Perspective projection matrix

gl_FragCoord is window-relative (screen) coordinates. .xy is pixel units of the center of the fra...

gl_FragCoord.z is the window-space depth value of the current fragment. It has nothing to do with...

gl_FragCoord.z is generated by the following process, assuming the usual transforms: Camera-space...

gl_fragcoord和gl_fragdepth分別是片元著色器的輸入和輸出變數。 gl_fragcoord是個vec4，四個分量分別對應x, y, z和1/w。其中，x和y ...

gl_FragCoord.w 是裁剪空间clip.w 的倒数即1/clip.w , 由上面的透视投影矩阵的推导过程可以看出，为了凑透视除法， clip.w 值就是眼坐标系z 值的负数，也 ...