POLYGON: improve documentation

This commit is contained in:
hasufell 2015-01-09 04:01:43 +01:00
parent 903ba85f9f
commit 9917a7efd3
No known key found for this signature in database
GPG Key ID: 220CD1C5BDEED020

View File

@ -7,6 +7,8 @@ import Data.Maybe
import MyPrelude
-- |Split a polygon by a given segment which must be vertices of the
-- polygon (returns empty array otherwise).
splitPoly :: [PT]
-> Segment
-> [[PT]]
@ -18,6 +20,7 @@ splitPoly pts (a, b)
shiftedPoly = shiftM' a pts
-- |Get all edges of a polygon.
polySegments :: [PT] -> [Segment]
polySegments p@(x':_:_:_) = go p ++ [(last p, x')]
where
@ -26,6 +29,9 @@ polySegments p@(x':_:_:_) = go p ++ [(last p, x')]
polySegments _ = []
-- |Check whether the given segment is inside the polygon.
-- This doesn't check for segments that are completely outside
-- of the polygon yet.
isInsidePoly :: [PT] -> Segment -> Bool
isInsidePoly pts seg =
null
@ -34,18 +40,22 @@ isInsidePoly pts seg =
$ polySegments pts
-- |Check whether two points are adjacent vertices of a polygon.
adjacent :: PT -> PT -> [PT] -> Bool
adjacent u v = any (\x -> x == (u, v) || x == (v, u)) . polySegments
-- |Check whether the polygon is a triangle polygon.
isTrianglePoly :: [PT] -> Bool
isTrianglePoly [_, _, _] = True
isTrianglePoly _ = False
-- |Get all triangle polygons.
triangleOnly :: [[PT]] -> [[PT]]
triangleOnly = filter isTrianglePoly
-- |Get all non-triangle polygons.
nonTriangleOnly :: [[PT]] -> [[PT]]
nonTriangleOnly = filter (not . isTrianglePoly)