Remove output interpolation qualifier (#1070)

Ryujinx.Graphics.Gpu/Shader/ShaderCache.cs

@@ -145,8 +145,6 @@ namespace Ryujinx.Graphics.Gpu.Shader
             gpShaders.Shaders[3] = TranslateGraphicsShader(state, ShaderStage.Geometry,               addresses.Geometry);
             gpShaders.Shaders[4] = TranslateGraphicsShader(state, ShaderStage.Fragment,               addresses.Fragment);
 
-            BackpropQualifiers(gpShaders);
-
             List<IShader> hostShaders = new List<IShader>();
 
             for (int stage = 0; stage < gpShaders.Shaders.Length; stage++)
@@ -375,45 +373,6 @@ namespace Ryujinx.Graphics.Gpu.Shader
             return new CachedShader(program, codeCached);
         }
 
-        /// <summary>
-        /// Performs backwards propagation of interpolation qualifiers or later shader stages input,
-        /// to ealier shader stages output.
-        /// This is required by older versions of OpenGL (pre-4.3).
-        /// </summary>
-        /// <param name="program">Graphics shader cached code</param>
-        private void BackpropQualifiers(GraphicsShader program)
-        {
-            ShaderProgram fragmentShader = program.Shaders[4]?.Program;
-
-            bool isFirst = true;
-
-            for (int stage = 3; stage >= 0; stage--)
-            {
-                if (program.Shaders[stage] == null)
-                {
-                    continue;
-                }
-
-                // We need to iterate backwards, since we do name replacement,
-                // and it would otherwise replace a subset of the longer names.
-                for (int attr = 31; attr >= 0; attr--)
-                {
-                    string iq = fragmentShader?.Info.InterpolationQualifiers[attr].ToGlslQualifier() ?? string.Empty;
-
-                    if (isFirst && !string.IsNullOrEmpty(iq))
-                    {
-                        program.Shaders[stage].Program.Replace($"{DefineNames.OutQualifierPrefixName}{attr}", iq);
-                    }
-                    else
-                    {
-                        program.Shaders[stage].Program.Replace($"{DefineNames.OutQualifierPrefixName}{attr} ", string.Empty);
-                    }
-                }
-
-                isFirst = false;
-            }
-        }
-
         /// <summary>
         /// Gets the primitive topology for the current draw.
         /// This is required by geometry shaders.

Ryujinx.Graphics.Shader/CodeGen/Glsl/Declarations.cs

@@ -400,9 +400,7 @@ namespace Ryujinx.Graphics.Shader.CodeGen.Glsl
         {
             for (int attr = 0; attr < MaxAttributes; attr++)
             {
-                string iq = $"{DefineNames.OutQualifierPrefixName}{attr} ";
+                context.AppendLine($"layout (location = {attr}) out vec4 {DefaultNames.OAttributePrefix}{attr};");
-
-                context.AppendLine($"layout (location = {attr}) {iq}out vec4 {DefaultNames.OAttributePrefix}{attr};");
             }
 
             foreach (int attr in info.OAttributes.OrderBy(x => x).Where(x => x >= MaxAttributes))

Ryujinx.Graphics.Shader/DefineNames.cs

@@ -1,7 +0,0 @@
-namespace Ryujinx.Graphics.Shader
-{
-    public static class DefineNames
-    {
-        public const string OutQualifierPrefixName = "S_OUT_QUALIFIER";
-    }
-}

Ryujinx.Graphics.Shader/InterpolationQualifier.cs

@@ -3,7 +3,7 @@ using System;
 namespace Ryujinx.Graphics.Shader
 {
     [Flags]
-    public enum InterpolationQualifier
+    enum InterpolationQualifier
     {
         None = 0,
 
@@ -17,18 +17,17 @@ namespace Ryujinx.Graphics.Shader
         FlagsMask = Centroid | Sample
     }
 
-    public static class InterpolationQualifierExtensions
+    static class InterpolationQualifierExtensions
     {
         public static string ToGlslQualifier(this InterpolationQualifier iq)
         {
-            string output = string.Empty;
+            string output = (iq & ~InterpolationQualifier.FlagsMask) switch
-
-            switch (iq & ~InterpolationQualifier.FlagsMask)
             {
-                case InterpolationQualifier.Flat:          output = "flat";          break;
+                InterpolationQualifier.Flat => "flat",
-                case InterpolationQualifier.NoPerspective: output = "noperspective"; break;
+                InterpolationQualifier.NoPerspective => "noperspective",
-                case InterpolationQualifier.Smooth:        output = "smooth";        break;
+                InterpolationQualifier.Smooth => "smooth",
-            }
+                _ => string.Empty
+            };
 
             if ((iq & InterpolationQualifier.Centroid) != 0)
             {

Ryujinx.Graphics.Shader/ShaderProgramInfo.cs

@@ -10,8 +10,6 @@ namespace Ryujinx.Graphics.Shader
         public ReadOnlyCollection<TextureDescriptor> Textures { get; }
         public ReadOnlyCollection<TextureDescriptor> Images   { get; }
 
-        public ReadOnlyCollection<InterpolationQualifier> InterpolationQualifiers { get; }
-
         public bool UsesInstanceId { get; }
 
         internal ShaderProgramInfo(
@@ -19,7 +17,6 @@ namespace Ryujinx.Graphics.Shader
             BufferDescriptor[]  sBuffers,
             TextureDescriptor[] textures,
             TextureDescriptor[] images,
-            InterpolationQualifier[] interpolationQualifiers,
             bool                usesInstanceId)
         {
             CBuffers = Array.AsReadOnly(cBuffers);
@@ -27,8 +24,6 @@ namespace Ryujinx.Graphics.Shader
             Textures = Array.AsReadOnly(textures);
             Images   = Array.AsReadOnly(images);
 
-            InterpolationQualifiers = Array.AsReadOnly(interpolationQualifiers);
-
             UsesInstanceId = usesInstanceId;
         }
     }

Ryujinx.Graphics.Shader/Translation/Translator.cs

@@ -79,7 +79,6 @@ namespace Ryujinx.Graphics.Shader.Translation
                 program.SBufferDescriptors,
                 program.TextureDescriptors,
                 program.ImageDescriptors,
-                sInfo.InterpolationQualifiers,
                 sInfo.UsesInstanceId);
 
             string glslCode = program.Code;