[d3d9] Force staging buffer mapping for pure SWVP devices

src/d3d9/d3d9_common_buffer.cpp

@@ -57,6 +57,28 @@ namespace dxvk {
     }
   }
 
+  
+  D3D9_COMMON_BUFFER_MAP_MODE D3D9CommonBuffer::DetermineMapMode(const D3D9Options* options) const {
+    if (m_desc.Pool != D3DPOOL_DEFAULT)
+      return D3D9_COMMON_BUFFER_MAP_MODE_BUFFER;
+
+    if (!(m_desc.Usage & (D3DUSAGE_DYNAMIC | D3DUSAGE_WRITEONLY)))
+      return D3D9_COMMON_BUFFER_MAP_MODE_BUFFER;
+
+    // Tests show that DISCARD does not work for pure SWVP devices.
+    // So force staging buffer path to avoid stalls.
+    // Dark Romance: Vampire in Love also expects draws to be synchronous
+    // and breaks if we respect NOOVERWRITE.
+    // D&D Temple of Elemental Evil breaks if we respect DISCARD. 
+    if (m_parent->CanOnlySWVP())
+      return D3D9_COMMON_BUFFER_MAP_MODE_BUFFER;
+
+    if (!options->allowDirectBufferMapping)
+      return D3D9_COMMON_BUFFER_MAP_MODE_BUFFER;
+
+    return D3D9_COMMON_BUFFER_MAP_MODE_DIRECT;
+  }
+
 
   Rc<DxvkBuffer> D3D9CommonBuffer::CreateBuffer() const {
     DxvkBufferCreateInfo  info;

src/d3d9/d3d9_common_buffer.h

@@ -89,11 +89,7 @@ namespace dxvk {
     /**
     * \brief Determine the mapping mode of the buffer, (ie. direct mapping or backed)
     */
-    inline D3D9_COMMON_BUFFER_MAP_MODE DetermineMapMode(const D3D9Options* options) const {
-      return (m_desc.Pool == D3DPOOL_DEFAULT && (m_desc.Usage & (D3DUSAGE_DYNAMIC | D3DUSAGE_WRITEONLY)) && options->allowDirectBufferMapping)
-        ? D3D9_COMMON_BUFFER_MAP_MODE_DIRECT
-        : D3D9_COMMON_BUFFER_MAP_MODE_BUFFER;
-    }
+    D3D9_COMMON_BUFFER_MAP_MODE DetermineMapMode(const D3D9Options* options) const;
 
     /**
     * \brief Get the mapping mode of the buffer, (ie. direct mapping or backed)

src/d3d9/d3d9_device.h

@@ -998,6 +998,10 @@ namespace dxvk {
       }
     }
 
+    bool CanOnlySWVP() const {
+      return m_behaviorFlags & D3DCREATE_SOFTWARE_VERTEXPROCESSING;
+    }
+
   private:
 
     DxvkCsChunkRef AllocCsChunk() {
@@ -1024,10 +1028,9 @@ namespace dxvk {
       }
     }
 
-    bool CanSWVP() {
+    bool CanSWVP() const {
       return m_behaviorFlags & (D3DCREATE_MIXED_VERTEXPROCESSING | D3DCREATE_SOFTWARE_VERTEXPROCESSING);
     }
-
     void DetermineConstantLayouts(bool canSWVP);
 
     D3D9BufferSlice AllocUPBuffer(VkDeviceSize size);