Posts: 29
Joined: Sat Sep 23, 2017 10:43 am

VCSM and the FBO

Fri Dec 21, 2018 3:49 am

assuming a 2048x1024 vcsm buffer because I need to turn it into an opengl texture and so the vcsm buffer needs to be a power of 2 because of the hardware.

When using EGL_IMAGE_BRCM_VCSM to generate an opengl texture do opengl functions like glClear(GL_COLOR_BUFFER_BIT) clear the entire 2048x1024 buffer? if this is the case is there no way to restrict this clear to only a portion of the buffer?

I ask this because the actual incoming frame from the camera is 1280x720 and so I don't need the whole 2048x1024 buffer that the vcsm is providing.

Raspberry Pi Engineer & Forum Moderator
Raspberry Pi Engineer & Forum Moderator
Posts: 505
Joined: Thu Jun 21, 2018 4:30 pm

Re: VCSM and the FBO

Thu Jan 03, 2019 10:25 am

You could use glScissor to restrict the size of the drawing / clearing region ... cissor.xml

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