From 5e42230b954353d5643f02791bfafe2256dee7c7 Mon Sep 17 00:00:00 2001
From: Philip Rebohle <philip.rebohle@tu-dortmund.de>
Date: Mon, 9 Jan 2023 14:54:55 +0100
Subject: [PATCH] [dxvk] Add patch vertex count to shader info struct

---
 src/dxvk/dxvk_graphics.cpp | 7 +++++++
 src/dxvk/dxvk_shader.cpp   | 7 +++++++
 src/dxvk/dxvk_shader.h     | 2 ++
 3 files changed, 16 insertions(+)

diff --git a/src/dxvk/dxvk_graphics.cpp b/src/dxvk/dxvk_graphics.cpp
index 424e5c36..1a653c87 100644
--- a/src/dxvk/dxvk_graphics.cpp
+++ b/src/dxvk/dxvk_graphics.cpp
@@ -1093,6 +1093,13 @@ namespace dxvk {
      || state.rs.conservativeMode() != VK_CONSERVATIVE_RASTERIZATION_MODE_DISABLED_EXT)
       return false;
 
+    if (m_shaders.tcs != nullptr) {
+      // If tessellation shaders are present, the input patch
+      // vertex count must match the shader's definition.
+      if (m_shaders.tcs->info().patchVertexCount != state.ia.patchVertexCount())
+        return false;
+    }
+
     if (m_shaders.fs != nullptr) {
       // If the fragment shader has inputs not produced by the last
       // pre-rasterization stage, we need to patch the fragment shader
diff --git a/src/dxvk/dxvk_shader.cpp b/src/dxvk/dxvk_shader.cpp
index 740276da..7a51eda8 100644
--- a/src/dxvk/dxvk_shader.cpp
+++ b/src/dxvk/dxvk_shader.cpp
@@ -1107,6 +1107,12 @@ namespace dxvk {
     dyInfo.dynamicStateCount  = dynamicStateCount;
     dyInfo.pDynamicStates     = dynamicStates.data();
 
+    // If a tessellation control shader is present, grab the patch vertex count
+    VkPipelineTessellationStateCreateInfo tsInfo = { VK_STRUCTURE_TYPE_PIPELINE_TESSELLATION_STATE_CREATE_INFO };
+
+    if (m_shaders.tcs)
+      tsInfo.patchControlPoints = m_shaders.tcs->info().patchVertexCount;
+
     // All viewport state is dynamic, so we do not need to initialize this.
     VkPipelineViewportStateCreateInfo vpInfo = { VK_STRUCTURE_TYPE_PIPELINE_VIEWPORT_STATE_CREATE_INFO };
 
@@ -1140,6 +1146,7 @@ namespace dxvk {
     info.flags                = VK_PIPELINE_CREATE_LIBRARY_BIT_KHR | flags;
     info.stageCount           = stageInfo.getStageCount();
     info.pStages              = stageInfo.getStageInfos();
+    info.pTessellationState   = m_shaders.tcs ? &tsInfo : nullptr;
     info.pViewportState       = &vpInfo;
     info.pRasterizationState  = &rsInfo;
     info.pDynamicState        = &dyInfo;
diff --git a/src/dxvk/dxvk_shader.h b/src/dxvk/dxvk_shader.h
index 9ab46fb4..b3f6123a 100644
--- a/src/dxvk/dxvk_shader.h
+++ b/src/dxvk/dxvk_shader.h
@@ -58,6 +58,8 @@ namespace dxvk {
     const char* uniformData = nullptr;
     /// Rasterized stream, or -1
     int32_t xfbRasterizedStream = 0;
+    /// Tess control patch vertex count
+    uint32_t patchVertexCount = 0;
     /// Transform feedback vertex strides
     uint32_t xfbStrides[MaxNumXfbBuffers] = { };
   };