Maintainer | diagrams-discuss@googlegroups.com |
---|---|

Safe Haskell | None |

Basic types for three-dimensional Euclidean space.

- data R3
- r3 :: (Double, Double, Double) -> R3
- unr3 :: R3 -> (Double, Double, Double)
- mkR3 :: Double -> Double -> Double -> R3
- type P3 = Point R3
- p3 :: (Double, Double, Double) -> P3
- unp3 :: P3 -> (Double, Double, Double)
- mkP3 :: Double -> Double -> Double -> P3
- type T3 = Transformation R3
- r3Iso :: Iso' R3 (Double, Double, Double)
- p3Iso :: Iso' P3 (Double, Double, Double)
- data Angle
- rad :: Iso' Angle Double
- turn :: Iso' Angle Double
- deg :: Iso' Angle Double
- (@@) :: b -> Iso' a b -> a
- fullTurn :: Angle
- angleRatio :: Angle -> Angle -> Double
- class Direction d where
- toSpherical :: d -> Spherical
- fromSpherical :: Spherical -> d

- data Spherical = Spherical Angle Angle
- asSpherical :: Spherical -> Spherical

# 3D Euclidean space

The three-dimensional Euclidean vector space R^3.

type T3 = Transformation R3Source

Transformations in R^3.

# Two-dimensional angles

These are defined in Diagrams.TwoD.Types but reëxported here for convenience.

Angles can be expressed in a variety of units. Internally, they are represented in radians.

rad :: Iso' Angle DoubleSource

The radian measure of an `Angle`

`a`

can be accessed as ```
a
^. rad
```

. A new `Angle`

can be defined in radians as `pi @@ rad`

.

turn :: Iso' Angle DoubleSource

The measure of an `Angle`

`a`

in full circles can be accessed as
`a ^. turn`

. A new `Angle`

of one-half circle can be defined in as
`1/2 @@ turn`

.

deg :: Iso' Angle DoubleSource

The degree measure of an `Angle`

`a`

can be accessed as ```
a
^. deg
```

. A new `Angle`

can be defined in degrees as ```
180 @@
deg
```

.

(@@) :: b -> Iso' a b -> aSource

`30 @@ deg`

is an `Angle`

of the given measure and units.

More generally, `@@`

reverses the `Iso'`

on its right, and
applies the `Iso'`

to the value on the left. `Angle`

s are the
motivating example where this order improves readability.

angleRatio :: Angle -> Angle -> DoubleSource

Calculate ratio between two angles.

# Directions in 3D

Direction is a type class representing directions in R3. The interface is based on that of the Angle class in 2D.

toSpherical :: d -> SphericalSource

Convert to spherical coördinates

fromSpherical :: Spherical -> dSource

Convert from spherical coördinates

A direction expressed as a pair of spherical coordinates.
`Spherical 0 0` is the direction of `unitX`

. The first coordinate
represents rotation about the Z axis, the second rotation towards the Z axis.

asSpherical :: Spherical -> SphericalSource

The identity function with a restricted type, for conveniently
restricting unwanted polymorphism. For example, ```
fromDirection
. asSpherical . camForward
```

gives a unit vector pointing in the
direction of the camera view. Without `asSpherical`

, the
intermediate type would be ambiguous.