diff options
Diffstat (limited to 'src/utils.lisp')
| -rw-r--r-- | src/utils.lisp | 20 |
1 files changed, 17 insertions, 3 deletions
diff --git a/src/utils.lisp b/src/utils.lisp index 165f29a..bcb4cb2 100644 --- a/src/utils.lisp +++ b/src/utils.lisp @@ -41,8 +41,14 @@ and B intersects the linesegment between C and D, NIL otherwise." while b2 thereis (segments-intersect-p a1 a2 b1 b2)))) -(defun path-contains-point (path pt) + +(defun closed-path-p (path) + (equalp (first path) + (first (last path)))) + +(defun path-encloses-point-p (path pt) "Path is a list of vectors, pt is a single vector." + (assert (closed-path-p path) () "Enclosing path must be a closed path.") (let* ((bounds (path-bounds path)) (corner @@ -57,8 +63,16 @@ and B intersects the linesegment between C and D, NIL otherwise." finally (return (oddp intersection-count))))) -(defun path-encloses-p (path other) - ) + + +(defun path-encloses-path-p (path-a path-b) + "T if path-b is totally contained in path-a and does not intersect path-a" + (assert (closed-path-p path-a) () "Enclosing path must be a closed path.") + (and + (loop for (p1 p2 . more) on path-b + while p2 + always (path-encloses-point-p path-a p1)) + (not (paths-intersect-p path-a path-b)))) (defun path-bounds (path) "Path is a list of vectors representing 2d points. Returns the |