occlusion_map)
                return texture(occlusion_map, texcoord.xy).r;
@@ -44,7 +63,7 @@ float get_occlusion_value()
                return 1.0;
 }
 
-vec3 get_emission_color()
+virtual vec3 get_emission_color()
 {
        if(use_emission_map)
                return texture(emission_map, texcoord.xy).rgb;
@@ -64,13 +83,11 @@ vec3 lambert_diffuse(vec3 base_color)
 float normal_distribution_ggxtr(vec3 normal, vec3 halfway, float roughness)
 {
        float n_dot_h = max(dot(normal, halfway), 0.0);
-       //return n_dot_h;
        float rough_q = roughness * roughness;
        rough_q *= rough_q;
        float denom = n_dot_h*n_dot_h*(rough_q-1)+1;
-       //return (n_dot_h*n_dot_h-0.8)*5.0;
-       //return rough_q*10;
-       // Scale by pi to get a result per steradian, suitable for integration
+       /* Scale by pi to normalize the total area of the microfacets as projected
+       to the macrosurface */
        return rough_q/(PI*denom*denom);
 }
 
@@ -97,35 +114,29 @@ vec3 fresnel_schlick(vec3 halfway, vec3 look, vec3 base_color, float metalness)
 {
        // 0.04 is a decent approximation for dielectric base reflectivity
        vec3 f0 = mix(vec3(0.04), base_color, metalness);
-       return mix(f0, vec3(1.0), pow(1.0-dot(halfway, look), 5.0));
+       return mix(f0, vec3(1.0), pow(max(1.0-dot(halfway, look), 0.0), 5.0));
 }
 
 /* Computes the full contribution of a single light */
 vec3 cooktorrance_one_light_direct(vec3 normal, vec3 look, vec3 light, vec3 light_color, vec3 base_color, float metalness, float roughness)
 {
        vec3 halfway = normalize(light-look);
-       //return normal;
        float ndist = normal_distribution_ggxtr(normal, halfway, roughness);
        float geom = geometry_smith(normal, -look, light, roughness);
-       //return vec3(ndist);
 
        vec3 k_spec = fresnel_schlick(halfway, light, base_color, metalness);
        vec3 k_diff = (1.0-k_spec)*(1.0-metalness);
 
-       float denom = max(4.0*max(dot(normal, -look), 0.0)*max(dot(normal, light), 0.0), 0.001);
-       return max(dot(normal, light), 0.0)*(k_diff*lambert_diffuse(base_color)+k_spec*ndist*geom/denom);
+       float spec_denom = max(4.0*max(dot(normal, -look), 0.0)*max(dot(normal, light), 0.0), 0.001);
+       return max(dot(normal, light), 0.0)*light_color*(k_diff*lambert_diffuse(base_color)+k_spec*ndist*geom/spec_denom);
 }
 
 vec3 cooktorrance_lighting(vec3 normal, vec3 look, vec3 base_color, float metalness, float roughness)
 {
-       vec3 light;
-       if(use_normal_map)
-               light = normalize(tbn_light_dir);
-       else
-               light = normalize(eye_light_dir);
+       vec3 light = normalize(world_light_dir);
 
        float shadow = get_shadow_factor(0);
-       vec3 color = cooktorrance_one_light_direct(normal, look, light, light_sources[0].diffuse.rgb, base_color, metalness, roughness)*shadow;
+       vec3 color = cooktorrance_one_light_direct(normal, look, light, light_sources[0].color, base_color, metalness, roughness)*shadow;
 
        color *= get_occlusion_value();
 
@@ -137,18 +148,8 @@ vec3 cooktorrance_lighting(vec3 normal, vec3 look, vec3 base_color, float metaln
 
 void main()
 {
-       vec3 normal;
-       vec3 look;
-       if(use_normal_map)
-       {
-               normal = get_fragment_normal();
-               look = normalize(tbn_look_dir);
-       }
-       else
-       {
-               normal = normalize(eye_normal);
-               look = normalize(eye_look_dir);
-       }
+       vec3 normal = get_fragment_normal();
+       vec3 look = normalize(world_look_dir);
 
        vec4 base_color = get_base_color();
        float metalness = get_metalness_value();