slopeOfLine method
this function returns the slope of a single word this can be very useful
Implementation
slopeOfLine(Line l) {
var xRight = (l.cornerList![1].x + l.cornerList![2].x) / 2;
var yRight = (l.cornerList![1].y + l.cornerList![2].y) / 2;
var xLeft = (l.cornerList![0].x + l.cornerList![3].x) / 2;
var yLeft = (l.cornerList![0].y + l.cornerList![3].y) / 2;
var slope = (xLeft - xRight) / (yLeft - yRight);
return slope;
}