>Psychtoolbox>PsychGLImageProcessing

rval = kPsychUseExternalSinkTextures

Return a flag that you can pass to the ‘imagingmode’ parameter of
Screen(‘OpenWindow’) together with the ‘kPsychNeedFinalizedFBOSinks’
flag. If this kPsychUseExternalSinkTextures flag is given then the
OpenGL framebuffer objects which are created and attached as final
output image sinks due to the ‘kPsychNeedFinalizedFBOSinks’ flag will
not use Screen() internally created OpenGL textures as color attachments,
and thereby as final target of the output images. Instead, externally
created suitable (color render-to-texture capable) non-power-of-two
OpenGL textures will get dynamically attached as render targets during
the relevant render pass. Producers of such external target textures can
be 3rd party SDKs or runtimes, e.g., the Oculus VR 1.x SDK and runtime
which would send such textures with the final rendered output images to
a VR compositor for output on a suitable VR headset. Other applications
are conceivable, but this is the initial target application of this flag.