This is just stuff I noticed while working on the wikiheaders updates. A
thorough pass over all the docs would not be terrible, and maybe a simple
script to check for consistency (does everything have a `\since` on it? etc)
might be nice, too.
This pull request adds an implementation of a Vulkan Render backend to SDL. I have so far tested this primarily on Windows, but also smoke tested on Linux and macOS (MoltenVK). I have not tried it yet on Android, but it should be usable there as well (sans any bugs I missed). This began as a port of the SDL Direct3D12 Renderer, which is the closest thing to Vulkan as existed in the SDL codebase. The shaders are more or less identical (with the only differences being in descriptor bindings vs root descriptors). The shaders are built using the HLSL frontend of glslang.
Everything in the code is pure Vulkan 1.0 (no extensions), with the exception of HDR support which requires the Vulkan instance extension `VK_EXT_swapchain_colorspace`. The code could have been simplified considerably if I used dynamic rendering, push descriptors, extended dynamic state, and other modern Vulkan-isms, but I felt it was more important to make the code as vanilla Vulkan as possible so that it would run on any Vulkan implementation.
The main differences with the Direct3D12 renderer are:
* Having to manage renderpasses for performing clears. There is likely some optimization that would still remain for more efficient use of TBDR hardware where there might be some unnecessary load/stores, but it does attempt to do clears using renderpasses.
* Constant buffer data couldn't be directly updated in the command buffer since I didn't want to rely on push descriptors, so there is a persistently mapped buffer with increasing offset per swapchain image where CB data gets written.
* Many more resources are dependent on the swapchain resizing due to i.e. Vulkan requiring the VkFramebuffer to reference the VkImageView of the swapchain, so there is a bit more code around handling that than was necessary in D3D12.
* For NV12/NV21 textures, rather than there being plane data in the texture itself, the UV data is placed in a separate `VkImage`/`VkImageView`.
I've verified that `testcolorspace` works with both sRGB and HDR linear. I've tested `testoverlay` works with the various YUV/NV12/NV21 formats. I've tested `testsprite`. I've checked that window resizing and swapchain out-of-date handling when minimizing are working. I've run through `testautomation` with the render tests. I also have run several of the tests with Vulkan validation and synchronization validation. Surely I will have missed some things, but I think it's in a good state to be merged and build out from here.
This better reflects how HDR content is actually used, e.g. most content is in the SDR range, with specular highlights and bright details beyond the SDR range, in the HDR headroom.
This more closely matches how HDR is handled on Apple platforms, as EDR.
This also greatly simplifies application code which no longer has to think about color scaling. SDR content is rendered at the appropriate brightness automatically, and HDR content is scaled to the correct range for the display HDR headroom.
Renamed the following property define names to have a type suffix to
match other property names.
SDL_PROP_TEXTURE_OPENGL_TEXTURE_TARGET (number)
SDL_PROP_TEXTURE_OPENGLES2_TEXTURE_TARGET (number)
SDL_PROP_WINDOW_CREATE_WAYLAND_SCALE_TO_DISPLAY (boolean)
SDL_PROP_WINDOW_RENDERER (pointer)
SDL_PROP_WINDOW_TEXTUREDATA (pointer)
Eventually we can re-add a fast path for that data down to the individual renderers. Setting color scale would still require converting to float, and most hardware accelerated renderers prefer to consume colors as float, so this requires some thought and performance testing.
Fixes https://github.com/libsdl-org/SDL/issues/9009
The renderer will always use the sRGB colorspace for drawing, and will default to the sRGB output colorspace. If you want blending in linear space and HDR support, you can select the scRGB output colorspace, which is supported by the direct3d11 and direct3d12
This allows color operations to happen in linear space between sRGB input and sRGB output. This is currently supported on the direct3d11, direct3d12 and opengl renderers.
This is a good resource on blending in linear space vs sRGB space:
https://blog.johnnovak.net/2016/09/21/what-every-coder-should-know-about-gamma/
Also added testcolorspace to verify colorspace changes
This uses the same `SDL_VerbNoun` format as the rest of SDL3, and also
adds stronger effort to invalidate cached state in the backend, so cooperation
improves with apps that are using lowlevel rendering APIs directly.
Fixes#367.
The following objects now have properties that can be user modified:
* SDL_AudioStream
* SDL_Gamepad
* SDL_Joystick
* SDL_RWops
* SDL_Renderer
* SDL_Sensor
* SDL_Surface
* SDL_Texture
* SDL_Window
Also switched the D3D11 and D3D12 renderers to use real NV12 textures for NV12 data.
The combination of these two changes allows us to implement 0-copy video decode and playback for D3D11 in testffmpeg without any access to the renderer internals.
Render targets are a core feature of SDL 3.0, so this flag has been removed.
The OpenGL ES renderer still doesn't support them, but we'll deal with that later.
Fixes https://github.com/libsdl-org/SDL/issues/8059
We have gotten feedback that abstracting the coordinate system based on the display scale is unexpected and it is difficult to adapt existing applications to the proposed API.
The new approach is to provide the coordinate systems that people expect, but provide additional information that will help applications properly handle high DPI situations.
The concepts needed for high DPI support are documented in README-highdpi.md. An example of automatically adapting the content to display scale changes can be found in SDL_test_common.c, where auto_scale_content is checked.
Also, the SDL_WINDOW_ALLOW_HIGHDPI window flag has been replaced by the SDL_HINT_VIDEO_ENABLE_HIGH_PIXEL_DENSITY hint.
Fixes https://github.com/libsdl-org/SDL/issues/7709
Sam Lantinga
Frank Praznik
Anonymous Maarten
SDL Wiki Bot
Ryan C. Gordon
Petar Popovic
Susko3
Sylvain
Dan Ginsburg
Zack Middleton