Sharpen Corner.py

from fontTools.misc.fixedTools import otRound

def findIntersection(p0, p1, p2, p3):
    """
    Find the intersection of two segments given two selected points.
    """
    # get the coordinates of the points
    x0, y0 = p0.x, p0.y
    x1, y1 = p1.x, p1.y
    x2, y2 = p2.x, p2.y
    x3, y3 = p3.x, p3.y
    # calculate the denominator
    denominator = (x0 - x1) * (y2 - y3) - (y0 - y1) * (x2 - x3)
    # if the denominator is zero, the segments are parallel
    if denominator == 0:
        return None
    # calculate the intersection
    x = ((x0 * y1 - y0 * x1) * (x2 - x3) - (x0 - x1) * (x2 * y3 - y2 * x3)) / denominator
    y = ((x0 * y1 - y0 * x1) * (y2 - y3) - (y0 - y1) * (x2 * y3 - y2 * x3)) / denominator
    # return the intersection
    return (otRound(x), otRound(y))

def main():
    g = CurrentGlyph()
    # set an undo point
    with g.undo("Sharpen Corner"):
        # hold change notifications while we're working
        with g.holdChanges():
            # loop through contours
            for c in g.contours:
                removePoints = []
                # break c.selectedPoints list into pairs of two
                for p1, p2 in zip(c.selectedPoints[::2], c.selectedPoints[1::2]):
                    # get the points before and after the selected points
                    p0 = c.points[(p1.index - 1) % len(c.points)]
                    p3 = c.points[(p2.index + 1) % len(c.points)]

                    # find the intersection of the segments
                    intersection = findIntersection(p0, p1, p2, p3)
                
                    if intersection:
                        # if intersection, move the selected points to the intersection and add point indexes between p1 and p2 to a list for removal
                        p1.x, p1.y = intersection
                        p2.x, p2.y = intersection
                        
                        p1.smooth = False
                        p2.smooth = False
                        
                        p1.selected = False
                        p2.selected = False
                        
                        for i in range(p1.index, p2.index):
                            removePoints.append(i)

                for p in sorted(removePoints, reverse=True):
                    # remove the points between the selected points
                    c.removePoint(p)
    g.changed()

main()