2024932 - Wayland zero-readback presentation should check wl_surface/compositor modifiers

Status: RESOLVED DUPLICATE of bug 2028402

(Core :: Graphics: WebGPU, defect, P1)

Description

[Teodor Tanasoaia [:teoxoy]]

Currently we create textures with modifiers queried from the Vulkan device only. We should be using the intersection of the modifiers queried from the Vulkan device and those of the wl_surface/compositor.

We can get those via the zwp_linux_dmabuf_v1::modifier event before v4 and via get_default_feedback or get_surface_feedback after v4.

References:

• Negotiation bullet point of https://docs.vulkan.org/refpages/latest/refpages/source/VK_EXT_image_drm_format_modifier.html#_usage_patterns
• https://wayland.app/protocols/linux-dmabuf-v1#zwp_linux_dmabuf_v1:event:modifier

Comment 1

[Sotaro Ikeda [:sotaro]]

It seems that this problem could be covered by querying dma buf modifiers from EGL like like Bug 2024932.

Comment 2

[Martin Stránský [:stransky] (ni? me)]

dmabuf modifiers are already loaded by GlobalDMABufFormats() class. Just get the format + modifiers as:

format = GetGlobalDMABufFormats()->GetDRMFormat(FOURCC format);
nsTArray<uint64_t>*  format->GetModifiers();

https://searchfox.org/firefox-main/rev/5f15185120f488edb4b4f2f38599fff543b9aa5a/widget/gtk/DMABufFormats.h#28

We also export RGBA modifiers as gfxVars to child processes.

Comment 3

[Martin Stránský [:stransky] (ni? me)]

(In reply to Sotaro Ikeda [:sotaro] from comment #1)

It seems that this problem could be covered by querying dma buf modifiers from EGL like like Bug 2024932.

EGL modifiers may be queued on X11 where dmabuf feedback is missing.

Comment 4

[Martin Stránský [:stransky] (ni? me)]

D300528 / Bug 2028402 load the EGL modifiers directly to gfxVars.