Implement experimental Vulkan backend

Source/Core/VideoBackends/Vulkan/TextureEncoder.h

@@ -0,0 +1,57 @@
+// Copyright 2016 Dolphin Emulator Project
+// Licensed under GPLv2+
+// Refer to the license.txt file included.
+
+#pragma once
+
+#include <memory>
+
+#include "VideoBackends/Vulkan/StreamBuffer.h"
+
+#include "VideoCommon/VideoCommon.h"
+
+namespace Vulkan
+{
+class StagingTexture2D;
+class StateTracker;
+class Texture2D;
+
+class TextureEncoder
+{
+public:
+  TextureEncoder();
+  ~TextureEncoder();
+
+  bool Initialize();
+
+  // Uses an encoding shader to copy src_texture to dest_ptr.
+  // Assumes that no render pass is currently in progress.
+  // WARNING: Executes the current command buffer.
+  void EncodeTextureToRam(StateTracker* state_tracker, VkImageView src_texture, u8* dest_ptr,
+                          u32 format, u32 native_width, u32 bytes_per_row, u32 num_blocks_y,
+                          u32 memory_stride, PEControl::PixelFormat src_format, bool is_intensity,
+                          int scale_by_half, const EFBRectangle& source);
+
+private:
+  // From OGL.
+  static const u32 NUM_TEXTURE_ENCODING_SHADERS = 64;
+  static const u32 ENCODING_TEXTURE_WIDTH = EFB_WIDTH * 4;
+  static const u32 ENCODING_TEXTURE_HEIGHT = 1024;
+  static const VkFormat ENCODING_TEXTURE_FORMAT = VK_FORMAT_B8G8R8A8_UNORM;
+
+  bool CompileShaders();
+  bool CreateEncodingRenderPass();
+  bool CreateEncodingTexture();
+  bool CreateDownloadTexture();
+
+  std::array<VkShaderModule, NUM_TEXTURE_ENCODING_SHADERS> m_texture_encoding_shaders = {};
+
+  VkRenderPass m_encoding_render_pass = VK_NULL_HANDLE;
+
+  std::unique_ptr<Texture2D> m_encoding_texture;
+  VkFramebuffer m_encoding_texture_framebuffer = VK_NULL_HANDLE;
+
+  std::unique_ptr<StagingTexture2D> m_download_texture;
+};
+
+}  // namespace Vulkan