1 files changed, 227 insertions, 0 deletions
diff --git a/Ryujinx.Graphics.Shader/CodeGen/Spirv/ScalingHelpers.cs b/Ryujinx.Graphics.Shader/CodeGen/Spirv/ScalingHelpers.cs
new file mode 100644
index 00000000..8503771c
--- /dev/null
+++ b/Ryujinx.Graphics.Shader/CodeGen/Spirv/ScalingHelpers.cs
@@ -0,0 +1,227 @@
+using Ryujinx.Graphics.Shader.IntermediateRepresentation;
+using Ryujinx.Graphics.Shader.StructuredIr;
+using Ryujinx.Graphics.Shader.Translation;
+using static Spv.Specification;
+
+namespace Ryujinx.Graphics.Shader.CodeGen.Spirv
+{
+    using SpvInstruction = Spv.Generator.Instruction;
+
+    static class ScalingHelpers
+    {
+        public static SpvInstruction ApplyScaling(
+            CodeGenContext context,
+            AstTextureOperation texOp,
+            SpvInstruction vector,
+            bool intCoords,
+            bool isBindless,
+            bool isIndexed,
+            bool isArray,
+            int pCount)
+        {
+            if (intCoords)
+            {
+                if (context.Config.Stage.SupportsRenderScale() &&
+                    !isBindless &&
+                    !isIndexed)
+                {
+                    int index = texOp.Inst == Instruction.ImageLoad
+                        ? context.Config.GetTextureDescriptors().Length + context.Config.FindImageDescriptorIndex(texOp)
+                        : context.Config.FindTextureDescriptorIndex(texOp);
+
+                    if (pCount == 3 && isArray)
+                    {
+                        return ApplyScaling2DArray(context, vector, index);
+                    }
+                    else if (pCount == 2 && !isArray)
+                    {
+                        return ApplyScaling2D(context, vector, index);
+                    }
+                }
+            }
+
+            return vector;
+        }
+
+        private static SpvInstruction ApplyScaling2DArray(CodeGenContext context, SpvInstruction vector, int index)
+        {
+            // The array index is not scaled, just x and y.
+            var vectorXY = context.VectorShuffle(context.TypeVector(context.TypeS32(), 2), vector, vector, 0, 1);
+            var vectorZ = context.CompositeExtract(context.TypeS32(), vector, 2);
+            var vectorXYScaled = ApplyScaling2D(context, vectorXY, index);
+            var vectorScaled = context.CompositeConstruct(context.TypeVector(context.TypeS32(), 3), vectorXYScaled, vectorZ);
+
+            return vectorScaled;
+        }
+
+        private static SpvInstruction ApplyScaling2D(CodeGenContext context, SpvInstruction vector, int index)
+        {
+            var pointerType = context.TypePointer(StorageClass.Uniform, context.TypeFP32());
+            var fieldIndex = context.Constant(context.TypeU32(), 4);
+            var scaleIndex = context.Constant(context.TypeU32(), index);
+
+            if (context.Config.Stage == ShaderStage.Vertex)
+            {
+                var scaleCountPointerType = context.TypePointer(StorageClass.Uniform, context.TypeS32());
+                var scaleCountElemPointer = context.AccessChain(scaleCountPointerType, context.SupportBuffer, context.Constant(context.TypeU32(), 3));
+                var scaleCount = context.Load(context.TypeS32(), scaleCountElemPointer);
+
+                scaleIndex = context.IAdd(context.TypeU32(), scaleIndex, scaleCount);
+            }
+
+            scaleIndex = context.IAdd(context.TypeU32(), scaleIndex, context.Constant(context.TypeU32(), 1));
+
+            var scaleElemPointer = context.AccessChain(pointerType, context.SupportBuffer, fieldIndex, scaleIndex);
+            var scale = context.Load(context.TypeFP32(), scaleElemPointer);
+
+            var ivector2Type = context.TypeVector(context.TypeS32(), 2);
+            var localVector = context.CoordTemp;
+
+            var passthrough = context.FOrdEqual(context.TypeBool(), scale, context.Constant(context.TypeFP32(), 1f));
+
+            var mergeLabel = context.Label();
+
+            if (context.Config.Stage == ShaderStage.Fragment)
+            {
+                var scaledInterpolatedLabel = context.Label();
+                var scaledNoInterpolationLabel = context.Label();
+
+                var needsInterpolation = context.FOrdLessThan(context.TypeBool(), scale, context.Constant(context.TypeFP32(), 0f));
+
+                context.SelectionMerge(mergeLabel, SelectionControlMask.MaskNone);
+                context.BranchConditional(needsInterpolation, scaledInterpolatedLabel, scaledNoInterpolationLabel);
+
+                // scale < 0.0
+                context.AddLabel(scaledInterpolatedLabel);
+
+                ApplyScalingInterpolated(context, localVector, vector, scale);
+                context.Branch(mergeLabel);
+
+                // scale >= 0.0
+                context.AddLabel(scaledNoInterpolationLabel);
+
+                ApplyScalingNoInterpolation(context, localVector, vector, scale);
+                context.Branch(mergeLabel);
+
+                context.AddLabel(mergeLabel);
+
+                var passthroughLabel = context.Label();
+                var finalMergeLabel = context.Label();
+
+                context.SelectionMerge(finalMergeLabel, SelectionControlMask.MaskNone);
+                context.BranchConditional(passthrough, passthroughLabel, finalMergeLabel);
+
+                context.AddLabel(passthroughLabel);
+
+                context.Store(localVector, vector);
+                context.Branch(finalMergeLabel);
+
+                context.AddLabel(finalMergeLabel);
+
+                return context.Load(ivector2Type, localVector);
+            }
+            else
+            {
+                var passthroughLabel = context.Label();
+                var scaledLabel = context.Label();
+
+                context.SelectionMerge(mergeLabel, SelectionControlMask.MaskNone);
+                context.BranchConditional(passthrough, passthroughLabel, scaledLabel);
+
+                // scale == 1.0
+                context.AddLabel(passthroughLabel);
+
+                context.Store(localVector, vector);
+                context.Branch(mergeLabel);
+
+                // scale != 1.0
+                context.AddLabel(scaledLabel);
+
+                ApplyScalingNoInterpolation(context, localVector, vector, scale);
+                context.Branch(mergeLabel);
+
+                context.AddLabel(mergeLabel);
+
+                return context.Load(ivector2Type, localVector);
+            }
+        }
+
+        private static void ApplyScalingInterpolated(CodeGenContext context, SpvInstruction output, SpvInstruction vector, SpvInstruction scale)
+        {
+            var vector2Type = context.TypeVector(context.TypeFP32(), 2);
+
+            var scaleNegated = context.FNegate(context.TypeFP32(), scale);
+            var scaleVector = context.CompositeConstruct(vector2Type, scaleNegated, scaleNegated);
+
+            var vectorFloat = context.ConvertSToF(vector2Type, vector);
+            var vectorScaled = context.VectorTimesScalar(vector2Type, vectorFloat, scaleNegated);
+
+            var fragCoordPointer = context.Inputs[AttributeConsts.PositionX];
+            var fragCoord = context.Load(context.TypeVector(context.TypeFP32(), 4), fragCoordPointer);
+            var fragCoordXY = context.VectorShuffle(vector2Type, fragCoord, fragCoord, 0, 1);
+
+            var scaleMod = context.FMod(vector2Type, fragCoordXY, scaleVector);
+            var vectorInterpolated = context.FAdd(vector2Type, vectorScaled, scaleMod);
+
+            context.Store(output, context.ConvertFToS(context.TypeVector(context.TypeS32(), 2), vectorInterpolated));
+        }
+
+        private static void ApplyScalingNoInterpolation(CodeGenContext context, SpvInstruction output, SpvInstruction vector, SpvInstruction scale)
+        {
+            if (context.Config.Stage == ShaderStage.Vertex)
+            {
+                scale = context.GlslFAbs(context.TypeFP32(), scale);
+            }
+
+            var vector2Type = context.TypeVector(context.TypeFP32(), 2);
+
+            var vectorFloat = context.ConvertSToF(vector2Type, vector);
+            var vectorScaled = context.VectorTimesScalar(vector2Type, vectorFloat, scale);
+
+            context.Store(output, context.ConvertFToS(context.TypeVector(context.TypeS32(), 2), vectorScaled));
+        }
+
+        public static SpvInstruction ApplyUnscaling(
+            CodeGenContext context,
+            AstTextureOperation texOp,
+            SpvInstruction size,
+            bool isBindless,
+            bool isIndexed)
+        {
+            if (context.Config.Stage.SupportsRenderScale() &&
+                !isBindless &&
+                !isIndexed)
+            {
+                int index = context.Config.FindTextureDescriptorIndex(texOp);
+
+                var pointerType = context.TypePointer(StorageClass.Uniform, context.TypeFP32());
+                var fieldIndex = context.Constant(context.TypeU32(), 4);
+                var scaleIndex = context.Constant(context.TypeU32(), index);
+
+                if (context.Config.Stage == ShaderStage.Vertex)
+                {
+                    var scaleCountPointerType = context.TypePointer(StorageClass.Uniform, context.TypeS32());
+                    var scaleCountElemPointer = context.AccessChain(scaleCountPointerType, context.SupportBuffer, context.Constant(context.TypeU32(), 3));
+                    var scaleCount = context.Load(context.TypeS32(), scaleCountElemPointer);
+
+                    scaleIndex = context.IAdd(context.TypeU32(), scaleIndex, scaleCount);
+                }
+
+                scaleIndex = context.IAdd(context.TypeU32(), scaleIndex, context.Constant(context.TypeU32(), 1));
+
+                var scaleElemPointer = context.AccessChain(pointerType, context.SupportBuffer, fieldIndex, scaleIndex);
+                var scale = context.GlslFAbs(context.TypeFP32(), context.Load(context.TypeFP32(), scaleElemPointer));
+
+                var passthrough = context.FOrdEqual(context.TypeBool(), scale, context.Constant(context.TypeFP32(), 1f));
+
+                var sizeFloat = context.ConvertSToF(context.TypeFP32(), size);
+                var sizeUnscaled = context.FDiv(context.TypeFP32(), sizeFloat, scale);
+                var sizeUnscaledInt = context.ConvertFToS(context.TypeS32(), sizeUnscaled);
+
+                return context.Select(context.TypeS32(), passthrough, size, sizeUnscaledInt);
+            }
+
+            return size;
+        }
+    }
+}
+\ No newline at end of file