Standard command-line options for OpenGL programs

Standard command-line options (for programs with a graphical interface)

Most of the programs using Castle Game Engine (online docs) accept the command-line options listed below. (Developers: use this in your own programs).

--fullscreen

Start in fullscreen mode.

For some programs, you can also switch between fullscreen and windowed mode at runtime. Standard key shortcut for this is F11.

--fullscreen-custom WIDTHxHEIGHT

Start in fullscreen mode with screen resolution changed to WIDTH x HEIGHT.

If given WIDTH x HEIGHT resolution is not available then error message will be shown and program will start in fullscreen mode using current screen resolution.

--geometry WIDTHxHEIGHT<sign>XOFF<sign>YOFF

Start in window mode with given WIDTH and HEIGHT positioned at (XOFF, YOFF).

<sign> is either "+" or "-". +XOFF means that left window border should be XOFF pixels from left screen border. Note that XOFF itself may be negative (e.g. in --geometry 100x100+-100+100) and then window will be positioned slightly offscreen. Similarly, -XOFF means that right window border should be XOFF pixels from right screen border. Similar for +YOFF or -YOFF — they specify distance from upper or lower screen border.

You can omit the <sign>XOFF<sign>YOFF part and provide only WIDTHxHEIGHT part. You can also omit WIDTHxHEIGHT part and provide only <sign>XOFF<sign>YOFF part.

This option works the same as standard -geometry option for most XWindows programs.

Note that window manager may disallow or modify requested window position and/or size. Note that you can also of course change window size and position of the window while the program is running (by dragging window border and such).

--display DISPLAY-NAME

(Only on platforms using X Windows, in practice: Unix)
Set the XWindows display to use.