Copyright | (c) 2011 diagrams-lib team (see LICENSE) |
---|---|

License | BSD-style (see LICENSE) |

Maintainer | diagrams-discuss@googlegroups.com |

Safe Haskell | None |

Language | Haskell2010 |

Two-dimensional arcs, approximated by cubic bezier curves.

## Synopsis

- arc :: (InSpace V2 n t, OrderedField n, TrailLike t) => Direction V2 n -> Angle n -> t
- arc' :: (InSpace V2 n t, OrderedField n, TrailLike t) => n -> Direction V2 n -> Angle n -> t
- arcT :: OrderedField n => Direction V2 n -> Angle n -> Trail V2 n
- arcCCW :: (InSpace V2 n t, RealFloat n, TrailLike t) => Direction V2 n -> Direction V2 n -> t
- arcCW :: (InSpace V2 n t, RealFloat n, TrailLike t) => Direction V2 n -> Direction V2 n -> t
- bezierFromSweep :: OrderedField n => Angle n -> [Segment Closed V2 n]
- wedge :: (InSpace V2 n t, OrderedField n, TrailLike t) => n -> Direction V2 n -> Angle n -> t
- arcBetween :: (TrailLike t, V t ~ V2, N t ~ n, RealFloat n) => Point V2 n -> Point V2 n -> n -> t
- annularWedge :: (TrailLike t, V t ~ V2, N t ~ n, RealFloat n) => n -> n -> Direction V2 n -> Angle n -> t

# Documentation

arc :: (InSpace V2 n t, OrderedField n, TrailLike t) => Direction V2 n -> Angle n -> t #

Given a start direction `d`

and a sweep angle `s`

,

is the
path of a radius one arc starting at `arc`

d s`d`

and sweeping out the angle
`s`

counterclockwise (for positive s). The resulting
`Trail`

is allowed to wrap around and overlap itself.

arc' :: (InSpace V2 n t, OrderedField n, TrailLike t) => n -> Direction V2 n -> Angle n -> t #

Given a radus `r`

, a start direction `d`

and an angle `s`

,

is the path of a radius `arc'`

r d s`(abs r)`

arc starting at
`d`

and sweeping out the angle `s`

counterclockwise (for positive
s). The origin of the arc is its center.

arc'Ex = mconcat [ arc' r xDir (1/4 @@ turn) | r <- [0.5,-1,1.5] ] # centerXY # pad 1.1

arcCCW :: (InSpace V2 n t, RealFloat n, TrailLike t) => Direction V2 n -> Direction V2 n -> t #

Given a start direction `s`

and end direction `e`

, `arcCCW s e`

is the
path of a radius one arc counterclockwise between the two directions.
The origin of the arc is its center.

arcCW :: (InSpace V2 n t, RealFloat n, TrailLike t) => Direction V2 n -> Direction V2 n -> t #

Like `arcAngleCCW`

but clockwise.

bezierFromSweep :: OrderedField n => Angle n -> [Segment Closed V2 n] #

`bezierFromSweep s`

constructs a series of `Cubic`

segments that
start in the positive y direction and sweep counter clockwise
through the angle `s`

. If `s`

is negative, it will start in the
negative y direction and sweep clockwise. When `s`

is less than
0.0001 the empty list results. If the sweep is greater than `fullTurn`

later segments will overlap earlier segments.

wedge :: (InSpace V2 n t, OrderedField n, TrailLike t) => n -> Direction V2 n -> Angle n -> t #

Create a circular wedge of the given radius, beginning at the given direction and extending through the given angle.

wedgeEx = hcat' (with & sep .~ 0.5) [ wedge 1 xDir (1/4 @@ turn) , wedge 1 (rotate (7/30 @@ turn) xDir) (4/30 @@ turn) , wedge 1 (rotate (1/8 @@ turn) xDir) (3/4 @@ turn) ] # fc blue # centerXY # pad 1.1

arcBetween :: (TrailLike t, V t ~ V2, N t ~ n, RealFloat n) => Point V2 n -> Point V2 n -> n -> t #

`arcBetween p q height`

creates an arc beginning at `p`

and
ending at `q`

, with its midpoint at a distance of `abs height`

away from the straight line from `p`

to `q`

. A positive value of
`height`

results in an arc to the left of the line from `p`

to
`q`

; a negative value yields one to the right.

arcBetweenEx = mconcat [ arcBetween origin (p2 (2,1)) ht | ht <- [-0.2, -0.1 .. 0.2] ] # centerXY # pad 1.1

annularWedge :: (TrailLike t, V t ~ V2, N t ~ n, RealFloat n) => n -> n -> Direction V2 n -> Angle n -> t #

Create an annular wedge of the given radii, beginning at the first direction and extending through the given sweep angle. The radius of the outer circle is given first.

annularWedgeEx = hsep 0.50 [ annularWedge 1 0.5 xDir (1/4 @@ turn) , annularWedge 1 0.3 (rotate (7/30 @@ turn) xDir) (4/30 @@ turn) , annularWedge 1 0.7 (rotate (1/8 @@ turn) xDir) (3/4 @@ turn) ] # fc blue # centerXY # pad 1.1