It seems I found a bug. glDepthMask(GL_FALSE) - disables writing to Z-buffer and also disables clearing Z-buffer using glClear function.
But
From documentation:"glDepthMask
does not affect glClear
."
http://www.khronos.org/opengles/documentation/opengles1_0/html/glDepthMask.html
I tell about win32 implementation from v2.3 SDK
The statement on that man page is incorrect, glDepthMask does affect glClear. In general the man pages for ES 1.1 are in a much better state than the ones for ES 1.0:
http://www.khronos.org/opengles/sdk/1.1/docs/man/
According to the ES 1.1 full spec:
enabled) are the pixel ownership test, the scissor test, and dithering. The masking
operations described in the last section (4.2.2) are also effective.
Hmm!
From 1.1 documentation
http://www.khronos.org/opengles/sdk/1.1/docs/man/
Alpha function, blend function, logical operation, stenciling, texture mapping, and depth-buffering are ignored by glClear.
This is also incorrect or I misunderstands this statement?
This should probably say that the depth test is ignored. Obviously not depth buffering as a whole, otherwise there would be no way of clearing the depth buffer.