[rcore][drm] Replace DRM swap buffer implementation with asynchronous page-flipping and triple framebuffer caching #4988
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…ge-flipping and framebuffer caching The original implementation created/destroyed framebuffers (FBs) per-frame, leading to kernel overhead and screen tearing. This commit replaces it with a different approach using: - Asynchronous `drmModePageFlip()` with vblank sync - Framebuffer caching to reduce repeated FB creation/removal operations - Proper resource management through BO callbacks and buffer release synchronization - Added error handling for busy displays, cache overflows, and flip failures - Event-driven cleanup via page_flip_handler to prevent GPU/scanout conflicts Co-authored-by: rob-bits
rob-bits
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rob-bits
changed the title
raysan5
reviewed
Jun 6, 2025
| @@ -910,7 +1099,8 @@ int InitPlatform(void) | |||
| EGL_BLUE_SIZE, 8, // BLUE color bit depth (alternative: 5) | |||
| EGL_ALPHA_SIZE, 8, // ALPHA bit depth (required for transparent framebuffer) | |||
| //EGL_TRANSPARENT_TYPE, EGL_NONE, // Request transparent framebuffer (EGL_TRANSPARENT_RGB does not work on RPI) | |||
| EGL_DEPTH_SIZE, 24, // Depth buffer size (Required to use Depth testing!) | |||
| //ToDo: verify this. In 5.5 it is 16, in master it was 24 | |||
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Yes, that's correct, it was increased to address some z-fighting isssues. Afaik, most devies already support 24bit depth buffers.
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@rob-bits Thanks for the improvement, it would be nie to keep both methods to be selected with a compilation flag. Please, could you first review the code to follow raylib coding conventions? |
Yeah, will review it and revisit the code if it brokes any convention. And will add a compiler define to have control which one should be used. |
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The original implementation created/destroyed framebuffers (FBs) per-frame, leading to kernel overhead and screen tearing. This commit replaces it with a different approach using:
drmModePageFlip()with vblank syncWould you please review this code?
In my case it works better, has less framedrop or tearing.
Tested it on a Raspberry Pi Zero 2W.
Maybe this implementation should be handled as a compiler option for the user. To select if he wants the minimal DRM or the page-flipping, cached DRM.
Summary: Key Differences
SwapScreenBuffer - Original)SwapScreenBuffer new)drmModePageFlip()with vblank sync to prevent tearing.