glfw: add Window.create

Signed-off-by: Stephen Gutekanst <stephen@hexops.com>

glfw/src/Window.zig

@@ -5,9 +5,12 @@ const c = @import("c.zig").c;
 
 const Error = @import("errors.zig").Error;
 const getError = @import("errors.zig").getError;
+const Monitor = @import("Monitor.zig");
 
 const Window = @This();
 
+handle: *c.GLFWwindow,
+
 /// Resets all window hints to their default values.
 ///
 /// This function resets all window hints to their default values.
@@ -75,6 +78,133 @@ pub fn hintString(hint_const: usize, value: [:0]const u8) Error!void {
     try getError();
 }
 
+/// Creates a window and its associated context.
+///
+/// This function creates a window and its associated OpenGL or OpenGL ES context. Most of the
+/// options controlling how the window and its context should be created are specified with window
+/// hints using `glfw.Window.hint`.
+///
+/// Successful creation does not change which context is current. Before you can use the newly
+/// created context, you need to make it current using `glfw.Window.makeContextCurrent`. For
+/// information about the `share` parameter, see context_sharing.
+///
+/// The created window, framebuffer and context may differ from what you requested, as not all
+/// parameters and hints are hard constraints. This includes the size of the window, especially for
+/// full screen windows. To query the actual attributes of the created window, framebuffer and
+/// context, see glfw.Window.getAttrib, glfw.Window.getSize and glfw.window.getFramebufferSize.
+///
+/// To create a full screen window, you need to specify the monitor the window will cover. If no
+/// monitor is specified, the window will be windowed mode. Unless you have a way for the user to
+/// choose a specific monitor, it is recommended that you pick the primary monitor. For more
+/// information on how to query connected monitors, see @ref monitor_monitors.
+///
+/// For full screen windows, the specified size becomes the resolution of the window's _desired
+/// video mode_. As long as a full screen window is not iconified, the supported video mode most
+/// closely matching the desired video mode is set for the specified monitor. For more information
+/// about full screen windows, including the creation of so called _windowed full screen_ or
+/// _borderless full screen_ windows, see window_windowed_full_screen.
+///
+/// Once you have created the window, you can switch it between windowed and full screen mode with
+/// glfw.Window.setMonitor. This will not affect its OpenGL or OpenGL ES context.
+///
+/// By default, newly created windows use the placement recommended by the window system. To create
+/// the window at a specific position, make it initially invisible using the glfw.version window
+/// hint, set its position and then show it.
+///
+/// As long as at least one full screen window is not iconified, the screensaver is prohibited from
+/// starting.
+///
+/// Window systems put limits on window sizes. Very large or very small window dimensions may be
+/// overridden by the window system on creation. Check the actual size after creation.
+///
+/// The swap interval is not set during window creation and the initial value may vary depending on
+/// driver settings and defaults.
+///
+/// Possible errors include glfw.Error.NotInitialized, glfw.Error.InvalidEnum, glfw.Error.InvalidValue,
+/// glfw.Error.APIUnavailable, glfw.Error.VersionUnavailable, glfw.Error.FormatUnavailable and
+/// glfw.Error.PlatformError.
+///
+/// Parameters are as follows:
+///
+/// * `width` The desired width, in screen coordinates, of the window.
+/// * `height` The desired height, in screen coordinates, of the window.
+/// * `title` The initial, UTF-8 encoded window title.
+/// * `monitor` The monitor to use for full screen mode, or `null` for windowed mode.
+/// * `share` The window whose context to share resources with, or `null` to not share resources.
+///
+/// win32: Window creation will fail if the Microsoft GDI software OpenGL implementation is the
+/// only one available.
+///
+/// win32: If the executable has an icon resource named `GLFW_ICON`, it will be set as the initial
+/// icon for the window. If no such icon is present, the `IDI_APPLICATION` icon will be used
+/// instead. To set a different icon, see glfw.Window.setIcon.
+///
+/// win32: The context to share resources with must not be current on any other thread.
+///
+/// macos: The OS only supports forward-compatible core profile contexts for OpenGL versions 3.2
+/// and later. Before creating an OpenGL context of version 3.2 or later you must set the
+/// `glfw.opengl_forward_compat` and `glfw.opengl_profile` hints accordingly. OpenGL 3.0 and 3.1
+/// contexts are not supported at all on macOS.
+///
+/// macos: The GLFW window has no icon, as it is not a document window, but the dock icon will be
+/// the same as the application bundle's icon. For more information on bundles, see the
+/// [Bundle Programming Guide](https://developer.apple.com/library/mac/documentation/CoreFoundation/Conceptual/CFBundles/)
+/// in the Mac Developer Library.
+///
+/// macos: The first time a window is created the menu bar is created. If GLFW finds a `MainMenu.nib`
+/// it is loaded and assumed to contain a menu bar. Otherwise a minimal menu bar is created
+/// manually with common commands like Hide, Quit and About. The About entry opens a minimal about
+/// dialog with information from the application's bundle. Menu bar creation can be disabled
+/// entirely with the glfw.cocoa_menubar init hint.
+///
+/// macos: On OS X 10.10 and later the window frame will not be rendered at full resolution on
+/// Retina displays unless the glfw.cocoa_retina_framebuffer hint is true (1) and the `NSHighResolutionCapable`
+/// key is enabled in the application bundle's `Info.plist`. For more information, see
+/// [High Resolution Guidelines for OS X](https://developer.apple.com/library/mac/documentation/GraphicsAnimation/Conceptual/HighResolutionOSX/Explained/Explained.html)
+/// in the Mac Developer Library. The GLFW test and example programs use a custom `Info.plist`
+/// template for this, which can be found as `CMake/MacOSXBundleInfo.plist.in` in the source tree.
+///
+/// macos: When activating frame autosaving with glfw.cocoa_frame_name, the specified window size
+/// and position may be overridden by previously saved values.
+///
+/// x11: Some window managers will not respect the placement of initially hidden windows.
+///
+/// x11: Due to the asynchronous nature of X11, it may take a moment for a window to reach its
+/// requested state. This means you may not be able to query the final size, position or other
+/// attributes directly after window creation.
+///
+/// x11: The class part of the `WM_CLASS` window property will by default be set to the window title
+/// passed to this function. The instance part will use the contents of the `RESOURCE_NAME`
+/// environment variable, if present and not empty, or fall back to the window title. Set the glfw.x11_class_name
+/// and glfw.x11_instance_name window hints to override this.
+///
+/// wayland: Compositors should implement the xdg-decoration protocol for GLFW to decorate the
+/// window properly. If this protocol isn't supported, or if the compositor prefers client-side
+/// decorations, a very simple fallback frame will be drawn using the wp_viewporter protocol. A
+/// compositor can still emit close, maximize or fullscreen events, using for instance a keybind
+/// mechanism. If neither of these protocols is supported, the window won't be decorated.
+///
+/// wayland: A full screen window will not attempt to change the mode, no matter what the
+/// requested size or refresh rate.
+///
+/// wayland: Screensaver inhibition requires the idle-inhibit protocol to be implemented in the
+/// user's compositor.
+///
+/// @thread_safety This function must only be called from the main thread.
+///
+/// see also: window_creation, glfw.Window.destroy
+pub fn create(width: usize, height: usize, title: [*c]const u8, monitor: ?Monitor, share: ?Window) Error!Window {
+    const handle = c.glfwCreateWindow(
+        @intCast(c_int, width),
+        @intCast(c_int, height),
+        &title[0],
+        if (monitor) |m| m.handle else null,
+        if (share) |w| w.handle else null,
+    );
+    try getError();
+    return Window{ .handle = handle.? };
+}
+
 test "defaultHints" {
     const glfw = @import("main.zig");
     try glfw.init();
@@ -99,3 +229,17 @@ test "hintString" {
 
     try hintString(glfw.x11_class_name, "myclass");
 }
+
+test "createWindow" {
+    const glfw = @import("main.zig");
+    try glfw.init();
+    defer glfw.terminate();
+
+    const window = glfw.Window.create(640, 480, "Hello, Zig!", null, null) catch |err| {
+        // return without fail, because most of our CI environments are headless / we cannot open
+        // windows on them.
+        std.debug.print("note: failed to create window: {}\n", .{err});
+        return;
+    };
+    c.glfwDestroyWindow(window.handle);
+}