go-collide – git.sr.ht/~adnano/go-collide Index | Files

package collide

import "git.sr.ht/~adnano/go-collide"

Package collide implements 2D collision detection.

Index

Functions

func Cross 

func Cross(p, q Point) float64

Cross returns the cross product of p and q.

func Distance 

func Distance(a Shape, xfa Transform, b Shape, xfb Transform) float64

Distance returns the distance between a and b.

func Dot 

func Dot(p, q Point) float64

Dot returns the dot product of p and q.

func TimeOfImpact 

func TimeOfImpact(simplex *Simplex, a Shape, sweepA Sweep, b Shape, sweepB Sweep) float64

CCD via the local separating axis method. This seeks progression by computing the largest time at which separation is maintained.

Types

type Circle 

type Circle struct {
	Center Point
	Radius float64
}

Circle represents a circle shape.

type Collision 

type Collision struct {
	Normal Point
	Depth  float64
}

Collision represents a collision.

func Collide 

func Collide(a Shape, xfa Transform, b Shape, xfb Transform) *Collision

Collide calculates a collision for two shapes.

func CollideCircleAndPolygon 

func CollideCircleAndPolygon(a *Circle, xfa Transform, b *Polygon, xfb Transform) *Collision

func CollideCircles 

func CollideCircles(a *Circle, xfa Transform, b *Circle, xfb Transform) *Collision

func CollidePolygonAndCircle 

func CollidePolygonAndCircle(a *Polygon, xfa Transform, b *Circle, xfb Transform) *Collision

func CollidePolygons 

func CollidePolygons(a *Polygon, xfa Transform, b *Polygon, xfb Transform) *Collision

type Point 

type Point struct {
	X, Y float64
}

A Point is an X, Y coordinate pair.

func CrossPS 

func CrossPS(p Point, s float64) Point

func CrossSP 

func CrossSP(s float64, p Point) Point

func Pt 

func Pt(X, Y float64) Point

Pt is shorthand for Point{X, Y}.

func (Point) Add 

func (p Point) Add(q Point) Point

Add returns the vector p+q.

func (Point) Div 

func (p Point) Div(k float64) Point

Div returns the vector p/k.

func (Point) IsZero 

func (p Point) IsZero() bool

IsZero reports whether the point has zero length.

func (Point) Length 

func (p Point) Length() float64

Length returns the length of the vector p.

func (Point) LengthSquared 

func (p Point) LengthSquared() float64

LengthSquared returns the squared length of the vector p.

func (Point) Mul 

func (p Point) Mul(k float64) Point

Mul returns the vector p*k.

func (Point) Neg 

func (p Point) Neg() Point

Neg returns the vector -p.

func (Point) Normalize 

func (p Point) Normalize() Point

Normalize returns the unit vector in the direction of p.

func (Point) Sub 

func (p Point) Sub(q Point) Point

Sub returns the vector p-q.

type Polygon 

type Polygon struct {
	Points  []Point
	Normals []Point
}

Polygon represents a collection of points.

func NewPolygon 

func NewPolygon(points ...Point) *Polygon

NewPolygon returns a polygon with the given points specified in clockwise order.

func Rect 

func Rect(x, y, w, h float64) *Polygon

Rect is shorthand for Rectangle(Point{x, y}, Point{w/2, h/2}).

func Rectangle 

func Rectangle(center, extents Point) *Polygon

Rectangle returns a rectangular polygon shape with the given center and half extents.

type Rotation 

type Rotation struct {
	Sin, Cos float64
}

Rotation represents a rotation.

func NewRotation 

func NewRotation(theta float64) Rotation

NewRotation returns a new rotation of theta radians.

func (Rotation) Mul 

func (r Rotation) Mul(p Point) Point

Mul returns the vector p rotated.

func (Rotation) MulT 

func (r Rotation) MulT(p Point) Point

MulT returns the vector p inverse rotated.

type Shape 

type Shape interface {
	// contains filtered or unexported methods
}

Shape represents a shape.

type Simplex 

type Simplex struct {
	// contains filtered or unexported fields
}

Simplex represents a simplex.

func (*Simplex) ClosestPoint 

func (s *Simplex) ClosestPoint() Point

ClosestPoint returns the closest point on the simplex to the origin.

func (*Simplex) GJK 

func (s *Simplex) GJK(a Shape, xfa Transform, b Shape, xfb Transform)

GJK implements the Gilbert-Johnson-Keerthi distance algorithm.

func (*Simplex) Metric 

func (s *Simplex) Metric() float64

Metric returns a metric that identifies this simplex.

func (*Simplex) ReadCache 

func (s *Simplex) ReadCache(cache *SimplexCache, a Shape, xfa Transform, b Shape, xfb Transform)

ReadCache populates the simplex from the cache.

func (*Simplex) WitnessPoints 

func (s *Simplex) WitnessPoints() (Point, Point)

WitnessPoints returns the witness points on the original shapes.

func (*Simplex) WriteCache 

func (s *Simplex) WriteCache(cache *SimplexCache)

WriteCache populates the cache.

type SimplexCache 

type SimplexCache struct {
	// contains filtered or unexported fields
}

SimplexCache is used to speed up repeated calls to distance functions.

type Sweep 

type Sweep struct {
	P0, P1 Point   // position
	R0, R1 float64 // rotation
}

A Sweep interpolates between two positions and orientations.

func (Sweep) Advance 

func (s Sweep) Advance(t float64) Sweep

Advance advances the position and rotation to time t.

func (Sweep) GetTransform 

func (s Sweep) GetTransform(t float64) Transform

GetTransform returns the transform at time t.

type Transform 

type Transform struct {
	Position Point
	Rotation Rotation
}

A Transform represents translation and rotation.

func NewTransform 

func NewTransform(position Point, rotation float64) Transform

NewTransform returns a Transform with the given position and rotation.

func (Transform) Mul 

func (t Transform) Mul(p Point) Point

Mul returns the transformation of the vector p.

func (Transform) MulT 

func (t Transform) MulT(p Point) Point

MulT returns the inverse transformation of the vector p.

Source Files

collide.go distance.go doc.go math.go shape.go toi.go

Version
v0.0.0-20220221183648-c04b3ee7ccb2 (latest)
Published
Feb 21, 2022
Platform
linux/amd64
Imports
1 packages
Last checked
1 month ago –

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