xcb: add Vulkan init to sample

packages/xcb/sample/Vulkan.zig

@@ -0,0 +1,176 @@
+const Vulkan = @This();
+
+const std = @import("std");
+const vk = @import("vulkan");
+const xcb = @import("xcb");
+
+vulkan_loader: *DynamicLibrary,
+
+base: vk.BaseWrapper,
+instance: vk.InstanceProxy,
+surface: vk.SurfaceKHR,
+device: vk.DeviceProxy,
+
+queue_family: u32,
+queue: vk.Queue,
+command_pool: vk.CommandPool,
+
+pub fn init(allocator: std.mem.Allocator, connection: *xcb.Connection, window: xcb.Window) !Vulkan {
+    const vulkan_loader = try DynamicLibrary.open("libvulkan.so.1");
+    errdefer vulkan_loader.close();
+
+    const vkGetInstanceProcAddr = try vulkan_loader.sym(vk.PfnGetInstanceProcAddr, "vkGetInstanceProcAddr");
+
+    const base = vk.BaseWrapper.load(vkGetInstanceProcAddr);
+
+    const instance_handle = blk: {
+        const enabled_layers: []const [*:0]const u8 = &.{};
+        const enabled_extensions: []const [*:0]const u8 = &.{
+            vk.extensions.khr_surface.name,
+            vk.extensions.khr_xcb_surface.name,
+        };
+
+        break :blk try base.createInstance(&.{
+            .p_application_info = &.{
+                .p_application_name = "xcb_sample",
+                .application_version = vk.makeApiVersion(0, 0, 0, 0).toU32(),
+                .p_engine_name = "xcb_sample",
+                .engine_version = vk.makeApiVersion(0, 0, 0, 0).toU32(),
+                .api_version = vk.API_VERSION_1_0.toU32(),
+            },
+            .enabled_layer_count = @intCast(enabled_layers.len),
+            .pp_enabled_layer_names = enabled_layers.ptr,
+            .enabled_extension_count = @intCast(enabled_extensions.len),
+            .pp_enabled_extension_names = enabled_extensions.ptr,
+        }, null);
+    };
+
+    const instance_wrapper_ptr = try allocator.create(vk.InstanceWrapper);
+    errdefer allocator.destroy(instance_wrapper_ptr);
+
+    instance_wrapper_ptr.* = .load(instance_handle, vkGetInstanceProcAddr);
+    const instance = vk.InstanceProxy.init(instance_handle, instance_wrapper_ptr);
+    errdefer instance.destroyInstance(null);
+
+    const surface = try instance.createXcbSurfaceKHR(&.{
+        .connection = connection,
+        .window = window,
+    }, null);
+    errdefer instance.destroySurfaceKHR(surface, null);
+
+    const physical_device = blk: {
+        const physical_devices = try instance.enumeratePhysicalDevicesAlloc(allocator);
+        defer allocator.free(physical_devices);
+
+        if (physical_devices.len > 0) {
+            break :blk physical_devices[0];
+        }
+
+        return error.NoDevice;
+    };
+
+    const queue_family: u32 = blk: {
+        const queue_families_properties = try instance.getPhysicalDeviceQueueFamilyPropertiesAlloc(physical_device, allocator);
+        defer allocator.free(queue_families_properties);
+
+        // Look for the first family that has the `graphics_bit` set and
+        // supports presentation to a given surface.
+
+        for (queue_families_properties, 0..) |queue_family_properties, i| {
+            const graphics_bit = queue_family_properties.queue_flags.graphics_bit;
+            const supports_presentation = try instance.getPhysicalDeviceSurfaceSupportKHR(physical_device, @intCast(i), surface) != .false;
+
+            if (graphics_bit and supports_presentation) {
+                break :blk @intCast(i);
+            }
+        }
+
+        return error.NoQueue;
+    };
+
+    const device_handle = blk: {
+        const queue_create_infos: []const vk.DeviceQueueCreateInfo = &.{
+            .{
+                .queue_family_index = queue_family,
+                .queue_count = 1,
+                .p_queue_priorities = &.{0},
+            },
+        };
+        const enabled_extensions: []const [*:0]const u8 = &.{
+            vk.extensions.khr_swapchain.name,
+        };
+
+        break :blk try instance.createDevice(physical_device, &.{
+            .queue_create_info_count = @intCast(queue_create_infos.len),
+            .p_queue_create_infos = queue_create_infos.ptr,
+            .enabled_extension_count = @intCast(enabled_extensions.len),
+            .pp_enabled_extension_names = enabled_extensions.ptr,
+        }, null);
+    };
+
+    const device_wrapper_ptr = try allocator.create(vk.DeviceWrapper);
+    errdefer allocator.destroy(device_wrapper_ptr);
+
+    device_wrapper_ptr.* = .load(device_handle, instance.wrapper.dispatch.vkGetDeviceProcAddr.?);
+    const device = vk.DeviceProxy.init(device_handle, device_wrapper_ptr);
+    errdefer device.destroyDevice(null);
+
+    const queue = device.getDeviceQueue(queue_family, 0);
+
+    const command_pool = try device.createCommandPool(&.{
+        .flags = .{ .transient_bit = true },
+        .queue_family_index = queue_family,
+    }, null);
+    errdefer device.destroyCommandPool(command_pool, null);
+
+    return .{
+        .vulkan_loader = vulkan_loader,
+
+        .base = base,
+        .instance = instance,
+        .surface = surface,
+        .device = device,
+
+        .queue_family = queue_family,
+        .queue = queue,
+        .command_pool = command_pool,
+    };
+}
+
+pub fn deinit(self: *Vulkan, allocator: std.mem.Allocator) void {
+    self.device.destroyCommandPool(self.command_pool, null);
+
+    self.device.destroyDevice(null);
+    allocator.destroy(self.device.wrapper);
+    self.instance.destroySurfaceKHR(self.surface, null);
+    self.instance.destroyInstance(null);
+    allocator.destroy(self.instance.wrapper);
+
+    self.vulkan_loader.close();
+
+    self.* = undefined;
+}
+
+const DynamicLibrary = opaque {
+    fn open(path: [*:0]const u8) !*DynamicLibrary {
+        const ptr = std.c.dlopen(path, .{ .NOW = true }) orelse {
+            std.debug.print("{s}\n", .{std.c.dlerror().?});
+            return error.DlOpen;
+        };
+
+        return @ptrCast(ptr);
+    }
+
+    fn close(self: *DynamicLibrary) void {
+        _ = std.c.dlclose(self);
+    }
+
+    fn sym(self: *DynamicLibrary, comptime Ptr: type, symbol: [*:0]const u8) !Ptr {
+        const ptr = std.c.dlsym(self, symbol) orelse {
+            std.debug.print("{s}\n", .{std.c.dlerror().?});
+            return error.DlSym;
+        };
+
+        return @ptrCast(@alignCast(ptr));
+    }
+};

packages/xcb/sample/root.zig

@@ -1,9 +1,15 @@
 const std = @import("std");
 const xcb = @import("xcb");
 
-pub fn main(init: std.process.Init) !void {
-    _ = init;
+const Vulkan = @import("Vulkan.zig");
 
+// Declarations picked up by "vulkan" module
+
+pub const xcb_connection_t = xcb.Connection;
+pub const xcb_visualid_t = xcb.Visualid;
+pub const xcb_window_t = xcb.Window;
+
+pub fn main(init: std.process.Init) !void {
     const connection = xcb.Connection.connect(null, null);
     defer connection.disconnect();
 
@@ -64,6 +70,9 @@ pub fn main(init: std.process.Init) !void {
     _ = connection.mapWindow(window);
     _ = connection.flush();
 
+    var vulkan = try Vulkan.init(init.gpa, connection, window);
+    defer vulkan.deinit(init.gpa);
+
     var running = true;
     while (running) {
         if (connection.waitForEvent()) |event| {