From 8e84b919d6e01ed592bf7fe6af704ea0f3076a00 Mon Sep 17 00:00:00 2001
From: Colin Cornaby <colin.cornaby@mac.com>
Date: Sun, 20 Aug 2023 11:21:37 -0700
Subject: [PATCH] Preventing redundant binds of samplers by tracking them
 locally

---
 .../pfMetalPipeline/plMetalMaterialShaderRef.cpp       |  9 +++++++--
 .../FeatureLib/pfMetalPipeline/plMetalPipeline.cpp     |  5 +++++
 .../FeatureLib/pfMetalPipeline/plMetalPipeline.h       | 10 ++++++++++
 3 files changed, 22 insertions(+), 2 deletions(-)

diff --git a/Sources/Plasma/FeatureLib/pfMetalPipeline/plMetalMaterialShaderRef.cpp b/Sources/Plasma/FeatureLib/pfMetalPipeline/plMetalMaterialShaderRef.cpp
index 0f16b27fd4..c4c85ad2d4 100644
--- a/Sources/Plasma/FeatureLib/pfMetalPipeline/plMetalMaterialShaderRef.cpp
+++ b/Sources/Plasma/FeatureLib/pfMetalPipeline/plMetalMaterialShaderRef.cpp
@@ -311,8 +311,13 @@ void plMetalMaterialShaderRef::IBuildLayerTexture(MTL::RenderCommandEncoder *enc
         
     }
     
-    MTL::SamplerState* samplerState = fPipeline->fDevice.SampleStateForClampFlags(hsGMatState::hsGMatClampFlags(layer->GetClampFlags()));
-    encoder->setFragmentSamplerState(samplerState, offsetFromRootLayer);
+    if (fPipeline->fState.layerStates[offsetFromRootLayer].clampFlag != layer->GetClampFlags())
+    {
+        MTL::SamplerState* samplerState = fPipeline->fDevice.SampleStateForClampFlags(hsGMatState::hsGMatClampFlags(layer->GetClampFlags()));
+        encoder->setFragmentSamplerState(samplerState, offsetFromRootLayer);
+        
+        fPipeline->fState.layerStates[offsetFromRootLayer].clampFlag = hsGMatState::hsGMatClampFlags(layer->GetClampFlags());
+    }
 }
 
 uint32_t plMetalMaterialShaderRef::ILayersAtOnce(uint32_t which)
diff --git a/Sources/Plasma/FeatureLib/pfMetalPipeline/plMetalPipeline.cpp b/Sources/Plasma/FeatureLib/pfMetalPipeline/plMetalPipeline.cpp
index 86f34a269f..83cec3f098 100644
--- a/Sources/Plasma/FeatureLib/pfMetalPipeline/plMetalPipeline.cpp
+++ b/Sources/Plasma/FeatureLib/pfMetalPipeline/plMetalPipeline.cpp
@@ -4619,4 +4619,9 @@ void plMetalPipeline::plMetalPipelineCurrentState::Reset()
     fCurrentDepthStencilState = nullptr;
     fCurrentVertexBuffer = nullptr;
     fCurrentCullMode.reset();
+    
+    for(auto& layer: layerStates)
+    {
+        layer.clampFlag = hsGMatState::hsGMatClampFlags(-1);
+    }
 }
diff --git a/Sources/Plasma/FeatureLib/pfMetalPipeline/plMetalPipeline.h b/Sources/Plasma/FeatureLib/pfMetalPipeline/plMetalPipeline.h
index 20101abe69..bdd4e4e123 100644
--- a/Sources/Plasma/FeatureLib/pfMetalPipeline/plMetalPipeline.h
+++ b/Sources/Plasma/FeatureLib/pfMetalPipeline/plMetalPipeline.h
@@ -269,7 +269,17 @@ class plMetalPipeline : public pl3DPipeline<plMetalDevice>
     
     NS::AutoreleasePool* fCurrentPool;
     
+    /// Describes the state for the "fixed function" shader.
     struct plMetalPipelineCurrentState {
+        
+        // notes state of a given layer for a draw pass
+        // index is the offset from the curent root layer
+        // for the draw pass, not the overall index in the
+        // material
+        struct plMetalPipelineLayerState {
+            hsGMatState::hsGMatClampFlags clampFlag;
+        } layerStates[8];
+        
         std::optional<MTL::CullMode>            fCurrentCullMode;
         const MTL::RenderPipelineState*         fCurrentPipelineState;
         MTL::Buffer*                            fCurrentVertexBuffer;