Rotate 90º seems to send contours upward.



  • I'm wondering if it'd make sense to slightly alter the built-in RF way to rotate. Continuing to rotate often won't return you to your home position, and instead send the glyph up or down, presumably because the bounds are odd.

    See video demo, and alternative script suggestion:

    g = CurrentGlyph()
    
    # gather midpoint of selection
    xs = []
    ys = []
    for pt in g.selection:
        xs.append(pt.x)
        ys.append(pt.y)
    mid_x = round((max(xs) + min(xs)) / 2) 
    mid_y = round((max(ys) + min(ys)) / 2)
        
    # rotate around midpoint
    for pt in g.selection:
        pt.rotateBy(90, origin = (mid_x, mid_y))
        
    g.update()
    

    This is for the selection, but you get the idea.

    TIA!


  • admin

    RoboFont is using otRound from fontTools.misc.fixedTools

    see the difference here:

    from fontTools.misc.fixedTools import otRound
    
    value = .5
    print(otRound(value))
    print(round(value))
    
    value = .49
    print(otRound(value))
    print(round(value))
    
    value = .51
    print(otRound(value))
    print(round(value))
    

    see https://github.com/fonttools/fonttools/blob/master/Lib/fontTools/misc/fixedTools.py#L24-L32



  • @frederik said in Rotate 90º seems to always round up.:

    otRound

    RF’s native rotate still sends the contour upward, and otRound doesn’t: see here. Something else must be going on.


  • admin

    yeah, if this is the case then the numbers are just not working for you... by hitting a single r the points are rotated and rounded off, next them the same happens.

    I can reproduce all cases: moving up, moving right, doing nothing... with both the internal rotation and your example script. I just have to move a point 1 unit up/down/left/right.



  • @frederik I see. I just did some more testing with otRound and round and it looks like otRound goes rightward over several rotations, which I now notice from my last video. round seems to return home each time, though. Any reason round would be bad?

    odd-width-and-height bounds:
    r : upward
    round : stationary on average
    otRound : rightward

    Here's another video and test script:

    from fontTools.misc.fixedTools import otRound
    
    g = CurrentGlyph()
    
    # contour 0 : round
    c_0 = g[0]
    mid_x_0 = round((c_0.bounds[0] + c_0.bounds[2]) / 2) 
    mid_y_0 = round((c_0.bounds[1] + c_0.bounds[3]) / 2)
    c_0.rotateBy(90, origin = (mid_x_0, mid_y_0))
    
    # contour 1 : otRound
    c_1 = g[1]
    mid_x_1 = otRound((c_1.bounds[0] + c_1.bounds[2]) / 2) 
    mid_y_1 = otRound((c_1.bounds[1] + c_1.bounds[3]) / 2)
    c_1.rotateBy(90, origin = (mid_x_1, mid_y_1))
    
    g.update()
    

  • admin

    I tried when only the rounding the offset position with the default python round its that seems to be oke... And this will be "fixed" in the next beta/release.

    The reason why every rounding is with otRound is to keep a single rounding func for all sort of rounding.

    This is also the difference between round in py2 vs py3.



  • @frederik Makes sense to lean toward using one method. Did not know their were changes to round from py2 to py3! Appreciate you looking at this, Frederik!


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