1 files changed, 93 insertions, 0 deletions
diff --git a/src/Ryujinx.Graphics.Shader/Translation/Transforms/DrawParametersReplace.cs b/src/Ryujinx.Graphics.Shader/Translation/Transforms/DrawParametersReplace.cs
new file mode 100644
index 00000000..9e73013d
--- /dev/null
+++ b/src/Ryujinx.Graphics.Shader/Translation/Transforms/DrawParametersReplace.cs
@@ -0,0 +1,93 @@
+using Ryujinx.Graphics.Shader.IntermediateRepresentation;
+using System.Collections.Generic;
+
+using static Ryujinx.Graphics.Shader.IntermediateRepresentation.OperandHelper;
+
+namespace Ryujinx.Graphics.Shader.Translation.Transforms
+{
+    class DrawParametersReplace : ITransformPass
+    {
+        public static bool IsEnabled(IGpuAccessor gpuAccessor, ShaderStage stage, TargetLanguage targetLanguage, FeatureFlags usedFeatures)
+        {
+            return stage == ShaderStage.Vertex;
+        }
+
+        public static LinkedListNode<INode> RunPass(TransformContext context, LinkedListNode<INode> node)
+        {
+            Operation operation = (Operation)node.Value;
+
+            if (context.GpuAccessor.QueryHasConstantBufferDrawParameters())
+            {
+                if (ReplaceConstantBufferWithDrawParameters(node, operation))
+                {
+                    context.UsedFeatures |= FeatureFlags.DrawParameters;
+                }
+            }
+            else if (HasConstantBufferDrawParameters(operation))
+            {
+                context.UsedFeatures |= FeatureFlags.DrawParameters;
+            }
+
+            return node;
+        }
+
+        private static bool ReplaceConstantBufferWithDrawParameters(LinkedListNode<INode> node, Operation operation)
+        {
+            Operand GenerateLoad(IoVariable ioVariable)
+            {
+                Operand value = Local();
+                node.List.AddBefore(node, new Operation(Instruction.Load, StorageKind.Input, value, Const((int)ioVariable)));
+                return value;
+            }
+
+            bool modified = false;
+
+            for (int srcIndex = 0; srcIndex < operation.SourcesCount; srcIndex++)
+            {
+                Operand src = operation.GetSource(srcIndex);
+
+                if (src.Type == OperandType.ConstantBuffer && src.GetCbufSlot() == 0)
+                {
+                    switch (src.GetCbufOffset())
+                    {
+                        case Constants.NvnBaseVertexByteOffset / 4:
+                            operation.SetSource(srcIndex, GenerateLoad(IoVariable.BaseVertex));
+                            modified = true;
+                            break;
+                        case Constants.NvnBaseInstanceByteOffset / 4:
+                            operation.SetSource(srcIndex, GenerateLoad(IoVariable.BaseInstance));
+                            modified = true;
+                            break;
+                        case Constants.NvnDrawIndexByteOffset / 4:
+                            operation.SetSource(srcIndex, GenerateLoad(IoVariable.DrawIndex));
+                            modified = true;
+                            break;
+                    }
+                }
+            }
+
+            return modified;
+        }
+
+        private static bool HasConstantBufferDrawParameters(Operation operation)
+        {
+            for (int srcIndex = 0; srcIndex < operation.SourcesCount; srcIndex++)
+            {
+                Operand src = operation.GetSource(srcIndex);
+
+                if (src.Type == OperandType.ConstantBuffer && src.GetCbufSlot() == 0)
+                {
+                    switch (src.GetCbufOffset())
+                    {
+                        case Constants.NvnBaseVertexByteOffset / 4:
+                        case Constants.NvnBaseInstanceByteOffset / 4:
+                        case Constants.NvnDrawIndexByteOffset / 4:
+                            return true;
+                    }
+                }
+            }
+
+            return false;
+        }
+    }
+}