HostDisplay: Add texture dumping/saving support

src/duckstation-sdl/d3d11_host_display.cpp

@@ -168,6 +168,24 @@ void D3D11HostDisplay::UpdateTexture(HostDisplayTexture* texture, u32 x, u32 y,
   }
 }
 
+bool D3D11HostDisplay::DownloadTexture(const void* texture_handle, u32 x, u32 y, u32 width, u32 height, void* out_data,
+                                       u32 out_data_stride)
+{
+  ID3D11ShaderResourceView* srv =
+    const_cast<ID3D11ShaderResourceView*>(static_cast<const ID3D11ShaderResourceView*>(texture_handle));
+  ID3D11Resource* srv_resource;
+  D3D11_SHADER_RESOURCE_VIEW_DESC srv_desc;
+  srv->GetResource(&srv_resource);
+  srv->GetDesc(&srv_desc);
+
+  if (!m_readback_staging_texture.EnsureSize(m_context.Get(), width, height, srv_desc.Format, false))
+    return false;
+
+  m_readback_staging_texture.CopyFromTexture(m_context.Get(), srv_resource, 0, x, y, 0, 0, width, height);
+  return m_readback_staging_texture.ReadPixels<u32>(m_context.Get(), 0, 0, width, height, out_data_stride / sizeof(u32),
+                                                    static_cast<u32*>(out_data));
+}
+
 void D3D11HostDisplay::SetVSync(bool enabled)
 {
   m_vsync = enabled;