inconsistent results for a script

[garylyb]

I import a svg created in illustrator, and run this script on it:

use all
## Scale to caps height
##

set ymin 0

set F0 [ymax-ymin]

## set F0 ymax

set F1 [100*caps/F0]

stretch F1 F1
set rsb 0


The circle and square svg's bot line up perfectly at the 0 and caps height lines. They have been sized to caps height.

The capital T is a little off at the top, probably a rounding error.

The capital U has extra white space all around it. The ymin is 0, but the lowest point on the screen is 16. There seems to be an invisible 16 point around the character.

I've attached a zip that contains the circle, square, cap T, Cap U and script.





The U has white space between te lines, while the circle is on the lines

Attachments:

[garylyb]

this is version 3.2.023

[Allan Murray]

Yes, this is a bug.

What is happening is that the control points are being included when determining the bounds of the glyph. In the the second example, after the glyph has been scaled, the 'u' has a control point on the Caps height line, and a control point on the baseline.

Thank you - this will be fixed in the next update.

[garylyb]

I just tried this in 3.2.025, and there is no change. It doesn't appear to be fixed.

Thanks,

Gary

[Allan Murray]

Sorry - "the next update" mentioned got split into two. The recent 3.2.025 (and also 3.2.026 in a few days) are some toolbox related updates.

The above fix is not trivial and will share some code with a new (contour related) feature which is coming up. I will issue a fix as soon as that part of the code is done (approx couple of weeks), and will post here.


NOTE: If you insert nodes at the extrema of all outside curves (ie at the very left-most, right-most, top-most and bottom-most points), then the glyphs will scale correctly (possibly easier to do before you import). That way there are no control points higher or lower than any of the nodes. This is also generally considered good practice when designing glyphs for reasons other than the above (eg hinting).

eg

Attachments: