add fog on skybox

grafika_projekt/shaders/skybox.frag

@@ -5,7 +5,22 @@ in vec3 TexCoords;
 
 uniform samplerCube skybox;
 
+float near = 0.02f;
+float far = 100.0f;
+
+float linearizeDepth(float depth)
+{
+    return (2.0 * near * far) / (far + near - (depth * 2.0 - 1.0) * (far - near));
+}
+
+float logisticDepth(float depth, float steepness, float offset)
+{
+    float zVal = linearizeDepth(depth);
+    return (1 / (1 + exp(-steepness * (zVal - offset))));
+}
+
 void main()
 {    
-    FragColor = texture(skybox, TexCoords);
+    float depth = logisticDepth(gl_FragCoord.z, 0.1f, 3.0f);
+    FragColor = texture(skybox, TexCoords)* (1.0f - depth) + vec4(depth * vec3(0.0f, 0.109f, 0.447f), 1.0f);
 }