@@ -73,13 +73,20 @@ module CelticKnot # curve doubles back on itself). If such a self-intersection # exists, remove the intersection by reducing all lines between # the intersection to the point of intersection. + # + # intersections near the beginning or end of the list are ignored, + # since they represent overlaps caused by a segment that intersects + # itself at the same midpoint (e.g. a loop around a single node). + # such intersections will be taken care of when the over/under + # intersections are subtracted later in the process. def cull_overlap_for_list(list) - i = 0 + offset = list.length/4 + i = offset while i < list.length-2 line1 = Curves::LineSegment.new(list[i], list[i+1]) j = i+1 - while j < list.length-1 + while j < list.length-offset line2 = Curves::LineSegment.new(list[j], list[j+1]) if (intersection = line1.intersection(line2)) @@ -153,6 +160,7 @@ module CelticKnot end def subtract_intersection_between(segment, boundary, from) + operation = from == :start ? :shift : :pop reverseop = from == :start ? :unshift : :push lib/celtic_knot/knot_shape.rb 57aa7cd291d3be32e14733e90e6c90603ec292c7 Jamis Buck jamis@37signals.com http://github.com/jamis/celtic_knot/commit/7bb27773579cf14b4146645f33a2f384149b7ac1 7bb27773579cf14b4146645f33a2f384149b7ac1 2009-06-15T07:21:33-07:00 2009-06-15T07:21:33-07:00 only cull interior overlaps for the middle of thread segments this prevents overlaps in self-intersecting segment loops from being culled incorrectly. ab1e0a37382c140b24daa1ca7526489cd0fc06e1 Jamis Buck jamis@37signals.com