Added fog

data/shaders/terraintessellation/terrain.frag

@@ -10,6 +10,8 @@ layout (location = 0) in vec3 inNormal;
 layout (location = 1) in vec2 inUV;
 layout (location = 2) in vec3 inViewVec;
 layout (location = 3) in vec3 inLightVec;
+layout (location = 4) in vec3 inEyePos;
+layout (location = 5) in vec3 inWorldPos;
 
 layout (location = 0) out vec4 outFragColor;
 
@@ -40,11 +42,23 @@ vec3 sampleTerrainLayer()
 	return color;
 }
 
+float fog(float density)
+{
+	const float LOG2 = -1.442695;
+	float dist = gl_FragCoord.z / gl_FragCoord.w * 0.1;
+	float d = density * dist;
+	return 1.0 - clamp(exp2(d * d * LOG2), 0.0, 1.0);
+}
+
 void main()
 {
 	vec3 N = normalize(inNormal);
 	vec3 L = normalize(inLightVec);
 	vec3 ambient = vec3(0.5);
 	vec3 diffuse = max(dot(N, L), 0.0) * vec3(1.0);
-	outFragColor = vec4((ambient + diffuse) * sampleTerrainLayer(), 1.0);	
+
+	vec4 color = vec4((ambient + diffuse) * sampleTerrainLayer(), 1.0);
+
+	const vec4 fogColor = vec4(0.47, 0.5, 0.67, 0.0);
+	outFragColor  = mix(color, fogColor, fog(0.25));	
 }

data/shaders/terraintessellation/terrain.tese

@@ -26,6 +26,8 @@ layout (location = 0) out vec3 outNormal;
 layout (location = 1) out vec2 outUV;
 layout (location = 2) out vec3 outViewVec;
 layout (location = 3) out vec3 outLightVec;
+layout (location = 4) out vec3 outEyePos;
+layout (location = 5) out vec3 outWorldPos;
 
 void main()
 {
@@ -50,4 +52,6 @@ void main()
 	// Calculate vectors for lighting based on tessellated position
 	outViewVec = -pos.xyz;
 	outLightVec = normalize(ubo.lightPos.xyz + outViewVec);
+	outWorldPos = pos.xyz;
+	outEyePos = vec3(ubo.modelview * pos);
 }