Check if framebuffer or stencilbuffer changed

[olmeca]

Hi,

I need to check if a shader changed at least one pixel of the framebuffer. Is there a solution without checking every pixel after the shader executed?

thx

[MickeyMouse]

You need occlusion queries (http://oss.sgi.com/projects/ogl-sample/registry/ARB/occlusion_query.txt) .

[olmeca]

Fine thanks! That solved the problem.