WindowOpen ( win_num, title$, x, y, w, h, mode, vsync )

Opens a graphics window.
Set x and y to WINDOWPOS_CENTERED to position window in middle of screen.

Mode is a bitmask of possible window flags that can be combined to achieve the desired window.
Possible flags that can be used are:

   WINDOW_VISIBLE - Makes the window visible when opened

   WINDOW_HIDDEN - Hides the window when opened

   WINDOW_FULLSCREEN - Opens the window in fullscreen ( Fullscreen mode will set a virtual resolution for the window rather than change the display resolution )

   WINDOW_RESIZABLE - Makes the window resizable ( Resizable windows will increase/decrease the resolution of the window rather than stretch the image )

   WINDOW_BORDERLESS - Draws the window without borders

   WINDOW_HIGHDPI - Enables highdpi for the window ( HighDPI is for increasing mouse sensitivity on the window )

Note: You can combine them with OrBit() or just set them with WindowMode()

Set VSync to true to enable vsync on the window. ( VSync is recommended for most applications. )
Example:

   my_window_mode = WindowMode(1,0,0,0,0)
   WindowOpen ( 0, "My App", WINDOWPOS_CENTERED, WINDOWPOS_CENTERED, 640, 480, my_window_mode, 1 )

   While WindowExists( 0 )
   Update()
   Wend

This will open a 640 x 480 window and wait for the user to close it.