New shader translator implementation (#654)

* Start implementing a new shader translator

* Fix shift instructions and a typo

* Small refactoring on StructuredProgram, move RemovePhis method to a separate class

* Initial geometry shader support

* Implement TLD4

* Fix -- There's no negation on FMUL32I

* Add constant folding and algebraic simplification optimizations, nits

* Some leftovers from constant folding

* Avoid cast for constant assignments

* Add a branch elimination pass, and misc small fixes

* Remove redundant branches, add expression propagation and other improvements on the code

* Small leftovers -- add missing break and continue, remove unused properties, other improvements

* Add null check to handle empty block cases on block visitor

* Add HADD2 and HMUL2 half float shader instructions

* Optimize pack/unpack sequences, some fixes related to half float instructions

* Add TXQ, TLD, TLDS and TLD4S shader texture instructions, and some support for bindless textures, some refactoring on codegen

* Fix copy paste mistake that caused RZ to be ignored on the AST instruction

* Add workaround for conditional exit, and fix half float instruction with constant buffer

* Add missing 0.0 source for TLDS.LZ variants

* Simplify the switch for TLDS.LZ

* Texture instructions related fixes

* Implement the HFMA instruction, and some misc. fixes

* Enable constant folding on UnpackHalf2x16 instructions

* Refactor HFMA to use OpCode* for opcode decoding rather than on the helper methods

* Remove the old shader translator

* Remove ShaderDeclInfo and other unused things

* Add dual vertex shader support

* Add ShaderConfig, used to pass shader type and maximum cbuffer size

* Move and rename some instruction enums

* Move texture instructions into a separate file

* Move operand GetExpression and locals management to OperandManager

* Optimize opcode decoding using a simple list and binary search

* Add missing condition for do-while on goto elimination

* Misc. fixes on texture instructions

* Simplify TLDS switch

* Address PR feedback, and a nit

1 files changed, 133 insertions, 0 deletions

diff --git a/Ryujinx.Graphics/Shader/CodeGen/Glsl/GlslGenerator.cs b/Ryujinx.Graphics/Shader/CodeGen/Glsl/GlslGenerator.cs
new file mode 100644
index 00000000..4edbda8b
--- /dev/null
+++ b/Ryujinx.Graphics/Shader/CodeGen/Glsl/GlslGenerator.cs
@@ -0,0 +1,133 @@
+using Ryujinx.Graphics.Gal;
+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.TextureDescriptors.ToArray(),
+                context.GetCode());
+        }
+
+        private static void PrintMainBlock(CodeGenContext context, StructuredProgramInfo info)
+        {
+            context.AppendLine("void main()");
+
+            context.EnterScope();
+
+            Declarations.DeclareLocals(context, info);
+
+            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)
+                {
+                    if (operation.Inst == Instruction.Return)
+                    {
+                        PrepareForReturn(context);
+                    }
+
+                    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.Type);
+                    }
+                    else
+                    {
+                        dest = InstGen.GetExpression(context, assignment.Destination);
+                    }
+
+                    string src = ReinterpretCast(context, assignment.Source, srcType, dstType);
+
+                    context.AppendLine(dest + " = " + src + ";");
+                }
+                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);
+        }
+
+        private static void PrepareForReturn(CodeGenContext context)
+        {
+            if (context.Config.Type == GalShaderType.Vertex)
+            {
+                context.AppendLine("gl_Position.xy *= flip;");
+            }
+        }
+    }
+}
\ No newline at end of file