cm

package module
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 Go to latest Published: Nov 8, 2024 License: MIT Imports: 6 Imported by: 7

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cm

Go language port of Chipmunk2D 7.0.3 physics library.

Documentation

Index

Constants

View Source 
const (
	// Arbiter is active and its the first collision.
	ArbiterStateFirstCollision = iota
	// Arbiter is active and its not the first collision.
	ArbiterStateNormal
	// Collision has been explicitly ignored. Either by returning false from a
	// begin collision handler or calling ArbiterIgnore().
	ArbiterStateIgnore
	// Collison is no longer active. A space will cache an arbiter for up to Space.
	// CollisionPersistence more steps.
	ArbiterStateCached
	// Collison arbiter is invalid because one of the shapes was removed.
	ArbiterStateInvalidated
)

Arbiter states

View Source 
const (
	// Value for group signifying that a shape is in no group.
	NoGroup uint = 0
	// Value for Shape layers signifying that a shape is in every layer.
	AllCategories uint = ^uint(0)
)
View Source 
const (
	DrawShapes          = 1 << 0
	DrawConstraints     = 1 << 1
	DrawCollisionPoints = 1 << 2
)

Draw flags

View Source 
const (
	MaxContactsPerArbiter int = 2
	ContactsBufferSize    int = 1024
)
View Source 
const (
	ShapeTypeNum = 3
)

Variables

View Source 
var BuiltinCollisionFuncs = [9]CollisionFunc{
	CircleToCircle,
	CollisionError,
	CollisionError,
	CircleToSegment,
	SegmentToSegment,
	CollisionError,
	CircleToPoly,
	SegmentToPoly,
	PolyToPoly,
}
View Source 
var CollisionHandlerDefault = CollisionHandler{
	WildcardCollisionType,
	WildcardCollisionType,
	DefaultBegin,
	DefaultPreSolve,
	DefaultPostSolve,
	DefaultSeparate,
	nil,
}
View Source 
var CollisionHandlerDoNothing = CollisionHandler{
	WildcardCollisionType,
	WildcardCollisionType,
	AlwaysCollide,
	AlwaysCollide,
	DoNothing,
	DoNothing,
	nil,
}
View Source 
var ShapeFilterAll = ShapeFilter{NoGroup, AllCategories, AllCategories}

ShapeFilterAll is s collision filter value for a shape that will collide with anything except ShapeFilterNone.

View Source 
var ShapeFilterNone = ShapeFilter{NoGroup, ^AllCategories, ^AllCategories}

ShapeFilterNone is a collision filter value for a shape that does not collide with anything.

View Source 
var ShapeUpdateFunc = func(shape *Shape) {
	shape.CacheBB()
}
View Source 
var ShapeVelocityFunc = func(obj any) vec.Vec2 {
	return obj.(*Shape).Body.velocity
}

Functions

func AlwaysCollide 

func AlwaysCollide(_ *Arbiter, _ *Space, _ any) bool

func AreaForCircle 

func AreaForCircle(r1, r2 float64) float64

AreaForCircle returns area of a hollow circle.

r1 and r2 are the inner and outer diameters. A solid circle has an inner diameter of 0.

func AreaForPoly 

func AreaForPoly(count int, verts []vec.Vec2, r float64) float64

AreaForPoly calculates the signed area of a polygon.

A Clockwise winding gives positive area. This is probably backwards from what you expect, but matches Chipmunk's the winding for poly shapes.

func AreaForSegment 

func AreaForSegment(a, b vec.Vec2, r float64) float64

AreaForSegment calculates the area of a fattened (capsule shaped) line segment.

func BodyUpdatePosition 

func BodyUpdatePosition(body *Body, dt float64)

BodyUpdatePosition is default position integration function.

func BodyUpdateVelocity 

func BodyUpdateVelocity(body *Body, gravity vec.Vec2, damping, dt float64)

BodyUpdateVelocity is default velocity integration function.

func CachedArbitersFilter 

func CachedArbitersFilter(arb *Arbiter, space *Space, shape *Shape, body *Body) bool

func CentroidForPoly 

func CentroidForPoly(count int, verts []vec.Vec2) vec.Vec2

CentroidForPoly calculates the natural centroid of a polygon.

func CircleSegmentQuery 

func CircleSegmentQuery(shape *Shape, center vec.Vec2, r1 float64, a, b vec.Vec2, r2 float64, info *SegmentQueryInfo)

func CircleToCircle 

func CircleToCircle(info *CollisionInfo)

func CircleToPoly 

func CircleToPoly(info *CollisionInfo)

func CircleToSegment 

func CircleToSegment(info *CollisionInfo)

func CollisionError 

func CollisionError(_ *CollisionInfo)

func ComponentActive 

func ComponentActive(root *Body, threshold float64) bool

func ContactPoints 

func ContactPoints(e1, e2 Edge, points ClosestPoints, info *CollisionInfo)

ContactPoints finds contact point pairs on two support edges' surfaces

func Contains 

func Contains(bodies []*Body, body *Body) bool

func DebugInfo 

func DebugInfo(space *Space) string

DebugInfo returns info of space

func DefaultBegin 

func DefaultBegin(arb *Arbiter, space *Space, _ any) bool

func DefaultPostSolve 

func DefaultPostSolve(arb *Arbiter, space *Space, _ any)

func DefaultPreSolve 

func DefaultPreSolve(arb *Arbiter, space *Space, _ any) bool

func DefaultSeparate 

func DefaultSeparate(arb *Arbiter, space *Space, _ any)

func DefaultSpringForce 

func DefaultSpringForce(spring *DampedSpring, dist float64) float64

func DoNothing 

func DoNothing(_ *Arbiter, _ *Space, _ any)

func DrawConstraint 

func DrawConstraint(constraint *Constraint, drawer IDrawer)

DrawConstraint draws constraints with the drawer implementation

func DrawShape 

func DrawShape(shape *Shape, drawer IDrawer)

DrawShape draws shapes with the drawer implementation

func DrawSpace 

func DrawSpace(space *Space, drawer IDrawer)

DrawSpace draws all shapes in space with the drawer implementation

func FloodFillComponent 

func FloodFillComponent(root *Body, body *Body)

func MomentForBox 

func MomentForBox(mass, width, height float64) float64

MomentForBox calculates the moment of inertia for a solid box.

func MomentForBox2 

func MomentForBox2(mass float64, box BB) float64

MomentForBox2 calculates the moment of inertia for a solid box.

func MomentForCircle 

func MomentForCircle(mass, d1, d2 float64, offset vec.Vec2) float64

MomentForCircle calculates the moment of inertia for a circle.

d1 and d2 are the inner and outer diameters. A solid circle has an inner diameter (d1) of 0. offset is a Vec2 representing the displacement of the circle's center of mass from the axis of rotation. If the center is not aligned with the axis, the offset increases the moment of inertia.

func MomentForCircle2 added in v1.10.0 

func MomentForCircle2(mass, radius float64) float64

MomentForCircle calculates the moment of inertia for a solid circle with radius and mass

func MomentForPoly 

func MomentForPoly(mass float64, count int, verts []vec.Vec2, offset vec.Vec2, r float64) float64

MomentForPoly calculates the moment of inertia for a solid polygon shape assuming it's center of gravity is at it's centroid.

The offset is added to each vertex.

func MomentForSegment 

func MomentForSegment(mass float64, a, b vec.Vec2, radius float64) float64

MomentForSegment calculates the moment of inertia for a line segment.

Beveling radius is not supported.

func NearestPointQueryNearest 

func NearestPointQueryNearest(obj any, shape *Shape, collisionId uint32, out any) uint32

func NodeSetA 

func NodeSetA(node, value *Node)

func NodeSetB 

func NodeSetB(node, value *Node)

func PolyLineCollectSegment 

func PolyLineCollectSegment(v0, v1 vec.Vec2, pls *PolyLineSet)

Add a segment to a polyline set. A segment will either start a new polyline, join two others, or add to or loop an existing polyline.

func PolySupportPointIndex 

func PolySupportPointIndex(count int, planes []SplittingPlane, n vec.Vec2) int

func PolyToPoly 

func PolyToPoly(info *CollisionInfo)

func PostStepDoNothing 

func PostStepDoNothing(space *Space, key, data any)

func QHullPartition 

func QHullPartition(verts []vec.Vec2, count int, a, b vec.Vec2, tol float64) int

func QHullReduce 

func QHullReduce(tol float64, verts []vec.Vec2, count int, a, pivot, b vec.Vec2, result []vec.Vec2) int

func QueryReject 

func QueryReject(a, b *Shape) bool

QueryReject returns true if shapes a and b reject to collide.

func QueryRejectConstraints 

func QueryRejectConstraints(a, b *Body) bool

func SegmentToPoly 

func SegmentToPoly(info *CollisionInfo)

func SegmentToSegment 

func SegmentToSegment(info *CollisionInfo)

func Sharpness 

func Sharpness(a, b, c vec.Vec2) float64

func SpaceArbiterSetFilter 

func SpaceArbiterSetFilter(arb *Arbiter, space *Space) bool

SpaceArbiterSetFilter throws away old arbiters.

func SpaceCollideShapesFunc 

func SpaceCollideShapesFunc(obj any, b *Shape, collisionId uint32, vspace any) uint32

func VoidQueryFunc 

func VoidQueryFunc(obj1 any, obj2 *Shape, collisionId uint32, data any) uint32

Types

type Arbiter 

type Arbiter struct {
	UserData any

	Contacts []Contact // a slice onto the current buffer array of contacts
	// contains filtered or unexported fields
}

Arbiter struct tracks pairs of colliding shapes.

They are also used in conjuction with collision handler callbacks allowing you to retrieve information on the collision or change it. A unique arbiter value is used for each pair of colliding objects. It persists until the shapes separate.

func ArbiterNext 

func ArbiterNext(arb *Arbiter, body *Body) *Arbiter

func (*Arbiter) ApplyCachedImpulse 

func (arbiter *Arbiter) ApplyCachedImpulse(dtCoef float64)

func (*Arbiter) ApplyImpulse 

func (arbiter *Arbiter) ApplyImpulse()

func (*Arbiter) Bodies 

func (arb *Arbiter) Bodies() (*Body, *Body)

Bodies returns the colliding bodies involved for this arbiter. The order of the space.CollisionType the bodies are associated with values will match the order set when the collision handler was registered.

func (*Arbiter) CallWildcardBeginA 

func (arb *Arbiter) CallWildcardBeginA(space *Space) bool

CallWildcardBeginA if you want a custom callback to invoke the wildcard callback for the first collision type, you must call this function explicitly.

You must decide how to handle the wildcard's return value since it may disagree with the other wildcard handler's return value or your own.

func (*Arbiter) CallWildcardBeginB 

func (arb *Arbiter) CallWildcardBeginB(space *Space) bool

CallWildcardBeginB If you want a custom callback to invoke the wildcard callback for the second collision type, you must call this function explicitly.

func (*Arbiter) CallWildcardPostSolveA 

func (arb *Arbiter) CallWildcardPostSolveA(space *Space)

func (*Arbiter) CallWildcardPostSolveB 

func (arb *Arbiter) CallWildcardPostSolveB(space *Space)

func (*Arbiter) CallWildcardPreSolveA 

func (arb *Arbiter) CallWildcardPreSolveA(space *Space) bool

CallWildcardPreSolveA If you want a custom callback to invoke the wildcard callback for the first collision type, you must call this function explicitly.

func (*Arbiter) CallWildcardPreSolveB 

func (arb *Arbiter) CallWildcardPreSolveB(space *Space) bool

CallWildcardPreSolveB If you want a custom callback to invoke the wildcard callback for the second collision type, you must call this function explicitly.

func (*Arbiter) CallWildcardSeparateA 

func (arb *Arbiter) CallWildcardSeparateA(space *Space)

func (*Arbiter) CallWildcardSeparateB 

func (arb *Arbiter) CallWildcardSeparateB(space *Space)

func (*Arbiter) ContactPointSet 

func (arb *Arbiter) ContactPointSet() ContactPointSet

ContactPointSet returns ContactPointSet

func (*Arbiter) Count 

func (arb *Arbiter) Count() int

func (*Arbiter) Ignore 

func (arb *Arbiter) Ignore() bool

Ignore marks a collision pair to be ignored until the two objects separate.

Pre-solve and post-solve callbacks will not be called, but the separate callback will be called.

func (*Arbiter) Init 

func (arbiter *Arbiter) Init(a, b *Shape) *Arbiter

Init initializes and returns Arbiter

func (*Arbiter) IsFirstContact 

func (arbiter *Arbiter) IsFirstContact() bool

func (*Arbiter) Next 

func (node *Arbiter) Next(body *Body) *Arbiter

func (*Arbiter) Normal 

func (arb *Arbiter) Normal() vec.Vec2

func (*Arbiter) PreStep 

func (arb *Arbiter) PreStep(dt, slop, bias float64)

func (*Arbiter) SetContactPointSet 

func (arb *Arbiter) SetContactPointSet(set *ContactPointSet)

SetContactPointSet replaces the contact point set.

This can be a very powerful feature, but use it with caution!

func (*Arbiter) Shapes 

func (arb *Arbiter) Shapes() (*Shape, *Shape)

Shapes return the colliding shapes involved for this arbiter. The order of their space.CollisionType values will match the order set when the collision handler was registered.

func (*Arbiter) ThreadForBody 

func (arbiter *Arbiter) ThreadForBody(body *Body) *ArbiterThread

func (*Arbiter) TotalImpulse 

func (arb *Arbiter) TotalImpulse() vec.Vec2

TotalImpulse calculates the total impulse including the friction that was applied by this arbiter.

This function should only be called from a post-solve, post-step or EachArbiter callback.

func (*Arbiter) Unthread 

func (arbiter *Arbiter) Unthread()

func (*Arbiter) Update 

func (arb *Arbiter) Update(info *CollisionInfo, space *Space)

type ArbiterThread 

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

type BB 

type BB struct {
	L, B, R, T float64
}

BB is Chipmunk's axis-aligned 2D bounding box type. (left, bottom, right, top)

func NewBB 

func NewBB(l, b, r, t float64) BB

NewBB is convenience constructor for BB structs.

func NewBBForCircle 

func NewBBForCircle(p vec.Vec2, r float64) BB

NewBBForCircle constructs a BB for a circle with the given position and radius.

func NewBBForExtents 

func NewBBForExtents(c vec.Vec2, hw, hh float64) BB

NewBBForExtents constructs a BB centered on a point with the given extents (half sizes).

func ShapeGetBB 

func ShapeGetBB(obj *Shape) BB

func (BB) Area 

func (bb BB) Area() float64

Area returns the area of the bounding box.

func (BB) Center 

func (bb BB) Center() vec.Vec2

Center returns the center of a bounding box.

func (BB) ClampVect 

func (bb BB) ClampVect(v *vec.Vec2) vec.Vec2

ClampVect clamps a vector to bounding box.

func (BB) Contains 

func (bb BB) Contains(other BB) bool

Contains returns true if other lies completely within bb.

func (BB) ContainsVect 

func (bb BB) ContainsVect(v vec.Vec2) bool

ContainsVect returns true if bb contains v.

func (BB) Expand 

func (bb BB) Expand(v vec.Vec2) BB

Expand returns a bounding box that holds both bb and v.

func (BB) Intersects 

func (bb BB) Intersects(b BB) bool

Intersects returns true if a and b intersect.

func (BB) IntersectsSegment 

func (bb BB) IntersectsSegment(a, b vec.Vec2) bool

IntersectsSegment returns true if the bounding box intersects the line segment with ends a and b.

func (BB) Merge 

func (a BB) Merge(b BB) BB

Merge returns a bounding box that holds both bounding boxes.

func (BB) MergedArea 

func (a BB) MergedArea(b BB) float64

MergedArea merges a and b and returns the area of the merged bounding box.

func (BB) Offset 

func (bb BB) Offset(v vec.Vec2) BB

Offset returns a bounding box offseted by v.

func (BB) Proximity 

func (a BB) Proximity(b BB) float64

func (BB) SegmentQuery 

func (bb BB) SegmentQuery(a, b vec.Vec2) float64

SegmentQuery returns the fraction along the segment query the BB is hit. Returns cm.INFINITY if it doesn't hit.

func (BB) String 

func (bb BB) String() string

func (BB) WrapVect 

func (bb BB) WrapVect(v vec.Vec2) vec.Vec2

WrapVect wraps a vector to bounding box.

type BBQueryContext 

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

type BBTree 

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

BBTree represents a bounding box tree used for spatial indexing and collision detection.

func (*BBTree) Contains 

func (bbt *BBTree) Contains(obj *Shape, hashId HashValue) bool

func (*BBTree) Count 

func (bbt *BBTree) Count() int

func (*BBTree) Each 

func (bbt *BBTree) Each(f SpatialIndexIterator)

func (*BBTree) GetBB 

func (bbt *BBTree) GetBB(obj *Shape) BB

func (*BBTree) GetMasterTree 

func (tree *BBTree) GetMasterTree() *BBTree

func (*BBTree) IncrementStamp 

func (tree *BBTree) IncrementStamp()

func (*BBTree) Insert 

func (bbt *BBTree) Insert(obj *Shape, hashId HashValue)

func (*BBTree) LeafAddPairs 

func (tree *BBTree) LeafAddPairs(leaf *Node)

func (*BBTree) LeafUpdate 

func (tree *BBTree) LeafUpdate(leaf *Node) bool

func (*BBTree) NewLeaf 

func (tree *BBTree) NewLeaf(obj *Shape) *Node

func (*BBTree) NewNode 

func (bbt *BBTree) NewNode(a, b *Node) *Node

func (*BBTree) NodeFromPool 

func (tree *BBTree) NodeFromPool() *Node

func (*BBTree) PairFromPool 

func (bbt *BBTree) PairFromPool() *Pair

func (*BBTree) PairInsert 

func (tree *BBTree) PairInsert(a *Node, b *Node)

func (*BBTree) PairsClear 

func (tree *BBTree) PairsClear(leaf *Node)

func (*BBTree) Query 

func (bbt *BBTree) Query(obj any, bb BB, f SpatialIndexQuery, data any)

func (*BBTree) RecycleNode 

func (tree *BBTree) RecycleNode(node *Node)

func (*BBTree) RecyclePair 

func (bbt *BBTree) RecyclePair(pair *Pair)

func (*BBTree) Reindex 

func (tree *BBTree) Reindex()

func (*BBTree) ReindexObject 

func (bbt *BBTree) ReindexObject(obj *Shape, hashId HashValue)

func (*BBTree) ReindexQuery 

func (tree *BBTree) ReindexQuery(f SpatialIndexQuery, data any)

func (*BBTree) Remove 

func (tree *BBTree) Remove(obj *Shape, hashId HashValue)

func (*BBTree) ReplaceChild 

func (tree *BBTree) ReplaceChild(parent, child, value *Node)

func (*BBTree) SegmentQuery 

func (bbt *BBTree) SegmentQuery(obj any, a, b vec.Vec2, tExit float64, f SpatialIndexSegmentQuery, data any)

func (*BBTree) SubtreeInsert 

func (bbt *BBTree) SubtreeInsert(subtree *Node, leaf *Node) *Node

func (*BBTree) SubtreeRemove 

func (tree *BBTree) SubtreeRemove(subtree *Node, leaf *Node) *Node

type BBTreeVelocityFunc 

type BBTreeVelocityFunc func(obj any) vec.Vec2

type Body 

type Body struct {
	// UserData is an object that this constraint is associated with.
	//
	// You can use this get a reference to your game object or controller object from within callbacks.
	UserData any
	Space    *Space

	Shapes []*Shape
	// contains filtered or unexported fields
}

func NewBody 

func NewBody(mass, moment float64) *Body

NewBody Initializes a rigid body with the given mass and moment of inertia.

Guessing the moment of inertia is usually a bad idea. Use the moment estimation functions MomentFor*().

func NewKinematicBody 

func NewKinematicBody() *Body

NewKinematicBody allocates and initializes a Body, and set it as a kinematic body.

func NewStaticBody 

func NewStaticBody() *Body

NewStaticBody allocates and initializes a Body, and set it as a static body.

func (*Body) AccumulateMassFromShapes 

func (body *Body) AccumulateMassFromShapes()

AccumulateMassFromShapes should *only* be called when shapes with mass info are modified, added or removed.

func (*Body) Activate 

func (body *Body) Activate()

Activate wakes up a sleeping or idle body.

func (*Body) ActivateStatic 

func (body *Body) ActivateStatic(filter *Shape)

ActivateStatic wakes up any sleeping or idle bodies touching this static body.

func (*Body) Angle 

func (body *Body) Angle() float64

Angle returns the angle of the body.

func (*Body) AngularVelocity 

func (body *Body) AngularVelocity() float64

AngularVelocity returns the angular velocity of the body.

func (*Body) ApplyForceAtLocalPoint 

func (body *Body) ApplyForceAtLocalPoint(force, point vec.Vec2)

ApplyForceAtLocalPoint applies a force at local point.

func (*Body) ApplyForceAtWorldPoint 

func (body *Body) ApplyForceAtWorldPoint(force, point vec.Vec2)

ApplyForceAtWorldPoint applies a force at world point.

func (*Body) ApplyImpulseAtLocalPoint 

func (body *Body) ApplyImpulseAtLocalPoint(impulse, point vec.Vec2)

ApplyImpulseAtLocalPoint applies impulse at local point

func (*Body) ApplyImpulseAtWorldPoint 

func (body *Body) ApplyImpulseAtWorldPoint(impulse, point vec.Vec2)

ApplyImpulseAtWorldPoint applies impulse at world point

func (*Body) AttachShape added in v1.10.0 

func (body *Body) AttachShape(shape *Shape)

AttachShape adds shape to the body

func (Body) CenterOfGravity 

func (body Body) CenterOfGravity() vec.Vec2

CenterOfGravity returns the offset of the center of gravity in body local coordinates.

func (*Body) ComponentAdd 

func (root *Body) ComponentAdd(body *Body)

func (*Body) ComponentRoot 

func (body *Body) ComponentRoot() *Body

func (*Body) EachArbiter 

func (body *Body) EachArbiter(f func(*Arbiter))

EachArbiter calls f once for each arbiter that is currently active on the body.

func (*Body) EachConstraint 

func (body *Body) EachConstraint(f func(*Constraint))

EachConstraint calls f once for each constraint attached to this body

func (*Body) EachShape 

func (body *Body) EachShape(f func(*Shape))

EachShape calls f once for each shape attached to this body

func (*Body) Force 

func (body *Body) Force() vec.Vec2

Force returns the force applied to the body for the next time step.

func (*Body) IdleTime 

func (body *Body) IdleTime() float64

IdleTime returns sleeping idle time of the body

func (*Body) IsSleeping 

func (body *Body) IsSleeping() bool

IsSleeping returns true if the body is sleeping.

func (*Body) KineticEnergy 

func (body *Body) KineticEnergy() float64

KineticEnergy returns the kinetic energy of this body.

func (*Body) LocalToWorld 

func (body *Body) LocalToWorld(point vec.Vec2) vec.Vec2

LocalToWorld converts from body local to world coordinates.

Convert a point in world (absolute) coordinates to body local coordinates affected by the position and rotation of the rigid body.

func (*Body) Mass 

func (body *Body) Mass() float64

Mass returns mass of the body

func (Body) Moment 

func (body Body) Moment() float64

Moment returns moment of inertia of the body.

func (*Body) Position 

func (body *Body) Position() vec.Vec2

Position returns the position of the body.

func (*Body) PushArbiter 

func (body *Body) PushArbiter(arb *Arbiter)

func (*Body) RemoveConstraint 

func (body *Body) RemoveConstraint(constraint *Constraint)

RemoveConstraint removes constraint from the body.

func (*Body) RemoveShape 

func (body *Body) RemoveShape(shape *Shape)

RemoveShape removes collision shape from the body.

func (*Body) RemoveShapeAtIndex added in v1.10.0 

func (body *Body) RemoveShapeAtIndex(index int)

RemoveShapeAtIndex removes collision shape from the body.

func (*Body) Rotation 

func (body *Body) Rotation() vec.Vec2

Rotation returns the rotation vector of the body.

(The x basis vector of it's transform.)

func (*Body) SetAngle 

func (body *Body) SetAngle(angle float64)

SetAngle sets the angle of body.

func (*Body) SetAngularVelocity 

func (body *Body) SetAngularVelocity(angularVelocity float64)

SetAngularVelocity sets the angular velocity of the body.

func (*Body) SetForce 

func (body *Body) SetForce(force vec.Vec2)

SetForce sets the force applied to the body for the next time step.

func (*Body) SetMass 

func (body *Body) SetMass(mass float64)

SetMass sets mass of the body

func (*Body) SetMoment 

func (body *Body) SetMoment(moment float64)

SetMoment sets moment of inertia of the body.

func (*Body) SetPosition 

func (body *Body) SetPosition(position vec.Vec2)

SetPosition sets the position of the body.

func (*Body) SetPositionUpdateFunc 

func (body *Body) SetPositionUpdateFunc(f BodyPositionFunc)

SetPositionUpdateFunc sets the callback used to update a body's position.

func (*Body) SetTorque 

func (body *Body) SetTorque(torque float64)

SetTorque sets the torque applied to the body for the next time step.

func (*Body) SetTransform 

func (body *Body) SetTransform(p vec.Vec2, a float64)

SetTransform sets transform

func (*Body) SetType 

func (body *Body) SetType(bt BodyType)

SetType sets the type of the body.

func (*Body) SetVelocity 

func (body *Body) SetVelocity(x, y float64)

SetVelocity sets the velocity of the body.

Shorthand for Body.SetVelocityVector()

func (*Body) SetVelocityUpdateFunc 

func (body *Body) SetVelocityUpdateFunc(f BodyVelocityFunc)

SetVelocityUpdateFunc sets the callback used to update a body's velocity.

func (*Body) SetVelocityVector 

func (body *Body) SetVelocityVector(v vec.Vec2)

SetVelocityVector sets the velocity of the body

func (*Body) ShapeAtIndex added in v1.10.0 

func (b *Body) ShapeAtIndex(index int) *Shape

ShapeAtIndex returns shape at index attached to this body

func (Body) String 

func (b Body) String() string

String returns body id as string

func (*Body) Torque 

func (body *Body) Torque() float64

Torque returns the torque applied to the body for the next time step.

func (*Body) Transform added in v1.6.0 

func (body *Body) Transform() Transform

Transform returns body's transform

func (*Body) Type added in v1.10.0 

func (body *Body) Type() BodyType

Type returns the type of the body.

func (*Body) UpdateVelocity 

func (body *Body) UpdateVelocity(gravity vec.Vec2, damping, dt float64)

UpdateVelocity is the default velocity integration function.

func (*Body) Velocity 

func (body *Body) Velocity() vec.Vec2

Velocity returns the velocity of the body.

func (*Body) VelocityAtLocalPoint 

func (body *Body) VelocityAtLocalPoint(point vec.Vec2) vec.Vec2

VelocityAtLocalPoint returns the velocity of a point on a body.

Get the world (absolute) velocity of a point on a rigid body specified in body local coordinates.

func (*Body) VelocityAtWorldPoint 

func (body *Body) VelocityAtWorldPoint(point vec.Vec2) vec.Vec2

VelocityAtWorldPoint returns the velocity of a point on a body.

Get the world (absolute) velocity of a point on a rigid body specified in world coordinates.

func (*Body) WorldToLocal 

func (body *Body) WorldToLocal(point vec.Vec2) vec.Vec2

WorldToLocal converts from world to body local Coordinates.

Convert a point in body local coordinates to world (absolute) coordinates.

type BodyPositionFunc 

type BodyPositionFunc func(body *Body, dt float64)

BodyPositionFunc is rigid body position update function type.

type BodyType added in v1.10.0 

type BodyType uint8

BodyType for bodies; Dynamic, Kinematic or Static 

const (
	Dynamic   BodyType = 0
	Kinematic BodyType = 1
	Static    BodyType = 2
)

type BodyVelocityFunc 

type BodyVelocityFunc func(body *Body, gravity vec.Vec2, damping float64, dt float64)

BodyVelocityFunc is rigid body velocity update function type.

type Children 

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

type Circle 

type Circle struct {
	*Shape
	// contains filtered or unexported fields
}

func (*Circle) CacheData 

func (circle *Circle) CacheData(transform Transform) BB

func (*Circle) PointQuery 

func (circle *Circle) PointQuery(p vec.Vec2, info *PointQueryInfo)

func (*Circle) Radius 

func (circle *Circle) Radius() float64

func (*Circle) SegmentQuery 

func (circle *Circle) SegmentQuery(a, b vec.Vec2, radius float64, info *SegmentQueryInfo)

func (*Circle) SetRadius 

func (circle *Circle) SetRadius(r float64)

func (*Circle) TransformC 

func (circle *Circle) TransformC() vec.Vec2

type ClosestPoints 

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

func EPA 

func EPA(ctx SupportContext, v0, v1, v2 MinkowskiPoint) ClosestPoints

EPA is called from GJK when two shapes overlap. Finds the closest points on the surface of two overlapping shapes using the EPA algorithm. This is a moderately expensive step! Avoid it by adding radii to your shapes so their inner polygons won't overlap.

func EPARecurse 

func EPARecurse(ctx SupportContext, count int, hull []MinkowskiPoint, iteration int) ClosestPoints

EPARecurse implementation of the EPA loop. Each recursion adds a point to the convex hull until it's known that we have the closest point on the surface.

func GJK 

func GJK(ctx SupportContext, collisionId *uint32) ClosestPoints

GJK finds the closest points between two shapes using the GJK algorithm.

func GJKRecurse 

func GJKRecurse(ctx SupportContext, v0, v1 MinkowskiPoint, iteration int) ClosestPoints

GJKRecurse implementation of the GJK loop.

type CollisionBeginFunc 

type CollisionBeginFunc func(arb *Arbiter, space *Space, userData any) bool

CollisionBeginFunc is collision begin event function callback type. Returning false from a begin callback causes the collision to be ignored until the the separate callback is called when the objects stop colliding.

type CollisionFunc 

type CollisionFunc func(info *CollisionInfo)

type CollisionHandler 

type CollisionHandler struct {
	// Collision type identifier of the first shape that this handler recognizes.
	// In the collision handler callback, the shape with this type will be the first argument. Read only.
	TypeA CollisionType
	// Collision type identifier of the second shape that this handler recognizes.
	// In the collision handler callback, the shape with this type will be the second argument. Read only.
	TypeB CollisionType
	// This function is called when two shapes with types that match this collision handler begin colliding.
	BeginFunc CollisionBeginFunc
	// This function is called each step when two shapes with types that match this collision handler are colliding.
	// It's called before the collision solver runs so that you can affect a collision's outcome.
	PreSolveFunc CollisionPreSolveFunc
	// This function is called each step when two shapes with types that match this collision handler are colliding.
	// It's called after the collision solver runs so that you can read back information about the collision to trigger events in your game.
	PostSolveFunc CollisionPostSolveFunc
	// This function is called when two shapes with types that match this collision handler stop colliding.
	SeparateFunc CollisionSeparateFunc
	// This is a user definable context pointer that is passed to all of the collision handler functions.
	UserData any
}

CollisionHandler is struct that holds function callback pointers to configure custom collision handling. Collision handlers have a pair of types; when a collision occurs between two shapes that have these types, the collision handler functions are triggered.

type CollisionInfo 

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

CollisionInfo collision info struct

func Collide 

func Collide(a, b *Shape, collisionID uint32, contacts []Contact) CollisionInfo

Collide performs a collision between two shapes

func (*CollisionInfo) PushContact 

func (info *CollisionInfo) PushContact(p1, p2 vec.Vec2, hash HashValue)

type CollisionPostSolveFunc 

type CollisionPostSolveFunc func(arb *Arbiter, space *Space, userData any)

CollisionPostSolveFunc is collision post-solve event function callback type.

type CollisionPreSolveFunc 

type CollisionPreSolveFunc func(arb *Arbiter, space *Space, userData any) bool

CollisionPreSolveFunc is collision pre-solve event function callback type.

Returning false from a pre-step callback causes the collision to be ignored until the next step.

type CollisionSeparateFunc 

type CollisionSeparateFunc func(arb *Arbiter, space *Space, userData any)

CollisionSeparateFunc is collision separate event function callback type.

type CollisionType 

type CollisionType uintptr
const WildcardCollisionType CollisionType = ^CollisionType(0)

type Constrainer 

type Constrainer interface {
	PreStep(dt float64)
	ApplyCachedImpulse(dtCoef float64)
	ApplyImpulse(dt float64)
	GetImpulse() float64
}

type Constraint 

type Constraint struct {
	Class Constrainer

	PreSolve  ConstraintPreSolveFunc
	PostSolve ConstraintPostSolveFunc

	UserData any
	// contains filtered or unexported fields
}

func NewConstraint 

func NewConstraint(class Constrainer, a, b *Body) *Constraint

func NewDampedRotarySpring 

func NewDampedRotarySpring(a, b *Body, restAngle, stiffness, damping float64) *Constraint

func NewDampedSpring 

func NewDampedSpring(a, b *Body, anchorA, anchorB vec.Vec2, restLength, stiffness, damping float64) *Constraint

func NewGearJoint 

func NewGearJoint(a, b *Body, phase, ratio float64) *Constraint

func NewGrooveJoint 

func NewGrooveJoint(a, b *Body, grooveA, grooveB, anchorB vec.Vec2) *Constraint

func NewPinJoint 

func NewPinJoint(a, b *Body, anchorA, anchorB vec.Vec2) *Constraint

func NewPivotJoint 

func NewPivotJoint(a, b *Body, pivot vec.Vec2) *Constraint

func NewPivotJoint2 

func NewPivotJoint2(a, b *Body, anchorA, anchorB vec.Vec2) *Constraint

func NewRatchetJoint 

func NewRatchetJoint(a, b *Body, phase, ratchet float64) *Constraint

func NewRotaryLimitJoint 

func NewRotaryLimitJoint(a, b *Body, min, max float64) *Constraint

func NewSimpleMotor 

func NewSimpleMotor(a, b *Body, rate float64) *Constraint

func NewSlideJoint 

func NewSlideJoint(a, b *Body, anchorA, anchorB vec.Vec2, min, max float64) *Constraint

func (*Constraint) ActivateBodies 

func (c *Constraint) ActivateBodies()

func (*Constraint) BodyA added in v1.6.0 

func (c *Constraint) BodyA() *Body

func (*Constraint) BodyB added in v1.6.0 

func (c *Constraint) BodyB() *Body

func (Constraint) ErrorBias 

func (c Constraint) ErrorBias() float64

func (Constraint) MaxBias 

func (c Constraint) MaxBias() float64

func (Constraint) MaxForce 

func (c Constraint) MaxForce() float64

func (*Constraint) Next 

func (c *Constraint) Next(body *Body) *Constraint

func (*Constraint) SetCollideBodies 

func (c *Constraint) SetCollideBodies(collideBodies bool)

func (*Constraint) SetErrorBias 

func (c *Constraint) SetErrorBias(errorBias float64)

func (*Constraint) SetMaxBias 

func (c *Constraint) SetMaxBias(max float64)

func (*Constraint) SetMaxForce 

func (c *Constraint) SetMaxForce(max float64)

type ConstraintPostSolveFunc 

type ConstraintPostSolveFunc func(*Constraint, *Space)

type ConstraintPreSolveFunc 

type ConstraintPreSolveFunc func(*Constraint, *Space)

type Contact 

type Contact struct {
	R1, R2 vec.Vec2
	// contains filtered or unexported fields
}

func (*Contact) Clone 

func (c *Contact) Clone() Contact

type ContactBuffer 

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

func NewContactBuffer 

func NewContactBuffer(stamp uint, slice *ContactBuffer) *ContactBuffer

func (*ContactBuffer) InitHeader 

func (c *ContactBuffer) InitHeader(stamp uint, splice *ContactBuffer) *ContactBuffer

type ContactPointSet 

type ContactPointSet struct {
	// Count is the number of contact points in the set.
	Count int
	// Normal is the normal of the collision.
	Normal vec.Vec2

	Points [MaxContactsPerArbiter]struct {
		// The position of the contact on the surface of each shape.
		PointA, PointB vec.Vec2
		// Distance is penetration distance of the two shapes. Overlapping means it will be negative.
		//
		// This value is calculated as p2.Sub(p1).Dot(n) and is ignored by Arbiter.SetContactPointSet().
		Distance float64
	}
}

ContactPointSet wraps up the important collision data for an arbiter.

func ShapesCollideInfo added in v1.11.0 

func ShapesCollideInfo(a, b *Shape) ContactPointSet

Return contact information about two shapes.

type DampedRotarySpring 

type DampedRotarySpring struct {
	*Constraint

	RestAngle, Stiffness, Damping float64
	SpringTorqueFunc              func(spring *DampedRotarySpring, relativeAngle float64) float64
	// contains filtered or unexported fields
}

func (*DampedRotarySpring) ApplyCachedImpulse 

func (joint *DampedRotarySpring) ApplyCachedImpulse(dtCoef float64)

func (*DampedRotarySpring) ApplyImpulse 

func (spring *DampedRotarySpring) ApplyImpulse(dt float64)

func (*DampedRotarySpring) GetImpulse 

func (joint *DampedRotarySpring) GetImpulse() float64

func (*DampedRotarySpring) PreStep 

func (spring *DampedRotarySpring) PreStep(dt float64)

type DampedSpring 

type DampedSpring struct {
	*Constraint

	AnchorA, AnchorB               vec.Vec2
	RestLength, Stiffness, Damping float64
	SpringForceFunc                DampedSpringForceFunc
	// contains filtered or unexported fields
}

func (*DampedSpring) ApplyCachedImpulse 

func (spring *DampedSpring) ApplyCachedImpulse(dtCoef float64)

func (*DampedSpring) ApplyImpulse 

func (spring *DampedSpring) ApplyImpulse(dt float64)

func (*DampedSpring) GetImpulse 

func (spring *DampedSpring) GetImpulse() float64

func (*DampedSpring) PreStep 

func (spring *DampedSpring) PreStep(dt float64)

type DampedSpringForceFunc 

type DampedSpringForceFunc func(spring *DampedSpring, dist float64) float64

type Edge 

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

func SupportEdgeForPoly 

func SupportEdgeForPoly(poly *PolyShape, n vec.Vec2) Edge

func SupportEdgeForSegment 

func SupportEdgeForSegment(seg *Segment, n vec.Vec2) Edge

type EdgePoint 

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

type FColor 

type FColor struct {
	R, G, B, A float32
}

16 bytes

type GearJoint 

type GearJoint struct {
	*Constraint
	// contains filtered or unexported fields
}

func (*GearJoint) ApplyCachedImpulse 

func (joint *GearJoint) ApplyCachedImpulse(dtCoef float64)

func (*GearJoint) ApplyImpulse 

func (joint *GearJoint) ApplyImpulse(dt float64)

func (*GearJoint) GetImpulse 

func (joint *GearJoint) GetImpulse() float64

func (*GearJoint) PreStep 

func (joint *GearJoint) PreStep(dt float64)

type GrooveJoint 

type GrooveJoint struct {
	*Constraint

	GrooveN, GrooveA, GrooveB vec.Vec2
	AnchorB                   vec.Vec2
	// contains filtered or unexported fields
}

func (*GrooveJoint) ApplyCachedImpulse 

func (joint *GrooveJoint) ApplyCachedImpulse(dtCoef float64)

func (*GrooveJoint) ApplyImpulse 

func (joint *GrooveJoint) ApplyImpulse(dt float64)

func (*GrooveJoint) GetImpulse 

func (joint *GrooveJoint) GetImpulse() float64

func (*GrooveJoint) PreStep 

func (joint *GrooveJoint) PreStep(dt float64)

type Handle 

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

func (*Handle) Init 

func (hand *Handle) Init(obj *Shape)

type HashSet 

type HashSet[T, U comparable] struct {
	// contains filtered or unexported fields
}

HashSet implements a hash set

func NewHashSet 

func NewHashSet[T, U comparable](isEqual func(ptr T, elt U) bool) *HashSet[T, U]

NewHashSet is a HashSet constructor

func (*HashSet[T, U]) Count 

func (set *HashSet[T, U]) Count() uint

Count returns the number of entries

func (*HashSet[T, U]) Each 

func (set *HashSet[T, U]) Each(f func(U))

Each calls f for every U in the HashSet.

func (*HashSet[T, U]) Filter 

func (set *HashSet[T, U]) Filter(f func(U) bool)

Filter removes elements if f returns false

func (*HashSet[T, U]) Find 

func (set *HashSet[T, U]) Find(hash HashValue, ptr T) U

Find returns the U the T is in, or nil.

func (*HashSet[T, U]) Insert 

func (set *HashSet[T, U]) Insert(hash HashValue, ptr T, transform func(obj T) U) U

Insert returns the U the T is in, or inserts a new U and returns it.

func (*HashSet[T, U]) Remove 

func (set *HashSet[T, U]) Remove(hash HashValue, ptr T) U

Remove removes the T from the HashSet, returning the U it was in.

type HashSetBin 

type HashSetBin[U comparable] struct {
	// contains filtered or unexported fields
}

HashSetBin implements a linked list

type HashValue 

type HashValue uintptr

func HashPair 

func HashPair(a, b HashValue) HashValue

type IDrawer added in v1.9.0 

type IDrawer interface {
	DrawCircle(pos vec.Vec2, angle, radius float64, outline, fill FColor, data any)
	DrawSegment(a, b vec.Vec2, fill FColor, data any)
	DrawFatSegment(a, b vec.Vec2, radius float64, outline, fill FColor, data any)
	DrawPolygon(count int, verts []vec.Vec2, radius float64, outline, fill FColor, data any)
	DrawDot(size float64, pos vec.Vec2, fill FColor, data any)

	Flags() uint
	OutlineColor() FColor
	ShapeColor(shape *Shape, data any) FColor
	ConstraintColor() FColor
	CollisionPointColor() FColor
	Data() any
}

type IShape added in v1.10.0 

type IShape interface {
	CacheData(transform Transform) BB
	PointQuery(p vec.Vec2, info *PointQueryInfo)
	SegmentQuery(a, b vec.Vec2, radius float64, info *SegmentQueryInfo)
}

type Leaf 

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

type MarkContext 

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

type Mat2x2 

type Mat2x2 struct {
	// contains filtered or unexported fields
}

Mat2x2 is a 2x2 matrix type used for tensors and such.

func (*Mat2x2) Transform 

func (m *Mat2x2) Transform(v vec.Vec2) vec.Vec2

Transform transforms Vector v

type MinkowskiPoint 

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

MinkowskiPoint is a point on the surface of two shapes' minkowski difference.

func NewMinkowskiPoint 

func NewMinkowskiPoint(a, b SupportPoint) MinkowskiPoint

func (MinkowskiPoint) ClosestPoints 

func (v0 MinkowskiPoint) ClosestPoints(v1 MinkowskiPoint) ClosestPoints

ClosestPoints calculates the closest points on two shapes given the closest edge on their minkowski difference to (0, 0)

type Node 

type Node struct {
	Children
	Leaf
	// contains filtered or unexported fields
}

func (*Node) IsLeaf 

func (node *Node) IsLeaf() bool

func (*Node) MarkLeaf 

func (leaf *Node) MarkLeaf(context *MarkContext)

func (*Node) MarkLeafQuery 

func (subtree *Node) MarkLeafQuery(leaf *Node, left bool, context *MarkContext)

func (*Node) MarkSubtree 

func (subtree *Node) MarkSubtree(context *MarkContext)

func (*Node) Other 

func (node *Node) Other(child *Node) *Node

func (*Node) SubtreeQuery 

func (subtree *Node) SubtreeQuery(obj any, bb BB, query SpatialIndexQuery, data any)

func (*Node) SubtreeSegmentQuery 

func (subtree *Node) SubtreeSegmentQuery(obj any, a, b vec.Vec2, tExit float64, f SpatialIndexSegmentQuery, data any) float64

type Pair 

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

type PinJoint 

type PinJoint struct {
	*Constraint
	AnchorA, AnchorB vec.Vec2
	Dist             float64
	// contains filtered or unexported fields
}

func (*PinJoint) ApplyCachedImpulse 

func (joint *PinJoint) ApplyCachedImpulse(dtCoef float64)

func (*PinJoint) ApplyImpulse 

func (joint *PinJoint) ApplyImpulse(dt float64)

func (*PinJoint) GetImpulse 

func (joint *PinJoint) GetImpulse() float64

func (*PinJoint) PreStep 

func (joint *PinJoint) PreStep(dt float64)

type PivotJoint 

type PivotJoint struct {
	*Constraint
	AnchorA, AnchorB vec.Vec2
	// contains filtered or unexported fields
}

func (*PivotJoint) ApplyCachedImpulse 

func (joint *PivotJoint) ApplyCachedImpulse(dtCoef float64)

func (*PivotJoint) ApplyImpulse 

func (joint *PivotJoint) ApplyImpulse(dt float64)

func (*PivotJoint) GetImpulse 

func (joint *PivotJoint) GetImpulse() float64

func (*PivotJoint) PreStep 

func (joint *PivotJoint) PreStep(dt float64)

type PointQueryContext 

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

type PointQueryInfo 

type PointQueryInfo struct {
	// The nearest shape, nil if no shape was within range.
	Shape *Shape
	// The closest point on the shape's surface. (in world space coordinates)
	Point vec.Vec2
	// The distance to the point. The distance is negative if the point is inside the shape.
	Distance float64
	// The gradient of the signed distance function.
	// The value should be similar to info.p/info.d, but accurate even for very small values of info.d.
	Gradient vec.Vec2
}

PointQueryInfo is point query info struct.

type PolyLine 

type PolyLine struct {
	Verts []vec.Vec2
}

func DouglasPeucker 

func DouglasPeucker(
	verts []vec.Vec2,
	reduced *PolyLine,
	length, start, end int,
	min, tol float64,
) *PolyLine

Recursive function used by PolylineSimplifyCurves().

func (*PolyLine) Enqueue 

func (pl *PolyLine) Enqueue(v vec.Vec2) *PolyLine

func (*PolyLine) IsClosed 

func (pl *PolyLine) IsClosed() bool

func (*PolyLine) IsShort 

func (pl *PolyLine) IsShort(count, start, end int, min float64) bool

IsShort checks if the total length of a polyline segment is less than 'min'. It iterates from 'start' to 'end', summing the distances between consecutive vertices. If the length exceeds 'min', it returns false, otherwise true. 

Parameters:
- count: // Total number of vertices in the polyline.
- start: // Starting index for the length calculation.
- end: // Ending index for the length calculation.
- min: // Minimum length threshold.

func (*PolyLine) Push 

func (pl *PolyLine) Push(v vec.Vec2) *PolyLine

func (*PolyLine) SimplifyCurves 

func (pl *PolyLine) SimplifyCurves(tol float64) *PolyLine

Recursively reduce the vertex count on a polyline. Works best for smooth shapes. 'tol' is the maximum error for the reduction. The reduced polyline will never be farther than this distance from the original polyline.

func (*PolyLine) SimplifyVertexes 

func (pl *PolyLine) SimplifyVertexes(tol float64) *PolyLine

Join similar adjacent line segments together. Works well for hard edged shapes. 'tol' is the minimum anglular difference in radians of a vertex.

type PolyLineSet 

type PolyLineSet struct {
	Lines []*PolyLine
}

func (*PolyLineSet) FindEnds 

func (pls *PolyLineSet) FindEnds(v vec.Vec2) int

Find the polyline that ends with v.

func (*PolyLineSet) FindStarts 

func (pls *PolyLineSet) FindStarts(v vec.Vec2) int

Find the polyline that starts with v.

func (*PolyLineSet) Join 

func (pls *PolyLineSet) Join(before, after int)

this may deletion could be slow? https://yourbasic.org/golang/delete-element-slice/

func (*PolyLineSet) Push 

func (pls *PolyLineSet) Push(v *PolyLine)

Add a new polyline to a polyline set.

type PolyShape 

type PolyShape struct {
	*Shape
	Radius float64

	// The untransformed Planes are appended at the end of the transformed Planes.
	Planes []SplittingPlane
	// contains filtered or unexported fields
}

func (*PolyShape) CacheData 

func (ps *PolyShape) CacheData(transform Transform) BB

func (*PolyShape) Count 

func (ps *PolyShape) Count() int

func (*PolyShape) PointQuery 

func (ps *PolyShape) PointQuery(p vec.Vec2, info *PointQueryInfo)

func (*PolyShape) SegmentQuery 

func (ps *PolyShape) SegmentQuery(a, b vec.Vec2, r2 float64, info *SegmentQueryInfo)

func (*PolyShape) SetVerts 

func (ps *PolyShape) SetVerts(count int, verts []vec.Vec2)

func (*PolyShape) SetVertsRaw 

func (p *PolyShape) SetVertsRaw(count int, verts []vec.Vec2)

func (*PolyShape) SetVertsUnsafe 

func (ps *PolyShape) SetVertsUnsafe(count int, verts []vec.Vec2, transform Transform)

func (*PolyShape) TransformVert 

func (ps *PolyShape) TransformVert(i int) vec.Vec2

func (*PolyShape) Vert 

func (ps *PolyShape) Vert(vertIndex int) vec.Vec2

type PostStepCallback 

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

type PostStepCallbackFunc 

type PostStepCallbackFunc func(space *Space, key any, data any)

type RatchetJoint 

type RatchetJoint struct {
	*Constraint

	Angle, Phase, Ratchet float64
	// contains filtered or unexported fields
}

func (*RatchetJoint) ApplyCachedImpulse 

func (joint *RatchetJoint) ApplyCachedImpulse(dtCoef float64)

func (*RatchetJoint) ApplyImpulse 

func (joint *RatchetJoint) ApplyImpulse(dt float64)

func (*RatchetJoint) GetImpulse 

func (joint *RatchetJoint) GetImpulse() float64

func (*RatchetJoint) PreStep 

func (joint *RatchetJoint) PreStep(dt float64)

type RotaryLimitJoint 

type RotaryLimitJoint struct {
	*Constraint

	Min, Max float64
	// contains filtered or unexported fields
}

func (*RotaryLimitJoint) ApplyCachedImpulse 

func (joint *RotaryLimitJoint) ApplyCachedImpulse(dtCoef float64)

func (*RotaryLimitJoint) ApplyImpulse 

func (joint *RotaryLimitJoint) ApplyImpulse(dt float64)

func (*RotaryLimitJoint) GetImpulse 

func (joint *RotaryLimitJoint) GetImpulse() float64

func (*RotaryLimitJoint) PreStep 

func (joint *RotaryLimitJoint) PreStep(dt float64)

type Segment 

type Segment struct {
	*Shape
	// contains filtered or unexported fields
}

Segment is a segment Shape

func (*Segment) A 

func (seg *Segment) A() vec.Vec2

func (*Segment) B 

func (seg *Segment) B() vec.Vec2

func (*Segment) CacheData 

func (seg *Segment) CacheData(transform Transform) BB

func (*Segment) Normal 

func (seg *Segment) Normal() vec.Vec2

func (*Segment) PointQuery 

func (seg *Segment) PointQuery(p vec.Vec2, info *PointQueryInfo)

func (*Segment) Radius 

func (seg *Segment) Radius() float64

func (*Segment) SegmentQuery 

func (seg *Segment) SegmentQuery(a, b vec.Vec2, r2 float64, info *SegmentQueryInfo)

func (*Segment) SetEndpoints 

func (seg *Segment) SetEndpoints(a, b vec.Vec2)

func (*Segment) SetRadius 

func (seg *Segment) SetRadius(r float64)

func (*Segment) TransformA 

func (seg *Segment) TransformA() vec.Vec2

func (*Segment) TransformB 

func (seg *Segment) TransformB() vec.Vec2

type SegmentQueryContext 

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

type SegmentQueryInfo 

type SegmentQueryInfo struct {
	// The shape that was hit, or nil if no collision occurred.
	Shape *Shape
	// The point of impact.
	Point vec.Vec2
	// The normal of the surface hit.
	Normal vec.Vec2
	// The normalized distance along the query segment in the range [0, 1].
	Alpha float64
}

SegmentQueryInfo is segment query info struct.

type Shape 

type Shape struct {
	Class    IShape
	Body     *Body
	Space    *Space
	UserData any
	Filter   ShapeFilter
	// You can assign types to collision shapes that triggercallbacks when objects
	// of certain types touch.
	CollisionType CollisionType
	// Sensor is a boolean value if this shape is a Sensor or not.
	// Sensors only call collision callbacks, and never generate real collisions.
	Sensor bool
	// The surface velocity of the object. Useful for creating conveyor belts or
	// players that move around. This value is only used when calculating friction,
	// not resolving the collision.
	SurfaceVelocity      vec.Vec2
	Elasticity, Friction float64
	BB                   BB
	// contains filtered or unexported fields
}

func NewBoxShape added in v1.11.0 

func NewBoxShape(body *Body, w, h, r float64) *Shape

NewBoxShape returns a Box shape with specified width 'w', height 'h', and rounding radius 'roundingRadius'. The shape is attached to the body.

Parameters:

  • body: The body to which the shape will be attached.
  • w: The width of the box.
  • h: The height of the box.
  • r: The rounding radius of the box corners.

func NewBoxShape2 added in v1.11.0 

func NewBoxShape2(body *Body, bb BB, r float64) *Shape

NewBoxShape2 returns a Box shape using a bounding box 'bb' and a rounding radius 'roundingRadius'. The shape is attached to the body.

Parameters:

  • body: The body to which the shape will be attached.
  • bb: The bounding box defining the shape dimensions.
  • r: The rounding radius of the box corners.

func NewCircleShape added in v1.11.0 

func NewCircleShape(b *Body, r float64, offset vec.Vec2) *Shape

NewCircleShape returns a Circle shape with a specified radius and offset.

The shape is attached to the given body.

Parameters:

  • b: The body to which the shape will be attached.
  • r: The radius of the circle.
  • offset: The position of the circle's center.

func NewPolyShape 

func NewPolyShape(b *Body, vertices []vec.Vec2, t Transform, r float64) *Shape

NewPolyShape returns a Polygon shape with a given vertices.

Parameters:

  • b: The body to which the shape will be attached.
  • vertices: The list of vertex positions.
  • t: The transformation applied to the vertex positions.
  • r: The rounding radius of the polygon corners.

func NewPolyShapeRaw 

func NewPolyShapeRaw(
	body *Body,
	count int,
	verts []vec.Vec2,
	roundingRadius float64,
) *Shape

Initialize a polygon shape with rounded corners. The vertexes must be convex with a counter-clockwise winding.

func NewSegmentShape added in v1.11.0 

func NewSegmentShape(body *Body, a, b vec.Vec2, r float64) *Shape

NewSegmentShape returns a new Segment shape using two points 'a' and 'b' and rounding radius 'r'. The shape is attached to the given body.

Parameters:

  • body: The body to which the shape will be attached.
  • a: The first point of the segment.
  • b: The second point of the segment.
  • r: The radius of the segment shape.

func NewShape 

func NewShape(class IShape, body *Body, massInfo *ShapeMassInfo) *Shape

func (*Shape) Area 

func (sh *Shape) Area() float64

func (*Shape) CacheBB 

func (sh *Shape) CacheBB() BB

func (*Shape) CenterOfGravity 

func (sh *Shape) CenterOfGravity() vec.Vec2

func (*Shape) Density 

func (sh *Shape) Density() float64

func (*Shape) HashId 

func (sh *Shape) HashId() HashValue

func (*Shape) Mass 

func (sh *Shape) Mass() float64

func (*Shape) MassInfo 

func (sh *Shape) MassInfo() *ShapeMassInfo

func (*Shape) Moment 

func (sh *Shape) Moment() float64

func (*Shape) Order 

func (s *Shape) Order() int

func (*Shape) Point 

func (sh *Shape) Point(i uint32) SupportPoint

func (*Shape) PointQuery 

func (sh *Shape) PointQuery(p vec.Vec2) PointQueryInfo

Perform a nearest point query.

It finds the closest point on the surface of shape to a specific point. The value returned is the distance between the points. A negative distance means the point is inside the shape.

func (*Shape) SegmentQuery 

func (sh *Shape) SegmentQuery(a, b vec.Vec2, radius float64, info *SegmentQueryInfo) bool

Perform a segment query against a shape.

info must be a pointer to a valid SegmentQueryInfo structure.

func (*Shape) SetBody added in v1.10.0 

func (sh *Shape) SetBody(b *Body)

func (*Shape) SetCollisionType 

func (sh *Shape) SetCollisionType(collisionType CollisionType)

SetCollisionType sets collision type. You can assign types to shapes that trigger callbacks (CollisionHandler) when objects of certain types touch

func (*Shape) SetDensity 

func (sh *Shape) SetDensity(density float64)

func (*Shape) SetElasticity 

func (sh *Shape) SetElasticity(e float64)

SetElasticity sets elasticity (0-1 range)

func (*Shape) SetFriction 

func (sh *Shape) SetFriction(u float64)

func (*Shape) SetHashId 

func (sh *Shape) SetHashId(hashid HashValue)

func (*Shape) SetMass 

func (sh *Shape) SetMass(mass float64)

SetMass wakes up sleeping or idle body then sets mass

func (*Shape) SetSensor 

func (sh *Shape) SetSensor(sensor bool)

SetSensor wakes up sleeping or idle body then sets Shape.Sensor. sensor is a boolean value if this shape is a sensor or not. Sensors only call collision callbacks, and never generate real collisions.

func (*Shape) SetShapeFilter added in v1.0.1 

func (sh *Shape) SetShapeFilter(filter ShapeFilter)

func (Shape) String 

func (s Shape) String() string

func (*Shape) Update 

func (sh *Shape) Update(transform Transform) BB

type ShapeFilter 

type ShapeFilter struct {
	// Two objects with the same non-zero group value do not collide.
	// This is generally used to group objects in a composite object together to disable self collisions.
	Group uint
	// A bitmask of user definable categories that this object belongs to.
	// The category/mask combinations of both objects in a collision must agree for a collision to occur.
	Categories uint
	// A bitmask of user definable category types that this object object collides with.
	// The category/mask combinations of both objects in a collision must agree for a collision to occur.
	Mask uint
}

ShapeFilter is fast collision filtering type that is used to determine if two objects collide before calling collision or query callbacks.

func (ShapeFilter) Reject 

func (sf ShapeFilter) Reject(other ShapeFilter) bool

Reject checks whether two ShapeFilter objects should be considered incompatible. It returns true if the filters should be rejected based on the following conditions: - If both filters belong to the same group (and the group is not 0). - If the category/mask combination of either filter does not match the other.

  • Specifically, it checks if the categories of the first filter don't match the mask of the second, or vice versa.

Returns true if the filters are considered incompatible, otherwise false.

type ShapeMassInfo 

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

ShapeMassInfo is mass info struct

func CircleShapeMassInfo 

func CircleShapeMassInfo(mass, radius float64, center vec.Vec2) *ShapeMassInfo

func NewSegmentMassInfo 

func NewSegmentMassInfo(mass float64, a, b vec.Vec2, r float64) *ShapeMassInfo

func PolyShapeMassInfo 

func PolyShapeMassInfo(mass float64, count int, verts []vec.Vec2, r float64) *ShapeMassInfo

type ShapePair 

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

type SimpleMotor 

type SimpleMotor struct {
	*Constraint

	Rate float64
	// contains filtered or unexported fields
}

func (*SimpleMotor) ApplyCachedImpulse 

func (motor *SimpleMotor) ApplyCachedImpulse(dtCoef float64)

func (*SimpleMotor) ApplyImpulse 

func (motor *SimpleMotor) ApplyImpulse(dt float64)

func (*SimpleMotor) GetImpulse 

func (motor *SimpleMotor) GetImpulse() float64

func (*SimpleMotor) PreStep 

func (motor *SimpleMotor) PreStep(dt float64)

type SlideJoint 

type SlideJoint struct {
	*Constraint

	AnchorA, AnchorB vec.Vec2
	Min, Max         float64
	// contains filtered or unexported fields
}

func (*SlideJoint) ApplyCachedImpulse 

func (joint *SlideJoint) ApplyCachedImpulse(dtCoef float64)

func (*SlideJoint) ApplyImpulse 

func (joint *SlideJoint) ApplyImpulse(dt float64)

func (*SlideJoint) GetImpulse 

func (joint *SlideJoint) GetImpulse() float64

func (*SlideJoint) PreStep 

func (joint *SlideJoint) PreStep(dt float64)

type Space 

type Space struct {
	UserData any

	// Iterations is number of iterations to use in the impulse solver to solve
	// contacts and other constrain. Must be non-zero.
	Iterations uint

	// IdleSpeedThreshold is speed threshold for a body to be considered idle.
	// The default value of 0 means to let the space guess a good threshold based on gravity.
	IdleSpeedThreshold float64

	// SleepTimeThreshold is time a group of bodies must remain idle in order to fall asleep.
	// Enabling sleeping also implicitly enables the the contact graph.
	// The default value of INFINITY disables the sleeping algorithm.
	SleepTimeThreshold float64

	// StaticBody is the Space provided static body for a given s.
	// This is merely provided for convenience and you are not required to use it.
	StaticBody *Body

	// Gravity to pass to rigid bodies when integrating velocity.
	Gravity vec.Vec2

	// Damping rate expressed as the fraction of velocity bodies retain each second.
	//
	// A value of 0.9 would mean that each body's velocity will drop 10% per second.
	// The default value is 1.0, meaning no Damping is applied.
	// @note This Damping value is different than those of DampedSpring and DampedRotarySpring.
	Damping float64

	// CollisionSlop is amount of encouraged penetration between colliding shapes.
	//
	// Used to reduce oscillating contacts and keep the collision cache warm.
	// Defaults to 0.1. If you have poor simulation quality,
	// increase this number as much as possible without allowing visible amounts of overlap.
	CollisionSlop float64

	// CollisionBias determines how fast overlapping shapes are pushed apart.
	//
	// Expressed as a fraction of the error remaining after each second.
	// Defaults to math.Pow(0.9, 60) meaning that Chipmunk fixes 10% of overlap each frame at 60Hz.
	CollisionBias float64

	// Number of frames that contact information should persist.
	// Defaults to 3. There is probably never a reason to change this value.
	CollisionPersistence uint
	Arbiters             []*Arbiter
	DynamicBodies        []*Body
	StaticBodies         []*Body

	PostStepCallbacks []*PostStepCallback
	// contains filtered or unexported fields
}

func NewSpace 

func NewSpace() *Space

NewSpace allocates and initializes a Space

func (*Space) Activate 

func (s *Space) Activate(body *Body)

func (*Space) AddBody 

func (s *Space) AddBody(body *Body)

AddBody adds body to the space.

Do not add the same Body twice.

func (*Space) AddBodyWithShapes added in v1.10.0 

func (s *Space) AddBodyWithShapes(body *Body)

AddBodyWithShapes adds body to the space with body's shapes.

Do not add the same Body twice.

func (*Space) AddCollisionHandler added in v1.13.1 

func (s *Space) AddCollisionHandler(a, b CollisionType) *CollisionHandler

AddCollisionHandler adds and returns the CollisionHandler for collisions between objects of type a and b.

Fill the desired collision callback functions, for details see the CollisionHandler object.

Whenever shapes with collision types (Shape.CollisionType) a and b collide, this handler will be used to process the collision events. When a new collision handler is created, the callbacks will all be set to builtin callbacks that perform the default behavior (call the wildcard handlers, and accept all collisions).

func (*Space) AddCollisionHandler2 added in v1.13.1 

func (s *Space) AddCollisionHandler2(handler *CollisionHandler)

AddCollisionHandler adds handler to space, for details see the CollisionHandler{} struct.

func (*Space) AddConstraint 

func (s *Space) AddConstraint(constraint *Constraint) *Constraint

func (*Space) AddPostStepCallback 

func (s *Space) AddPostStepCallback(f PostStepCallbackFunc, key, data any) bool

AddPostStepCallback defines a callback to be run just before s.Step() finishes.

The main reason you want to define post-step callbacks is to get around the restriction that you cannot call the add/remove methods from a collision handler callback. Post-step callbacks run right before the next (or current) call to s.Step() returns when it is safe to add and remove objects. You can only schedule one post-step callback per key value, this prevents you from accidentally removing an object twice. Registering a second callback for the same key is a no-op.

example: type PostStepCallbackFunc func(space *Space, key any, data any)

func (*Space) AddShape 

func (s *Space) AddShape(shape *Shape) *Shape

AddShape adds a collision shape to the simulation.

If the shape is attached to a static body, it will be added as a static shape

func (*Space) AddWildcardCollisionHandler added in v1.13.1 

func (s *Space) AddWildcardCollisionHandler(typeA CollisionType) *CollisionHandler

AddWildcardCollisionHandler sets a collision handler for given collision type. This handler will be used any time an object with this type collides with another object, regardless of its type. A good example is a projectile that should be destroyed the first time it hits anything. There may be a specific collision handler and two wildcard handlers. It’s up to the specific handler to decide if and when to call the wildcard handlers and what to do with their return values. When a new wildcard handler is created, the callbacks will all be set to builtin callbacks that perform the default behavior. (accept all collisions in Begin() and PreSolve(), or do nothing for PostSolve() and Separate().

func (*Space) BBQuery 

func (s *Space) BBQuery(bb BB, filter ShapeFilter, f SpaceBBQueryFunc, data any)

func (*Space) ContactBufferGetArray 

func (s *Space) ContactBufferGetArray() []Contact

func (*Space) ContainsBody 

func (s *Space) ContainsBody(body *Body) bool

func (*Space) ContainsConstraint 

func (s *Space) ContainsConstraint(constraint *Constraint) bool

func (*Space) ContainsShape 

func (s *Space) ContainsShape(shape *Shape) bool

func (*Space) Deactivate 

func (s *Space) Deactivate(body *Body)

func (*Space) DynamicBodyCount 

func (s *Space) DynamicBodyCount() int

DynamicBodyCount returns the total number of dynamic bodies in space

func (*Space) DynamicShapeCount added in v1.10.0 

func (s *Space) DynamicShapeCount() int

func (*Space) EachBody 

func (s *Space) EachBody(f func(b *Body))

EachBody calls func f for each body in the space

Example: 

s.EachBody(func(body *cm.Body) {
	fmt.Println(body.Position())
})

func (*Space) EachConstraint 

func (s *Space) EachConstraint(f func(*Constraint))

func (*Space) EachDynamicBody added in v1.7.1 

func (s *Space) EachDynamicBody(f func(b *Body))

EachDynamicBody calls func f for each dynamic body in the space

func (*Space) EachDynamicShape added in v1.7.1 

func (s *Space) EachDynamicShape(f func(*Shape))

EachDynamicShape calls func f for each dynamic shape in the space

func (*Space) EachShape 

func (s *Space) EachShape(f func(*Shape))

EachShape calls func f for each shape in the space

func (*Space) EachStaticBody added in v1.7.1 

func (s *Space) EachStaticBody(f func(b *Body))

EachStaticBody calls func f for each static body in the space

func (*Space) EachStaticShape added in v1.7.1 

func (s *Space) EachStaticShape(f func(*Shape))

EachStaticShape calls func f for each static shape in the space

func (*Space) FilterArbiters 

func (s *Space) FilterArbiters(body *Body, filter *Shape)

func (*Space) IsLocked added in v1.7.0 

func (s *Space) IsLocked() bool

IsLocked returns true from inside a callback when objects cannot be added/removed.

func (*Space) Lock 

func (s *Space) Lock()

func (*Space) LookupHandler 

func (s *Space) LookupHandler(a, b CollisionType, defaultHandler *CollisionHandler) *CollisionHandler

LookupHandler finds and returns the matching a/b handler

func (*Space) PointQueryNearest 

func (s *Space) PointQueryNearest(point vec.Vec2, maxDistance float64, filter ShapeFilter) *PointQueryInfo

Query the space at a point and return the nearest shape found. Returns nil if no shapes were found.

func (*Space) PopContacts 

func (s *Space) PopContacts(count int)

func (*Space) PostStepCallback 

func (s *Space) PostStepCallback(key any) *PostStepCallback

func (*Space) ProcessComponents 

func (s *Space) ProcessComponents(dt float64)

func (*Space) PushContacts 

func (s *Space) PushContacts(count int)

func (*Space) PushFreshContactBuffer 

func (s *Space) PushFreshContactBuffer()

func (*Space) ReindexShape added in v1.9.1 

func (s *Space) ReindexShape(shape *Shape)

ReindexShape re-computes the hash of the shape in both the dynamic and static list.

func (*Space) RemoveBody 

func (s *Space) RemoveBody(body *Body)

RemoveBody removes a body from the simulation

func (*Space) RemoveBodyWithShapes added in v1.0.1 

func (s *Space) RemoveBodyWithShapes(body *Body)

RemoveBodyWithShapes removes a body and body's shapes from the simulation

func (*Space) RemoveConstraint 

func (s *Space) RemoveConstraint(constraint *Constraint)

func (*Space) RemoveShape 

func (s *Space) RemoveShape(shape *Shape)

RemoveShape removes a collision shape from the simulation.

func (*Space) SegmentQuery 

func (s *Space) SegmentQuery(start, end vec.Vec2, radius float64, filter ShapeFilter, f SpaceSegmentQueryFunc, data any)

func (*Space) SegmentQueryFirst 

func (s *Space) SegmentQueryFirst(start, end vec.Vec2, radius float64, filter ShapeFilter) SegmentQueryInfo

func (*Space) SetGravity 

func (s *Space) SetGravity(gravity vec.Vec2)

SetGravity sets gravity and wake up all of the sleeping bodies since the gravity changed.

func (*Space) SetStaticBody 

func (s *Space) SetStaticBody(body *Body)

func (*Space) ShapeCount added in v1.10.0 

func (s *Space) ShapeCount() int

func (*Space) ShapeQuery 

func (s *Space) ShapeQuery(shape *Shape, callback func(shape *Shape, points *ContactPointSet)) bool

ShapeQuery queries a space for any shapes overlapping the this shape and call the callback for each shape found.

func (*Space) SliceForBodyType added in v1.13.1 

func (s *Space) SliceForBodyType(t BodyType) *[]*Body

SliceForBodyType returns bodies of the given type in the space.

func (*Space) StaticBodyCount 

func (s *Space) StaticBodyCount() int

StaticBodyCount returns the total number of static bodies in space

func (*Space) StaticShapeCount added in v1.10.0 

func (s *Space) StaticShapeCount() int

func (*Space) Step 

func (s *Space) Step(dt float64)

func (*Space) TimeStep 

func (s *Space) TimeStep() float64

func (*Space) UncacheArbiter 

func (s *Space) UncacheArbiter(arb *Arbiter)

func (*Space) Unlock 

func (s *Space) Unlock(runPostStep bool)

func (*Space) UseSpatialHash 

func (s *Space) UseSpatialHash(dim float64, count int)

func (*Space) UseWildcardDefaultHandler 

func (s *Space) UseWildcardDefaultHandler()

type SpaceBBQueryFunc 

type SpaceBBQueryFunc func(shape *Shape, data any)

type SpaceHash 

type SpaceHash struct {
	*SpatialIndex
	// contains filtered or unexported fields
}

func (*SpaceHash) Contains 

func (hash *SpaceHash) Contains(obj *Shape, hashId HashValue) bool

func (*SpaceHash) Count 

func (hash *SpaceHash) Count() int

func (*SpaceHash) Each 

func (hash *SpaceHash) Each(f SpatialIndexIterator)

func (*SpaceHash) Insert 

func (hash *SpaceHash) Insert(obj *Shape, hashId HashValue)

func (*SpaceHash) Query 

func (hash *SpaceHash) Query(obj any, bb BB, f SpatialIndexQuery, data any)

func (*SpaceHash) Reindex 

func (hash *SpaceHash) Reindex()

func (*SpaceHash) ReindexObject 

func (hash *SpaceHash) ReindexObject(obj *Shape, hashId HashValue)

func (*SpaceHash) ReindexQuery 

func (hash *SpaceHash) ReindexQuery(f SpatialIndexQuery, data any)

func (*SpaceHash) Remove 

func (hash *SpaceHash) Remove(obj *Shape, hashId HashValue)

func (*SpaceHash) SegmentQuery 

func (hash *SpaceHash) SegmentQuery(obj any, a, b vec.Vec2, tExit float64, f SpatialIndexSegmentQuery, data any)

modified from http://playtechs.blogspot.com/2007/03/raytracing-on-grid.html

type SpaceHashBin 

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

type SpacePointQueryFunc 

type SpacePointQueryFunc func(*Shape, vec.Vec2, float64, vec.Vec2, any)

type SpaceSegmentQueryFunc 

type SpaceSegmentQueryFunc func(shape *Shape, point, normal vec.Vec2, alpha float64, data any)

type SpatialIndex 

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

func NewBBTree 

func NewBBTree(bbfunc SpatialIndexBB, staticIndex *SpatialIndex) *SpatialIndex

func NewSpaceHash 

func NewSpaceHash(celldim float64, num int, bbfunc SpatialIndexBB, staticIndex *SpatialIndex) *SpatialIndex

func NewSpatialIndex 

func NewSpatialIndex(klass SpatialIndexer, bbfunc SpatialIndexBB, staticIndex *SpatialIndex) *SpatialIndex

func (*SpatialIndex) CollideStatic 

func (dynamicIndex *SpatialIndex) CollideStatic(staticIndex *SpatialIndex, f SpatialIndexQuery, data any)

func (*SpatialIndex) GetRootIfTree 

func (index *SpatialIndex) GetRootIfTree() *Node

func (*SpatialIndex) GetTree 

func (index *SpatialIndex) GetTree() *BBTree

type SpatialIndexBB 

type SpatialIndexBB func(obj *Shape) BB

type SpatialIndexIterator 

type SpatialIndexIterator func(obj *Shape)

type SpatialIndexQuery 

type SpatialIndexQuery func(obj1 any, obj2 *Shape, collisionId uint32, data any) uint32

type SpatialIndexSegmentQuery 

type SpatialIndexSegmentQuery func(obj1 any, obj2 *Shape, data any) float64

type SpatialIndexer 

type SpatialIndexer interface {
	// Count returns the number of objects currently stored in the index.
	Count() int

	// Each iterates over all objects in the spatial index, applying
	// the provided iterator function `f` to each object.
	Each(f SpatialIndexIterator)

	// Contains checks if a given object `obj` with the specified
	// `hashId` exists in the spatial index.
	Contains(obj *Shape, hashId HashValue) bool

	// Insert adds a new object `obj` with the specified `hashId` to
	// the spatial index.
	Insert(obj *Shape, hashId HashValue)

	// Remove deletes the object `obj` with the specified `hashId`
	// from the spatial index, if it exists.
	Remove(obj *Shape, hashId HashValue)

	// Reindex rebuilds the spatial index from the existing objects
	// to optimize query performance.
	Reindex()

	// ReindexObject updates the spatial position of the given object
	// `obj` in the index using the specified `hashId`.
	ReindexObject(obj *Shape, hashId HashValue)

	// ReindexQuery performs a reindexing query using the given
	// spatial query function `f` and additional `data`.
	ReindexQuery(f SpatialIndexQuery, data any)

	// Query allows querying the spatial index for objects that intersect
	// or are contained within the bounding box `bb` using the provided
	// query function `f` and additional `data`.
	Query(obj any, bb BB, f SpatialIndexQuery, data any)

	// SegmentQuery performs a segment-based query using the line segment
	// defined by points `a` and `b`. It allows querying objects affected
	// by the segment based on the `tExit` parameter, applying the
	// provided segment query function `f` and additional `data`.
	SegmentQuery(obj any, a, b vec.Vec2, tExit float64, f SpatialIndexSegmentQuery, data any)
}

SpatialIndexer is an interface for spatial indexing that provides methods to manage spatial objects efficiently. It is implemented by a BBTree structure, which organizes objects in a bounding volume tree.

type SplittingPlane 

type SplittingPlane struct {
	V0, N vec.Vec2
}

type SupportContext 

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

func (*SupportContext) Support 

func (ctx *SupportContext) Support(n vec.Vec2) MinkowskiPoint

Support calculates the maximal point on the minkowski difference of two shapes along a particular axis.

type SupportPoint 

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

func CircleSupportPoint 

func CircleSupportPoint(shape *Shape, _ vec.Vec2) SupportPoint

func NewSupportPoint 

func NewSupportPoint(p vec.Vec2, index uint32) SupportPoint

func PolySupportPoint 

func PolySupportPoint(shape *Shape, n vec.Vec2) SupportPoint

func SegmentSupportPoint 

func SegmentSupportPoint(shape *Shape, n vec.Vec2) SupportPoint

type SupportPointFunc 

type SupportPointFunc func(shape *Shape, n vec.Vec2) SupportPoint

type Thread 

type Thread struct {
	// contains filtered or unexported fields
}
func (thread *Thread) Unlink()

type Transform 

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

Transform represents a 2D affine transformation using a 2x3 matrix. This structure can be used to perform various transformations such as translation, rotation, scaling, and shearing of 2D objects.

The transformation matrix is represented as follows: 

| a  b  tx |   -> X' = a * X + b * Y + tx
| c  d  ty |   -> Y' = c * X + d * Y + ty

Where:

  • a: Scaling factor in the X direction and component for rotation.
  • b: Shearing factor in the X direction (affects X based on Y).
  • c: Shearing factor in the Y direction (affects Y based on X).
  • d: Scaling factor in the Y direction and component for rotation.
  • tx: Translation in the X direction.
  • ty: Translation in the Y direction.

The Transform type can be used to compose multiple transformations, enabling complex transformations by multiplying matrices together.

func NewTransform 

func NewTransform(a, c, tx, b, d, ty float64) Transform

NewTransform returns a new transform matrix.

Parameters:

  • (a, b) is the x basis vector.
  • (c, d) is the y basis vector.
  • (tx, ty) is the translation.

func NewTransformIdentity 

func NewTransformIdentity() Transform

NewTransformIdentity creates and returns an identity transformation. The identity transformation is a special case of affine transformation that leaves the object's coordinates unchanged.

The identity matrix in 2D transforms points according to the following: 

| 1  0  0 |   -> X' = 1 * X + 0 * Y + 0 = X
| 0  1  0 |   -> Y' = 0 * X + 1 * Y + 0 = Y

The identity transform is useful as a starting point for composing transformations, as applying it to any object will yield the same object without any modifications.

func NewTransformRigid 

func NewTransformRigid(translate vec.Vec2, rotation float64) Transform

NewTransformRigid creates a new rigid transformation that combines translation and rotation.

Rigid transformation, or rigid motion, refers to a transformation that preserves the shape and size of objects while allowing them to change position and orientation in space. It includes translation, rotation, and reflection, maintaining distances and angles within the object.

Parameters:

  • translate: A 2D vector specifying the translation component.
  • rotation: The angle of rotation in radians.

Returns:

  • A Transform representing the combined translation and rotation.

func NewTransformRigidInverse 

func NewTransformRigidInverse(t Transform) Transform

NewTransformRigidInverse returns the inverse of a given rigid transformation.

Rigid transformation, or rigid motion, refers to a transformation that preserves the shape and size of objects while allowing them to change position and orientation in space. It includes translation, rotation, and reflection, maintaining distances and angles within the object.

Parameters:

  • t: The original Transform to invert.

Returns:

  • The inverted Transform.

func NewTransformRotate 

func NewTransformRotate(rotation float64) Transform

NewTransformRotate returns a new rigid transformation with rotation

func NewTransformScale 

func NewTransformScale(scaleX, scaleY float64) Transform

NewTransformScale returns a new transformation with scaling

func NewTransformTranslate 

func NewTransformTranslate(translate vec.Vec2) Transform

NewTransformTranslate returns a new transformation matrix with translation

func NewTransformTranspose 

func NewTransformTranspose(a, c, tx, b, d, ty float64) Transform

NewTransformTranspose returns a new transformation matrix in transposed order.

func (Transform) Apply added in v1.11.0 

func (t Transform) Apply(p vec.Vec2) vec.Vec2

Apply applies the transformation to a given abs point `p` and returns the transformed point. This transformation involves scaling, rotation, and translation based on the matrix values.

func (Transform) ApplyVector added in v1.11.0 

func (t Transform) ApplyVector(v vec.Vec2) vec.Vec2

ApplyVector applies the transformation matrix (t) to a vector (v). This transformation modifies the vector's direction based on the current transformation without affecting its position.

Parameters:

  • v: the vector (Vec2) to be transformed, represented by X and Y coordinates.

Returns:

  • Vec2: the transformed vector after applying the matrix transformation.

func (Transform) AxialScale 

func (t Transform) AxialScale(axis, pivot vec.Vec2, scale float64) Transform

Creates a transformation matrix for scaling along a given axis.

This function generates a transformation matrix that scales along a specified axis around a pivot point. If the scaling factor (scale) is different from 1.0, the transformation matrix will apply scaling along the direction of the axis.

Parameters:

  • axis: A vector representing the axis along which scaling will be applied.
  • pivot: The pivot point around which scaling is applied.
  • scale: The scaling factor. Values other than 1.0 scale the axis direction accordingly.

Returns:

  • Transform: Axial scale transformation matrix.

func (Transform) BB 

func (t Transform) BB(bb BB) BB

BB applies the current transformation (t) to a bounding box (BB). It scales and rotates the bounding box around its center to create a transformed bounding box that accounts for the dimensions after transformation.

Parameters:

  • bb: the bounding box (BB) to be transformed, defined by its left (L), right (R), top (T), and bottom (B) boundaries.

Returns:

  • BB: the transformed bounding box, with dimensions adjusted based on the transformation applied.

func (Transform) BoneScale 

func (t Transform) BoneScale(v0, v1 vec.Vec2) Transform

BoneScale creates a scaling and rotation transformation matrix based on a bone vector defined by the start and end points v0 and v1. It translates to v0 and scales along the direction to v1.

Parameters: - v0: The starting vector of the bone. - v1: The ending vector of the bone.

Returns: - A Transform that represents the scaling and rotation transformation matrix.

func (Transform) Inverse 

func (t Transform) Inverse() Transform

Inverse returns the inverse of this matrix t.

func (Transform) Mult 

func (t Transform) Mult(t2 Transform) Transform

Mult multiplies this and t2

Parameters:

  • t2 - The Transform to be multiplied with the receiver.

Returns:

  • A new Transform representing the result of the multiplication.

func (Transform) Ortho 

func (t Transform) Ortho(bb BB) Transform

Ortho creates an orthographic transformation matrix based on the given bounding box (bb). It performs scaling and translation to fit coordinates within the bounding box.

Parameters: - bb: A bounding box with left (L), right (R), bottom (B), and top (T) boundaries.

Returns: - A Transform that represents the orthographic projection transformation matrix.

func (*Transform) Scale added in v1.11.0 

func (t *Transform) Scale(x, y float64)

Scale matrix inplace

func (Transform) Wrap 

func (t Transform) Wrap(inner Transform) Transform

Wrap applies the inverse of the current transformation (t) around another transformation (inner). This wraps inner with the inverse of t, then applies t, effectively creating a nested transformation.

Parameters:

  • inner: the Transform to wrap with the inverse of the current transformation.

Returns:

  • Transform: the resulting transformation after wrapping.

Source Files

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