Account for the case surface_capabilities.currentExtent is unset

Wayland in particular sets surface_capabilities.currentExtent.width to
the special value 0xFFFFFFFF, which is valid per spec.
Fixes godotengine#98779

It may also fix misc issues when resizing on all platforms.

Superseedes PR godotengine#98780 , thanks to user tdaven for the original patch.
PR godotengine#98780 would break Android support as it did not account that width
and height might need to be swapped.

Replaced manual swap by Godot's SWAP(), which indicates intention much
easier.

drivers/vulkan/rendering_device_driver_vulkan.cpp

@@ -2887,21 +2887,28 @@ Error RenderingDeviceDriverVulkan::swap_chain_resize(CommandQueueID p_cmd_queue,
 
 	// No swapchain yet, this is the first time we're creating it.
 	if (!swap_chain->vk_swapchain) {
-		uint32_t width = surface_capabilities.currentExtent.width;
-		uint32_t height = surface_capabilities.currentExtent.height;
+		if (surface_capabilities.currentExtent.width == 0xFFFFFFFF) {
+			// The current extent is currently undefined, so the current surface width and height will be clamped to the surface's capabilities.
+			// We make sure to overwrite surface_capabilities.currentExtent.width so that the same check further below
+			// does not set extent.width = CLAMP( surface->width, ... ) on the first run of this function, because
+			// that'd be potentially unswapped.
+			surface_capabilities.currentExtent.width = CLAMP(surface->width, surface_capabilities.minImageExtent.width, surface_capabilities.maxImageExtent.width);
+			surface_capabilities.currentExtent.height = CLAMP(surface->height, surface_capabilities.minImageExtent.height, surface_capabilities.maxImageExtent.height);
+		}
+
+		// We must SWAP() only once otherwise we'll keep ping-ponging between
+		// the right and wrong resolutions after multiple calls to swap_chain_resize().
 		if (surface_capabilities.currentTransform & VK_SURFACE_TRANSFORM_ROTATE_90_BIT_KHR ||
 				surface_capabilities.currentTransform & VK_SURFACE_TRANSFORM_ROTATE_270_BIT_KHR) {
 			// Swap to get identity width and height.
-			surface_capabilities.currentExtent.height = width;
-			surface_capabilities.currentExtent.width = height;
+			SWAP(surface_capabilities.currentExtent.width, surface_capabilities.currentExtent.height);
 		}
-
-		native_display_size = surface_capabilities.currentExtent;
 	}
 
 	VkExtent2D extent;
 	if (surface_capabilities.currentExtent.width == 0xFFFFFFFF) {
 		// The current extent is currently undefined, so the current surface width and height will be clamped to the surface's capabilities.
+		// We can only be here on the second call to swap_chain_resize(), by which time surface->width & surface->height should already be swapped if needed.
 		extent.width = CLAMP(surface->width, surface_capabilities.minImageExtent.width, surface_capabilities.maxImageExtent.width);
 		extent.height = CLAMP(surface->height, surface_capabilities.minImageExtent.height, surface_capabilities.maxImageExtent.height);
 	} else {
@@ -2991,7 +2998,7 @@ Error RenderingDeviceDriverVulkan::swap_chain_resize(CommandQueueID p_cmd_queue,
 	swap_create_info.minImageCount = desired_swapchain_images;
 	swap_create_info.imageFormat = swap_chain->format;
 	swap_create_info.imageColorSpace = swap_chain->color_space;
-	swap_create_info.imageExtent = native_display_size;
+	swap_create_info.imageExtent = extent;
 	swap_create_info.imageArrayLayers = 1;
 	swap_create_info.imageUsage = VK_IMAGE_USAGE_COLOR_ATTACHMENT_BIT;
 	swap_create_info.imageSharingMode = VK_SHARING_MODE_EXCLUSIVE;

drivers/vulkan/rendering_device_driver_vulkan.h

@@ -366,7 +366,6 @@ class RenderingDeviceDriverVulkan : public RenderingDeviceDriver {
 	};
 
 	void _swap_chain_release(SwapChain *p_swap_chain);
-	VkExtent2D native_display_size;
 
 public:
 	virtual SwapChainID swap_chain_create(RenderingContextDriver::SurfaceID p_surface) override final;