Add support for alpha to coverage dithering (#3069)

* Add support for alpha to coverage dithering

* Shader cache version bump

* Fix wrong alpha register

* Ensure support buffer is cleared

* New shader specialization based approach

2 files changed, 56 insertions, 26 deletions

diff --git a/Ryujinx.Graphics.OpenGL/HwCapabilities.cs b/Ryujinx.Graphics.OpenGL/HwCapabilities.cs
index 773c9f63..13b5b412 100644
--- a/Ryujinx.Graphics.OpenGL/HwCapabilities.cs
+++ b/Ryujinx.Graphics.OpenGL/HwCapabilities.cs
@@ -5,19 +5,20 @@ namespace Ryujinx.Graphics.OpenGL
 {
     static class HwCapabilities
     {
-        private static readonly Lazy<bool> _supportsAstcCompression           = new Lazy<bool>(() => HasExtension("GL_KHR_texture_compression_astc_ldr"));
-        private static readonly Lazy<bool> _supportsDrawTexture               = new Lazy<bool>(() => HasExtension("GL_NV_draw_texture"));
-        private static readonly Lazy<bool> _supportsFragmentShaderInterlock   = new Lazy<bool>(() => HasExtension("GL_ARB_fragment_shader_interlock"));
-        private static readonly Lazy<bool> _supportsFragmentShaderOrdering    = new Lazy<bool>(() => HasExtension("GL_INTEL_fragment_shader_ordering"));
-        private static readonly Lazy<bool> _supportsImageLoadFormatted        = new Lazy<bool>(() => HasExtension("GL_EXT_shader_image_load_formatted"));
-        private static readonly Lazy<bool> _supportsIndirectParameters        = new Lazy<bool>(() => HasExtension("GL_ARB_indirect_parameters"));
-        private static readonly Lazy<bool> _supportsParallelShaderCompile     = new Lazy<bool>(() => HasExtension("GL_ARB_parallel_shader_compile"));
-        private static readonly Lazy<bool> _supportsPolygonOffsetClamp        = new Lazy<bool>(() => HasExtension("GL_EXT_polygon_offset_clamp"));
-        private static readonly Lazy<bool> _supportsQuads                     = new Lazy<bool>(SupportsQuadsCheck);
-        private static readonly Lazy<bool> _supportsSeamlessCubemapPerTexture = new Lazy<bool>(() => HasExtension("GL_ARB_seamless_cubemap_per_texture"));
-        private static readonly Lazy<bool> _supportsShaderBallot              = new Lazy<bool>(() => HasExtension("GL_ARB_shader_ballot"));
-        private static readonly Lazy<bool> _supportsTextureShadowLod          = new Lazy<bool>(() => HasExtension("GL_EXT_texture_shadow_lod"));
-        private static readonly Lazy<bool> _supportsViewportSwizzle           = new Lazy<bool>(() => HasExtension("GL_NV_viewport_swizzle"));
+        private static readonly Lazy<bool> _supportsAlphaToCoverageDitherControl = new Lazy<bool>(() => HasExtension("GL_NV_alpha_to_coverage_dither_control"));
+        private static readonly Lazy<bool> _supportsAstcCompression              = new Lazy<bool>(() => HasExtension("GL_KHR_texture_compression_astc_ldr"));
+        private static readonly Lazy<bool> _supportsDrawTexture                  = new Lazy<bool>(() => HasExtension("GL_NV_draw_texture"));
+        private static readonly Lazy<bool> _supportsFragmentShaderInterlock      = new Lazy<bool>(() => HasExtension("GL_ARB_fragment_shader_interlock"));
+        private static readonly Lazy<bool> _supportsFragmentShaderOrdering       = new Lazy<bool>(() => HasExtension("GL_INTEL_fragment_shader_ordering"));
+        private static readonly Lazy<bool> _supportsImageLoadFormatted           = new Lazy<bool>(() => HasExtension("GL_EXT_shader_image_load_formatted"));
+        private static readonly Lazy<bool> _supportsIndirectParameters           = new Lazy<bool>(() => HasExtension("GL_ARB_indirect_parameters"));
+        private static readonly Lazy<bool> _supportsParallelShaderCompile        = new Lazy<bool>(() => HasExtension("GL_ARB_parallel_shader_compile"));
+        private static readonly Lazy<bool> _supportsPolygonOffsetClamp           = new Lazy<bool>(() => HasExtension("GL_EXT_polygon_offset_clamp"));
+        private static readonly Lazy<bool> _supportsQuads                        = new Lazy<bool>(SupportsQuadsCheck);
+        private static readonly Lazy<bool> _supportsSeamlessCubemapPerTexture    = new Lazy<bool>(() => HasExtension("GL_ARB_seamless_cubemap_per_texture"));
+        private static readonly Lazy<bool> _supportsShaderBallot                 = new Lazy<bool>(() => HasExtension("GL_ARB_shader_ballot"));
+        private static readonly Lazy<bool> _supportsTextureShadowLod             = new Lazy<bool>(() => HasExtension("GL_EXT_texture_shadow_lod"));
+        private static readonly Lazy<bool> _supportsViewportSwizzle              = new Lazy<bool>(() => HasExtension("GL_NV_viewport_swizzle"));
 
         private static readonly Lazy<int> _maximumComputeSharedMemorySize = new Lazy<int>(() => GetLimit(All.MaxComputeSharedMemorySize));
         private static readonly Lazy<int> _storageBufferOffsetAlignment   = new Lazy<int>(() => GetLimit(All.ShaderStorageBufferOffsetAlignment));
@@ -43,19 +44,20 @@ namespace Ryujinx.Graphics.OpenGL
 
         public static bool UsePersistentBufferForFlush       => _gpuVendor.Value == GpuVendor.AmdWindows || _gpuVendor.Value == GpuVendor.Nvidia;
 
-        public static bool SupportsAstcCompression           => _supportsAstcCompression.Value;
-        public static bool SupportsDrawTexture               => _supportsDrawTexture.Value;
-        public static bool SupportsFragmentShaderInterlock   => _supportsFragmentShaderInterlock.Value;
-        public static bool SupportsFragmentShaderOrdering    => _supportsFragmentShaderOrdering.Value;
-        public static bool SupportsImageLoadFormatted        => _supportsImageLoadFormatted.Value;
-        public static bool SupportsIndirectParameters        => _supportsIndirectParameters.Value;
-        public static bool SupportsParallelShaderCompile     => _supportsParallelShaderCompile.Value;
-        public static bool SupportsPolygonOffsetClamp        => _supportsPolygonOffsetClamp.Value;
-        public static bool SupportsQuads                     => _supportsQuads.Value;
-        public static bool SupportsSeamlessCubemapPerTexture => _supportsSeamlessCubemapPerTexture.Value;
-        public static bool SupportsShaderBallot              => _supportsShaderBallot.Value;
-        public static bool SupportsTextureShadowLod          => _supportsTextureShadowLod.Value;
-        public static bool SupportsViewportSwizzle           => _supportsViewportSwizzle.Value;
+        public static bool SupportsAlphaToCoverageDitherControl => _supportsAlphaToCoverageDitherControl.Value;
+        public static bool SupportsAstcCompression              => _supportsAstcCompression.Value;
+        public static bool SupportsDrawTexture                  => _supportsDrawTexture.Value;
+        public static bool SupportsFragmentShaderInterlock      => _supportsFragmentShaderInterlock.Value;
+        public static bool SupportsFragmentShaderOrdering       => _supportsFragmentShaderOrdering.Value;
+        public static bool SupportsImageLoadFormatted           => _supportsImageLoadFormatted.Value;
+        public static bool SupportsIndirectParameters           => _supportsIndirectParameters.Value;
+        public static bool SupportsParallelShaderCompile        => _supportsParallelShaderCompile.Value;
+        public static bool SupportsPolygonOffsetClamp           => _supportsPolygonOffsetClamp.Value;
+        public static bool SupportsQuads                        => _supportsQuads.Value;
+        public static bool SupportsSeamlessCubemapPerTexture    => _supportsSeamlessCubemapPerTexture.Value;
+        public static bool SupportsShaderBallot                 => _supportsShaderBallot.Value;
+        public static bool SupportsTextureShadowLod             => _supportsTextureShadowLod.Value;
+        public static bool SupportsViewportSwizzle              => _supportsViewportSwizzle.Value;
 
         public static bool SupportsMismatchingViewFormat    => _gpuVendor.Value != GpuVendor.AmdWindows && _gpuVendor.Value != GpuVendor.IntelWindows;
         public static bool SupportsNonConstantTextureOffset => _gpuVendor.Value == GpuVendor.Nvidia;
diff --git a/Ryujinx.Graphics.OpenGL/Pipeline.cs b/Ryujinx.Graphics.OpenGL/Pipeline.cs
index 62d4dee9..fde86424 100644
--- a/Ryujinx.Graphics.OpenGL/Pipeline.cs
+++ b/Ryujinx.Graphics.OpenGL/Pipeline.cs
@@ -918,6 +918,34 @@ namespace Ryujinx.Graphics.OpenGL
             }
         }
 
+        public void SetMultisampleState(MultisampleDescriptor multisample)
+        {
+            if (multisample.AlphaToCoverageEnable)
+            {
+                GL.Enable(EnableCap.SampleAlphaToCoverage);
+
+                if (multisample.AlphaToOneEnable)
+                {
+                    GL.Enable(EnableCap.SampleAlphaToOne);
+                }
+                else
+                {
+                    GL.Disable(EnableCap.SampleAlphaToOne);
+                }
+
+                if (HwCapabilities.SupportsAlphaToCoverageDitherControl)
+                {
+                    GL.NV.AlphaToCoverageDitherControl(multisample.AlphaToCoverageDitherEnable
+                        ? NvAlphaToCoverageDitherControl.AlphaToCoverageDitherEnableNv
+                        : NvAlphaToCoverageDitherControl.AlphaToCoverageDitherDisableNv);
+                }
+            }
+            else
+            {
+                GL.Disable(EnableCap.SampleAlphaToCoverage);
+            }
+        }
+
         public void SetLineParameters(float width, bool smooth)
         {
             if (smooth)