[Bf-committers] GL_AUX buffers

[Ton Roosendaal]

Hi,

For the swapbuffers bug at OSX (while vertex paint, the selection codes  
in the backbuffer gets swapped to the front) I decided to give AUX  
buffers a test. This is an option, to assign another drawing buffer  
(RGBA+Z) to a window. It works (at OSX) surprisingly well.

Makes me think to make it default for all platforms... with the aux  
buffers being accessible for selection codes in general... or think of  
other interesting things you want to draw in a hidden space. Apple  
confirms AUX buffers are h.w accellerated, but it is very hard to find  
the info on other cards/OS's.

So before even committing it to the tree for a cross platform test,  
anyone here knows of it not being supported?

Calls involved are:

Defining OpenGL context:
	GLX_AUX_BUFFERS (X)
	AGL_AUX_BUFFERS (OSX)
	iPixelFormat cAuxBuffers (windows)

And in the code:
	glDrawBuffer(GL_AUX0);
	glReadBuffer(GL_AUX0);

The changes can be minimal, and will clean up ugly backdraw hacks in  
the code as well.

-Ton-


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Ton Roosendaal  Blender Foundation ton@blender.org  
http://www.blender.org