Sadly, the new API is not backwards compatible with the old API. Since
we have already switched all users in wlroots to the new API compositors
are already practically mandated to implement the new API. Let's get rid
of the old one since there is no point.
When a texel from the Vulkan format VK_FORMAT_B8G8R8A8_SRGB is read,
the sRGB to linear conversion is applied independently to the R, G,
and B channels; the A channel has no influence on this. However,
DRM_FORMAT_ARGB8888 buffers are, per Wayland protocol, not encoded
in this fashion; one must first unpremultiply the color channels
before doing sRGB to linear conversion. This commit switches to
handling ARGB8888 and ABGR8888 formats using the general fragment
shader conversion from electrical to optical values.
If the compositor were to try to handle a GPU reset within the lost
signal (by recreating the renderer) we should avoid referencing renderer
resources after the lost signal. This prevents use after free for such
compositors.
This will become necessary when we switch away from scissoring. For the
time being, this cleans things up a bit and allows for a trivial
blending implementation for textures when that comes.
Avoids repeating the common bits between dma_tex_features and
dma_tex_ycbcr_features, and we will need just the YCbCr-related
flags for shm YCbCr support soon.
These features are required for shm only: the TRANSFER stuff is
for texture upload. We don't need these for DMA-BUFs. Make this
clearer by changing the name.
Also re-order the definitions to group all texture-related features
together.
Based on five calls:
wlr_render_timer_create - creates a timer which can be reused across
frames on the same renderer
wlr_renderer_begin_buffer_pass - now takes a timer so that backends can
record when the rendering starts and finishes
wlr_render_timer_get_time - should be called as late as possible so that
queries can make their way back from the GPU
wlr_render_timer_destroy - self-explanatory
The timer is exposed as an opaque `struct wlr_render_timer` so that
backends can store whatever they want in there.
The Vulkan spec states:
> For the purposes of range expansion and Y′CBCR model conversion,
> the R and B components contain color difference (chroma) values
> and the G component contains luma.
The equations below that sentence also help understand the mapping.