In article <38B### [at] aolcom> , Lummox JR <Lum### [at] aolcom>  wrote:

> Here's the problem: I want to modify truetype.c in the POV-Ray source to
> allow text objects to be bent around a circle (without distorting the
> characters). I would like to be able to specify either an inner radius
> for the text or a desired total arc angle. The characters would be
> separated by chords equal in length to the distance normally separating
> each character, plus two more chords equal to half of the character
> widths on each end.
> Now when radius is specified, the total angle is easy to compute because
> it's the sum of all the chord angles. Given the radius, those angles are
> easy to find. But when the problem is reversed, only a total angle and
> the individual chords are known, but so far I haven't figured out any
> way to calculate the radius that fits. (It's pretty easy to determine
> that there is such a radius, and the minimum possible value of that
> radius is easy to find. But the exact value I can only think to find by
> guessing.)
> Without a radius given, finding the radius is awfully hard. Yet the
> value of this solution is obvious, since being able to fill in a
> specific arc angle will often be far more useful than fitting text
> around a specific radius.
> This seems like it should be a simple problem, so I've asked elsewhere,
> but so far with no results. Since it came up in the course of my working
> with POV-Ray, I figured I'd take a whack at asking here.

Hmm, did you ever pay attention in your math classes? ;-)

Given that you know the total length you can use 2*pi*r (perimeter of a
circle) and the fact that  2*pi*r*360/angle = length


     Thorsten


____________________________________________________
Thorsten Froehlich, Duisburg, Germany
e-mail: tho### [at] trfde

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