Vulkan: Make validation layers optional

They're now disabled by default, and can be enabled with the command line
argument `--vk-layers`.

When enabled, the errors about them being missing are now warnings, as
users were confused and thought this meant Vulkan is broken for them.

Fix crash in `~VulkanContext` when validation layers are disabled (exposed by
this PR since before they could not be disabled without source modification).

Also moved VulkanContext member initializations to header.

Fixes #37102.

2 files changed, 34 insertions, 41 deletions

diff --git a/drivers/vulkan/vulkan_context.cpp b/drivers/vulkan/vulkan_context.cpp
index 997ed3935f..8840391966 100644
--- a/drivers/vulkan/vulkan_context.cpp
+++ b/drivers/vulkan/vulkan_context.cpp
@@ -154,7 +154,7 @@ VkBool32 VulkanContext::_check_layers(uint32_t check_count, const char **check_n
 			}
 		}
 		if (!found) {
-			ERR_PRINT("Can't find layer: " + String(check_names[i]));
+			WARN_PRINT("Can't find layer: " + String(check_names[i]));
 			return 0;
 		}
 	}
@@ -1479,23 +1479,6 @@ VkPhysicalDeviceLimits VulkanContext::get_device_limits() const {
 	return gpu_props.limits;
 }
 
-VulkanContext::VulkanContext() {
-	queue_props = nullptr;
-	command_buffer_count = 0;
-	instance_validation_layers = nullptr;
-	use_validation_layers = true;
-	VK_KHR_incremental_present_enabled = true;
-	VK_GOOGLE_display_timing_enabled = true;
-
-	command_buffer_queue.resize(1); //first one is the setup command always
-	command_buffer_queue.write[0] = nullptr;
-	command_buffer_count = 1;
-	queues_initialized = false;
-
-	buffers_prepared = false;
-	swapchainImageCount = 0;
-}
-
 RID VulkanContext::local_device_create() {
 	LocalDevice ld;
 
@@ -1583,6 +1566,13 @@ void VulkanContext::local_device_free(RID p_local_device) {
 	local_device_owner.free(p_local_device);
 }
 
+VulkanContext::VulkanContext() {
+	use_validation_layers = Engine::get_singleton()->is_validation_layers_enabled();
+
+	command_buffer_queue.resize(1); // First one is always the setup command.
+	command_buffer_queue.write[0] = nullptr;
+}
+
 VulkanContext::~VulkanContext() {
 	if (queue_props) {
 		free(queue_props);
@@ -1596,7 +1586,7 @@ VulkanContext::~VulkanContext() {
 				vkDestroySemaphore(device, image_ownership_semaphores[i], nullptr);
 			}
 		}
-		if (inst_initialized) {
+		if (inst_initialized && use_validation_layers) {
 			DestroyDebugUtilsMessengerEXT(inst, dbg_messenger, nullptr);
 		}
 		vkDestroyDevice(device, nullptr);
diff --git a/drivers/vulkan/vulkan_context.h b/drivers/vulkan/vulkan_context.h
index 9ebea42ecb..59e404512a 100644
--- a/drivers/vulkan/vulkan_context.h
+++ b/drivers/vulkan/vulkan_context.h
@@ -37,6 +37,7 @@
 #include "core/rid_owner.h"
 #include "core/ustring.h"
 #include "servers/display_server.h"
+
 #include <vulkan/vulkan.h>
 
 class VulkanContext {
@@ -51,13 +52,15 @@ class VulkanContext {
 	VkPhysicalDevice gpu;
 	VkPhysicalDeviceProperties gpu_props;
 	uint32_t queue_family_count;
-	VkQueueFamilyProperties *queue_props;
+	VkQueueFamilyProperties *queue_props = nullptr;
 	VkDevice device;
 	bool device_initialized = false;
 	bool inst_initialized = false;
 
-	//present
-	bool queues_initialized;
+	bool buffers_prepared = false;
+
+	// Present queue.
+	bool queues_initialized = false;
 	uint32_t graphics_queue_family_index;
 	uint32_t present_queue_family_index;
 	bool separate_present_queue;
@@ -78,7 +81,6 @@ class VulkanContext {
 		VkCommandBuffer graphics_to_present_cmd;
 		VkImageView view;
 		VkFramebuffer framebuffer;
-
 	} SwapchainImageResources;
 
 	struct Window {
@@ -89,7 +91,7 @@ class VulkanContext {
 		uint32_t current_buffer = 0;
 		int width = 0;
 		int height = 0;
-		VkCommandPool present_cmd_pool; //for separate present queue
+		VkCommandPool present_cmd_pool; // For separate present queue.
 		VkRenderPass render_pass = VK_NULL_HANDLE;
 	};
 
@@ -102,19 +104,24 @@ class VulkanContext {
 	RID_Owner<LocalDevice, true> local_device_owner;
 
 	Map<DisplayServer::WindowID, Window> windows;
-	uint32_t swapchainImageCount;
+	uint32_t swapchainImageCount = 0;
 
-	//commands
+	// Commands.
 
 	bool prepared;
 
-	//extensions
-	bool VK_KHR_incremental_present_enabled;
-	bool VK_GOOGLE_display_timing_enabled;
-	const char **instance_validation_layers;
-	uint32_t enabled_extension_count;
-	uint32_t enabled_layer_count;
+	Vector<VkCommandBuffer> command_buffer_queue;
+	int command_buffer_count = 1;
+
+	// Extensions.
+
+	bool VK_KHR_incremental_present_enabled = true;
+	bool VK_GOOGLE_display_timing_enabled = true;
+	uint32_t enabled_extension_count = 0;
 	const char *extension_names[MAX_EXTENSIONS];
+
+	const char **instance_validation_layers = nullptr;
+	uint32_t enabled_layer_count = 0;
 	const char *enabled_layers[MAX_LAYERS];
 
 	PFN_vkCreateDebugUtilsMessengerEXT CreateDebugUtilsMessengerEXT;
@@ -142,7 +149,8 @@ class VulkanContext {
 	Error _initialize_extensions();
 
 	VkBool32 _check_layers(uint32_t check_count, const char **check_names, uint32_t layer_count, VkLayerProperties *layers);
-	static VKAPI_ATTR VkBool32 VKAPI_CALL _debug_messenger_callback(VkDebugUtilsMessageSeverityFlagBitsEXT messageSeverity,
+	static VKAPI_ATTR VkBool32 VKAPI_CALL _debug_messenger_callback(
+			VkDebugUtilsMessageSeverityFlagBitsEXT messageSeverity,
 			VkDebugUtilsMessageTypeFlagsEXT messageType,
 			const VkDebugUtilsMessengerCallbackDataEXT *pCallbackData,
 			void *pUserData);
@@ -160,12 +168,11 @@ class VulkanContext {
 	Error _create_swap_chain();
 	Error _create_semaphores();
 
-	Vector<VkCommandBuffer> command_buffer_queue;
-	int command_buffer_count;
-
 protected:
 	virtual const char *_get_platform_surface_extension() const = 0;
-	//	virtual VkResult _create_surface(VkSurfaceKHR *surface, VkInstance p_instance) = 0;
+
+	// Enabled via command line argument.
+	bool use_validation_layers = false;
 
 	virtual Error _window_create(DisplayServer::WindowID p_window_id, VkSurfaceKHR p_surface, int p_width, int p_height);
 
@@ -173,10 +180,6 @@ protected:
 		return inst;
 	}
 
-	bool buffers_prepared;
-
-	bool use_validation_layers;
-
 public:
 	VkDevice get_device();
 	VkPhysicalDevice get_physical_device();