Physics.Hipmunk.Constraint

newConstraint b1 b2 type_ connects the two bodies b1 and b2 with a constraint of the given type. Note that you should add the Constraint to a space.

The ConstraintType type class is implemented by all constraint types to allow them to be manipulated by the same framework while retaining type-safety, consequently it isn't exported.

redefineC :: ConstraintType a => Constraint a -> a -> IO ()

Source

redefine constr type_ redefines constr's parameters on-the-fly, allowing you to dynamically change the constraint's behaviour.

setBiasCoefC :: BiasCoef -> Constraint a -> IO ()

Source

Sets the constraint's bias coefficient. By default it is equal to the last value set globally with setConstraintBiasCoef, which initially is 0.1

data Constraint a

Source

Represents a constraint between two bodies. Don't forget to add the bodies and the constraint itself to the space. The phantom type indicates the type of the constraint.

Instances

Eq (Constraint a)

Ord (Constraint a)

Entity (Constraint a)

Forgetting the phantom type

These functions discard the phantom type of the constraint. They're useful, for example, if you want to put different constraints in a homogeneous data structure (such as a list).

data Unknown

Source

An unknown constraint "type". Note that this isn't a ConstraintType because you can't create a constraint of Unknown type.

forgetC :: Constraint a -> Constraint Unknown

Source

Completely safe function that discards the constraint type (which is a phantom type). You can "remember" it again by using unsafeRemember from the Unsafe module.

Constraint types

There are currently nine types of constraints. When appending a number to a property, we hint that it refer to one of the bodies that the constraint is intercting with (e.g. "Second anchor" is the position of the anchor on the second body in its coordinates).

Pin joint

data Pin

Source

A pin joint connects the bodies with a solid pin. The anchor points are kept at a fixed distance.

Constructors

Pin

pinAnchor1 :: !Position	First anchor.
pinAnchor2 :: !Position	Second anchor.

Instances

ConstraintType Pin

data Slide

A slide joint is similar to a pin joint, however it has a minimum and a maximum distance.

Constructors

Slide

slideAnchor1 :: !Position	First anchor.
slideAnchor2 :: !Position	Second anchor.
slideMinDist :: !Distance	Minimum distance.
slideMaxDist :: !Distance	Maximum distance.

Instances

ConstraintType Slide

data Pivot

A pivot joint allows the bodies to pivot around a single point.

Constructors

Pivot1

You may specify the pivot point in world's coordinates (so both bodies should be already in place).

pivotPos :: !Position

Pivot point in world's coordinates.

Pivot2

Or you may specify the joint as two anchors (on each body's coordinates), removing the need having the bodies already in place.

pivotAnchor1 :: !Position	First anchor.
pivotAnchor2 :: !Position	Second anchor.

Instances

ConstraintType Pivot

data Groove

A groove joint attaches a point on the second body to a groove in the first one.

Constructors

Groove

groovePoints :: !(Position, Position)	Groove, in first body's coordinates.
groovePivot :: !Position	Pivot, in second body's coordinates.

Instances

Eq Groove

Ord Groove

Show Groove

ConstraintType Groove

Gear joint

data Gear

Source

A gear joint restricts the bodies movement to be coordinated as if they were attached like dented gears.

Constructors

Gear

gearPhase :: !Angle	Phase of the movement.
gearRatio :: !CpFloat	Ratio between the gears.

Instances

ConstraintType Gear

data DampedSpring

Source

A simple damped spring. Generally this constraint should be used instead of applyDampedSpring.

Constructors

DampedSpring

dampedAnchor1 :: !Position	First anchor.
dampedAnchor2 :: !Position	Second anchor.
dampedRestLength :: !Distance	Rest length.
dampedStiffness :: !CpFloat	Stiffness.
dampedDamping :: !Damping	Damping.