[dxvk] Apply render target bindings at draw time

This should help reduce the number of redundant render pass spills,
especially in games which use deferred contexts for rendering. This
optimization mostly helps in GPU-bound scenarios.

src/dxvk/dxvk_context.cpp

@@ -98,19 +98,18 @@ namespace dxvk {
       
       m_state.om.framebuffer = fb;
     }
+    
+    m_state.om.renderTargets = fb != nullptr
+      ? fb->renderTargets()
+      : DxvkRenderTargets();
+    m_flags.clr(DxvkContextFlag::GpDirtyFramebuffer);
   }
   
   
   void DxvkContext::bindRenderTargets(const DxvkRenderTargets& targets) {
-    bool sameAsCurr = m_state.om.framebuffer != nullptr
-                   && m_state.om.framebuffer->renderTargets().matches(targets);
-    
-    if (!sameAsCurr) {
-      Rc<DxvkFramebuffer> fb = targets.hasAttachments()
-        ? m_device->createFramebuffer(targets)
-        : nullptr;
-      
-      this->bindFramebuffer(fb);
+    if (m_state.om.framebuffer == nullptr || !m_state.om.framebuffer->renderTargets().matches(targets)) {
+      m_state.om.renderTargets = targets;
+      m_flags.set(DxvkContextFlag::GpDirtyFramebuffer);
     }
   }
   
@@ -392,6 +391,8 @@ namespace dxvk {
     const VkClearRect&          clearRect,
           VkImageAspectFlags    clearAspects,
     const VkClearValue&         clearValue) {
+    this->updateFramebuffer();
+    
     // Check whether the render target view is an attachment
     // of the current framebuffer. If not, we need to create
     // a temporary framebuffer.
@@ -1798,6 +1799,23 @@ namespace dxvk {
   }
   
   
+  void DxvkContext::updateFramebuffer() {
+    if (m_flags.test(DxvkContextFlag::GpDirtyFramebuffer)) {
+      m_flags.clr(DxvkContextFlag::GpDirtyFramebuffer);
+      
+      this->spillRenderPass();
+      
+      auto fb = m_device->createFramebuffer(m_state.om.renderTargets);
+      
+      m_state.gp.state.msSampleCount = fb->sampleCount();
+      m_state.gp.state.omRenderPass  = fb->renderPass();
+      m_state.om.framebuffer = fb;
+      
+      m_flags.set(DxvkContextFlag::GpDirtyPipelineState);
+    }
+  }
+  
+  
   void DxvkContext::updateIndexBufferBinding() {
     if (m_flags.test(DxvkContextFlag::GpDirtyIndexBuffer)) {
       m_flags.clr(DxvkContextFlag::GpDirtyIndexBuffer);
@@ -1881,6 +1899,7 @@ namespace dxvk {
   
   
   void DxvkContext::commitGraphicsState() {
+    this->updateFramebuffer();
     this->startRenderPass();
     this->updateGraphicsPipeline();
     this->updateIndexBufferBinding();

src/dxvk/dxvk_context.h

@@ -662,9 +662,7 @@ namespace dxvk {
       const DxvkBindingState&       bindingState,
       const Rc<DxvkPipelineLayout>& layout);
     
-    void updateViewports();
-    void updateBlendConstants();
-    void updateStencilReference();
+    void updateFramebuffer();
     
     void updateIndexBufferBinding();
     void updateVertexBufferBindings();

src/dxvk/dxvk_context_state.h

@@ -22,6 +22,7 @@ namespace dxvk {
    */
   enum class DxvkContextFlag : uint64_t  {
     GpRenderPassBound,          ///< Render pass is currently bound
+    GpDirtyFramebuffer,         ///< Framebuffer binding is out of date
     GpDirtyPipeline,            ///< Graphics pipeline binding is out of date
     GpDirtyPipelineState,       ///< Graphics pipeline needs to be recompiled
     GpDirtyResources,           ///< Graphics pipeline resource bindings are out of date
@@ -53,6 +54,7 @@ namespace dxvk {
   
   
   struct DxvkOutputMergerState {
+    DxvkRenderTargets   renderTargets;
     Rc<DxvkFramebuffer> framebuffer       = nullptr;
     
     DxvkBlendConstants  blendConstants    = { 0.0f, 0.0f, 0.0f, 0.0f };