Off-curve Extreme Coordinates

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1

I’m trying to clean up some fonts that have errors in them, and I am having problems with “off-curve extreme coordinates”. It seems to be very easy to produce this error, and for no visible reason.

For example, when producing a curved contour, I might have a series of five points - Point 1 is on-contour, 2 is off, 3 is on, 4 is off., and 5 is on. The two off-contour points are on the same side of the contour. This makes a smooth contour. As I proceed from 1 to 5, I am following the countour clockwise, with the interior to the right, and the off-contour points to the left.

I see point 4 marked as “off-curve extreme”, a property which it keeps even when it is moved until it is almost colinear with 3 and 5. Point 2 is much further from the curve than point 4, but is never marked as being “off-curve extreme”.

There is no obvious logic to what is happening. How to I make this message go away?

2

Can you please provide us a screenshot?

3

Off-curve extreme points can be close to the curve or far away from it. It just means off-curve points that are outside an orthogonal line drawn through the adjacent on-curve points.
Off-curve Extreme Points.png
Use the Validation toolbar to fix them, or the Glyph validation wizard.

4

Extreme points may or may not be a problem.

I prefer to avoid them. For more information you may want to look at Circle Secrets