Technical question about control points

[Gare]

There was a time when I was certain of the number and location of control poiunts in a given character in a typeface I'd use, because Program X or Program Y flashed a little thing on its splash screen "reading font metrics"...

Does Xara even read font metrics at all?

The reason I ask it that frequently I need to modify a glyph to make a logo or something. And Xara Designer 11 produces way more control points than I'd expect or want whenever I do the Ctrl+Shift+S thing:



This is a fair comparison above: Here'a glyph shown with its original control points in FontLab (a font editor), at bottom. And then there's the glyph (top) when reduced to a path in Xara.


Why? And is there a way to curtail this excessive control point thing?

TIA,

Gary

[mwenz]

Metrics? Yes, to a point (no pun intended). I don't think that control points are part of a font's metrics. Maybe, but I have never thought of them that way.

Fundamentally, unless an application actually can utilize and draw curves according to whether a font is TT or OT, I think that the addition/subtraction of curves are needed. I would be extremely happy if application X would implement the control nodes as smooth curves where appropriate instead of cusps when type is converted to curves.

I also think that this may be character related. In the screen shot below the on-curve points line up fairly well and the cusp handle adjustments match the off-curve points well.



Mike

[Gare]

Mike, you're saying that the conversion from glyph to path involves absolutely no culling of control point info?

Seems bass-ackwards to me when the data is already mapped out in the file.

Thanks, though.

Life sucks sometimes...

-g

[mwenz]

No, I didn't mean that. In my example, the on-curve points as shown in my editor and the cusp points from XDP'S conversion literally are aligned (some are simply very close). The off-curve points from the font editor are still seen when they are outside curves.

Techically in my example, XDP has about 30% fewer points than the font editor if the on- and off-curve points are added together. XDP has 50 some points on the same character as in my font editor, which has 95 points.

What I was getting at, in my example XDP converted that A character with fewer points than are in the font editor. Your example has more points than your font editor. So perhaps it all depends on what character is converted to curves. Maybe even whether it is a TT or OT, seeing how technically they are different types of curves.

[Gare]

Thanks for your explanation, Mike.

However, I still do not understand—and the lack of understanding is my own problem—why, if a program can "see", parse, understand a curve, why it doesn't see the tension and bias values of bounding control points and just use them when a gylph is "decompiled into a simpler vector form.

In any event, it's a chore to eliminate unnecessary control points!

My Best,

Gary

[mwenz]

Dunno the answer, Gary.

It works in the reverse--I can go from XDP or AI or CD and the on-curve control points are near identical in my font editor. So I think it can be done. That said, most of the characters I tried other than that 'A' convert fairly well.

What font are you using in your example?