Initial transform feedback support (#1370)

* Initial transform feedback support

* Some nits and fixes

* Update ReportCounterType and Write method

* Can't change shader or TFB bindings while TFB is active

* Fix geometry shader input names with new naming

1 files changed, 69 insertions, 0 deletions

diff --git a/Ryujinx.Graphics.Shader/CodeGen/Glsl/Varying.cs b/Ryujinx.Graphics.Shader/CodeGen/Glsl/Varying.cs
new file mode 100644
index 00000000..b9b2afb4
--- /dev/null
+++ b/Ryujinx.Graphics.Shader/CodeGen/Glsl/Varying.cs
@@ -0,0 +1,69 @@
+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