Fix incorrect fragment origin when YNegate is enabled (#4673)

* Fix incorrect fragment origin when YNegate is enabled

* Shader cache version bump

* Do not update support buffer if shader does not read gl_FragCoord

* Pass unscaled viewport size to the support buffer

src/Ryujinx.Graphics.Gpu/Engine/Threed/SpecializationStateUpdater.cs

@@ -342,5 +342,19 @@ namespace Ryujinx.Graphics.Gpu.Engine.Threed
                 Signal();
             }
         }
+
+        /// <summary>
+        /// Sets the Y negate enabled state.
+        /// </summary>
+        /// <param name="enabled">True if Y negate of the fragment coordinates is enabled</param>
+        public void SetYNegateEnabled(bool enabled)
+        {
+            if (enabled != _graphics.YNegateEnabled)
+            {
+                _graphics.YNegateEnabled = enabled;
+
+                Signal();
+            }
+        }
     }
 }

src/Ryujinx.Graphics.Gpu/Engine/Threed/StateUpdater.cs

@@ -37,6 +37,7 @@ namespace Ryujinx.Graphics.Gpu.Engine.Threed
 
         private ProgramPipelineState _pipeline;
 
+        private bool _fsReadsFragCoord;
         private bool _vsUsesDrawParameters;
         private bool _vtgWritesRtLayer;
         private byte _vsClipDistancesWritten;
@@ -692,12 +693,11 @@ namespace Ryujinx.Graphics.Gpu.Engine.Threed
             var face = _state.State.FaceState;
 
             bool disableTransform = _state.State.ViewportTransformEnable == 0;
+            bool yNegate = yControl.HasFlag(YControl.NegateY);
 
             UpdateFrontFace(yControl, face.FrontFace);
             UpdateDepthMode();
 
-            bool flipY = yControl.HasFlag(YControl.NegateY);
-
             Span<Viewport> viewports = stackalloc Viewport[Constants.TotalViewports];
 
             for (int index = 0; index < Constants.TotalViewports; index++)
@@ -719,7 +719,7 @@ namespace Ryujinx.Graphics.Gpu.Engine.Threed
                 float scaleX = MathF.Abs(transform.ScaleX);
                 float scaleY = transform.ScaleY;
 
-                if (flipY)
+                if (yNegate)
                 {
                     scaleY = -scaleY;
                 }
@@ -771,8 +771,17 @@ namespace Ryujinx.Graphics.Gpu.Engine.Threed
                 _channel.TextureManager.RenderTargetScale,
                 disableTransform);
 
+            // Viewport size is only used on the shader when YNegate is enabled,
+            // and if the fragment shader accesses gl_FragCoord,
+            // so there's no need to update it in other cases.
+            if (yNegate && _fsReadsFragCoord)
+            {
+                UpdateSupportBufferViewportSize();
+            }
+
             _currentSpecState.SetViewportTransformDisable(disableTransform);
             _currentSpecState.SetDepthMode(GetDepthMode() == DepthMode.MinusOneToOne);
+            _currentSpecState.SetYNegateEnabled(yNegate);
         }
 
         /// <summary>
@@ -1415,9 +1424,41 @@ namespace Ryujinx.Graphics.Gpu.Engine.Threed
                 _currentProgramInfo[stageIndex] = info;
             }
 
+            if (gs.Shaders[5]?.Info.UsesFragCoord == true)
+            {
+                // Make sure we update the viewport size on the support buffer if it will be consumed on the new shader.
+
+                if (!_fsReadsFragCoord && _state.State.YControl.HasFlag(YControl.NegateY))
+                {
+                    UpdateSupportBufferViewportSize();
+                }
+
+                _fsReadsFragCoord = true;
+            }
+            else
+            {
+                _fsReadsFragCoord = false;
+            }
+
             _context.Renderer.Pipeline.SetProgram(gs.HostProgram);
         }
 
+        /// <summary>
+        /// Updates the viewport size on the support buffer for fragment shader access.
+        /// </summary>
+        private void UpdateSupportBufferViewportSize()
+        {
+            ref var transform = ref _state.State.ViewportTransform[0];
+
+            float scaleX = MathF.Abs(transform.ScaleX);
+            float scaleY = transform.ScaleY;
+
+            float width = scaleX * 2;
+            float height = scaleY * 2;
+
+            _context.SupportBufferUpdater.SetViewportSize(width, MathF.Abs(height));
+        }
+
         /// <summary>
         /// Updates bindings consumed by the shader on the texture and buffer managers.
         /// </summary>

src/Ryujinx.Graphics.Gpu/Memory/SupportBufferUpdater.cs

@@ -112,6 +112,17 @@ namespace Ryujinx.Graphics.Gpu.Memory
             MarkDirty(SupportBuffer.ViewportInverseOffset, SupportBuffer.FieldSize);
         }
 
+        /// <summary>
+        /// Updates the viewport size vector.
+        /// </summary>
+        /// <param name="data">Viewport size vector</param>
+        private void UpdateViewportSize(Vector4<float> data)
+        {
+            _data.ViewportSize = data;
+
+            MarkDirty(SupportBuffer.ViewportSizeOffset, SupportBuffer.FieldSize);
+        }
+
         /// <summary>
         /// Sets the scale of all output render targets (they should all have the same scale).
         /// </summary>
@@ -192,6 +203,25 @@ namespace Ryujinx.Graphics.Gpu.Memory
             }
         }
 
+        /// <summary>
+        /// Sets the viewport size, used to invert the fragment coordinates Y value.
+        /// </summary>
+        /// <param name="viewportWidth">Value used as viewport width</param>
+        /// <param name="viewportHeight">Value used as viewport height</param>
+        public void SetViewportSize(float viewportWidth, float viewportHeight)
+        {
+            if (_data.ViewportSize.X != viewportWidth || _data.ViewportSize.Y != viewportHeight)
+            {
+                UpdateViewportSize(new Vector4<float>
+                {
+                    X = viewportWidth,
+                    Y = viewportHeight,
+                    Z = 1,
+                    W = 0
+                });
+            }
+        }
+
         /// <summary>
         /// Submits all pending buffer updates to the GPU.
         /// </summary>

src/Ryujinx.Graphics.Gpu/Shader/DiskCache/DiskCacheGpuAccessor.cs

@@ -247,6 +247,12 @@ namespace Ryujinx.Graphics.Gpu.Shader.DiskCache
             return _oldSpecState.GraphicsState.ViewportTransformDisable;
         }
 
+        /// <inheritdoc/>
+        public bool QueryYNegateEnabled()
+        {
+            return _oldSpecState.GraphicsState.YNegateEnabled;
+        }
+
         /// <inheritdoc/>
         public void RegisterTexture(int handle, int cbufSlot)
         {

src/Ryujinx.Graphics.Gpu/Shader/DiskCache/DiskCacheHostStorage.cs

@@ -22,7 +22,7 @@ namespace Ryujinx.Graphics.Gpu.Shader.DiskCache
         private const ushort FileFormatVersionMajor = 1;
         private const ushort FileFormatVersionMinor = 2;
         private const uint FileFormatVersionPacked = ((uint)FileFormatVersionMajor << 16) | FileFormatVersionMinor;
-        private const uint CodeGenVersion = 5266;
+        private const uint CodeGenVersion = 4675;
 
         private const string SharedTocFileName = "shared.toc";
         private const string SharedDataFileName = "shared.data";
@@ -140,6 +140,11 @@ namespace Ryujinx.Graphics.Gpu.Shader.DiskCache
             /// </summary>
             public ShaderStage Stage;
 
+            /// <summary>
+            /// Indicates if the fragment shader accesses the fragment coordinate built-in variable.
+            /// </summary>
+            public bool UsesFragCoord;
+
             /// <summary>
             /// Indicates if the shader accesses the Instance ID built-in variable.
             /// </summary>
@@ -781,6 +786,7 @@ namespace Ryujinx.Graphics.Gpu.Shader.DiskCache
                 ShaderIdentification.None,
                 0,
                 dataInfo.Stage,
+                dataInfo.UsesFragCoord,
                 dataInfo.UsesInstanceId,
                 dataInfo.UsesDrawParameters,
                 dataInfo.UsesRtLayer,
@@ -807,6 +813,7 @@ namespace Ryujinx.Graphics.Gpu.Shader.DiskCache
                 TexturesCount = (ushort)info.Textures.Count,
                 ImagesCount = (ushort)info.Images.Count,
                 Stage = info.Stage,
+                UsesFragCoord = info.UsesFragCoord,
                 UsesInstanceId = info.UsesInstanceId,
                 UsesDrawParameters = info.UsesDrawParameters,
                 UsesRtLayer = info.UsesRtLayer,

src/Ryujinx.Graphics.Gpu/Shader/GpuAccessor.cs

@@ -113,6 +113,13 @@ namespace Ryujinx.Graphics.Gpu.Shader
             return _state.GraphicsState.AttributeTypes[location];
         }
 
+        /// <inheritdoc/>
+        public bool QueryEarlyZForce()
+        {
+            _state.SpecializationState?.RecordEarlyZForce();
+            return _state.GraphicsState.EarlyZForce;
+        }
+
         /// <inheritdoc/>
         public AttributeType QueryFragmentOutputType(int location)
         {
@@ -275,19 +282,18 @@ namespace Ryujinx.Graphics.Gpu.Shader
             return _state.TransformFeedbackDescriptors[bufferIndex].Stride;
         }
 
-        /// <inheritdoc/>
-        public bool QueryEarlyZForce()
-        {
-            _state.SpecializationState?.RecordEarlyZForce();
-            return _state.GraphicsState.EarlyZForce;
-        }
-
         /// <inheritdoc/>
         public bool QueryViewportTransformDisable()
         {
             return _state.GraphicsState.ViewportTransformDisable;
         }
 
+        /// <inheritdoc/>
+        public bool QueryYNegateEnabled()
+        {
+            return _state.GraphicsState.YNegateEnabled;
+        }
+
         /// <inheritdoc/>
         public void RegisterTexture(int handle, int cbufSlot)
         {

src/Ryujinx.Graphics.Gpu/Shader/GpuChannelGraphicsState.cs

@@ -97,6 +97,11 @@ namespace Ryujinx.Graphics.Gpu.Shader
         /// </summary>
         public bool DualSourceBlendEnable;
 
+        /// <summary>
+        /// Indicates whether Y negate of the fragment coordinates is enabled.
+        /// </summary>
+        public bool YNegateEnabled;
+
         /// <summary>
         /// Creates a new GPU graphics state.
         /// </summary>
@@ -116,7 +121,8 @@ namespace Ryujinx.Graphics.Gpu.Shader
         /// <param name="hasConstantBufferDrawParameters">Indicates that the draw is writing the base vertex, base instance and draw index to Constant Buffer 0</param>
         /// <param name="hasUnalignedStorageBuffer">Indicates that any storage buffer use is unaligned</param>
         /// <param name="fragmentOutputTypes">Type of the fragment shader outputs</param>
-        /// <param name="dualSourceBlendEnable">Type of the vertex attributes consumed by the shader</param>
+        /// <param name="dualSourceBlendEnable">Indicates whether dual source blend is enabled</param>
+        /// <param name="yNegateEnabled">Indicates whether Y negate of the fragment coordinates is enabled</param>
         public GpuChannelGraphicsState(
             bool earlyZForce,
             PrimitiveTopology topology,
@@ -134,7 +140,8 @@ namespace Ryujinx.Graphics.Gpu.Shader
             bool hasConstantBufferDrawParameters,
             bool hasUnalignedStorageBuffer,
             ref Array8<AttributeType> fragmentOutputTypes,
-            bool dualSourceBlendEnable)
+            bool dualSourceBlendEnable,
+            bool yNegateEnabled)
         {
             EarlyZForce = earlyZForce;
             Topology = topology;
@@ -153,6 +160,7 @@ namespace Ryujinx.Graphics.Gpu.Shader
             HasUnalignedStorageBuffer = hasUnalignedStorageBuffer;
             FragmentOutputTypes = fragmentOutputTypes;
             DualSourceBlendEnable = dualSourceBlendEnable;
+            YNegateEnabled = yNegateEnabled;
         }
     }
 }

src/Ryujinx.Graphics.Gpu/Shader/ShaderSpecializationState.cs

@@ -540,6 +540,11 @@ namespace Ryujinx.Graphics.Gpu.Shader
                 return false;
             }
 
+            if (graphicsState.YNegateEnabled != GraphicsState.YNegateEnabled)
+            {
+                return false;
+            }
+
             return Matches(channel, ref poolState, checkTextures, isCompute: false);
         }