Set side bearings based on a base glyph

set_sidebearings.py

from mojo.tools import IntersectGlyphWithLine
font = CurrentFont()

glyphs = {  'e':['eacute', 'egrave', 'ediresis'],
            'i':['iacute', 'igrave']
}

for base, accented in glyphs.items():
   if base in font.keys():
       base = font[base]
       for g in accented:
           if g in font.keys():
               g = font[g]
               
               if base.box[2] - base.box[0] < g.box[2] - g.box[0]:
                   y = (base.box[3] - base.box[1])/2
                   
                   bl = [x[0] for x in IntersectGlyphWithLine(base, ((-10000, y), (10000, y)), canHaveComponent=True, addSideBearings=True)]
                   gl = [x[0] for x in IntersectGlyphWithLine(g, ((-10000, y), (10000, y)), canHaveComponent=True, addSideBearings=True)]
                   
                   bl.sort()
                   gl.sort()
                   
                   bLeft = abs(bl[:2][0] - bl[:2][1])
                   bRight = abs(bl[-2:][0] - bl[-2:][1])
                   
                   gLeft = abs(gl[:2][0] - gl[:2][1])
                   gRight = abs(gl[-2:][0] - gl[-2:][1])
                   
                   if bLeft != gLeft:
                       d = gLeft - bLeft
                       g.leftMargin = g.leftMargin - d
                       
                   if bRight != gRight:
                       d = gRight - bRight
                       g.rightMargin = g.rightMargin - d
                   
               else:
                   g.leftMargin = base.leftMargin
                   g.rightMargin = base.rightMargin

print 'done'