05_window_surface.zig

const std = @import("std");
const builtin = @import("builtin");
const Allocator = std.mem.Allocator;

const glfw = @import("glfw");
const vk = @import("vulkan");

const WIDTH: u32 = 800;
const HEIGHT: u32 = 600;

const validation_layers = [_][*:0]const u8{"VK_LAYER_KHRONOS_validation"};

const enable_validation_layers: bool = switch (builtin.mode) {
    .Debug, .ReleaseSafe => true,
    else => false,
};

const BaseDispatch = vk.BaseWrapper(.{
    .createInstance = true,
    .enumerateInstanceLayerProperties = true,
});

const InstanceDispatch = vk.InstanceWrapper(.{
    .createDebugUtilsMessengerEXT = enable_validation_layers,
    .createDevice = true,
    .destroyDebugUtilsMessengerEXT = enable_validation_layers,
    .destroyInstance = true,
    .destroySurfaceKHR = true,
    .enumeratePhysicalDevices = true,
    .getDeviceProcAddr = true,
    .getPhysicalDeviceQueueFamilyProperties = true,
    .getPhysicalDeviceSurfaceSupportKHR = true,
});

const DeviceDispatch = vk.DeviceWrapper(.{
    .destroyDevice = true,
    .getDeviceQueue = true,
});

const QueueFamilyIndices = struct {
    graphics_family: ?u32 = null,
    present_family: ?u32 = null,

    fn isComplete(self: *const QueueFamilyIndices) bool {
        return self.graphics_family != null and self.present_family != null;
    }
};

const HelloTriangleApplication = struct {
    const Self = @This();
    allocator: Allocator,

    window: ?glfw.Window = null,

    vkb: BaseDispatch = undefined,
    vki: InstanceDispatch = undefined,
    vkd: DeviceDispatch = undefined,

    instance: vk.Instance = .null_handle,
    debug_messenger: vk.DebugUtilsMessengerEXT = .null_handle,
    surface: vk.SurfaceKHR = .null_handle,

    physical_device: vk.PhysicalDevice = .null_handle,
    device: vk.Device = .null_handle,

    graphics_queue: vk.Queue = .null_handle,
    present_queue: vk.Queue = .null_handle,

    pub fn init(allocator: Allocator) Self {
        return Self{ .allocator = allocator };
    }

    pub fn run(self: *Self) !void {
        try self.initWindow();
        try self.initVulkan();
        try self.mainLoop();
    }

    fn initWindow(self: *Self) !void {
        try glfw.init(.{});
        self.window = try glfw.Window.create(WIDTH, HEIGHT, "Vulkan", null, null, .{
            .client_api = .no_api,
            .resizable = false,
        });
    }

    fn initVulkan(self: *Self) !void {
        try self.createInstance();
        try self.setupDebugMessenger();
        try self.createSurface();
        try self.pickPhysicalDevice();
        try self.createLogicalDevice();
    }

    fn mainLoop(self: *Self) !void {
        while (!self.window.?.shouldClose()) {
            try glfw.pollEvents();
        }
    }

    pub fn deinit(self: *Self) void {
        if (self.device != .null_handle) self.vkd.destroyDevice(self.device, null);

        if (enable_validation_layers and self.debug_messenger != .null_handle) self.vki.destroyDebugUtilsMessengerEXT(self.instance, self.debug_messenger, null);

        if (self.surface != .null_handle) self.vki.destroySurfaceKHR(self.instance, self.surface, null);
        if (self.instance != .null_handle) self.vki.destroyInstance(self.instance, null);

        if (self.window != null) self.window.?.destroy();

        glfw.terminate();
    }

    fn createInstance(self: *Self) !void {
        const vk_proc = @ptrCast(*const fn (instance: vk.Instance, procname: [*:0]const u8) callconv(.C) vk.PfnVoidFunction, &glfw.getInstanceProcAddress);
        self.vkb = try BaseDispatch.load(vk_proc);

        if (enable_validation_layers and !try self.checkValidationLayerSupport()) {
            return error.MissingValidationLayer;
        }

        const app_info = vk.ApplicationInfo{
            .p_application_name = "Hello Triangle",
            .application_version = vk.makeApiVersion(1, 0, 0, 0),
            .p_engine_name = "No Engine",
            .engine_version = vk.makeApiVersion(1, 0, 0, 0),
            .api_version = vk.API_VERSION_1_2,
        };

        const extensions = try getRequiredExtensions(self.allocator);
        defer extensions.deinit();

        var create_info = vk.InstanceCreateInfo{
            .flags = .{},
            .p_application_info = &app_info,
            .enabled_layer_count = 0,
            .pp_enabled_layer_names = undefined,
            .enabled_extension_count = @intCast(u32, extensions.items.len),
            .pp_enabled_extension_names = extensions.items.ptr,
        };

        if (enable_validation_layers) {
            create_info.enabled_layer_count = validation_layers.len;
            create_info.pp_enabled_layer_names = &validation_layers;

            var debug_create_info: vk.DebugUtilsMessengerCreateInfoEXT = undefined;
            populateDebugMessengerCreateInfo(&debug_create_info);
            create_info.p_next = &debug_create_info;
        }

        self.instance = try self.vkb.createInstance(&create_info, null);

        self.vki = try InstanceDispatch.load(self.instance, vk_proc);
    }

    fn populateDebugMessengerCreateInfo(create_info: *vk.DebugUtilsMessengerCreateInfoEXT) void {
        create_info.* = .{
            .flags = .{},
            .message_severity = .{
                .verbose_bit_ext = true,
                .warning_bit_ext = true,
                .error_bit_ext = true,
            },
            .message_type = .{
                .general_bit_ext = true,
                .validation_bit_ext = true,
                .performance_bit_ext = true,
            },
            .pfn_user_callback = debugCallback,
            .p_user_data = null,
        };
    }

    fn setupDebugMessenger(self: *Self) !void {
        if (!enable_validation_layers) return;

        var create_info: vk.DebugUtilsMessengerCreateInfoEXT = undefined;
        populateDebugMessengerCreateInfo(&create_info);

        self.debug_messenger = try self.vki.createDebugUtilsMessengerEXT(self.instance, &create_info, null);
    }

    fn createSurface(self: *Self) !void {
        if ((try glfw.createWindowSurface(self.instance, self.window.?, null, &self.surface)) != @enumToInt(vk.Result.success)) {
            return error.SurfaceInitFailed;
        }
    }

    fn pickPhysicalDevice(self: *Self) !void {
        var device_count: u32 = undefined;
        _ = try self.vki.enumeratePhysicalDevices(self.instance, &device_count, null);

        if (device_count == 0) {
            return error.NoGPUsSupportVulkan;
        }

        const devices = try self.allocator.alloc(vk.PhysicalDevice, device_count);
        defer self.allocator.free(devices);
        _ = try self.vki.enumeratePhysicalDevices(self.instance, &device_count, devices.ptr);

        for (devices) |device| {
            if (try self.isDeviceSuitable(device)) {
                self.physical_device = device;
                break;
            }
        }

        if (self.physical_device == .null_handle) {
            return error.NoSuitableDevice;
        }
    }

    fn createLogicalDevice(self: *Self) !void {
        const indices = try self.findQueueFamilies(self.physical_device);
        const queue_priority = [_]f32{1};

        var queue_create_info = [_]vk.DeviceQueueCreateInfo{
            .{
                .flags = .{},
                .queue_family_index = indices.graphics_family.?,
                .queue_count = 1,
                .p_queue_priorities = &queue_priority,
            },
            .{
                .flags = .{},
                .queue_family_index = indices.present_family.?,
                .queue_count = 1,
                .p_queue_priorities = &queue_priority,
            },
        };

        var create_info = vk.DeviceCreateInfo{
            .flags = .{},
            .queue_create_info_count = queue_create_info.len,
            .p_queue_create_infos = &queue_create_info,
            .enabled_layer_count = 0,
            .pp_enabled_layer_names = undefined,
            .enabled_extension_count = 0,
            .pp_enabled_extension_names = undefined,
            .p_enabled_features = null,
        };

        if (enable_validation_layers) {
            create_info.enabled_layer_count = validation_layers.len;
            create_info.pp_enabled_layer_names = &validation_layers;
        }

        self.device = try self.vki.createDevice(self.physical_device, &create_info, null);

        self.vkd = try DeviceDispatch.load(self.device, self.vki.dispatch.vkGetDeviceProcAddr);

        self.graphics_queue = self.vkd.getDeviceQueue(self.device, indices.graphics_family.?, 0);
        self.present_queue = self.vkd.getDeviceQueue(self.device, indices.present_family.?, 0);
    }

    fn isDeviceSuitable(self: *Self, device: vk.PhysicalDevice) !bool {
        const indices = try self.findQueueFamilies(device);

        return indices.isComplete();
    }

    fn findQueueFamilies(self: *Self, device: vk.PhysicalDevice) !QueueFamilyIndices {
        var indices: QueueFamilyIndices = .{};

        var queue_family_count: u32 = 0;
        self.vki.getPhysicalDeviceQueueFamilyProperties(device, &queue_family_count, null);

        const queue_families = try self.allocator.alloc(vk.QueueFamilyProperties, queue_family_count);
        defer self.allocator.free(queue_families);
        self.vki.getPhysicalDeviceQueueFamilyProperties(device, &queue_family_count, queue_families.ptr);

        for (queue_families) |queue_family, i| {
            if (indices.graphics_family == null and queue_family.queue_flags.graphics_bit) {
                indices.graphics_family = @intCast(u32, i);
            } else if (indices.present_family == null and (try self.vki.getPhysicalDeviceSurfaceSupportKHR(device, @intCast(u32, i), self.surface)) == vk.TRUE) {
                indices.present_family = @intCast(u32, i);
            }

            if (indices.isComplete()) {
                break;
            }
        }

        return indices;
    }

    fn getRequiredExtensions(allocator: Allocator) !std.ArrayListAligned([*:0]const u8, null) {
        var extensions = std.ArrayList([*:0]const u8).init(allocator);
        try extensions.appendSlice(try glfw.getRequiredInstanceExtensions());

        if (enable_validation_layers) {
            try extensions.append(vk.extension_info.ext_debug_utils.name);
        }

        return extensions;
    }

    fn checkValidationLayerSupport(self: *Self) !bool {
        var layer_count: u32 = undefined;
        _ = try self.vkb.enumerateInstanceLayerProperties(&layer_count, null);

        var available_layers = try self.allocator.alloc(vk.LayerProperties, layer_count);
        defer self.allocator.free(available_layers);
        _ = try self.vkb.enumerateInstanceLayerProperties(&layer_count, available_layers.ptr);

        for (validation_layers) |layer_name| {
            var layer_found: bool = false;

            for (available_layers) |layer_properties| {
                const available_len = std.mem.indexOfScalar(u8, &layer_properties.layer_name, 0).?;
                const available_layer_name = layer_properties.layer_name[0..available_len];
                if (std.mem.eql(u8, std.mem.span(layer_name), available_layer_name)) {
                    layer_found = true;
                    break;
                }
            }

            if (!layer_found) {
                return false;
            }
        }

        return true;
    }

    fn debugCallback(_: vk.DebugUtilsMessageSeverityFlagsEXT, _: vk.DebugUtilsMessageTypeFlagsEXT, p_callback_data: ?*const vk.DebugUtilsMessengerCallbackDataEXT, _: ?*anyopaque) callconv(vk.vulkan_call_conv) vk.Bool32 {
        if (p_callback_data != null) {
            std.log.debug("validation layer: {s}", .{p_callback_data.?.p_message});
        }

        return vk.FALSE;
    }
};

pub fn main() void {
    var gpa = std.heap.GeneralPurposeAllocator(.{}){};
    defer {
        const leaked = gpa.deinit();
        if (leaked) std.log.err("MemLeak", .{});
    }
    const allocator = gpa.allocator();

    var app = HelloTriangleApplication.init(allocator);
    defer app.deinit();
    app.run() catch |err| {
        std.log.err("application exited with error: {any}", .{err});
        return;
    };
}