Function _getRelativeEdgeValue

docs/app/js/sanddance-app.js:31785–31788

* Flips the value depending on the edge. * If the edge is a "positive" edge, Top or Left, then the value should stay as it is. * If the edge is a "negative" edge, Bottom or Right, then the value should be flipped. * This is to account for the fact that the coordinates are effectively reveserved i

(edge, value)

 * If edge 1 is greater than edge 2 then it is out of bounds. This is reversed for top edge 1 and top edge 2.
 * If top edge 1 is less than edge 2 then it is out of bounds.
 */ function _getRelativeEdgeValue(edge, value) {
    if (edge > 0) return value;
    else return value * -1;
}
function _getRelativeRectEdgeValue(edge, rect) {
    return _getRelativeEdgeValue(edge, _getEdgeValue(rect, edge));
}