/**
* Set the window size to w-by-h pixels.
*
* @param w the width as a number of pixels
* @param h the height as a number of pixels
* @throws a RunTimeException if the width or height is 0 or negative
*/
public static void setCanvasSize(int w, int h) {
if (w < 1 || h < 1) throw new RuntimeException("width and height must be positive");
width = w;
height = h;
init();
}
// static initializer
static {
init();
}