Jonathan Marler 002659e6f4 backend/x11: add SHM readback fallback when buffer import fails ... On some NVIDIA systems, the DRI3 modifier list only advertises DRM_FORMAT_MOD_INVALID while the renderer requires a specific modifier (e.g. BLOCK_LINEAR). As a result, the X11 backend cannot import renderer buffers via DRI3 and output commits fail. Allow the renderer to allocate buffers with its preferred modifier when DRI3 doesn't expose explicit modifiers. If buffer import fails, fall back to CPU readback: read pixels from the rendered texture into shared memory and upload the result to a pixmap via xcb_shm_put_image before presenting it. This ensures the X11 backend can still produce output even when the X server cannot import the renderer's buffers. While implementing this fallback, split the existing SHM capability flag into two: have_shm: SHM extension available (required for readback fallback) have_shm_pixmaps: server supports shared pixmaps Also fix the SHM version check which incorrectly used || instead of a proper >= 1.2 comparison. Tested with labwc 0.9.5 (WLR_BACKENDS=x11) on Ubuntu 24.04 with an NVIDIA GeForce GTX 1650 (driver 580.126.18), where output commits previously failed with "Failed to commit frame".		2026-03-10 18:58:56 -06:00
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backend.c	backend/x11: add SHM readback fallback when buffer import fails	2026-03-10 18:58:56 -06:00
input_device.c	pointer: release pressed buttons on destroy	2024-09-24 19:53:54 +00:00
meson.build	backend: make DRM and libinput backends optional	2021-07-22 09:56:38 -04:00
output.c	backend/x11: add SHM readback fallback when buffer import fails	2026-03-10 18:58:56 -06:00