[UI] Image post-processing and full presentation/window rework

[GPU] Add FXAA post-processing
[UI] Add FidelityFX FSR and CAS post-processing
[UI] Add blue noise dithering from 10bpc to 8bpc
[GPU] Apply the DC PWL gamma ramp closer to the spec, supporting fully white color
[UI] Allow the GPU CP thread to present on the host directly, bypassing the UI thread OS paint event
[UI] Allow variable refresh rate (or tearing)
[UI] Present the newest frame (restart) on DXGI
[UI] Replace GraphicsContext with a far more advanced Presenter with more coherent surface connection and UI overlay state management
[UI] Connect presentation to windows via the Surface class, not native window handles
[Vulkan] Switch to simpler Vulkan setup with no instance/device separation due to interdependencies and to pass fewer objects around
[Vulkan] Lower the minimum required Vulkan version to 1.0
[UI/GPU] Various cleanup, mainly ComPtr usage
[UI] Support per-monitor DPI awareness v2 on Windows
[UI] DPI-scale Dear ImGui
[UI] Replace the remaining non-detachable window delegates with unified window event and input listeners
[UI] Allow listeners to safely destroy or close the window, and to register/unregister listeners without use-after-free and the ABA problem
[UI] Explicit Z ordering of input listeners and UI overlays, top-down for input, bottom-up for drawing
[UI] Add explicit window lifecycle phases
[UI] Replace Window virtual functions with explicit desired state, its application, actual state, its feedback
[UI] GTK: Apply the initial size to the drawing area
[UI] Limit internal UI frame rate to that of the monitor
[UI] Hide the cursor using a timer instead of polling due to no repeated UI thread paints with GPU CP thread presentation, and only within the window

src/xenia/ui/shaders/xesl.xesli

@@ -0,0 +1,45 @@
+#ifndef XENIA_UI_SHADERS_XESL_XESLI_
+#define XENIA_UI_SHADERS_XESL_XESLI_
+
+// XESL_LANGUAGE_GLSL / HLSL are expected to be defined via compiler arguments.
+
+// Vectors.
+#if XESL_LANGUAGE_GLSL
+  #define xesl_bool2 bvec2
+  #define xesl_bool3 bvec3
+  #define xesl_bool4 bvec4
+  #define xesl_int2 ivec2
+  #define xesl_int3 ivec3
+  #define xesl_int4 ivec4
+  #define xesl_uint2 uvec2
+  #define xesl_uint3 uvec3
+  #define xesl_uint4 uvec4
+  #define xesl_float2 vec2
+  #define xesl_float3 vec3
+  #define xesl_float4 vec4
+#else
+  #define xesl_bool2 bool2
+  #define xesl_bool3 bool3
+  #define xesl_bool4 bool4
+  #define xesl_int2 int2
+  #define xesl_int3 int3
+  #define xesl_int4 int4
+  #define xesl_uint2 uint2
+  #define xesl_uint3 uint3
+  #define xesl_uint4 uint4
+  #define xesl_float2 float2
+  #define xesl_float3 float3
+  #define xesl_float4 float4
+#endif  // XESL_LANGUAGE_GLSL
+
+// Declarations.
+#if XESL_LANGUAGE_HLSL
+  // HLSL requires static const to declare a constant in the global scope so it
+  // doesn't go to $Globals instead.
+  #define xesl_static static
+#else
+  // GLSL requires just const to declare a constant in the global scope.
+  #define xesl_static
+#endif  // XESL_LANGUAGE_HLSL
+
+#endif  // XENIA_UI_SHADERS_XESL_XESLI_