PBR Shader fix to code standard.

src/6.pbr/1.1.lighting/1.1.pbr.fs

@@ -3,7 +3,6 @@ out vec4 FragColor;
 in vec2 TexCoords;
 in vec3 WorldPos;
 in vec3 Normal;
-in mat3 TBN;
 
 // material parameters
 uniform vec3 albedo;
@@ -66,7 +65,7 @@ void main()
     vec3 V = normalize(camPos - WorldPos);
 
     // calculate reflectance at normal incidence; if dia-electric (like plastic) use F0 
-    // of 0.04 and if it's a metal, use their albedo color as F0 (metallic workflow)    
+    // of 0.04 and if it's a metal, use the albedo color as F0 (metallic workflow)    
     vec3 F0 = vec3(0.04); 
     F0 = mix(F0, albedo, metallic);
 
@@ -120,4 +119,4 @@ void main()
     color = pow(color, vec3(1.0/2.2)); 
 
     FragColor = vec4(color, 1.0);
-}
+}

src/6.pbr/1.1.lighting/1.1.pbr.vs

@@ -1,7 +1,7 @@
 #version 330 core
-layout (location = 0) in vec3 pos;
-layout (location = 1) in vec2 texCoords;
-layout (location = 2) in vec3 normal;
+layout (location = 0) in vec3 aPos;
+layout (location = 1) in vec2 aTexCoords;
+layout (location = 2) in vec3 aNormal;
 
 out vec2 TexCoords;
 out vec3 WorldPos;
@@ -13,9 +13,9 @@ uniform mat4 model;
 
 void main()
 {
-    TexCoords = texCoords;
-    WorldPos = vec3(model * vec4(pos, 1.0f));
-    Normal = mat3(model) * normal;
+    TexCoords = aTexCoords;
+    WorldPos = vec3(model * vec4(aPos, 1.0f));
+    Normal = mat3(model) * aNormal;   
 
     gl_Position =  projection * view * vec4(WorldPos, 1.0);
 }

src/6.pbr/1.2.lighting_textured/1.2.pbr.fs

@@ -3,7 +3,6 @@ out vec4 FragColor;
 in vec2 TexCoords;
 in vec3 WorldPos;
 in vec3 Normal;
-in mat3 TBN;
 
 // material parameters
 uniform sampler2D albedoMap;
@@ -93,7 +92,7 @@ void main()
     vec3 V = normalize(camPos - WorldPos);
 
     // calculate reflectance at normal incidence; if dia-electric (like plastic) use F0 
-    // of 0.04 and if it's a metal, use their albedo color as F0 (metallic workflow)    
+    // of 0.04 and if it's a metal, use the albedo color as F0 (metallic workflow)    
     vec3 F0 = vec3(0.04); 
     F0 = mix(F0, albedo, metallic);
 
@@ -147,4 +146,4 @@ void main()
     color = pow(color, vec3(1.0/2.2)); 
 
     FragColor = vec4(color, 1.0);
-}
+}

src/6.pbr/1.2.lighting_textured/1.2.pbr.vs

@@ -1,7 +1,7 @@
 #version 330 core
-layout (location = 0) in vec3 pos;
-layout (location = 1) in vec2 texCoords;
-layout (location = 2) in vec3 normal;
+layout (location = 0) in vec3 aPos;
+layout (location = 1) in vec2 aTexCoords;
+layout (location = 2) in vec3 aNormal;
 
 out vec2 TexCoords;
 out vec3 WorldPos;
@@ -13,9 +13,9 @@ uniform mat4 model;
 
 void main()
 {
-    TexCoords = texCoords;
-    WorldPos = vec3(model * vec4(pos, 1.0f));
-    Normal = mat3(model) * normal;   
+    TexCoords = aTexCoords;
+    WorldPos = vec3(model * vec4(aPos, 1.0f));
+    Normal = mat3(model) * aNormal;   
 
     gl_Position =  projection * view * vec4(WorldPos, 1.0);
 }

src/6.pbr/2.1.1.ibl_irradiance_conversion/2.1.1.background.vs

@@ -1,5 +1,5 @@
 #version 330 core
-layout (location = 0) in vec3 pos;
+layout (location = 0) in vec3 aPos;
 
 uniform mat4 projection;
 uniform mat4 view;
@@ -8,7 +8,7 @@ out vec3 WorldPos;
 
 void main()
 {
-    WorldPos = pos;
+    WorldPos = aPos;
 
 	mat4 rotView = mat4(mat3(view));
 	vec4 clipPos = projection * rotView * vec4(WorldPos, 1.0);

src/6.pbr/2.1.1.ibl_irradiance_conversion/2.1.1.cubemap.vs

@@ -1,5 +1,5 @@
 #version 330 core
-layout (location = 0) in vec3 pos;
+layout (location = 0) in vec3 aPos;
 
 out vec3 WorldPos;
 
@@ -8,7 +8,7 @@ uniform mat4 view;
 
 void main()
 {
-    WorldPos = pos;  
+    WorldPos = aPos;  
 
     gl_Position =  projection * view * vec4(WorldPos, 1.0);
 }

src/6.pbr/2.1.1.ibl_irradiance_conversion/2.1.1.pbr.fs

@@ -3,7 +3,6 @@ out vec4 FragColor;
 in vec2 TexCoords;
 in vec3 WorldPos;
 in vec3 Normal;
-in mat3 TBN;
 
 // material parameters
 uniform vec3 albedo;
@@ -71,7 +70,7 @@ void main()
     vec3 R = reflect(-V, N); 
 
     // calculate reflectance at normal incidence; if dia-electric (like plastic) use F0 
-    // of 0.04 and if it's a metal, use their albedo color as F0 (metallic workflow)    
+    // of 0.04 and if it's a metal, use the albedo color as F0 (metallic workflow)    
     vec3 F0 = vec3(0.04); 
     F0 = mix(F0, albedo, metallic);
 

src/6.pbr/2.1.1.ibl_irradiance_conversion/2.1.1.pbr.vs

@@ -1,7 +1,7 @@
 #version 330 core
-layout (location = 0) in vec3 pos;
-layout (location = 1) in vec2 texCoords;
-layout (location = 2) in vec3 normal;
+layout (location = 0) in vec3 aPos;
+layout (location = 1) in vec2 aTexCoords;
+layout (location = 2) in vec3 aNormal;
 
 out vec2 TexCoords;
 out vec3 WorldPos;
@@ -13,9 +13,9 @@ uniform mat4 model;
 
 void main()
 {
-    TexCoords = texCoords;
-    WorldPos = vec3(model * vec4(pos, 1.0f));
-    Normal = mat3(model) * normal;   
+    TexCoords = aTexCoords;
+    WorldPos = vec3(model * vec4(aPos, 1.0f));
+    Normal = mat3(model) * aNormal;   
 
     gl_Position =  projection * view * vec4(WorldPos, 1.0);
 }

src/6.pbr/2.1.1.ibl_irradiance_conversion/ibl_irradiance_conversion.cpp

@@ -75,9 +75,9 @@ int main()
 
     // build and compile shaders
     // -------------------------
-    Shader pbrShader("2.1.1.pbr.vs", "2.1.1.pbr.frag");
-    Shader equirectangularToCubemapShader("2.1.1.cubemap.vs", "2.1.1.equirectangular_to_cubemap.frag");
-    Shader backgroundShader("2.1.1.background.vs", "2.1.1.background.frag");
+    Shader pbrShader("2.1.1.pbr.vs", "2.1.1.pbr.fs");
+    Shader equirectangularToCubemapShader("2.1.1.cubemap.vs", "2.1.1.equirectangular_to_cubemap.fs");
+    Shader backgroundShader("2.1.1.background.vs", "2.1.1.background.fs");
 
 
     pbrShader.use();

src/6.pbr/2.1.2.ibl_irradiance/2.1.2.background.vs

@@ -1,5 +1,5 @@
 #version 330 core
-layout (location = 0) in vec3 pos;
+layout (location = 0) in vec3 aPos;
 
 uniform mat4 projection;
 uniform mat4 view;
@@ -8,7 +8,7 @@ out vec3 WorldPos;
 
 void main()
 {
-    WorldPos = pos;
+    WorldPos = aPos;
 
 	mat4 rotView = mat4(mat3(view));
 	vec4 clipPos = projection * rotView * vec4(WorldPos, 1.0);

src/6.pbr/2.1.2.ibl_irradiance/2.1.2.cubemap.vs

@@ -1,5 +1,5 @@
 #version 330 core
-layout (location = 0) in vec3 pos;
+layout (location = 0) in vec3 aPos;
 
 out vec3 WorldPos;
 
@@ -8,7 +8,7 @@ uniform mat4 view;
 
 void main()
 {
-    WorldPos = pos;  
+    WorldPos = aPos;  
 
     gl_Position =  projection * view * vec4(WorldPos, 1.0);
 }

src/6.pbr/2.1.2.ibl_irradiance/2.1.2.irradiance_convolution.fs

@@ -4,11 +4,11 @@ in vec3 WorldPos;
 
 uniform samplerCube environmentMap;
 
-const float PI = 3.14159265359f;
+const float PI = 3.14159265359;
 
 void main()
 {		
-	// NOTE(Joey): the world vector acts as the normal of a tangent surface
+	// The world vector acts as the normal of a tangent surface
     // from the origin, aligned to WorldPos. Given this normal, calculate all
     // incoming radiance of the environment. The result of this radiance
     // is the radiance of light coming from -Normal direction, which is what
@@ -17,13 +17,13 @@ void main()
 
     vec3 irradiance = vec3(0.0);   
     
-    // NOTE(Joey): tangent space calculation from origin point
+    // tangent space calculation from origin point
     vec3 up    = vec3(0.0, 1.0, 0.0);
     vec3 right = cross(up, N);
     up            = cross(N, right);
        
-    float sampleDelta = 0.025f;
-    float nrSamples = 0.0f;
+    float sampleDelta = 0.025;
+    float nrSamples = 0.0;
     for(float phi = 0.0; phi < 2.0 * PI; phi += sampleDelta)
     {
         for(float theta = 0.0; theta < 0.5 * PI; theta += sampleDelta)

src/6.pbr/2.1.2.ibl_irradiance/2.1.2.pbr.fs

@@ -3,7 +3,6 @@ out vec4 FragColor;
 in vec2 TexCoords;
 in vec3 WorldPos;
 in vec3 Normal;
-in mat3 TBN;
 
 // material parameters
 uniform vec3 albedo;
@@ -69,7 +68,7 @@ void main()
     vec3 R = reflect(-V, N); 
 
     // calculate reflectance at normal incidence; if dia-electric (like plastic) use F0 
-    // of 0.04 and if it's a metal, use their albedo color as F0 (metallic workflow)    
+    // of 0.04 and if it's a metal, use the albedo color as F0 (metallic workflow)    
     vec3 F0 = vec3(0.04); 
     F0 = mix(F0, albedo, metallic);
 
@@ -128,4 +127,4 @@ void main()
     color = pow(color, vec3(1.0/2.2)); 
 
     FragColor = vec4(color , 1.0);
-}
+}

src/6.pbr/2.1.2.ibl_irradiance/2.1.2.pbr.vs

@@ -1,7 +1,7 @@
 #version 330 core
-layout (location = 0) in vec3 pos;
-layout (location = 1) in vec2 texCoords;
-layout (location = 2) in vec3 normal;
+layout (location = 0) in vec3 aPos;
+layout (location = 1) in vec2 aTexCoords;
+layout (location = 2) in vec3 aNormal;
 
 out vec2 TexCoords;
 out vec3 WorldPos;
@@ -13,9 +13,9 @@ uniform mat4 model;
 
 void main()
 {
-    TexCoords = texCoords;
-    WorldPos = vec3(model * vec4(pos, 1.0f));
-    Normal = mat3(model) * normal;   
+    TexCoords = aTexCoords;
+    WorldPos = vec3(model * vec4(aPos, 1.0f));
+    Normal = mat3(model) * aNormal;   
 
     gl_Position =  projection * view * vec4(WorldPos, 1.0);
 }

src/6.pbr/2.1.2.ibl_irradiance/ibl_irradiance.cpp

@@ -75,10 +75,10 @@ int main()
 
     // build and compile shaders
     // -------------------------
-    Shader pbrShader("2.1.2.pbr.vs", "2.1.2.pbr.frag");
-    Shader equirectangularToCubemapShader("2.1.2.cubemap.vs", "2.1.2.equirectangular_to_cubemap.frag");
-    Shader irradianceShader("2.1.2.cubemap.vs", "2.1.2.irradiance_convolution.frag");
-    Shader backgroundShader("2.1.2.background.vs", "2.1.2.background.frag");
+    Shader pbrShader("2.1.2.pbr.vs", "2.1.2.pbr.fs");
+    Shader equirectangularToCubemapShader("2.1.2.cubemap.vs", "2.1.2.equirectangular_to_cubemap.fs");
+    Shader irradianceShader("2.1.2.cubemap.vs", "2.1.2.irradiance_convolution.fs");
+    Shader backgroundShader("2.1.2.background.vs", "2.1.2.background.fs");
 
 
     pbrShader.use();

src/6.pbr/2.2.1.ibl_specular/2.2.1.background.vs

@@ -1,5 +1,5 @@
 #version 330 core
-layout (location = 0) in vec3 pos;
+layout (location = 0) in vec3 aPos;
 
 uniform mat4 projection;
 uniform mat4 view;
@@ -8,7 +8,7 @@ out vec3 WorldPos;
 
 void main()
 {
-    WorldPos = pos;
+    WorldPos = aPos;
 
 	mat4 rotView = mat4(mat3(view));
 	vec4 clipPos = projection * rotView * vec4(WorldPos, 1.0);

src/6.pbr/2.2.1.ibl_specular/2.2.1.brdf.fs

@@ -2,7 +2,7 @@
 out vec2 FragColor;
 in vec2 TexCoords;
 
-const float PI = 3.14159265359f;
+const float PI = 3.14159265359;
 // ----------------------------------------------------------------------------
 // http://holger.dammertz.org/stuff/notes_HammersleyOnHemisphere.html
 // efficient VanDerCorpus calculation.
@@ -29,13 +29,13 @@ vec3 ImportanceSampleGGX(vec2 Xi, vec3 N, float roughness)
 	float cosTheta = sqrt((1.0 - Xi.y) / (1.0 + (a*a - 1.0) * Xi.y));
 	float sinTheta = sqrt(1.0 - cosTheta*cosTheta);
 	
-	// NOTE(Joey): from spherical coordinates to cartesian coordinates - halfway vector
+	// from spherical coordinates to cartesian coordinates - halfway vector
 	vec3 H;
 	H.x = cos(phi) * sinTheta;
 	H.y = sin(phi) * sinTheta;
 	H.z = cosTheta;
 	
-	// NOTE(Joey): from tangent-space H vector to world-space sample vector
+	// from tangent-space H vector to world-space sample vector
 	vec3 up          = abs(N.z) < 0.999 ? vec3(0.0, 0.0, 1.0) : vec3(1.0, 0.0, 0.0);
 	vec3 tangent   = normalize(cross(up, N));
 	vec3 bitangent = cross(N, tangent);
@@ -81,7 +81,7 @@ vec2 IntegrateBRDF(float NdotV, float roughness)
     const uint SAMPLE_COUNT = 1024u;
     for(uint i = 0u; i < SAMPLE_COUNT; ++i)
     {
-        // NOTE(Joey): generates a sample vector that's biased towards the
+        // generates a sample vector that's biased towards the
         // preferred alignment direction (importance sampling).
         vec2 Xi = Hammersley(i, SAMPLE_COUNT);
         vec3 H = ImportanceSampleGGX(Xi, N, roughness);

src/6.pbr/2.2.1.ibl_specular/2.2.1.brdf.vs

@@ -1,11 +1,11 @@
 #version 330 core
-layout (location = 0) in vec3 pos;
-layout (location = 1) in vec2 texCoords;
+layout (location = 0) in vec3 aPos;
+layout (location = 1) in vec2 aTexCoords;
 
 out vec2 TexCoords;
 
 void main()
 {
-    TexCoords = texCoords;
-	gl_Position = vec4(pos, 1.0);
+    TexCoords = aTexCoords;
+	gl_Position = vec4(aPos, 1.0);
 }

src/6.pbr/2.2.1.ibl_specular/2.2.1.cubemap.vs

@@ -1,5 +1,5 @@
 #version 330 core
-layout (location = 0) in vec3 pos;
+layout (location = 0) in vec3 aPos;
 
 out vec3 WorldPos;
 
@@ -8,7 +8,7 @@ uniform mat4 view;
 
 void main()
 {
-    WorldPos = pos;  
+    WorldPos = aPos;  
 
     gl_Position =  projection * view * vec4(WorldPos, 1.0);
 }

src/6.pbr/2.2.1.ibl_specular/2.2.1.irradiance_convolution.fs

@@ -4,7 +4,7 @@ in vec3 WorldPos;
 
 uniform samplerCube environmentMap;
 
-const float PI = 3.14159265359f;
+const float PI = 3.14159265359;
 
 void main()
 {		
@@ -17,7 +17,7 @@ void main()
     vec3 right = cross(up, N);
     up            = cross(N, right);
        
-    float sampleDelta = 0.025f;
+    float sampleDelta = 0.025;
     float nrSamples = 0.0f;
     for(float phi = 0.0; phi < 2.0 * PI; phi += sampleDelta)
     {

src/6.pbr/2.2.1.ibl_specular/2.2.1.pbr.fs

@@ -3,7 +3,6 @@ out vec4 FragColor;
 in vec2 TexCoords;
 in vec3 WorldPos;
 in vec3 Normal;
-in mat3 TBN;
 
 // material parameters
 uniform vec3 albedo;
@@ -76,7 +75,7 @@ void main()
     vec3 R = reflect(-V, N); 
 
     // calculate reflectance at normal incidence; if dia-electric (like plastic) use F0 
-    // of 0.04 and if it's a metal, use their albedo color as F0 (metallic workflow)    
+    // of 0.04 and if it's a metal, use the albedo color as F0 (metallic workflow)    
     vec3 F0 = vec3(0.04); 
     F0 = mix(F0, albedo, metallic);
 

src/6.pbr/2.2.1.ibl_specular/2.2.1.pbr.vs

@@ -1,7 +1,7 @@
 #version 330 core
-layout (location = 0) in vec3 pos;
-layout (location = 1) in vec2 texCoords;
-layout (location = 2) in vec3 normal;
+layout (location = 0) in vec3 aPos;
+layout (location = 1) in vec2 aTexCoords;
+layout (location = 2) in vec3 aNormal;
 
 out vec2 TexCoords;
 out vec3 WorldPos;
@@ -13,9 +13,9 @@ uniform mat4 model;
 
 void main()
 {
-    TexCoords = texCoords;
-    WorldPos = vec3(model * vec4(pos, 1.0f));
-    Normal = mat3(model) * normal;   
+    TexCoords = aTexCoords;
+    WorldPos = vec3(model * vec4(aPos, 1.0f));
+    Normal = mat3(model) * aNormal;   
 
     gl_Position =  projection * view * vec4(WorldPos, 1.0);
 }

src/6.pbr/2.2.1.ibl_specular/2.2.1.prefilter.fs

@@ -5,7 +5,7 @@ in vec3 WorldPos;
 uniform samplerCube environmentMap;
 uniform float roughness;
 
-const float PI = 3.14159265359f;
+const float PI = 3.14159265359;
 // ----------------------------------------------------------------------------
 float DistributionGGX(vec3 N, vec3 H, float roughness)
 {

src/6.pbr/2.2.1.ibl_specular/ibl_specular.cpp

@@ -79,12 +79,12 @@ int main()
 
     // build and compile shaders
     // -------------------------
-    Shader pbrShader("2.2.1.pbr.vs", "2.2.1.pbr.frag");
-    Shader equirectangularToCubemapShader("2.2.1.cubemap.vs", "2.2.1.equirectangular_to_cubemap.frag");
-    Shader irradianceShader("2.2.1.cubemap.vs", "2.2.1.irradiance_convolution.frag");
-    Shader prefilterShader("2.2.1.cubemap.vs", "2.2.1.prefilter.frag");
-    Shader brdfShader("2.2.1.brdf.vs", "2.2.1.brdf.frag");
-    Shader backgroundShader("2.2.1.background.vs", "2.2.1.background.frag");
+    Shader pbrShader("2.2.1.pbr.vs", "2.2.1.pbr.fs");
+    Shader equirectangularToCubemapShader("2.2.1.cubemap.vs", "2.2.1.equirectangular_to_cubemap.fs");
+    Shader irradianceShader("2.2.1.cubemap.vs", "2.2.1.irradiance_convolution.fs");
+    Shader prefilterShader("2.2.1.cubemap.vs", "2.2.1.prefilter.fs");
+    Shader brdfShader("2.2.1.brdf.vs", "2.2.1.brdf.fs");
+    Shader backgroundShader("2.2.1.background.vs", "2.2.1.background.fs");
 
     pbrShader.use();
     pbrShader.setInt("irradianceMap", 0);

src/6.pbr/2.2.2.ibl_specular_textured/2.2.2.background.fs

@@ -0,0 +1,16 @@
+#version 330 core
+out vec4 FragColor;
+in vec3 WorldPos;
+
+uniform samplerCube environmentMap;
+
+void main()
+{		
+    vec3 envColor = textureLod(environmentMap, WorldPos, 0.0).rgb;
+    
+    // HDR tonemap and gamma correct
+    envColor = envColor / (envColor + vec3(1.0));
+    envColor = pow(envColor, vec3(1.0/2.2)); 
+    
+    FragColor = vec4(envColor, 1.0);
+}

src/6.pbr/2.2.2.ibl_specular_textured/2.2.2.background.vs

@@ -0,0 +1,17 @@
+#version 330 core
+layout (location = 0) in vec3 aPos;
+
+uniform mat4 projection;
+uniform mat4 view;
+
+out vec3 WorldPos;
+
+void main()
+{
+    WorldPos = aPos;
+
+	mat4 rotView = mat4(mat3(view));
+	vec4 clipPos = projection * rotView * vec4(WorldPos, 1.0);
+
+	gl_Position = clipPos.xyww;
+}

src/6.pbr/2.2.2.ibl_specular_textured/2.2.2.brdf.fs

@@ -0,0 +1,113 @@
+#version 330 core
+out vec2 FragColor;
+in vec2 TexCoords;
+
+const float PI = 3.14159265359;
+// ----------------------------------------------------------------------------
+// http://holger.dammertz.org/stuff/notes_HammersleyOnHemisphere.html
+// efficient VanDerCorpus calculation.
+float RadicalInverse_VdC(uint bits) 
+{
+     bits = (bits << 16u) | (bits >> 16u);
+     bits = ((bits & 0x55555555u) << 1u) | ((bits & 0xAAAAAAAAu) >> 1u);
+     bits = ((bits & 0x33333333u) << 2u) | ((bits & 0xCCCCCCCCu) >> 2u);
+     bits = ((bits & 0x0F0F0F0Fu) << 4u) | ((bits & 0xF0F0F0F0u) >> 4u);
+     bits = ((bits & 0x00FF00FFu) << 8u) | ((bits & 0xFF00FF00u) >> 8u);
+     return float(bits) * 2.3283064365386963e-10; // / 0x100000000
+}
+// ----------------------------------------------------------------------------
+vec2 Hammersley(uint i, uint N)
+{
+	return vec2(float(i)/float(N), RadicalInverse_VdC(i));
+}
+// ----------------------------------------------------------------------------
+vec3 ImportanceSampleGGX(vec2 Xi, vec3 N, float roughness)
+{
+	float a = roughness*roughness;
+	
+	float phi = 2.0 * PI * Xi.x;
+	float cosTheta = sqrt((1.0 - Xi.y) / (1.0 + (a*a - 1.0) * Xi.y));
+	float sinTheta = sqrt(1.0 - cosTheta*cosTheta);
+	
+	// from spherical coordinates to cartesian coordinates - halfway vector
+	vec3 H;
+	H.x = cos(phi) * sinTheta;
+	H.y = sin(phi) * sinTheta;
+	H.z = cosTheta;
+	
+	// from tangent-space H vector to world-space sample vector
+	vec3 up          = abs(N.z) < 0.999 ? vec3(0.0, 0.0, 1.0) : vec3(1.0, 0.0, 0.0);
+	vec3 tangent   = normalize(cross(up, N));
+	vec3 bitangent = cross(N, tangent);
+	
+	vec3 sampleVec = tangent * H.x + bitangent * H.y + N * H.z;
+	return normalize(sampleVec);
+}
+// ----------------------------------------------------------------------------
+float GeometrySchlickGGX(float NdotV, float roughness)
+{
+    // note that we use a different k for IBL
+    float a = roughness;
+    float k = (a * a) / 2.0;
+
+    float nom   = NdotV;
+    float denom = NdotV * (1.0 - k) + k;
+
+    return nom / denom;
+}
+// ----------------------------------------------------------------------------
+float GeometrySmith(vec3 N, vec3 V, vec3 L, float roughness)
+{
+    float NdotV = max(dot(N, V), 0.0);
+    float NdotL = max(dot(N, L), 0.0);
+    float ggx2 = GeometrySchlickGGX(NdotV, roughness);
+    float ggx1 = GeometrySchlickGGX(NdotL, roughness);
+
+    return ggx1 * ggx2;
+}
+// ----------------------------------------------------------------------------
+vec2 IntegrateBRDF(float NdotV, float roughness)
+{
+    vec3 V;
+    V.x = sqrt(1.0 - NdotV*NdotV);
+    V.y = 0.0;
+    V.z = NdotV;
+
+    float A = 0.0;
+    float B = 0.0; 
+
+    vec3 N = vec3(0.0, 0.0, 1.0);
+    
+    const uint SAMPLE_COUNT = 1024u;
+    for(uint i = 0u; i < SAMPLE_COUNT; ++i)
+    {
+        // generates a sample vector that's biased towards the
+        // preferred alignment direction (importance sampling).
+        vec2 Xi = Hammersley(i, SAMPLE_COUNT);
+        vec3 H = ImportanceSampleGGX(Xi, N, roughness);
+        vec3 L = normalize(2.0 * dot(V, H) * H - V);
+
+        float NdotL = max(L.z, 0.0);
+        float NdotH = max(H.z, 0.0);
+        float VdotH = max(dot(V, H), 0.0);
+
+        if(NdotL > 0.0)
+        {
+            float G = GeometrySmith(N, V, L, roughness);
+            float G_Vis = (G * VdotH) / (NdotH * NdotV);
+            float Fc = pow(1.0 - VdotH, 5.0);
+
+            A += (1.0 - Fc) * G_Vis;
+            B += Fc * G_Vis;
+        }
+    }
+    A /= float(SAMPLE_COUNT);
+    B /= float(SAMPLE_COUNT);
+    return vec2(A, B);
+}
+// ----------------------------------------------------------------------------
+void main() 
+{
+    vec2 integratedBRDF = IntegrateBRDF(TexCoords.x, TexCoords.y);
+    FragColor = integratedBRDF;
+}

src/6.pbr/2.2.2.ibl_specular_textured/2.2.2.brdf.vs

@@ -0,0 +1,11 @@
+#version 330 core
+layout (location = 0) in vec3 aPos;
+layout (location = 1) in vec2 aTexCoords;
+
+out vec2 TexCoords;
+
+void main()
+{
+    TexCoords = aTexCoords;
+	gl_Position = vec4(aPos, 1.0);
+}

src/6.pbr/2.2.2.ibl_specular_textured/2.2.2.cubemap.vs

@@ -0,0 +1,14 @@
+#version 330 core
+layout (location = 0) in vec3 aPos;
+
+out vec3 WorldPos;
+
+uniform mat4 projection;
+uniform mat4 view;
+
+void main()
+{
+    WorldPos = aPos;  
+
+    gl_Position =  projection * view * vec4(WorldPos, 1.0);
+}

src/6.pbr/2.2.2.ibl_specular_textured/2.2.2.equirectangular_to_cubemap.fs

@@ -0,0 +1,22 @@
+#version 330 core
+out vec4 FragColor;
+in vec3 WorldPos;
+
+uniform sampler2D equirectangularMap;
+
+const vec2 invAtan = vec2(0.1591, 0.3183);
+vec2 SampleSphericalMap(vec3 v)
+{
+    vec2 uv = vec2(atan(v.z, v.x), asin(v.y));
+    uv *= invAtan;
+    uv += 0.5;
+    return uv;
+}
+
+void main()
+{		
+    vec2 uv = SampleSphericalMap(normalize(WorldPos));
+    vec3 color = texture(equirectangularMap, uv).rgb;
+    
+    FragColor = vec4(color, 1.0);
+}

src/6.pbr/2.2.2.ibl_specular_textured/2.2.2.irradiance_convolution.fs

@@ -0,0 +1,38 @@
+#version 330 core
+out vec4 FragColor;
+in vec3 WorldPos;
+
+uniform samplerCube environmentMap;
+
+const float PI = 3.14159265359;
+
+void main()
+{		
+    vec3 N = normalize(WorldPos);
+
+    vec3 irradiance = vec3(0.0);   
+    
+    // tangent space calculation from origin point
+    vec3 up    = vec3(0.0, 1.0, 0.0);
+    vec3 right = cross(up, N);
+    up            = cross(N, right);
+       
+    float sampleDelta = 0.025;
+    float nrSamples = 0.0f;
+    for(float phi = 0.0; phi < 2.0 * PI; phi += sampleDelta)
+    {
+        for(float theta = 0.0; theta < 0.5 * PI; theta += sampleDelta)
+        {
+            // spherical to cartesian (in tangent space)
+            vec3 tangentSample = vec3(sin(theta) * cos(phi),  sin(theta) * sin(phi), cos(theta));
+            // tangent space to world
+            vec3 sampleVec = tangentSample.x * right + tangentSample.y * up + tangentSample.z * N; 
+
+            irradiance += texture(environmentMap, sampleVec).rgb * cos(theta) * sin(theta);
+            nrSamples++;
+        }
+    }
+    irradiance = PI * irradiance * (1.0 / float(nrSamples));
+    
+    FragColor = vec4(irradiance, 1.0);
+}

src/6.pbr/2.2.2.ibl_specular_textured/2.2.2.pbr.fs

@@ -3,7 +3,6 @@ out vec4 FragColor;
 in vec2 TexCoords;
 in vec3 WorldPos;
 in vec3 Normal;
-in mat3 TBN;
 
 // material parameters
 uniform sampler2D albedoMap;
@@ -98,15 +97,14 @@ void main()
     float metallic = texture(metallicMap, TexCoords).r;
     float roughness = texture(roughnessMap, TexCoords).r;
     float ao = texture(aoMap, TexCoords).r;
-    
-    
+       
     // input lighting data
     vec3 N = getNormalFromMap();
     vec3 V = normalize(camPos - WorldPos);
     vec3 R = reflect(-V, N); 
 
     // calculate reflectance at normal incidence; if dia-electric (like plastic) use F0 
-    // of 0.04 and if it's a metal, use their albedo color as F0 (metallic workflow)    
+    // of 0.04 and if it's a metal, use the albedo color as F0 (metallic workflow)    
     vec3 F0 = vec3(0.04); 
     F0 = mix(F0, albedo, metallic);
 

src/6.pbr/2.2.2.ibl_specular_textured/2.2.2.pbr.vs

@@ -1,7 +1,7 @@
 #version 330 core
-layout (location = 0) in vec3 pos;
-layout (location = 1) in vec2 texCoords;
-layout (location = 2) in vec3 normal;
+layout (location = 0) in vec3 aPos;
+layout (location = 1) in vec2 aTexCoords;
+layout (location = 2) in vec3 aNormal;
 
 out vec2 TexCoords;
 out vec3 WorldPos;
@@ -13,9 +13,9 @@ uniform mat4 model;
 
 void main()
 {
-    TexCoords = texCoords;
-    WorldPos = vec3(model * vec4(pos, 1.0f));
-    Normal = mat3(model) * normal;   
+    TexCoords = aTexCoords;
+    WorldPos = vec3(model * vec4(aPos, 1.0f));
+    Normal = mat3(model) * aNormal;   
 
     gl_Position =  projection * view * vec4(WorldPos, 1.0);
 }

src/6.pbr/2.2.2.ibl_specular_textured/2.2.2.prefilter.fs

@@ -0,0 +1,106 @@
+#version 330 core
+out vec4 FragColor;
+in vec3 WorldPos;
+
+uniform samplerCube environmentMap;
+uniform float roughness;
+
+const float PI = 3.14159265359;
+// ----------------------------------------------------------------------------
+float DistributionGGX(vec3 N, vec3 H, float roughness)
+{
+    float a = roughness*roughness;
+    float a2 = a*a;
+    float NdotH = max(dot(N, H), 0.0);
+    float NdotH2 = NdotH*NdotH;
+
+    float nom   = a2;
+    float denom = (NdotH2 * (a2 - 1.0) + 1.0);
+    denom = PI * denom * denom;
+
+    return nom / denom;
+}
+// ----------------------------------------------------------------------------
+// http://holger.dammertz.org/stuff/notes_HammersleyOnHemisphere.html
+// efficient VanDerCorpus calculation.
+float RadicalInverse_VdC(uint bits) 
+{
+     bits = (bits << 16u) | (bits >> 16u);
+     bits = ((bits & 0x55555555u) << 1u) | ((bits & 0xAAAAAAAAu) >> 1u);
+     bits = ((bits & 0x33333333u) << 2u) | ((bits & 0xCCCCCCCCu) >> 2u);
+     bits = ((bits & 0x0F0F0F0Fu) << 4u) | ((bits & 0xF0F0F0F0u) >> 4u);
+     bits = ((bits & 0x00FF00FFu) << 8u) | ((bits & 0xFF00FF00u) >> 8u);
+     return float(bits) * 2.3283064365386963e-10; // / 0x100000000
+}
+// ----------------------------------------------------------------------------
+vec2 Hammersley(uint i, uint N)
+{
+	return vec2(float(i)/float(N), RadicalInverse_VdC(i));
+}
+// ----------------------------------------------------------------------------
+vec3 ImportanceSampleGGX(vec2 Xi, vec3 N, float roughness)
+{
+	float a = roughness*roughness;
+	
+	float phi = 2.0 * PI * Xi.x;
+	float cosTheta = sqrt((1.0 - Xi.y) / (1.0 + (a*a - 1.0) * Xi.y));
+	float sinTheta = sqrt(1.0 - cosTheta*cosTheta);
+	
+	// from spherical coordinates to cartesian coordinates - halfway vector
+	vec3 H;
+	H.x = cos(phi) * sinTheta;
+	H.y = sin(phi) * sinTheta;
+	H.z = cosTheta;
+	
+	// from tangent-space H vector to world-space sample vector
+	vec3 up          = abs(N.z) < 0.999 ? vec3(0.0, 0.0, 1.0) : vec3(1.0, 0.0, 0.0);
+	vec3 tangent   = normalize(cross(up, N));
+	vec3 bitangent = cross(N, tangent);
+	
+	vec3 sampleVec = tangent * H.x + bitangent * H.y + N * H.z;
+	return normalize(sampleVec);
+}
+// ----------------------------------------------------------------------------
+void main()
+{		
+    vec3 N = normalize(WorldPos);
+    
+    // make the simplyfying assumption that V equals R equals the normal 
+    vec3 R = N;
+    vec3 V = R;
+
+    const uint SAMPLE_COUNT = 1024u;
+    vec3 prefilteredColor = vec3(0.0);
+    float totalWeight = 0.0;
+    
+    for(uint i = 0u; i < SAMPLE_COUNT; ++i)
+    {
+        // generates a sample vector that's biased towards the preferred alignment direction (importance sampling).
+        vec2 Xi = Hammersley(i, SAMPLE_COUNT);
+        vec3 H = ImportanceSampleGGX(Xi, N, roughness);
+        vec3 L  = normalize(2.0 * dot(V, H) * H - V);
+
+        float NdotL = max(dot(N, L), 0.0);
+        if(NdotL > 0.0)
+        {
+            // sample from the environment's mip level based on roughness/pdf
+            float D   = DistributionGGX(N, H, roughness);
+            float NdotH = max(dot(N, H), 0.0);
+            float HdotV = max(dot(H, V), 0.0);
+            float pdf = D * NdotH / (4.0 * HdotV) + 0.0001; 
+
+            float resolution = 512.0; // resolution of source cubemap (per face)
+            float saTexel  = 4.0 * PI / (6.0 * resolution * resolution);
+            float saSample = 1.0 / (float(SAMPLE_COUNT) * pdf + 0.0001);
+
+            float mipLevel = roughness == 0.0 ? 0.0 : 0.5 * log2(saSample / saTexel); 
+            
+            prefilteredColor += textureLod(environmentMap, L, mipLevel).rgb * NdotL;
+            totalWeight      += NdotL;
+        }
+    }
+
+    prefilteredColor = prefilteredColor / totalWeight;
+
+    FragColor = vec4(prefilteredColor, 1.0);
+}

src/6.pbr/2.2.2.ibl_specular_textured/ibl_specular_textured.cpp

@@ -80,12 +80,12 @@ int main()
 
     // build and compile shaders
     // -------------------------
-    Shader pbrShader("2.2.2.pbr.vs", "2.2.2.pbr.frag");
-    Shader equirectangularToCubemapShader("2.2.1.cubemap.vs", "2.2.1.equirectangular_to_cubemap.frag");
-    Shader irradianceShader("2.2.1.cubemap.vs", "2.2.1.irradiance_convolution.frag");
-    Shader prefilterShader("2.2.1.cubemap.vs", "2.2.1.prefilter.frag");
-    Shader brdfShader("2.2.1.brdf.vs", "2.2.1.brdf.frag");
-    Shader backgroundShader("2.2.1.background.vs", "2.2.1.background.frag");
+    Shader pbrShader("2.2.2.pbr.vs", "2.2.2.pbr.fs");
+    Shader equirectangularToCubemapShader("2.2.2.cubemap.vs", "2.2.2.equirectangular_to_cubemap.fs");
+    Shader irradianceShader("2.2.2.cubemap.vs", "2.2.2.irradiance_convolution.fs");
+    Shader prefilterShader("2.2.2.cubemap.vs", "2.2.2.prefilter.fs");
+    Shader brdfShader("2.2.2.brdf.vs", "2.2.2.brdf.fs");
+    Shader backgroundShader("2.2.2.background.vs", "2.2.2.background.fs");
 
     pbrShader.use();
     pbrShader.setInt("irradianceMap", 0);