Graphics.Triangulation.Triangulation

Documentation

type TriangulationFunction = Vector V2 -> [(Int, Int, Int)]

data Tree

Constructors

Node Int Int [Tree]

Instances

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triangulate :: TriangulationFunction -> Geometry -> Geometry

since there are a lot of triangulation algorithms a triangulation function can be passed

v2s :: Vector V3 -> Vector Int -> Vector V2

gjpTri :: Vector V2 -> [(Int, Int, Int)]

deleteHoles :: Geometry -> Geometry

some triangulation algorithms on't support polygons with holes These polygons with (nested) holes have to be cut so that they consist of only one outline I.e. the chars a,b,d,e,g,o,p,q contain holes tat have to be deleted.

flatten :: Vector V2 -> [Tree] -> Vector (Vector Int) -> Vector (Vector Int)

embed :: Vector V2 -> Vector (Vector Int) -> Vector Int -> Vector Int

cut a polygon at a good position and insert the contained hole-polygon with opposite direction

alternate :: Int -> Bool -> Vector Int -> Vector Int

make sure that direction (clockwise or ccw) of polygons alternates depending on the nesting number c of poly

generateTrees :: Vector V3 -> (Vector V2 -> Vector V2 -> Bool) -> Vector (Vector Int) -> [Tree]

f should be the funtion to test contains the trees then are the hierarchy of containedness of outlines

treesList :: [[Int]] -> [Tree] -> [Tree]

insertTrees :: [Int] -> [Tree] -> [Tree]

insertTree :: [Int] -> Tree -> (Bool, Tree)

rotatePoly :: V2 -> Vector V2 -> (Int, Float)

how many positions to rotate a polygon until the start point is nearest to some other point call i.e. with nearest (3,4) [(0,0),(1,2), ... ] 0 0

nearest :: V2 -> Vector V2 -> Float -> Int -> Int -> (Int, Float)

insidePoly :: Vector V2 -> Vector V2 -> Bool

returns True iff the first point of the first polygon is inside the second poylgon

pointInside :: V2 -> Vector V2 -> Bool

A point is inside a polygon if it has an odd number of intersections with the boundary (Jordan Curve theorem)

polygonDirection :: Vector V2 -> Bool

the direction of a polygon can be obtained by looking at a maximal point returns True if counterclockwise False if clockwise

maxim :: Vector V2 -> Int -> Int -> (Float, Float) -> Int

isLeftTurn :: V2 -> V2 -> V2 -> Bool