main/src/georegression/struct/shapes/Rectangle2D_I32.java
public void enforceExtents() {
		if( x1 < x0 ) {
			int tmp = x1;
			x1 = x0;
			x0 = tmp;
		}
		if( y1 < y0 ) {
			int tmp = y1;
			y1 = y0;
			y0 = tmp;
		}
	}
public void enforceExtents() {
		if( x1 < x0 ) {
			int tmp = x1;
			x1 = x0;
			x0 = tmp;
		}
		if( y1 < y0 ) {
			int tmp = y1;
			y1 = y0;
			y0 = tmp;
		}
	}
Makes sure x0,y0 is the lower extent and x1,y1 is the upper extent