Re: [Mesa-dev] Dmabuf based render buffers!?
Hi and thanks for your replies! Note though that I want to get hold of the image/pixels after they have been processed by shader(s). So not the raw texture being fed in. So maybe it would be the contents of a FBO or similar. Cheers Fred On Fri, Jan 15, 2021 at 3:59 AM Christian König < ckoenig.leichtzumer...@gmail.com> wrote: > Am 15.01.21 um 11:26 schrieb Michel Dänzer: > > On 2021-01-14 8:02 p.m., Blueroom wrote: > >> > >> Hi Everyone! > >> > >> I have a program that’s using dmabuf’s to create a zero copy > >> camera->GL texture pipeline and it’s working great on my RPi4. > >> > >> Now as a last step I want to access the pixels that Iv’e processed in > >> gl with shaders, on the cpu. > >> > >> Iv’e been told that on the Raspberry Pi OpenGL is sharing the same > >> memory as the cpu so I’m hoping it would be possible to do something > >> like a dmabuf on the ‘way out’ too? > >> > >> Does anyone have any pointers in how this could work? > > > > I'd recommend using glGetTexImage or other similar GL APIs for getting > > the data out of the GL texture. > > > > While mmap of a dma-buf file descriptor works in theory, direct CPU > > reads from GPU accessible memory can be very slow on some platforms. > > > > Yeah, agree. Additional to that you don't know the format of the DMA-buf > of the texture. > > The input image is most likely linear, but the output might be tiled. > > Christian. > ___ mesa-dev mailing list mesa-dev@lists.freedesktop.org https://lists.freedesktop.org/mailman/listinfo/mesa-dev
Re: [Mesa-dev] Dmabuf based render buffers!?
Am 15.01.21 um 11:26 schrieb Michel Dänzer: On 2021-01-14 8:02 p.m., Blueroom wrote: Hi Everyone! I have a program that’s using dmabuf’s to create a zero copy camera->GL texture pipeline and it’s working great on my RPi4. Now as a last step I want to access the pixels that Iv’e processed in gl with shaders, on the cpu. Iv’e been told that on the Raspberry Pi OpenGL is sharing the same memory as the cpu so I’m hoping it would be possible to do something like a dmabuf on the ‘way out’ too? Does anyone have any pointers in how this could work? I'd recommend using glGetTexImage or other similar GL APIs for getting the data out of the GL texture. While mmap of a dma-buf file descriptor works in theory, direct CPU reads from GPU accessible memory can be very slow on some platforms. Yeah, agree. Additional to that you don't know the format of the DMA-buf of the texture. The input image is most likely linear, but the output might be tiled. Christian. ___ mesa-dev mailing list mesa-dev@lists.freedesktop.org https://lists.freedesktop.org/mailman/listinfo/mesa-dev
Re: [Mesa-dev] Dmabuf based render buffers!?
On 2021-01-14 8:02 p.m., Blueroom wrote: Hi Everyone! I have a program that’s using dmabuf’s to create a zero copy camera->GL texture pipeline and it’s working great on my RPi4. Now as a last step I want to access the pixels that Iv’e processed in gl with shaders, on the cpu. Iv’e been told that on the Raspberry Pi OpenGL is sharing the same memory as the cpu so I’m hoping it would be possible to do something like a dmabuf on the ‘way out’ too? Does anyone have any pointers in how this could work? I'd recommend using glGetTexImage or other similar GL APIs for getting the data out of the GL texture. While mmap of a dma-buf file descriptor works in theory, direct CPU reads from GPU accessible memory can be very slow on some platforms. -- Earthling Michel Dänzer | https://redhat.com Libre software enthusiast | Mesa and X developer ___ mesa-dev mailing list mesa-dev@lists.freedesktop.org https://lists.freedesktop.org/mailman/listinfo/mesa-dev
[Mesa-dev] Supporting macOS / XQuartz on master
Hey folks, I finally had a little bit of time to take a look at mesa and XQuartz for the first time in ~4 years. I am incredibly impressed that there wasn't more bitrot. I was expecting a painful few days since I've never looked at meson, but I was able to get it functional relatively quickly. I have a few pull requests which I'd like to have some eyes on. These first two are a meson configuration changes to pickup the system libexpat and libunwind (plus a build fix due to bad implicit casting in mesa's libunwind usage). I'd appreciate someone with meson-fu to look them over and let me know if there's a better way to do this: https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/8501 https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/8502 This last one is probably a bit more political as it bumps our C language version from C99 to C11. This is being done because we make use of timespec_get() which was added to C11. Using -std=c99 will cause the prototype to be omitted from system headers on strictly compliant systems (eg: macOS) even when the system supports this function. https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/8496 Thanks in advance for looking these over. --Jeremy ___ mesa-dev mailing list mesa-dev@lists.freedesktop.org https://lists.freedesktop.org/mailman/listinfo/mesa-dev
[Mesa-dev] Dmabuf based render buffers!?
Hi Everyone! I have a program that’s using dmabuf’s to create a zero copy camera->GL texture pipeline and it’s working great on my RPi4. Now as a last step I want to access the pixels that Iv’e processed in gl with shaders, on the cpu. Iv’e been told that on the Raspberry Pi OpenGL is sharing the same memory as the cpu so I’m hoping it would be possible to do something like a dmabuf on the ‘way out’ too? Does anyone have any pointers in how this could work? Cheers Fred ___ mesa-dev mailing list mesa-dev@lists.freedesktop.org https://lists.freedesktop.org/mailman/listinfo/mesa-dev
