rightDragDisplacement = curveStart - x + BORDER_LEFT + curveWidth - curveIndent;
rightDragDisplacement = curveStart - x + curveWidth - curveIndent;
void onMouseDown (int x, int y) {	if (curveRect.contains(x, y)) {		dragging = true;		rightDragDisplacement = curveStart - x + BORDER_LEFT + curveWidth - curveIndent;	}}