[Lib2geom-devel] cy2geom questions

[Susan S. <sus...@gm...>]

Hi developers,

Here are some examples of current output using
the tmtp library <https://github.com/sconklin/tmtp.git> for pattern design.

https://docs.google.com/open?id=0BxsnjDIHW4yvNGZEMGlNSGpzblk
https://docs.google.com/open?id=0BxsnjDIHW4yvTVFndHIyYnBoZjA
https://docs.google.com/open?id=0BxsnjDIHW4yvck9iMGVVTWFXMFU


It would improve the tmtp project to replace functions like
pointOnCurveAtLength() and lengthOnCurveAtPoint()
with calls to cy2geom/lib2geom code.

The data structures are very simple,
a point is a python object with x & y values.
Point A is A.x, A.y, and A.name = 'A'
Curve paths are python lists where a cubic curve P0 c1 c2 P1
is stored as curve[0],curve[1],curve[2],curve[3]
Longer curves P0 c11 c12 P1 c21 c22 P2 are stored as
curve[0],curve[1],curve[2],curve[3], curve[4],curve[5],curve[6]
where the shared points (eg P1 in example) are not repeated.

Can anyone give me examples for:
1.) returning a point at a known length on a curve,
2.) returning the length at a known or interpolated point on a curve,
3.) the point at an intersection of a line and a curve,
4.) the point at an intersection of two curves
5.) interpolating a curve.
I have very simple code for these functions in tmtp,
but I need to improve accuracy.

Bonus points if anyone can produce an example for Bend Path!!!
I obviously don't have code for this - see the 2nd file in list above.


Thanks!
You guys rock.

- Susan