poly

Documentation

Index

• func CalcEllipseSegmentCount[T constraints.Float](r, e T) int
• type Contour
  • func (c Contour[T]) Bounds() geom.Rect[T]
  • func (c Contour[T]) Clone() Contour[T]
  • func (c Contour[T]) Contains(pt geom.Point[T]) bool
• type Contour32
• type Contour64
• type Polygon
  • func ApproximateEllipse[T constraints.Float](bounds geom.Rect[T], sections int) Polygon[T]
  • func ApproximateEllipseAuto[T constraints.Float](bounds geom.Rect[T]) Polygon[T]
  • func Rect[T constraints.Float](bounds geom.Rect[T]) Polygon[T]
  • func (p Polygon[T]) Bounds() geom.Rect[T]
  • func (p Polygon[T]) ClipLine(other Polygon[T]) Polygon[T]
  • func (p Polygon[T]) Clone() Polygon[T]
  • func (p Polygon[T]) Contains(pt geom.Point[T]) bool
  • func (p Polygon[T]) ContainsEvenOdd(pt geom.Point[T]) bool
  • func (p Polygon[T]) Intersect(other Polygon[T]) Polygon[T]
  • func (p Polygon[T]) Simplify() Polygon[T]
  • func (p Polygon[T]) Subtract(other Polygon[T]) Polygon[T]
  • func (p Polygon[T]) Union(other Polygon[T]) Polygon[T]
  • func (p Polygon[T]) Xor(other Polygon[T]) Polygon[T]
• type Polygon32
• type Polygon64
• type Segment
  • func (s Segment[T]) CoincidesWith(start, end geom.Point[T]) bool
  • func (s Segment[T]) FindIntersection(other Segment[T], tryBothDirections bool) (count int, pi0, pi1 geom.Point[T])
• type Segment32
• type Segment64

Functions

func CalcEllipseSegmentCount

func CalcEllipseSegmentCount[T constraints.Float](r, e T) int

CalcEllipseSegmentCount returns a suggested number of segments to use when generating an ellipse. 'r' is the largest radius of the ellipse. 'e' is the acceptable error, typically 1 or less.

Types

type Contour

type Contour[T constraints.Float] []geom.Point[T]

Contour is a sequence of vertices connected by line segments, forming a closed shape.

func (Contour[T]) Bounds

func (c Contour[T]) Bounds() geom.Rect[T]

Bounds returns the bounding rectangle of a contour.

func (Contour[T]) Clone

func (c Contour[T]) Clone() Contour[T]

Clone returns a copy of this contour.

func (Contour[T]) Contains

func (c Contour[T]) Contains(pt geom.Point[T]) bool

Contains returns true if the point is contained by the contour.

type Contour32

type Contour32 = Contour[float32]

Contour32 is an alias for the float32 version of Contour.

type Contour64

type Contour64 = Contour[float64]

Contour64 is an alias for the float64 version of Contour.

type Polygon

type Polygon[T constraints.Float] []Contour[T]

Polygon holds one or more contour lines. The polygon may contain holes and may be self-intersecting.

func ApproximateEllipse

func ApproximateEllipse[T constraints.Float](bounds geom.Rect[T], sections int) Polygon[T]

ApproximateEllipse creates a polygon that approximates an ellipse. 'sections' indicates how many segments to break the ellipse contour into.

func ApproximateEllipseAuto

func ApproximateEllipseAuto[T constraints.Float](bounds geom.Rect[T]) Polygon[T]

ApproximateEllipseAuto creates a polygon that approximates an ellipse, automatically choose the number of segments to break the ellipse contour into. This uses CalcEllipseSegmentCount() with an 'e' of 0.2.

func Rect

func Rect[T constraints.Float](bounds geom.Rect[T]) Polygon[T]

Rect creates a new polygon in the shape of a rectangle.

func (Polygon[T]) Bounds

func (p Polygon[T]) Bounds() geom.Rect[T]

Bounds returns the bounding rectangle of this polygon.

func (Polygon[T]) ClipLine

func (p Polygon[T]) ClipLine(other Polygon[T]) Polygon[T]

ClipLine assumes p is actually a line and clips it.

func (Polygon[T]) Clone

func (p Polygon[T]) Clone() Polygon[T]

Clone returns a duplicate of this polygon.

func (Polygon[T]) Contains

func (p Polygon[T]) Contains(pt geom.Point[T]) bool

Contains returns true if the point is contained by the polygon.

func (Polygon[T]) ContainsEvenOdd

func (p Polygon[T]) ContainsEvenOdd(pt geom.Point[T]) bool

ContainsEvenOdd returns true if the point is contained by the polygon using the even-odd rule. https://en.wikipedia.org/wiki/Even-odd_rule

func (Polygon[T]) Intersect

func (p Polygon[T]) Intersect(other Polygon[T]) Polygon[T]

Intersect returns the intersection of both polygons. Does not handle self-intersecting polygons. Use Simplify() first, if necessary.

func (Polygon[T]) Simplify

func (p Polygon[T]) Simplify() Polygon[T]

Simplify creates a new Polygon without self-intersections or repeated edges.

func (Polygon[T]) Subtract

func (p Polygon[T]) Subtract(other Polygon[T]) Polygon[T]

Subtract returns the result of removing the other polygon from this polygon. Does not handle self-intersecting polygons. Use Simplify() first, if necessary.

func (Polygon[T]) Union

func (p Polygon[T]) Union(other Polygon[T]) Polygon[T]

Union returns the union of both polygons. Does not handle self-intersecting polygons. Use Simplify() first, if necessary.

func (Polygon[T]) Xor

func (p Polygon[T]) Xor(other Polygon[T]) Polygon[T]

Xor returns the result of xor'ing this polygon with the other polygon. Does not handle self-intersecting polygons. Use Simplify() first, if necessary.

type Polygon32

type Polygon32 = Polygon[float32]

Polygon32 is an alias for the float32 version of Polygon.

type Polygon64

type Polygon64 = Polygon[float64]

Polygon64 is an alias for the float64 version of Polygon.

type Segment

type Segment[T constraints.Float] struct {
	Start geom.Point[T]
	End   geom.Point[T]
}

Segment holds the start and end point of a single segment within a contour of a polygon.

func (Segment[T]) CoincidesWith

func (s Segment[T]) CoincidesWith(start, end geom.Point[T]) bool

CoincidesWith returns true if the segment matches the given start and end in either direction.

func (Segment[T]) FindIntersection

func (s Segment[T]) FindIntersection(other Segment[T], tryBothDirections bool) (count int, pi0, pi1 geom.Point[T])

FindIntersection finds the points where the two segments intersect, if any.

type Segment32

type Segment32 = Segment[float32]

Segment32 is an alias for the float32 version of Segment.

type Segment64

type Segment64 = Segment[float64]

Segment64 is an alias for the float64 version of Segment.