uidriver/glfw: Set No-API when creating a hidden window first

GLFW tries to create an OpenGL context by default when creating a
window. This is not necessary when OpenGL is not used. This is an
optimization by skipping to create an OpenGL context if possible.

Fixes #1237

internal/glfw/const.go

@@ -97,6 +97,7 @@ const (
 	CursorHidden   = 0x00034002
 	CursorNormal   = 0x00034001
 	NoAPI          = 0
+	OpenGLAPI      = 0x00030001
 )
 
 const (

internal/uidriver/glfw/ui.go

@@ -129,6 +129,7 @@ func initialize() error {
 		return err
 	}
 	glfw.WindowHint(glfw.Visible, glfw.False)
+	glfw.WindowHint(glfw.ClientAPI, glfw.NoAPI)
 
 	// Create a window to set the initial monitor.
 	w, err := glfw.CreateWindow(16, 16, "", nil, nil)
@@ -657,6 +658,7 @@ func (u *UserInterface) run(context driver.UIContext) error {
 		u.window = nil
 
 		if u.Graphics().IsGL() {
+			glfw.WindowHint(glfw.ClientAPI, glfw.OpenGLAPI)
 			glfw.WindowHint(glfw.ContextVersionMajor, 2)
 			glfw.WindowHint(glfw.ContextVersionMinor, 1)
 		} else {