015cc6a broke texture format selection for this kind of surface if the
renderer's first texture format doesn't happen to have an alpha
channel. This happens for on-screen software renderers on Windows,
whose preferred format is the window's own `SDL_PIXELFORMAT_XRGB8888`.
This fixed check also cover the intent behind 015cc6a, assuming that
indexed and alpha formats are mutually exclusive.
On Android, if you create a window with SDL_WINDOW_OPENGL, you can't create a Vulkan surface. The error message has been improved to reflect this, and the error is propagated back up to the application.
Also added warn level logging if the renderer couldn't be created.
SDL_CreateGPURenderer() now allows passing in an existing GPU device and passing in a NULL window to create an offscreen renderer.
Also renamed SDL_SetRenderGPUState() to SDL_SetGPURenderState().
Each texture gets its own palette, the palette is updated when it is rendered if necessary, rendering is flushed if a texture render is already queued up.
Trying to share palettes and handle the different cases of queued rendering and changing palettes in the middle of the frame ends up being very complicated, so we'll keep it simple for now.
SDL supports the following use cases:
* Normal operation with fast parameter checks (default):
SDL_SetHint(SDL_HINT_INVALID_PARAM_CHECKS, "1");
* Object parameters are checked for use-after-free issues:
SDL_SetHint(SDL_HINT_INVALID_PARAM_CHECKS, "2");
* Enable full validation, plus assert on invalid parameters:
#define SDL_ASSERT_INVALID_PARAMS
* Disable all parameter validation:
#define SDL_DISABLE_INVALID_PARAMS
This still logs backend choices, but we might use it for other things. For
example, what Android device is being used, or all the devices we enumerated,
etc.
Ideally this eventually logs all the stuff we often have to ask followup
questions about.
The main view always reflects the size of the output, so don't use the dimensions of the currently bound render target texture when updating it, or it will reflect an incorrect size when the render target texture is unbound.
The platforms that needed this (Windows Phone and Windows RT) are no longer supported, and if this is needed in the future it should be done at the renderer level, not here.
Fixes https://github.com/libsdl-org/SDL/issues/12475
