Function Init

window/glfw.go:217–366

Init initializes the GlfwWindow singleton with the specified width, height, and title.

(width, height int, title string)

// Init initializes the GlfwWindow singleton with the specified width, height, and title.
func Init(width, height int, title string) error {

	// Panic if already created
	if win != nil {
		panic(fmt.Errorf("can only call window.Init() once"))
	}

	// OpenGL functions must be executed in the same thread where
	// the context was created (by wmgr.CreateWindow())
	runtime.LockOSThread()

	// Create wrapper window with dispatcher
	w := new(GlfwWindow)
	w.Dispatcher.Initialize()
	var err error

	// Initialize GLFW
	err = glfw.Init()
	if err != nil {
		return err
	}

	// Set window hints
	glfw.WindowHint(glfw.ContextVersionMajor, 3)
	glfw.WindowHint(glfw.ContextVersionMinor, 3)
	glfw.WindowHint(glfw.OpenGLProfile, glfw.OpenGLCoreProfile)
	glfw.WindowHint(glfw.Samples, 8)
	// Set OpenGL forward compatible context only for OSX because it is required for OSX.
	// When this is set, glLineWidth(width) only accepts width=1.0 and generates an error
	// for any other values although the spec says it should ignore unsupported widths
	// and generate an error only when width <= 0.
	if runtime.GOOS == "darwin" {
		glfw.WindowHint(glfw.OpenGLForwardCompatible, glfw.True)
	}

	// Create window and set it as the current context.
	// The window is created always as not full screen because if it is
	// created as full screen it not possible to revert it to windowed mode.
	// At the end of this function, the window will be set to full screen if requested.
	w.Window, err = glfw.CreateWindow(width, height, title, nil, nil)
	if err != nil {
		return err
	}
	w.MakeContextCurrent()

	// Create OpenGL state
	w.gls, err = gls.New()
	if err != nil {
		return err
	}

	// Compute and store scale
	fbw, fbh := w.GetFramebufferSize()
	w.scaleX = float64(fbw) / float64(width)
	w.scaleY = float64(fbh) / float64(height)

	// Create map for cursors
	w.cursors = make(map[Cursor]*glfw.Cursor)