Add in-place swapchain recreation

Lots of todos, this should probably just be its own self-contained
object to allow the emulator to render "headlessly" regardless of a
swapchain existing or not.

include/renderer_vk/renderer_vk.hpp

@@ -4,6 +4,8 @@
 class GPU;
 
 class RendererVK final : public Renderer {
+	SDL_Window* targetWindow;
+
 	// The order of these `Unique*` members is important, they will be destroyed in RAII order
 	vk::UniqueInstance instance = {};
 	vk::UniqueDebugUtilsMessengerEXT debugMessenger = {};
@@ -12,6 +14,8 @@ class RendererVK final : public Renderer {
 
 	vk::PhysicalDevice physicalDevice = {};
 
+	vk::UniqueDevice device = {};
+
 	vk::Queue presentQueue = {};
 	u32 presentQueueFamily = ~0u;
 	vk::Queue graphicsQueue = {};
@@ -21,18 +25,13 @@ class RendererVK final : public Renderer {
 	vk::Queue transferQueue = {};
 	u32 transferQueueFamily = ~0u;
 
-	vk::UniqueDevice device = {};
+	vk::UniqueCommandPool commandPool = {};
 
 	vk::UniqueSwapchainKHR swapchain = {};
 	u32 swapchainImageCount = ~0u;
 	std::vector<vk::Image> swapchainImages = {};
 	std::vector<vk::UniqueImageView> swapchainImageViews = {};
 
-
-	// Global synchronization primitives
-
-	vk::UniqueCommandPool commandPool = {};
-
 	// Per-swapchain-image data
 	// Each vector is `swapchainImageCount` in size
 	std::vector<vk::UniqueCommandBuffer> presentCommandBuffers = {};
@@ -40,6 +39,9 @@ class RendererVK final : public Renderer {
 	std::vector<vk::UniqueSemaphore> renderFinishedSemaphore = {};
 	std::vector<vk::UniqueFence> frameFinishedFences = {};
 
+	// Recreate the swapchain, possibly re-using the old one in the case of a resize
+	vk::Result recreateSwapchain(vk::SurfaceKHR surface, vk::Extent2D swapchainExtent);
+
 	u64 currentFrame = 0;
   public:
 	RendererVK(GPU& gpu, const std::array<u32, regNum>& internalRegs);