- add vk_submit_multithread for doing command buffer submit calls on a worker thread

- add vk_submit_size for testing various command buffer sizes before flushing them
- add submitted command buffer count to renderstats

src/rendering/vulkan/system/vk_framebuffer.h

@@ -3,6 +3,9 @@
 #include "gl_sysfb.h"
 #include "vk_device.h"
 #include "vk_objects.h"
+#include <thread>
+#include <mutex>
+#include <condition_variable>
 
 struct FRenderViewpoint;
 class VkSamplerManager;
@@ -111,6 +114,10 @@ private:
 	void CopyScreenToBuffer(int w, int h, void *data);
 	void UpdateShadowMap();
 	void DeleteFrameObjects();
+	void StartSubmitThread();
+	void StopSubmitThread();
+	void SubmitThreadMain();
+	void FlushCommands(VulkanCommandBuffer **commands, size_t count);
 
 	std::unique_ptr<VkShaderManager> mShaderManager;
 	std::unique_ptr<VkSamplerManager> mSamplerManager;
@@ -134,6 +141,14 @@ private:
 	std::unique_ptr<VulkanFence> mRenderFinishedFence;
 
 	VkRenderBuffers *mActiveRenderBuffers = nullptr;
+
+	std::thread mSubmitThread;
+	std::condition_variable mSubmitCondVar;
+	std::condition_variable mSubmitDone;
+	std::mutex mSubmitMutex;
+	std::vector<VulkanCommandBuffer*> mSubmitQueue;
+	size_t mSubmitItemsActive = 0;
+	bool mSubmitExitFlag = false;
 };
 
 inline VulkanFrameBuffer *GetVulkanFrameBuffer() { return static_cast<VulkanFrameBuffer*>(screen); }