depth_fs.glsl revision 185268942b946028b65f5cff9b335af97f9aeab8 
1void main() {
2    // Non-linear depth value
3    float z = gl_FragCoord.z;
4    // Near and far planes from the projection
5    // In practice, these values can be used to tweak
6    // the focus range
7    float n = UNI_near;
8    float f = UNI_far;
9    // Linear depth value
10    z = (2.0 * n) / (f + n - z * (f - n));
11
12    gl_FragColor = vec4(z, z, z, 1.0);
13}
14