Added basic HDR rendering example (wip)

data/shaders/hdr/gbuffer.frag

@@ -0,0 +1,101 @@
+#version 450
+
+#extension GL_ARB_separate_shader_objects : enable
+#extension GL_ARB_shading_language_420pack : enable
+
+layout (binding = 1) uniform sampler2D samplerEnvMap;
+
+layout (location = 0) in vec3 inUVW;
+layout (location = 1) in vec3 inPos;
+layout (location = 2) in vec3 inNormal;
+layout (location = 3) in vec3 inViewVec;
+layout (location = 4) in vec3 inLightVec;
+layout (location = 5) in mat4 inInvModelView;
+
+layout (location = 0) out vec4 outColor0;
+layout (location = 1) out vec4 outColor1;
+
+layout (constant_id = 0) const int type = 0;
+
+#define PI 3.1415926
+#define TwoPI (2.0 * PI)
+
+layout (binding = 2) uniform UBO {
+	float exposure;
+} ubo;
+
+vec2 envMapEquirect(vec3 normal) 
+{
+	float phi = acos(-normal.y);
+	float theta = atan(-1.0 * normal.x, normal.z) + PI;
+	return vec2(theta / TwoPI, phi / PI);
+}
+
+void main() 
+{
+	vec4 color;
+	vec3 wcNormal;
+
+	switch (type) {
+		case 0: // Skybox			
+			{
+				vec3 normal = normalize(inUVW);
+				color = texture(samplerEnvMap, envMapEquirect(normal));
+			}
+			break;
+		
+		case 1: // Reflect
+			{
+				vec3 wViewVec = mat3(inInvModelView) * normalize(inViewVec);
+				vec3 normal = normalize(inNormal);
+				vec3 wNormal = mat3(inInvModelView) * normal;
+
+				float NdotL = max(dot(normal, inLightVec), 0.0);
+
+				vec3 eyeDir = normalize(inViewVec);		
+				vec3 halfVec = normalize(inLightVec + eyeDir);
+				float NdotH = max(dot(normal, halfVec), 0.0); 
+				float NdotV = max(dot(normal, eyeDir), 0.0); 
+				float VdotH = max(dot(eyeDir, halfVec), 0.0);
+		
+				// Geometric attenuation
+				float NH2 = 2.0 * NdotH;
+				float g1 = (NH2 * NdotV) / VdotH;
+				float g2 = (NH2 * NdotL) / VdotH;
+				float geoAtt = min(1.0, min(g1, g2));
+
+				const float F0 = 0.6;
+				const float k = 0.2;
+
+				// Fresnel (schlick approximation)
+				float fresnel = pow(1.0 - VdotH, 5.0);
+				fresnel *= (1.0 - F0);
+				fresnel += F0;
+		
+				float spec = (fresnel * geoAtt) / (NdotV * NdotL * 3.14);
+ 
+				color = texture(samplerEnvMap, envMapEquirect(reflect(-wViewVec, wNormal)));	 	
+
+				color = vec4(color.rgb * NdotL * (k + spec * (1.0 - k)), 1.0);
+			}
+			break;
+
+		case 2: // Refract			
+			{
+				vec3 wViewVec = mat3(inInvModelView) * normalize(inViewVec);
+				vec3 wNormal = mat3(inInvModelView) * inNormal;
+				color = texture(samplerEnvMap, envMapEquirect(refract(-wViewVec, wNormal, 1.0/1.6)));		
+			}
+			break;
+	}
+
+
+	// Color with manual exposure into attachment 0
+	outColor0.rgb = vec3(1.0) - exp(-color.rgb * ubo.exposure);
+
+	// Bright parts for bloom into attachment 1
+	float l = dot(outColor0.rgb, vec3(0.2126, 0.7152, 0.0722));
+	float threshold = 0.75;
+	outColor1.rgb = (l > threshold) ? outColor0.rgb : vec3(0.0);
+	outColor1.a = 1.0;
+}