Initial work

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

@@ -0,0 +1,141 @@
+using Ryujinx.Graphics.Shader.CodeGen.Glsl.Instructions;
+using Ryujinx.Graphics.Shader.IntermediateRepresentation;
+using Ryujinx.Graphics.Shader.StructuredIr;
+using System;
+
+using static Ryujinx.Graphics.Shader.CodeGen.Glsl.TypeConversion;
+
+namespace Ryujinx.Graphics.Shader.CodeGen.Glsl
+{
+    static class GlslGenerator
+    {
+        public static GlslProgram Generate(StructuredProgramInfo info, ShaderConfig config)
+        {
+            CodeGenContext context = new CodeGenContext(config);
+
+            Declarations.Declare(context, info);
+
+            PrintMainBlock(context, info);
+
+            return new GlslProgram(
+                context.CBufferDescriptors.ToArray(),
+                context.SBufferDescriptors.ToArray(),
+                context.TextureDescriptors.ToArray(),
+                context.GetCode());
+        }
+
+        private static void PrintMainBlock(CodeGenContext context, StructuredProgramInfo info)
+        {
+            context.AppendLine("void main()");
+
+            context.EnterScope();
+
+            Declarations.DeclareLocals(context, info);
+
+            // Ensure that unused attributes are set, otherwise the downstream
+            // compiler may eliminate them.
+            // (Not needed for fragment shader as it is the last stage).
+            if (context.Config.Stage != ShaderStage.Compute &&
+                context.Config.Stage != ShaderStage.Fragment)
+            {
+                for (int attr = 0; attr < Declarations.MaxAttributes; attr++)
+                {
+                    if (info.OAttributes.Contains(attr))
+                    {
+                        continue;
+                    }
+
+                    context.AppendLine($"{DefaultNames.OAttributePrefix}{attr} = vec4(0);");
+                }
+            }
+
+            PrintBlock(context, info.MainBlock);
+
+            context.LeaveScope();
+        }
+
+        private static void PrintBlock(CodeGenContext context, AstBlock block)
+        {
+            AstBlockVisitor visitor = new AstBlockVisitor(block);
+
+            visitor.BlockEntered += (sender, e) =>
+            {
+                switch (e.Block.Type)
+                {
+                    case AstBlockType.DoWhile:
+                        context.AppendLine("do");
+                        break;
+
+                    case AstBlockType.Else:
+                        context.AppendLine("else");
+                        break;
+
+                    case AstBlockType.ElseIf:
+                        context.AppendLine($"else if ({GetCondExpr(context, e.Block.Condition)})");
+                        break;
+
+                    case AstBlockType.If:
+                        context.AppendLine($"if ({GetCondExpr(context, e.Block.Condition)})");
+                        break;
+
+                    default: throw new InvalidOperationException($"Found unexpected block type \"{e.Block.Type}\".");
+                }
+
+                context.EnterScope();
+            };
+
+            visitor.BlockLeft += (sender, e) =>
+            {
+                context.LeaveScope();
+
+                if (e.Block.Type == AstBlockType.DoWhile)
+                {
+                    context.AppendLine($"while ({GetCondExpr(context, e.Block.Condition)});");
+                }
+            };
+
+            foreach (IAstNode node in visitor.Visit())
+            {
+                if (node is AstOperation operation)
+                {
+                    context.AppendLine(InstGen.GetExpression(context, operation) + ";");
+                }
+                else if (node is AstAssignment assignment)
+                {
+                    VariableType srcType = OperandManager.GetNodeDestType(assignment.Source);
+                    VariableType dstType = OperandManager.GetNodeDestType(assignment.Destination);
+
+                    string dest;
+
+                    if (assignment.Destination is AstOperand operand && operand.Type == OperandType.Attribute)
+                    {
+                        dest = OperandManager.GetOutAttributeName(operand, context.Config.Stage);
+                    }
+                    else
+                    {
+                        dest = InstGen.GetExpression(context, assignment.Destination);
+                    }
+
+                    string src = ReinterpretCast(context, assignment.Source, srcType, dstType);
+
+                    context.AppendLine(dest + " = " + src + ";");
+                }
+                else if (node is AstComment comment)
+                {
+                    context.AppendLine("// " + comment.Comment);
+                }
+                else
+                {
+                    throw new InvalidOperationException($"Found unexpected node type \"{node?.GetType().Name ?? "null"}\".");
+                }
+            }
+        }
+
+        private static string GetCondExpr(CodeGenContext context, IAstNode cond)
+        {
+            VariableType srcType = OperandManager.GetNodeDestType(cond);
+
+            return ReinterpretCast(context, cond, srcType, VariableType.Bool);
+        }
+    }
+}