opensolid/geometry/1.0.3

NOTE: this package is not compatible with Elm 0.19.1

OpenSolid.LineSegment3d

LineSegment3d

A LineSegment3d is a line between two points in 3D. This module contains functionality such as:

  • Interpolating within a line segment or measuring its length
  • Scaling, rotating, translating, mirroring or projecting a line segment
  • Converting a line segment between local and global coordinates in different reference frames

Line segments can be constructed by passing a tuple of start and end points to the LineSegment3d constructor, for example

exampleLineSegment =
    LineSegment3d
        ( Point3d ( 1, 2, 3 )
        , Point3d ( 4, 5, 6 )
        )

Endpoints

startPoint : LineSegment3d -> Point3d

Get the start point of a line segment.

LineSegment3d.startPoint exampleLineSegment
-- Point3d ( 1, 2, 3 )
endPoint : LineSegment3d -> Point3d

Get the end point of a line segment.

LineSegment3d.endPoint exampleLineSegment
-- Point3d ( 4, 5, 6 )
endpoints : LineSegment3d -> ( Point3d, Point3d )

Get the endpoints of a line segment as a tuple.

( p1, p2 ) =
    LineSegment3d.endpoints lineSegment
reverse : LineSegment3d -> LineSegment3d

Reverse a line segment, swapping its start and end points.

LineSegment3d.reverse exampleLineSegment
-- LineSegment3d
--     ( Point3d ( 4, 5, 6 )
--     , Point3d ( 1, 2, 3 )
--     )

Interpolation

midpoint : LineSegment3d -> Point3d

Get the midpoint of a line segment.

LineSegment3d.midpoint exampleLineSegment
-- Point3d ( 2.5, 3.5, 4.5 )
interpolate : LineSegment3d -> Float -> Point3d

Interpolate a line segment between its start and end points; a value of 0.0 corresponds to the start point of the line segment, a value of 0.5 corresponds to its midpoint and a value of 1.0 corresponds to its end point. Negative values or values greater than 1 can be used to extrapolate.

LineSegment3d.interpolate exampleLineSegment (1 / 3)
-- Point3d ( 2, 4, 5 )


LineSegment3d.interpolate exampleLineSegment (-1 / 3)
-- Point3d ( 0, 1, 2 )

Length and direction

length : LineSegment3d -> Float

Get the length of a line segment.

LineSegment3d.length exampleLineSegment
-- 5.1962
squaredLength : LineSegment3d -> Float

Get the squared length of a line segment. Slightly more efficient than length since it avoids a square root.

LineSegment3d.squaredLength exampleLineSegment
-- 27
direction : LineSegment3d -> Maybe Direction3d

Get the direction from a line segment's start point to its end point. If the line segment has zero length (the start and end points are the same), returns Nothing.

LineSegment3d.direction exampleLineSegment
-- Just (Direction3d ( 0.5774, 0.5774, 0.5774 ))
normalDirection : LineSegment3d -> Maybe Direction3d

Get an arbitrary direction perpendicular to a line segment. If the line segment has zero length, returns Nothing.

LineSegment3d.normalDirection exampleLineSegment
-- Just (Direction3d ( 0, -0.7071, 0.7071 ))
vector : LineSegment3d -> Vector3d

Get the vector from a line segment's start point to its end point.

LineSegment3d.vector exampleLineSegment
-- Vector3d ( 2, 2, 2 )

Transformations

Transforming a line segment is equivalent to transforming its start and end points and forming a new line segment between the resulting points.

scaleAbout : Point3d -> Float -> LineSegment3d -> LineSegment3d

Scale a line segment about the given center point by the given scale.

point =
    Point3d ( 1, 1, 1 )


LineSegment3d.scaleAbout point 2 exampleLineSegment
-- LineSegment3d
--     ( Point3d ( 1, 3, 5 )
--     , Point3d ( 7, 9, 11 )
--     )
rotateAround : Axis3d -> Float -> LineSegment3d -> LineSegment3d

Rotate around a given axis by a given angle (in radians).

LineSegment3d.rotateAround Axis3d.z (degrees 90) exampleLineSegment
-- LineSegment3d
--     ( Point3d ( -2, 1, 3 )
--     , Point3d ( -5, 4, 6 )
--     )
translateBy : Vector3d -> LineSegment3d -> LineSegment3d

Translate a line segment by a given displacement.

displacement =
    Vector3d ( 1, 2, 3 )


LineSegment3d.translateBy displacement exampleLineSegment
-- LineSegment3d
--     ( Point3d ( 2, 4, 6 )
--     , Point3d ( 5, 7, 9 )
--     )
mirrorAcross : Plane3d -> LineSegment3d -> LineSegment3d

Mirror a line segment across a plane.

LineSegment3d.mirrorAcross Plane3d.xy exampleLineSegment
-- LineSegment3d
--     ( Point3d ( 1, 2, -3 )
--     , Point3d ( 4, 5, -6 )
--     )
projectOnto : Plane3d -> LineSegment3d -> LineSegment3d

Project a line segment onto a plane.

LineSegment3d.projectOnto Plane3d.yz exampleLineSegment
-- LineSegment3d
--     ( Point3d ( 0, 2, 3 )
--     , Point3d ( 0, 5, 6 )
--     )
map : (Point3d -> Point3d) -> LineSegment3d -> LineSegment3d

Transform the start and end points of a line segment by a given function and create a new line segment from the resulting points. Most other transformation functions can be defined in terms of map; for example,

LineSegment3d.projectOnto Plane3d.xy

is equivalent to

LineSegment3d.map (Point3d.projectOnto Plane3d.xy)

Coordinate frames

Functions for transforming line segments between local and global coordinates in different coordinate frames.

relativeTo : Frame3d -> LineSegment3d -> LineSegment3d

Take a line segment defined in global coordinates, and return it expressed in local coordinates relative to a given reference frame.

localFrame =
    Frame3d.at (Point3d ( 1, 2, 3 ))


LineSegment3d.relativeTo localFrame exampleLineSegment
-- LineSegment3d
--     ( Point3d ( 0, 0, 0 )
--     , Point3d ( 3, 3, 3 )
--     )
placeIn : Frame3d -> LineSegment3d -> LineSegment3d

Take a line segment considered to be defined in local coordinates relative to a given reference frame, and return that line segment expressed in global coordinates.

localFrame =
    Frame3d.at (Point3d ( 1, 2, 3 ))


LineSegment3d.placeIn localFrame exampleLineSegment
-- LineSegment3d
--     ( Point3d ( 2, 4, 6 )
--     , Point3d ( 5, 7, 9 )
--     )

Sketch planes

projectInto : SketchPlane3d -> LineSegment3d -> LineSegment2d

Project a line segment into a given sketch plane. Conceptually, this projects the line segment onto the plane and then expresses the projected line segment in 2D sketch coordinates.

LineSegment3d.projectInto SketchPlane3d.xy exampleLineSegment
-- LineSegment2d
--     ( Point2d ( 1, 2 )
--     , Point2d ( 4, 5 )
--     )


LineSegment3d.projectInto SketchPlane3d.yz exampleLineSegment
-- LineSegment2d
--     ( Point2d ( 2, 3 )
--     , Point2d ( 5, 6 )
--     )


LineSegment3d.projectInto SketchPlane3d.zx exampleLineSegment
-- LineSegment2d
--     ( Point2d ( 3, 1 )
--     , Point2d ( 6, 4 )
--     )

Bounds

boundingBox : LineSegment3d -> BoundingBox3d

Get the minimal bounding box containing a line segment.

LineSegment3d.boundingBox exampleLineSegment
-- BoundingBox3d
--     { minX = 1
--     , maxX = 4
--     , minY = 2
--     , maxY = 5
--     , minZ = 3
--     , maxZ = 6
--     }