gl_FragCoord

[^DaNiEl^]

Hi, what gl_FragCoord means ? I want to port a GLSL shader into Cg code but i don't know how to translate this command. Can anyone help me ?

[Relic]

Straight from the GLSL spec:

"The variable gl_FragCoord is available as a read-only variable from within fragment shaders and it holds
the window relative coordinates x, y, z, and 1/w values for the fragment. This value is the result of the
fixed functionality that interpolates primitives after vertex processing to generate fragments. The z
component is the depth value that would be used for the fragment’s depth if a shader contained no writes
to gl_FragDepth. This is useful for invariance if a shader conditionally computes gl_FragDepth but
otherwise wants the fixed functionality fragment depth."

The Cg equivalent should be the fragment programs varying input binding semantics "WPOS".