Abstract Base class for colliders. More...

#include <Collider.h>

Inheritance diagram for ime::Collider:

Public Types
enum	Type { Type::Circle, Type::Box, Type::Polygon, Type::Edge }
	The type of the collider. More...

using	Ptr = std::shared_ptr< Collider >
	Shared collider pointer. More...

using	BodyPtr = std::shared_ptr< Body >
	Shared Body pointer. More...

Public Member Functions
	Collider (Type type)
	Construct a collider. More...

	Collider (Collider &&) noexcept
	Move constructor. More...

Collider &	operator= (Collider &&) noexcept
	Move assignment operator. More...

virtual Collider::Ptr	clone () const =0
	Create a copy of the collider. More...

std::string	getClassType () const override
	Get the name of this class. More...

Type	getType () const
	Get the type of the collider. More...

void	setDensity (float density)
	Set the density of the collider. More...

float	getDensity () const
	Get the density of the collider. More...

void	setFriction (float friction)
	Set the coefficient of friction. More...

float	getFriction () const
	Get the coefficient of friction. More...

void	setRestitution (float restitution)
	Set the coefficient of restitution. More...

float	getRestitution () const
	Get the coefficient of restitution of the collider. More...

void	setRestitutionThreshold (float threshold)
	Set the restitution threshold of the collider. More...

float	getRestitutionThreshold () const
	Get the restitution velocity threshold of the collider. More...

void	setSensor (bool sensor)
	Set if the collider is a sensor or not. More...

bool	isSensor () const
	Check whether or not the collider is a sensor. More...

void	setCollisionFilter (const CollisionFilterData &filterData)
	Set the collision filter data of the collider. More...

const CollisionFilterData &	getCollisionFilterData () const
	Get the collision filter data for the collider. More...

void	resetCollisionFilterData ()
	Reset the collision filtering data to default. More...

void	setEnable (bool enable)
	Enable or disable the collider. More...

BodyPtr	getBody ()
	Get the body the collider is attached to. More...

const BodyPtr &	getBody () const

bool	containsPoint (Vector2f point) const
	Check if the collider contains a point or not. More...

PropertyContainer &	getUserData ()
	Get the user data extracted from the collider definition. More...

	~Collider () override=0
	Destructor. More...

void	setTag (const std::string &tag)
	Assign the object an alias. More...

const std::string &	getTag () const
	Get the alias of the object. More...

unsigned int	getObjectId () const
	Get the id of the object. More...

virtual std::string	getClassName () const =0
	Get the name of the concrete class. More...

int	onPropertyChange (const std::string &property, const Callback< Property > &callback)
	Add an event listener to a specific property change event. More...

void	onPropertyChange (const Callback< Property > &callback)
	Add an event listener to a property change event. More...

int	onEvent (const std::string &event, const Callback<> &callback)
	Add an event listener to an event. More...

bool	unsubscribe (const std::string &event, int id)
	Remove an event listener from an event. More...

int	onDestruction (const Callback<> &callback)
	Add a destruction listener. More...

bool	removeDestructionListener (int id)
	Remove a destruction listener form the object. More...

bool	operator== (const Object &rhs) const
	Check if two objects are the same object or not. More...

bool	operator!= (const Object &rhs) const
	Check if two objects are not the same object. More...

Protected Member Functions
	Collider (const Collider &)
	Copy constructor. More...

Collider &	operator= (const Collider &)
	Copy assignment operator. More...

virtual b2Shape &	getInternalShape ()=0

virtual const b2Shape &	getInternalShape () const =0

void	emitChange (const Property &property)
	Dispatch a property change event. More...

void	emit (const std::string &event)
	Dispatch an action event. More...

Friends
class	Body
	Needs access to constructor. More...

Detailed Description

Abstract Base class for colliders.

A collider enables collisions between rigid bodies/game objects. It defines the shape of a rigid body/game object for the purpose of physical collisions. Usually a collider is attached to a rigid Body which is then attached to a GameObject. A game object that has a rigid body attached to it which does not have a collider will be affected by physics (impulses, gravity, friction etc), but the game object cannot react/respond to collisions.

Colliders are invisible however they may be drawn on the render window during debug mode by enabling debug drawing of the physics World.

Rigid bodies enable physics while colliders enable collisions

Definition at line 118 of file Collider.h.

Member Typedef Documentation

◆ BodyPtr

using ime::Collider::BodyPtr = std::shared_ptr<Body>

Shared Body pointer.

Definition at line 121 of file Collider.h.

◆ Ptr

using ime::Collider::Ptr = std::shared_ptr<Collider>

Shared collider pointer.

Definition at line 120 of file Collider.h.

Member Enumeration Documentation

◆ Type

enum ime::Collider::Type

strong

The type of the collider.

Enumerator
Circle	Circle collider.
Box	Box collider.
Polygon	Polygon collider.
Edge	Edge collider.

Definition at line 126 of file Collider.h.

Constructor & Destructor Documentation

◆ Collider() [1/3]

ime::Collider::Collider ( Type type )

explicit

Construct a collider.

Parameters

type	Type of the collider

Warning: The collider must be attached to a rigid body before any of its functions are are called. Calling a member function without a rigid body is undefined behavior

◆ Collider() [2/3]

ime::Collider::Collider ( Collider && )

noexcept

Move constructor.

◆ ~Collider()

ime::Collider::~Collider ( )

overridepure virtual

Destructor.

◆ Collider() [3/3]

ime::Collider::Collider ( const Collider & )

protected

Copy constructor.

Member Function Documentation

◆ clone()

virtual Collider::Ptr ime::Collider::clone ( ) const

pure virtual

Create a copy of the collider.

Returns: A copy of the collider

Warning: The collider must be attached to a rigid body before any of its functions are are called. Calling a member function before attaching the collider to a rigid body is undefined behavior

Implemented in ime::PolygonCollider, ime::EdgeCollider, ime::CircleCollider, and ime::BoxCollider.

◆ containsPoint()

bool ime::Collider::containsPoint ( Vector2f point ) const

Check if the collider contains a point or not.

Parameters

point The point to be checked in world coordinates

Returns: True if the collider contains the point, otherwise false

◆ emit()

void ime::Object::emit ( const std::string & event )

protectedinherited

Dispatch an action event.

Parameters

event The name of the event to be dispatched

This function will invoke all event listeners of the specified event. The function should be used for events that represent an action, rather than those that represent a property change (Use emitChange for that)

See also: emitChange

◆ emitChange()

void ime::Object::emitChange ( const Property & property )

protectedinherited

Dispatch a property change event.

Parameters

property The property that changed

This function will invoke all the event listeners of the specified property

See also: emit

◆ getBody()

BodyPtr ime::Collider::getBody ( )

Get the body the collider is attached to.

Returns: The body this collider is attached to if any, otherwise a nullptr

◆ getClassName()

virtual std::string ime::Object::getClassName ( ) const

pure virtualinherited

Get the name of the concrete class.

Returns: The name of the objects concrete class

This function is implemented by all internal classes that inherit from this class.

See also: getClassType

Implemented in ime::Tile, ime::SpriteSheet, ime::Sprite, ime::RectangleShape, ime::ConvexShape, ime::CircleShape, ime::Camera, ime::Scene, ime::RenderLayerContainer, ime::RenderLayer, ime::TargetGridMover, ime::RandomGridMover, ime::KeyboardGridMover, ime::DistanceJoint, ime::PolygonCollider, ime::EdgeCollider, ime::CircleCollider, ime::BoxCollider, ime::Body, ime::AABB, and ime::GameObject.

◆ getClassType()

std::string ime::Collider::getClassType ( ) const

overridevirtual

Get the name of this class.

Returns: The name of this class

Note that this function is only implemented by child classes of Object which also serve as a base class for other classes

See also: Object::getClassType and Object::getClassName

Reimplemented from ime::Object.

◆ getCollisionFilterData()

const CollisionFilterData& ime::Collider::getCollisionFilterData ( ) const

Get the collision filter data for the collider.

Returns: The collision filter data of the collider

◆ getDensity()

float ime::Collider::getDensity ( ) const

Get the density of the collider.

Returns: The density of the collider

◆ getFriction()

float ime::Collider::getFriction ( ) const

Get the coefficient of friction.

Returns: The coefficient of friction

◆ getObjectId()

unsigned int ime::Object::getObjectId ( ) const

inherited

Get the id of the object.

Returns: The id of the object

Each object has a unique id

◆ getRestitution()

float ime::Collider::getRestitution ( ) const

Get the coefficient of restitution of the collider.

Returns: The coefficient of restitution of the collider

◆ getRestitutionThreshold()

float ime::Collider::getRestitutionThreshold ( ) const

Get the restitution velocity threshold of the collider.

Returns: The restitution velocity

◆ getTag()

const std::string& ime::Object::getTag ( ) const

inherited

Get the alias of the object.

Returns: The alias of the object

See also: setTag and getObjectId

◆ getType()

Type ime::Collider::getType ( ) const

Get the type of the collider.

Returns: The type of the collider

◆ getUserData()

PropertyContainer& ime::Collider::getUserData ( )

Get the user data extracted from the collider definition.

Returns: The user data

◆ isSensor()

bool ime::Collider::isSensor ( ) const

Check whether or not the collider is a sensor.

Returns: True if the collider is a sensor, otherwise false

◆ onDestruction()

int ime::Object::onDestruction ( const Callback<> & callback )

inherited

Add a destruction listener.

Parameters

callback Function to be executed when the object is destroyed

Returns: The id of the destruction listener

Note that an object may have more than one destruction listeners, however, you have to keep the returned id if you may want to remove the callback at a later time

Warning: The callback is called when the object is destroyed. Do not try to access the object in the callback. Doing so is undefined behavior

See also: removeDestructionListener

◆ onEvent()

int ime::Object::onEvent	(	const std::string &	event,
		const Callback<> &	callback
	)

inherited

Add an event listener to an event.

Parameters

event	The name of the event to add an an event listener to
callback	The function to be executed when the event takes place

Returns: The unique identification number of the event listener

Unlike onPropertyChange, this function registers event listeners to events that occur when something happens to the object, or when the object does something (action events). Usually the name of the event/action is the name of the function:

// Add event listeners to the object
object.onEvent("attachRigidBody", [] {
    std::cout << "Rigid body attached to object << std::endl;
});
 
object.onEvent("removeRigidBody", [] {
    std::cout << "Rigid body removed from object << std::endl;
});
 
// Invokes event listener(s)
object.attachRigidBody(body);
object.removeRigidBody();

See also: onPropertyChange and unsubscribe

◆ onPropertyChange() [1/2]

void ime::Object::onPropertyChange ( const Callback< Property > & callback )

inherited

Add an event listener to a property change event.

Parameters

callback The function to be executed when the property changes

Returns: The unique id of the event listener

Note that only one callback function may be registered with this function. This means that adding a new event listener overwrites the previous event listener. To remove the callback, pass a nullptr as an argument. The function may be useful if you want to write the logic for property changes in one function.

See also: onPropertyChange(std::string, Callback)

◆ onPropertyChange() [2/2]

int ime::Object::onPropertyChange	(	const std::string &	property,
		const Callback< Property > &	callback
	)

inherited

Add an event listener to a specific property change event.

Parameters

property	The name of the property to listen for
callback	The function to be executed when the property changes

Returns: The unique id of the event listener

A property change event is triggered by any function that begins with set, where the the text after set is the name of the property. For example, for the setTag function, the property that the function modifies is Tag.

Note that when adding a property change event listener, the name of the property must be in lowercase:

// Prints the tag of the player object to the console everytime it changes
player.onPropertyChange("tag", [](const Property& property) {
     cout << "New tag: " <<  property.getValue<std::string>() << endl;
});
 
...
//Sets tag = "player1" and invokes event listener(s)
player.setTag("player1");

Unlike onPropertyChange(const Callback&) you can add multiple event listeners to the same property using this function. However you must store the unique id of the event listener if you wish to remove it at a later time

See also: unsubscribe and onPropertyChange(Callback)

◆ operator!=()

bool ime::Object::operator!= ( const Object & rhs ) const

inherited

Check if two objects are not the same object.

Parameters

rhs	Object to compare against this object

Returns: True if rhs is NOT the same object as this object, otherwise false

Two objects are different from each other if they have different object id's

See also: getObjectId and operator==

◆ operator=() [1/2]

Collider& ime::Collider::operator= ( Collider && )

noexcept

Move assignment operator.

◆ operator=() [2/2]

Collider& ime::Collider::operator= ( const Collider & )

protected

Copy assignment operator.

◆ operator==()

bool ime::Object::operator== ( const Object & rhs ) const

inherited

Check if two objects are the same object or not.

Parameters

rhs	Object to compare against this object

Returns: True if rhs is the same object as this object, otherwise false

Two objects are the same object if they have the same object id. Recall that each object instance has a unique id

See also: getObjectId and operator!=

◆ removeDestructionListener()

bool ime::Object::removeDestructionListener ( int id )

inherited

Remove a destruction listener form the object.

Parameters

The	id of the destruction listener to be removed

Returns: True if the destruction listener was removed or false if the listener with the given id does not exist

◆ resetCollisionFilterData()

void ime::Collider::resetCollisionFilterData ( )

Reset the collision filtering data to default.

By default, the collider does not belong to any collision group and the rigid body the collider is attached to will collide with any rigid body (that is also collidable) it comes into contact with

◆ setCollisionFilter()

void ime::Collider::setCollisionFilter ( const CollisionFilterData & filterData )

Set the collision filter data of the collider.

Parameters

filterData The new collision filter data

This function will not update contacts until the next time step when either parent body is active or awake

By default, the collider does not belong to any collision group and the rigid body the collider is attached to will collide with any rigid body (that is also collidable) it comes into contact with

◆ setDensity()

void ime::Collider::setDensity ( float density )

Set the density of the collider.

Parameters

density The density to set

The colliders density is used to compute the mass properties of the rigid body. The density can be zero or positive. You should use similar densities for all of your colliders. This will improve stacking stability

By default, the density is 1.0f

◆ setEnable()

void ime::Collider::setEnable ( bool enable )

Enable or disable the collider.

Parameters

enable True to enable or false to disable

This function will only modify the collision bitmask and leave the category bit and group index as is. When enable is set to false, the collision bitmask will be set to 0 causing the collider to not collide with any other collider and when enable is set to true, the collision bitmask will be set to the value it was before it was set to zero.

This function is a just a shortcut for:

// When set this way, you will also have to save/remember the previous
// collision bitmask value if you wish to restore it and not set a new
// one
auto filterData = collider.getCollisionFilterData();
filterData.collisionBitMask = 0;
collider.setCollisionFilter(filterData);

By default, the collider is enabled

See also: setCollisionFilter

◆ setFriction()

void ime::Collider::setFriction ( float friction )

Set the coefficient of friction.

Parameters

friction The coefficient to set

Friction is used to make objects slide along each other realistically The friction parameter is usually set between 0 and 1, but can be any non-negative value. A friction value of 0 turns off friction and a value of 1 makes the friction strong

Note: This will not change the coefficient of existing contacts

By default, the friction is 0.2f

◆ setRestitution()

void ime::Collider::setRestitution ( float restitution )

Set the coefficient of restitution.

Parameters

restitution The coefficient to set

Restitution is used to make objects bounce. The restitution value is usually set to be between 0 and 1. Consider dropping a ball on a table. A value of zero means the ball won't bounce. This is called an inelastic collision. A value of one means the ball's velocity will be exactly reflected. This is called a perfectly elastic collision

Note: This will not change the restitution of existing contacts

By default, the restitution is 0.0f

◆ setRestitutionThreshold()

void ime::Collider::setRestitutionThreshold ( float threshold )

Set the restitution threshold of the collider.

Parameters

threshold The new restitution threshold

Note: This will not change the restitution threshold of existing contacts

By default, the restitution threshold is 1.0f

◆ setSensor()

void ime::Collider::setSensor ( bool sensor )

Set if the collider is a sensor or not.

Parameters

sensor True to set as sensor, otherwise false

A sensor detects a collision but does not generate a collision response. This is useful if you only want to know when two colliders overlap. You can flag any collider as being a sensor. Sensors may be attached to static, kinematic, or dynamic bodies. Remember that you may have multiple colliders per body and you can have any mix of sensors and non-sensor colliders. Also, sensors only form contacts when at least one body is dynamic, so you will not get a contact for kinematic versus kinematic, kinematic versus static, or static versus static

By default, the collider is not a sensor

◆ setTag()

void ime::Object::setTag ( const std::string & tag )

inherited

Assign the object an alias.

Parameters

name	The alias of the object

This function is useful if you want to refer to the object by tag instead of its id. Unlike an object id, multiple objects may have the same tag.

By default, the tag is an empty string

◆ unsubscribe()

bool ime::Object::unsubscribe	(	const std::string &	event,
		int	id
	)

inherited

Remove an event listener from an event.

Parameters

event	The name of the event to remove event listener from
id	The unique id of the event listener to be removed

Returns: True if the event listener was removed or false if the event or the event listener is does not exist

// Display the name of the object to console every time it changes
auto nameChangeId = object.onPropertyChange("name", [](Property name) {
     std::cout << name.getValue<std::string>() << std::endl;
});
 
// Stop displaying the name of the object when it changes
object.unsubscribe("name", id);

Friends And Related Function Documentation

◆ Body

friend class Body

friend

Needs access to constructor.

Definition at line 406 of file Collider.h.

The documentation for this class was generated from the following file:

Collider.h

Public Types

Public Member Functions

Protected Member Functions

Friends

Detailed Description

Member Typedef Documentation

◆ BodyPtr

◆ Ptr

Member Enumeration Documentation

◆ Type

Constructor & Destructor Documentation

◆ Collider() [1/3]

◆ Collider() [2/3]

◆ ~Collider()

◆ Collider() [3/3]

Member Function Documentation

◆ clone()

◆ containsPoint()

◆ emit()

◆ emitChange()

◆ getBody()

◆ getClassName()

◆ getClassType()

◆ getCollisionFilterData()

◆ getDensity()

◆ getFriction()

◆ getObjectId()

◆ getRestitution()

◆ getRestitutionThreshold()

◆ getTag()

◆ getType()

◆ getUserData()

◆ isSensor()

◆ onDestruction()

◆ onEvent()

◆ onPropertyChange() [1/2]

◆ onPropertyChange() [2/2]

◆ operator!=()

◆ operator=() [1/2]

◆ operator=() [2/2]

◆ operator==()

◆ removeDestructionListener()

◆ resetCollisionFilterData()

◆ setCollisionFilter()

◆ setDensity()

◆ setEnable()

◆ setFriction()

◆ setRestitution()

◆ setRestitutionThreshold()

◆ setSensor()

◆ setTag()

◆ unsubscribe()

Friends And Related Function Documentation

◆ Body