The convert_texture() path only works for the GL renderer, the new
renderers potentially use dmabuf textures as result of render_texture(),
so they need to be smarter here.
This makes no sense by itself, but we want to create the EGLImage at
DmabufTexture construction so that we can actually reject dmabufs that
we can't create EGLImages for.
This will make it possible to bail when the stride limitation for AMD
GPUs hits.
Instead of having an add_formats() function, make the get_downloader()
function add the formats.
This allows putting the actual downloader in a different place from the
initialization code.
This is done without testing, just doing my best to map all the DRM
formats to VkFormats.
Once people start using them, they'll figure it out when it's wrong.
(Somebody needs to write a testsuite.)
When we use the builtin downloads via mmap(), it's a special case where
we don't need to initialize subsystems and query them for support. We
know what we can and can't do.
Also, we want to use these formats with the lowest priority but pick the
downloader first for supported formats, and queueing it in the
downloaders list doesn't reflect that. So don't do it.
This omission was noticed by Benjamin Otte. Add a premultiply
uniform to the external shader, and add a separate premultiply
shader for the non-external case.
When the GL renderer cannot upload a given format, print a FALLBACK
debug message with the failed format and the alternative that was
picked, for example:
Unsupported format b8g8r8a8, converting on CPU to b8g8r8a8-premultiplied
Makes it easier to figure out what's happening, especially when using
old GLES versions that don't support all formats.
Track fallback formats to use in the memoryformat directly instead of
using in the GL uploading code.
First of all, this allows sharing the code and ensuring all our
renderers use the same fallback mechanism.
But also, this allows tracking fallbacks per-format which is useful
because the fallback formats aren't really a tree. We want to make
FLOAT16 fall back to FLOAT32 when not available, but we also want
FLOAT32 fall back to FLOAT16.
By tracking the fallbacks per-format, we can achieve that.
Add gdk_memory_format_get_premultiplied() and
gdk_memory_format_get_straight() which return the matching
premultiplied/straight format.
Use this to pick the premultiplied format when uploading GL textures.
And remove the duplication in the dmabuf code, where we can now use
these functions instead of tracking both the premultiplied and straight
alpha versions.
Add an "RGBA" format that just maps to the swizzled version of the
default format.
This way, BGR gets mapped to RGB + swizzling first before trying to map
it to the default format for the depth.
The benefit here is that this format has the same memory width, so
uploading/downloading code can treat it equivalent to the original
format and there's no conversion neccessary later.
