Stop using glTransformFeedbackVaryings and use explicit layout on the shader (#3012)

* Stop using glTransformFeedbackVarying and use explicit layout on the shader

* This is no longer needed

* Shader cache version bump

* Fix gl_PerVertex output for tessellation control shaders

4 files changed, 38 insertions, 73 deletions

diff --git a/Ryujinx.Graphics.Shader/CodeGen/Glsl/CodeGenContext.cs b/Ryujinx.Graphics.Shader/CodeGen/Glsl/CodeGenContext.cs
index f0f8ea35..b4823019 100644
--- a/Ryujinx.Graphics.Shader/CodeGen/Glsl/CodeGenContext.cs
+++ b/Ryujinx.Graphics.Shader/CodeGen/Glsl/CodeGenContext.cs
@@ -103,6 +103,18 @@ namespace Ryujinx.Graphics.Shader.CodeGen.Glsl
             return _info.Functions[id];
         }
 
+        public TransformFeedbackOutput GetTransformFeedbackOutput(int location, int component)
+        {
+            int index = (AttributeConsts.UserAttributeBase / 4) + location * 4 + component;
+            return _info.TransformFeedbackOutputs[index];
+        }
+
+        public TransformFeedbackOutput GetTransformFeedbackOutput(int location)
+        {
+            int index = location / 4;
+            return _info.TransformFeedbackOutputs[index];
+        }
+
         private void UpdateIndentation()
         {
             _indentation = GetIndentation(_level);
diff --git a/Ryujinx.Graphics.Shader/CodeGen/Glsl/Declarations.cs b/Ryujinx.Graphics.Shader/CodeGen/Glsl/Declarations.cs
index d8956567..55d5551c 100644
--- a/Ryujinx.Graphics.Shader/CodeGen/Glsl/Declarations.cs
+++ b/Ryujinx.Graphics.Shader/CodeGen/Glsl/Declarations.cs
@@ -191,6 +191,20 @@ namespace Ryujinx.Graphics.Shader.CodeGen.Glsl
 
                     context.AppendLine();
                 }
+
+                if (context.Config.Stage != ShaderStage.Compute &&
+                    context.Config.Stage != ShaderStage.Fragment &&
+                    context.Config.TransformFeedbackEnabled)
+                {
+                    var tfOutput = context.GetTransformFeedbackOutput(AttributeConsts.PositionX);
+                    if (tfOutput.Valid)
+                    {
+                        context.AppendLine($"layout (xfb_buffer = {tfOutput.Buffer}, xfb_offset = {tfOutput.Offset}, xfb_stride = {tfOutput.Stride}) out gl_PerVertex");
+                        context.EnterScope();
+                        context.AppendLine("vec4 gl_Position;");
+                        context.LeaveScope(context.Config.Stage == ShaderStage.TessellationControl ? " gl_out[];" : ";");
+                    }
+                }
             }
             else
             {
@@ -514,7 +528,7 @@ namespace Ryujinx.Graphics.Shader.CodeGen.Glsl
             string pass = (context.Config.PassthroughAttributes & (1 << attr)) != 0 ? "passthrough, " : string.Empty;
             string name = $"{DefaultNames.IAttributePrefix}{attr}";
 
-            if ((context.Config.Options.Flags & TranslationFlags.Feedback) != 0)
+            if (context.Config.TransformFeedbackEnabled && context.Config.Stage != ShaderStage.Vertex)
             {
                 for (int c = 0; c < 4; c++)
                 {
@@ -559,13 +573,21 @@ namespace Ryujinx.Graphics.Shader.CodeGen.Glsl
             string suffix = OperandManager.IsArrayAttribute(context.Config.Stage, isOutAttr: true) ? "[]" : string.Empty;
             string name = $"{DefaultNames.OAttributePrefix}{attr}{suffix}";
 
-            if ((context.Config.Options.Flags & TranslationFlags.Feedback) != 0)
+            if (context.Config.TransformFeedbackEnabled && context.Config.Stage != ShaderStage.Fragment)
             {
                 for (int c = 0; c < 4; c++)
                 {
                     char swzMask = "xyzw"[c];
 
-                    context.AppendLine($"layout (location = {attr}, component = {c}) out float {name}_{swzMask};");
+                    string xfb = string.Empty;
+
+                    var tfOutput = context.GetTransformFeedbackOutput(attr, c);
+                    if (tfOutput.Valid)
+                    {
+                        xfb = $", xfb_buffer = {tfOutput.Buffer}, xfb_offset = {tfOutput.Offset}, xfb_stride = {tfOutput.Stride}";
+                    }
+
+                    context.AppendLine($"layout (location = {attr}, component = {c}{xfb}) out float {name}_{swzMask};");
                 }
             }
             else
diff --git a/Ryujinx.Graphics.Shader/CodeGen/Glsl/OperandManager.cs b/Ryujinx.Graphics.Shader/CodeGen/Glsl/OperandManager.cs
index 9680df27..b1bd8188 100644
--- a/Ryujinx.Graphics.Shader/CodeGen/Glsl/OperandManager.cs
+++ b/Ryujinx.Graphics.Shader/CodeGen/Glsl/OperandManager.cs
@@ -194,7 +194,7 @@ namespace Ryujinx.Graphics.Shader.CodeGen.Glsl
 
                     return name + $"[{(value >> 4)}]." + swzMask;
                 }
-                else if (config.Options.Flags.HasFlag(TranslationFlags.Feedback))
+                else if (config.TransformFeedbackEnabled && (config.Stage != ShaderStage.Vertex || isOutAttr))
                 {
                     string name = $"{prefix}{(value >> 4)}_{swzMask}";
 
diff --git a/Ryujinx.Graphics.Shader/CodeGen/Glsl/Varying.cs b/Ryujinx.Graphics.Shader/CodeGen/Glsl/Varying.cs
deleted file mode 100644
index b9b2afb4..00000000
--- a/Ryujinx.Graphics.Shader/CodeGen/Glsl/Varying.cs
+++ /dev/null
@@ -1,69 +0,0 @@
-using Ryujinx.Graphics.Shader.Translation;
-
-namespace Ryujinx.Graphics.Shader.CodeGen.Glsl
-{
-    public static class Varying
-    {
-        public static string GetName(int offset)
-        {
-            offset <<= 2;
-
-            if (offset >= AttributeConsts.UserAttributeBase &&
-                offset <  AttributeConsts.UserAttributeEnd)
-            {
-                offset -= AttributeConsts.UserAttributeBase;
-
-                string name = $"{ DefaultNames.OAttributePrefix}{(offset >> 4)}";
-
-                name += "_" + "xyzw"[(offset >> 2) & 3];
-
-                return name;
-            }
-
-            switch (offset)
-            {
-                case AttributeConsts.PositionX:
-                case AttributeConsts.PositionY:
-                case AttributeConsts.PositionZ:
-                case AttributeConsts.PositionW:
-                    return "gl_Position";
-                case AttributeConsts.PointSize:
-                    return "gl_PointSize";
-                case AttributeConsts.ClipDistance0:
-                    return "gl_ClipDistance[0]";
-                case AttributeConsts.ClipDistance1:
-                    return "gl_ClipDistance[1]";
-                case AttributeConsts.ClipDistance2:
-                    return "gl_ClipDistance[2]";
-                case AttributeConsts.ClipDistance3:
-                    return "gl_ClipDistance[3]";
-                case AttributeConsts.ClipDistance4:
-                    return "gl_ClipDistance[4]";
-                case AttributeConsts.ClipDistance5:
-                    return "gl_ClipDistance[5]";
-                case AttributeConsts.ClipDistance6:
-                    return "gl_ClipDistance[6]";
-                case AttributeConsts.ClipDistance7:
-                    return "gl_ClipDistance[7]";
-                case AttributeConsts.VertexId:
-                    return "gl_VertexID";
-            }
-
-            return null;
-        }
-
-        public static int GetSize(int offset)
-        {
-            switch (offset << 2)
-            {
-                case AttributeConsts.PositionX:
-                case AttributeConsts.PositionY:
-                case AttributeConsts.PositionZ:
-                case AttributeConsts.PositionW:
-                    return 4;
-            }
-
-            return 1;
-        }
-    }
-}
\ No newline at end of file