[d3d11] Adjust buffer memory flags if apitrace is attached

Using cached memory speeds up apitrace significantly as it
reads back mapped memory regions.

src/d3d11/d3d11_buffer.cpp

@@ -252,6 +252,11 @@ namespace dxvk {
         break;
     }
     
+    if (memoryFlags & VK_MEMORY_PROPERTY_HOST_VISIBLE_BIT && m_device->GetOptions()->apitraceMode) {
+      memoryFlags |= VK_MEMORY_PROPERTY_HOST_COHERENT_BIT
+                  |  VK_MEMORY_PROPERTY_HOST_CACHED_BIT;
+    }
+
     return memoryFlags;
   }
 

src/d3d11/d3d11_options.cpp

@@ -17,6 +17,18 @@ namespace dxvk {
     this->numBackBuffers        = config.getOption<int32_t>("dxgi.numBackBuffers", 0);
     this->maxFrameLatency       = config.getOption<int32_t>("dxgi.maxFrameLatency", 0);
     this->syncInterval          = config.getOption<int32_t>("dxgi.syncInterval", -1);
+
+    bool apitraceAttached = false;
+    #ifndef __WINE__
+    apitraceAttached = ::GetModuleHandle("dxgitrace.dll") != nullptr;
+    #endif
+
+    this->apitraceMode = config.getOption<bool>("d3d11.apitraceMode", apitraceAttached);
+
+    // Inform user in case they have the option enabled or a game
+    // ships a file called dxgitrace.dll for whatever reason.
+    if (this->apitraceMode)
+      Logger::warn("D3D11: Apitrace mode enabled, may affect performance!");
   }
   
 }

src/d3d11/d3d11_options.h

@@ -76,6 +76,10 @@ namespace dxvk {
     /// fixes issues with games that create multiple swap chains
     /// for a single window that may interfere with each other.
     bool deferSurfaceCreation;
+
+    /// Apitrace mode: Maps all buffers in cached memory.
+    /// Enabled automatically if dxgitrace.dll is attached.
+    bool apitraceMode;
   };
   
 }