[dxvk] Enable sample rate shading if needed

src/dxvk/dxvk_constant_state.h

@@ -59,11 +59,9 @@ namespace dxvk {
    * aspects of multisampling.
    */
   struct DxvkMultisampleState {
-    uint32_t                sampleMask;
-    VkBool32                enableAlphaToCoverage;
-    VkBool32                enableAlphaToOne;
-    VkBool32                enableSampleShading;
-    float                   minSampleShading;
+    uint32_t            sampleMask;
+    VkBool32            enableAlphaToCoverage;
+    VkBool32            enableAlphaToOne;
   };
   
   

src/dxvk/dxvk_context.cpp

@@ -1277,8 +1277,6 @@ namespace dxvk {
     m_state.gp.state.msSampleMask            = ms.sampleMask;
     m_state.gp.state.msEnableAlphaToCoverage = ms.enableAlphaToCoverage;
     m_state.gp.state.msEnableAlphaToOne      = ms.enableAlphaToOne;
-    m_state.gp.state.msEnableSampleShading   = ms.enableSampleShading;
-    m_state.gp.state.msMinSampleShading      = ms.minSampleShading;
     
     m_flags.set(DxvkContextFlag::GpDirtyPipelineState);
   }

src/dxvk/dxvk_graphics.cpp

@@ -64,6 +64,9 @@ namespace dxvk {
     
     m_vsIn  = vs != nullptr ? vs->interfaceSlots().inputSlots  : 0;
     m_fsOut = fs != nullptr ? fs->interfaceSlots().outputSlots : 0;
+    
+    m_common.msSampleShadingEnable = fs != nullptr && fs->hasCapability(spv::CapabilitySampleRateShading);
+    m_common.msSampleShadingFactor = 1.0f;
   }
   
   
@@ -183,8 +186,8 @@ namespace dxvk {
     msInfo.pNext                  = nullptr;
     msInfo.flags                  = 0;
     msInfo.rasterizationSamples   = state.msSampleCount;
-    msInfo.sampleShadingEnable    = state.msEnableSampleShading;
-    msInfo.minSampleShading       = state.msMinSampleShading;
+    msInfo.sampleShadingEnable    = m_common.msSampleShadingEnable;
+    msInfo.minSampleShading       = m_common.msSampleShadingFactor;
     msInfo.pSampleMask            = &state.msSampleMask;
     msInfo.alphaToCoverageEnable  = state.msEnableAlphaToCoverage;
     msInfo.alphaToOneEnable       = state.msEnableAlphaToOne;

src/dxvk/dxvk_graphics.h

@@ -59,8 +59,6 @@ namespace dxvk {
     uint32_t                            msSampleMask;
     VkBool32                            msEnableAlphaToCoverage;
     VkBool32                            msEnableAlphaToOne;
-    VkBool32                            msEnableSampleShading;
-    float                               msMinSampleShading;
     
     VkBool32                            dsEnableDepthTest;
     VkBool32                            dsEnableDepthWrite;
@@ -79,6 +77,18 @@ namespace dxvk {
   };
   
   
+  /**
+   * \brief Common graphics pipeline state
+   * 
+   * Non-dynamic pipeline state that cannot
+   * be changed dynamically.
+   */
+  struct DxvkGraphicsCommonPipelineStateInfo {
+    bool                                msSampleShadingEnable;
+    float                               msSampleShadingFactor;
+  };
+  
+  
   /**
    * \brief Graphics pipeline
    * 
@@ -135,8 +145,8 @@ namespace dxvk {
     const DxvkDevice* const m_device;
     const Rc<vk::DeviceFn>  m_vkd;
     
-    Rc<DxvkPipelineCache> m_cache;
-    Rc<DxvkPipelineLayout> m_layout;
+    Rc<DxvkPipelineCache>   m_cache;
+    Rc<DxvkPipelineLayout>  m_layout;
     
     Rc<DxvkShaderModule>  m_vs;
     Rc<DxvkShaderModule>  m_tcs;
@@ -147,6 +157,8 @@ namespace dxvk {
     uint32_t m_vsIn  = 0;
     uint32_t m_fsOut = 0;
     
+    DxvkGraphicsCommonPipelineStateInfo m_common;
+    
     std::vector<PipelineStruct> m_pipelines;
     
     VkPipeline m_basePipeline = VK_NULL_HANDLE;

src/dxvk/dxvk_shader.cpp

@@ -57,6 +57,20 @@ namespace dxvk {
   }
   
   
+  bool DxvkShader::hasCapability(spv::Capability cap) {
+    for (auto ins : m_code) {
+      // OpCapability instructions come first
+      if (ins.opCode() != spv::OpCapability)
+        return false;
+      
+      if (ins.arg(1) == cap)
+        return true;
+    }
+    
+    return false;
+  }
+  
+  
   void DxvkShader::defineResourceSlots(
           DxvkDescriptorSlotMapping& mapping) const {
     for (const auto& slot : m_slots)

src/dxvk/dxvk_shader.h

@@ -98,6 +98,18 @@ namespace dxvk {
     
     ~DxvkShader();
     
+    /**
+     * \brief Checks whether a capability is enabled
+     * 
+     * If the shader contains an \c OpCapability
+     * instruction with the given capability, it
+     * is considered enabled. This may be required
+     * to correctly set up certain pipeline states.
+     * \param [in] cap The capability to check
+     * \returns \c true if \c cap is enabled
+     */
+    bool hasCapability(spv::Capability cap);
+    
     /**
      * \brief Adds resource slots definitions to a mapping
      * 

src/dxvk/hud/dxvk_hud.cpp

@@ -198,8 +198,6 @@ namespace dxvk::hud {
     msState.sampleMask            = 0xFFFFFFFF;
     msState.enableAlphaToCoverage = VK_FALSE;
     msState.enableAlphaToOne      = VK_FALSE;
-    msState.enableSampleShading   = VK_FALSE;
-    msState.minSampleShading      = 1.0f;
     m_context->setMultisampleState(msState);
     
     VkStencilOpState stencilOp;