ramarren / cl-geometry Goto Github PK

It seems that the return value of intersect-p is incorrect if one of the line segment is horizontal.

GEOMETRY> (intersect-p (make-point 0 0)
               (make-point 50 0)
               (make-point 51 10)
               (make-point 100 0))
T
GEOMETRY> 

Hello,

I tried using your library, more specifically its polygon triangulation routine, and it crashed when trying to triangulate a simple 13-point polygon (no holes, no intersections). Looking at the code, I noticed you were using ear clipping method, so that wouldn't work for me in a general case anyway.

Digging further, I noticed lots of comments on the implementation being non-optimal, which is not a problem in itself, but seeing that the last real commits to this repository were done 7 years ago, makes me think that this project is abandoned, and that those algorithms are never going to get implemented in a better way.

I want to improve the library, but since there is no licensing information, forking is difficult. Before I commit myself to rewriting this otherwise great piece of work, I'd like to ask the following:

• Is this repository really abandoned, or would you be willing to review pull requests?
• Under what kind of license would you like to distribute this project?

Thank you!

I think the following should be NIL.

GEOMETRY> (intersect-p (make-point 0 0)
               (make-point 50 50)
               (make-point 51 51)
               (make-point 100 100))
T
GEOMETRY> 

Hi,

This may not be an error with your code but I just thought I'd bring it to your attention. If I define two instances of the same polygon but starting at two different points:

(defparameter *a* (make-polygon-from-coords 5 17 7 14 6 14 6 9 4 9 4 14 3 14))
(defparameter *b* (make-polygon-from-coords 4 9 4 14 3 14 5 17 7 14 6 14 6 9))

and then triangulate both, the triangulation of *a* is successful whereas that of *b* throws the following error:

The assertion (<= COUNTER NUM-VERTICES) failed with COUNTER = 5,
NUM-VERTICES = 3.
[Condition of type SIMPLE-ERROR]

I would like to use cl-geometry's bounding boxes. I would add some facilities, such as other primitives and their derivatives.

Will you consider contributions or address issues?

Thank you,

Mirko

Please consider adding :description, :author and :license information to your ASDF system(s). This will greatly help Quicklisp users and make it easier for them to report bugs.

More information:

http://blog.quicklisp.org/2015/05/looking-for-more-metadata.html
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