Add missing guards around use of physicalInputProfile.
Add explicit import of Foundation which seems to be needed on some
systems to get the NSArray definition.
Add __unsafe_unretained to ObjC types in struct so the compiler doesn't
complain about that not being allowed with ARC.
Closes: #8979
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
You can't do blending directly in PQ space, which means you have to create a scene render target in linear space and use shaders to convert PQ texture data to linear, etc. All of this is out of scope for the SDL 2D renderer at the moment.
Testing: Modified testgeometry to clear the background to 0.5 and then changed the triangle color to 0.5, and verified that they were the same color when using the D3D11 renderer.
Matches SDL2, and should be enough to keep most games from desyncing/timing out.
A proper fix for FIFO presentation without the frame callback mess is being worked on upstream, so this whole hack should be rendered obsolete in the near future.
When no source devices are connected, the default source string can contain a sink name. If the default source and sink match, it will be caught as a sink device first and handled correctly, but if the default sink/source don't match, which happens when the sink is an HDMI output and the source is still an onboard audio chipset output name, an assert can result since the requested source device won't be flagged as a capture device. Rather than asserting, simply don't assign default devices that don't match the correct capabilities, as it's not an uncommon scenario and can be handled gracefully.
Additionally, if asserting is a no-op in release mode, sinks can be returned as sources and vice versa, which is incorrect.
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
