We now store all the relevant state of the image inside the VulkanImage
struct, so we can delay barriers for as long as possible.
Whenever we want to use an image, we call the new
gsk_vulkan_image_transition() and it will add a barrier to the desired
state if one is necessary.
... and all the remaining functions still using it.
It's all unused and has been replaced by upload and download ops.
With this change, all GPU operations now go via GskVulkanOp.command()
and no more side channels exist.
Instead of using the upload vfunc and going via the code in
GskVulkanImage, copy/paste the relevant code into the command() vfunc.
This is meant to achieve multiple things:
1. Get rid of GskVulkanUploader and its own command buffer and general
non-integration with operations.
2. Get rid of GskVulkanOp:upload()
3. Get the upload/download code machinery for GskVulkanImage and put it
with the actual operations.
The current code can't do direct upload/download, that will follow in a
future commit.
If a node has a higher depth, pick the RGBA format that has that depth
as the texture format we're renderig to with render_texture().
Support for adapting the swapchain is not part of this.
This way, we unify the code paths for memory access to textures.
We also technically gain the ability to modify images, though I have no
use case for this.
That way, the offscreen can create images of different types.
Its not used in this commit, but will come in handy when we want to
support high bit depth.
This is unused now that all the code uses map/unmap.
The only thing that map/unmap doesn't do that the old code did, was use
a staging image instead as alternative to a staging buffer for image
uploads.
However, that code is not necessary for anything, so I'm sure we can do
without.
As an alternative to gsk_vulkan_image_new_from_data() that
takes a given data and creates an image from it, add a 3 step process:
gsk_vulkan_image_new_for_upload()
gsk_vulkan_image_map_memory()
/* put data into memory */
gsk_vulkan_image_unmap_memory()
The benefit of this approach is that it potentially avoids a copy;
instead of creating a buffer to pass and writing the data into it before
then memcpy()ing it into the image, the data can be written straight
into image memory.
So far, only the staging buffer upload is implemented.
There are also no users, those come in the next commit(s).
