addGuidelineAtSelection.py

# menuTitle : Add Guideline at Selection
# shortCut  : shift+control+g

'''
If two points are selected, add an angled guideline along them.
If one point is selected, add a horizontal guideline there.

Ryan Bugden
2020
'''

import math

g = CurrentGlyph()


with g.undo("Add guideline at selection"):
    
    if len(g.selectedPoints) > 1:
        pts = []
        for pt in g.selectedPoints:
            pts.append((pt.x, pt.y))
        
        if pts[-1][0] == pts[0][0]:
            g.appendGuideline((pts[-1][0], pts[-1][1]), angle=90)
        
        else:
            y_tri = pts[-1][1] - pts[0][1]
            x_tri = pts[-1][0] - pts[0][0]
            ang = math.atan(y_tri/x_tri) * (180/math.pi)
        
            g.appendGuideline((pts[0][0], pts[0][1]), angle=ang)
        
    elif len(g.selectedPoints) == 1:
        pt = g.selectedPoints[0]
    
        g.appendGuideline((pt.x, pt.y), angle=0)