How is gl_FragCoord calculated. ?

[Vadim]

I need to shift the depth of a fragment a little bit (converting circles to spheres). Can anyone explain me how the original gl_FragCoord.z value is calculatged ?

[Dark Photon]

I need to shift the depth of a fragment a little bit (converting circles to spheres). Can anyone explain me how the original gl_FragCoord.z value is calculatged ?

I'm sure there are lots of places, but here are a few:
* gl_FragCoord.z (OpenGL.org thread)
* Comparing Depth in Fragment Shader (OpenGL.org thread)

[overlay]

here is another OpenGL.org thread:
http://www.opengl.org/discussion_boa...766#Post255766