Support non-constant texture offsets on non-NVIDIA gpus

1 files changed, 220 insertions, 2 deletions

diff --git a/Ryujinx.Graphics.Shader/Translation/Lowering.cs b/Ryujinx.Graphics.Shader/Translation/Lowering.cs
index 9a17dd83..1cd1df37 100644
--- a/Ryujinx.Graphics.Shader/Translation/Lowering.cs
+++ b/Ryujinx.Graphics.Shader/Translation/Lowering.cs
@@ -1,5 +1,6 @@
 using Ryujinx.Graphics.Shader.IntermediateRepresentation;
 using System.Collections.Generic;
+using System.Diagnostics;
 
 using static Ryujinx.Graphics.Shader.IntermediateRepresentation.OperandHelper;
 using static Ryujinx.Graphics.Shader.Translation.GlobalMemory;
@@ -23,13 +24,18 @@ namespace Ryujinx.Graphics.Shader.Translation
 
                     if (UsesGlobalMemory(operation.Inst))
                     {
-                        node = LowerGlobal(node, config);
+                        node = RewriteGlobalAccess(node, config);
+                    }
+
+                    if (!config.Capabilities.SupportsNonConstantTextureOffset && operation.Inst == Instruction.TextureSample)
+                    {
+                        node = RewriteTextureSample(node);
                     }
                 }
             }
         }
 
-        private static LinkedListNode<INode> LowerGlobal(LinkedListNode<INode> node, ShaderConfig config)
+        private static LinkedListNode<INode> RewriteGlobalAccess(LinkedListNode<INode> node, ShaderConfig config)
         {
             Operation operation = (Operation)node.Value;
 
@@ -117,5 +123,217 @@ namespace Ryujinx.Graphics.Shader.Translation
 
             return node;
         }
+
+        private static LinkedListNode<INode> RewriteTextureSample(LinkedListNode<INode> node)
+        {
+            TextureOperation texOp = (TextureOperation)node.Value;
+
+            bool hasOffset  = (texOp.Flags & TextureFlags.Offset)  != 0;
+            bool hasOffsets = (texOp.Flags & TextureFlags.Offsets) != 0;
+
+            if (!(hasOffset || hasOffsets))
+            {
+                return node;
+            }
+
+            bool isBindless     = (texOp.Flags & TextureFlags.Bindless)    != 0;
+            bool isGather       = (texOp.Flags & TextureFlags.Gather)      != 0;
+            bool hasDerivatives = (texOp.Flags & TextureFlags.Derivatives) != 0;
+            bool hasLodBias     = (texOp.Flags & TextureFlags.LodBias)     != 0;
+            bool hasLodLevel    = (texOp.Flags & TextureFlags.LodLevel)    != 0;
+
+            bool isArray       = (texOp.Type & SamplerType.Array)       != 0;
+            bool isIndexed     = (texOp.Type & SamplerType.Indexed)     != 0;
+            bool isMultisample = (texOp.Type & SamplerType.Multisample) != 0;
+            bool isShadow      = (texOp.Type & SamplerType.Shadow)      != 0;
+
+            int coordsCount = texOp.Type.GetDimensions();
+
+            int offsetsCount = coordsCount * (hasOffsets ? 4 : 1);
+
+            Operand[] offsets = new Operand[offsetsCount];
+            Operand[] sources = new Operand[texOp.SourcesCount - offsetsCount];
+
+            int srcIndex = 0;
+            int dstIndex = 0;
+
+            int copyCount = 0;
+
+            if (isBindless || isIndexed)
+            {
+                copyCount++;
+            }
+
+            Operand[] lodSources = new Operand[copyCount + coordsCount];
+
+            for (int index = 0; index < lodSources.Length; index++)
+            {
+                lodSources[index] = texOp.GetSource(index);
+            }
+
+            copyCount += coordsCount;
+
+            if (isArray)
+            {
+                copyCount++;
+            }
+
+            if (isShadow)
+            {
+                copyCount++;
+            }
+
+            if (hasDerivatives)
+            {
+                copyCount += coordsCount * 2;
+            }
+
+            if (isMultisample)
+            {
+                copyCount++;
+            }
+            else if (hasLodLevel)
+            {
+                copyCount++;
+            }
+
+            for (int index = 0; index < copyCount; index++)
+            {
+                sources[dstIndex++] = texOp.GetSource(srcIndex++);
+            }
+
+            bool areAllOffsetsConstant = true;
+
+            for (int index = 0; index < offsetsCount; index++)
+            {
+                Operand offset = texOp.GetSource(srcIndex++);
+
+                areAllOffsetsConstant &= offset.Type == OperandType.Constant;
+
+                offsets[index] = offset;
+            }
+
+            if (areAllOffsetsConstant)
+            {
+                return node;
+            }
+
+            if (hasLodBias)
+            {
+               sources[dstIndex++] = texOp.GetSource(srcIndex++);
+            }
+
+            if (isGather && !isShadow)
+            {
+               sources[dstIndex++] = texOp.GetSource(srcIndex++);
+            }
+
+            Operand Int(Operand value)
+            {
+                Operand res = Local();
+
+                node.List.AddBefore(node, new Operation(Instruction.ConvertFPToS32, res, value));
+
+                return res;
+            }
+
+            Operand Float(Operand value)
+            {
+                Operand res = Local();
+
+                node.List.AddBefore(node, new Operation(Instruction.ConvertS32ToFP, res, value));
+
+                return res;
+            }
+
+            Operand lod = Local();
+
+            node.List.AddBefore(node, new TextureOperation(
+                Instruction.Lod,
+                texOp.Type,
+                texOp.Flags,
+                texOp.Handle,
+                1,
+                lod,
+                lodSources));
+
+            int coordsIndex = isBindless || isIndexed ? 1 : 0;
+
+            for (int index = 0; index < coordsCount; index++)
+            {
+                Operand coordSize = Local();
+
+                Operand[] texSizeSources;
+
+                if (isBindless || isIndexed)
+                {
+                    texSizeSources = new Operand[] { sources[0], Int(lod) };
+                }
+                else
+                {
+                    texSizeSources = new Operand[] { Int(lod) };
+                }
+
+                node.List.AddBefore(node, new TextureOperation(
+                    Instruction.TextureSize,
+                    texOp.Type,
+                    texOp.Flags,
+                    texOp.Handle,
+                    index,
+                    coordSize,
+                    texSizeSources));
+
+                Operand offset = Local();
+
+                Operand intOffset = offsets[index + (hasOffsets ? texOp.Index * coordsCount : 0)];
+
+                node.List.AddBefore(node, new Operation(Instruction.FP | Instruction.Divide, offset, Float(intOffset), Float(coordSize)));
+
+                Operand source = sources[coordsIndex + index];
+
+                Operand coordPlusOffset = Local();
+
+                node.List.AddBefore(node, new Operation(Instruction.FP | Instruction.Add, coordPlusOffset, source, offset));
+
+                sources[coordsIndex + index] = coordPlusOffset;
+            }
+
+            int componentIndex;
+
+            if (isGather && !isShadow)
+            {
+                Operand gatherComponent = sources[dstIndex - 1];
+
+                Debug.Assert(gatherComponent.Type == OperandType.Constant);
+
+                componentIndex = gatherComponent.Value;
+            }
+            else
+            {
+                componentIndex = texOp.Index;
+            }
+
+            TextureOperation newTexOp = new TextureOperation(
+                Instruction.TextureSample,
+                texOp.Type,
+                texOp.Flags & ~(TextureFlags.Offset | TextureFlags.Offsets),
+                texOp.Handle,
+                componentIndex,
+                texOp.Dest,
+                sources);
+
+            for (int index = 0; index < texOp.SourcesCount; index++)
+            {
+                texOp.SetSource(index, null);
+            }
+
+            LinkedListNode<INode> oldNode = node;
+
+            node = node.List.AddBefore(node, newTexOp);
+
+            node.List.Remove(oldNode);
+
+            return node;
+        }
     }
 }
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