An edge collider is a line segment. More...

#include <EdgeCollider.h>

Inheritance diagram for ime::EdgeCollider:

Public Types
using	Ptr = std::unique_ptr< EdgeCollider >
	Unique collider pointer. More...

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

using	CollisionCallback = std::function< void(Collider , Collider )>
	RigidBody collision callback. More...

Public Member Functions
	EdgeCollider ()
	Default constructor. More...

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

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

EdgeCollider::Ptr	copy () const
	Create a copy of the collider. More...

Collider::Ptr	clone () const override
	Create a copy of the collider. More...

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

void	setOneSided (const Vector2f &v0, const Vector2f &v1, const Vector2f &v2, const Vector2f &v3)
	Create a one sided collision edge. More...

void	setTwoSided (const Vector2f &v1, const Vector2f &v2)
	Create a two sided collision edge. More...

std::pair< Vector2f, Vector2f >	getEdgeVertices () const
	Get the vertices that make up the edge. More...

Vector2f	getFirstVertex () const
	Get the first vertex of the edge collider. More...

Vector2f	getSecondVertex () const
	Get the second vertex of the edge collider. More...

std::pair< Vector2f, Vector2f >	getGhostVertices () const
	Get the ghost vertices. More...

bool	isOneSided () const
	Check if the edge is collidable on one side or two sides. More...

	~EdgeCollider () override
	Destructor. 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 whether or not the collider acts as a sensor. 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...

bool	isAttachedToBody () const
	Check if the collider is attached to a rigid body or not. More...

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

const RigidBody *	getBody () const

bool	containsPoint (const 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...

const PropertyContainer &	getUserData () const

void	onContactBegin (const CollisionCallback &callback)
	Add an event listener to a collision start event. More...

void	onContactEnd (const CollisionCallback &callback)
	Add an event listener to a collision end event. More...

void	onContactStay (const CollisionCallback &callback)
	Add an event listener to a contact stay event. More...

void	emitContact (const std::string &event, Collider *other)

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

const std::string &	getTag () const
	Get the tag assigned to the object. More...

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

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

int	onPropertyChange (const Callback< Property > &callback, bool oneTime=false)
	Add an event listener to any property change event. More...

void	suspendedEventListener (int id, bool suspend)
	Pause or resume execution of an event listener. More...

bool	isEventListenerSuspended (int id) const
	Check if an event listener is suspended or not. More...

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

bool	removeEventListener (int id)
	Remove an event listener. More...

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

bool	isSameObjectAs (const Object &other) const
	Check if another object is the same instance as this object. More...

Static Public Member Functions
static EdgeCollider::Ptr	create ()
	Create a new edge collider. More...

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

void	emitDestruction ()
	Emit a destruction event. More...

Protected Attributes
EventEmitter	eventEmitter_
	Event dispatcher. More...

Detailed Description

An edge collider is a line segment.

Note that edge colliders can collide with circles and polygons but not with themselves because edge shapes have no volume

Definition at line 42 of file EdgeCollider.h.

Member Typedef Documentation

◆ CollisionCallback

using ime::Collider::CollisionCallback = std::function<void(Collider*, Collider*)>

inherited

RigidBody collision callback.

Definition at line 122 of file Collider.h.

◆ Ptr

using ime::EdgeCollider::Ptr = std::unique_ptr<EdgeCollider>

Unique collider pointer.

Definition at line 44 of file EdgeCollider.h.

Member Enumeration Documentation

◆ Type

enum class ime::Collider::Type

stronginherited

The type of the collider.

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

Definition at line 127 of file Collider.h.

Constructor & Destructor Documentation

◆ EdgeCollider() [1/2]

ime::EdgeCollider::EdgeCollider ( )

Default constructor.

◆ EdgeCollider() [2/2]

ime::EdgeCollider::EdgeCollider ( EdgeCollider && )

noexcept

Move constructor.

◆ ~EdgeCollider()

ime::EdgeCollider::~EdgeCollider ( )

override

Destructor.

Member Function Documentation

◆ clone()

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

overridevirtual

Create a copy of the collider.

Returns: A new edge collider

You should use this function if you don't care about the type of the collider, otherwise use the colliders copy function

Warning: You must attach a rigid Body to the returned collider before using it. Failure to do so is undefined behavior

See also: copy

Implements ime::Collider.

◆ containsPoint()

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

inherited

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

◆ copy()

EdgeCollider::Ptr ime::EdgeCollider::copy ( ) const

Create a copy of the collider.

Returns: A new edge collider

Warning: You must attach a rigid Body to the returned collider before using it. Failure to do so is undefined behavior

See also: clone

◆ create()

static EdgeCollider::Ptr ime::EdgeCollider::create ( )

static

Create a new edge collider.

Returns: The created edge collider

This function is just a helper function for creating a shared pointer to an edge collider. The class does not keep the pointer

◆ 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

◆ emitDestruction()

void ime::Object::emitDestruction ( )

protectedinherited

Emit a destruction event.

Note: This function must be the first statement in the definition of a destructor to avoid undefined behavior. In addition, note that destruction listeners are invoked once. Therefore, multiple classes in a hierarchy may call this function but the class that makes the call first will be the one that invokes the destruction listeners

◆ getBody()

RigidBody * ime::Collider::getBody ( )

inherited

Get the body the collider is attached to.

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

◆ getClassName()

std::string ime::EdgeCollider::getClassName ( ) const

overridevirtual

Get the name of this class.

Returns: The name of this class

Implements ime::Object.

◆ getClassType()

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

overridevirtualinherited

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

inherited

Get the collision filter data for the collider.

Returns: The collision filter data of the collider

◆ getDensity()

float ime::Collider::getDensity ( ) const

inherited

Get the density of the collider.

Returns: The density of the collider

◆ getEdgeVertices()

std::pair< Vector2f, Vector2f > ime::EdgeCollider::getEdgeVertices ( ) const

Get the vertices that make up the edge.

Returns: A pair, of which the first element is the first vertex and the second is the second vertex of the edge

◆ getFirstVertex()

Vector2f ime::EdgeCollider::getFirstVertex ( ) const

Get the first vertex of the edge collider.

Returns: The first vertex of the edge collider

◆ getFriction()

float ime::Collider::getFriction ( ) const

inherited

Get the coefficient of friction.

Returns: The coefficient of friction

◆ getGhostVertices()

std::pair< Vector2f, Vector2f > ime::EdgeCollider::getGhostVertices ( ) const

Get the ghost vertices.

Returns: A pair, of which the first element is the first ghost vertex and the second is the second ghost vertex

If the collider is two sided then the ghost vertices are all 0.0f

See also: setOneSided and setTwoSided

◆ getObjectId()

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

inherited

Get the unique id of the object.

Returns: The unique id of the object

Note that each instance of ime::Object has a unique id

See also: setTag

◆ getRestitution()

float ime::Collider::getRestitution ( ) const

inherited

Get the coefficient of restitution of the collider.

Returns: The coefficient of restitution of the collider

◆ getRestitutionThreshold()

float ime::Collider::getRestitutionThreshold ( ) const

inherited

Get the restitution velocity threshold of the collider.

Returns: The restitution velocity

◆ getSecondVertex()

Vector2f ime::EdgeCollider::getSecondVertex ( ) const

Get the second vertex of the edge collider.

Returns: The second vertex of the edge collider

◆ getTag()

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

inherited

Get the tag assigned to the object.

Returns: The tag of the object

See also: setTag

◆ getType()

Type ime::Collider::getType ( ) const

inherited

Get the type of the collider.

Returns: The type of the collider

◆ getUserData()

PropertyContainer & ime::Collider::getUserData ( )

inherited

Get the user data extracted from the collider definition.

Returns: The user data

◆ isAttachedToBody()

bool ime::Collider::isAttachedToBody ( ) const

inherited

Check if the collider is attached to a rigid body or not.

Returns: True if it is attached to a body, otherwise false

Note: A collider can only be attached to a single rigid Body

◆ isEventListenerSuspended()

bool ime::Object::isEventListenerSuspended ( int id ) const

inherited

Check if an event listener is suspended or not.

Parameters

id	The identification number of the listener to be checked

Returns: True if suspended, otherwise false

This function also returns false if the specified event listener does not exist

See also: suspendedEventListener

◆ isOneSided()

bool ime::EdgeCollider::isOneSided ( ) const

Check if the edge is collidable on one side or two sides.

Returns: True if collidable on one side or false if collidable on two sides

◆ isSameObjectAs()

bool ime::Object::isSameObjectAs ( const Object & other ) const

inherited

Check if another object is the same instance as this object.

Parameters

other The object to compare against this object

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

◆ isSensor()

bool ime::Collider::isSensor ( ) const

inherited

Check whether or not the collider is a sensor.

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

◆ onContactBegin()

void ime::Collider::onContactBegin ( const CollisionCallback & callback )

inherited

Add an event listener to a collision start event.

Parameters

callback The function to be executed when this collider starts overlapping with another collider

Note that the callback is called when the colliders come into contact and not when they remain in contact. In other words it is called once per interaction. On invocation, the callback is passed this collider and the collider that it started overlapping with respectively. In addition, only one event listener may be registered to this event, subsequent event listeners overwrite the current one. Pass nullptr to remove the current event listener

Note: The callback is invoked for sensor and non-sensor colliders

Warning: Don't keep the pointers passed to the callback, they are invalidated when the callback execution terminates

See also: onContactEnd, onContactStay and setSensor

◆ onContactEnd()

void ime::Collider::onContactEnd ( const CollisionCallback & callback )

inherited

Add an event listener to a collision end event.

Parameters

callback The function to be executed when the event is fired

The callback is called when this collider stops overlapping with another collider. The callback is passed this collider and the collider it stopped overlapping with respectively. Note that only only one event listener may be registered to this event, subsequent event listeners overwrite the current one. Pass nullptr to remove the current event listener

Note: The callback is invoked for sensor and non-sensor colliders

Warning: Don't keep the pointers passed to the callback, they are invalidated when the callback execution terminates

See also: onContactBegin, onContactStay and setSensor

◆ onContactStay()

void ime::Collider::onContactStay ( const CollisionCallback & callback )

inherited

Add an event listener to a contact stay event.

Parameters

callback The function to be executed when the event is fired

The callback is called while this collider remains in contact with another collider. On invocation, the callback is passed this collider and the collider its currently overlapping with respectively.

Note that only one event listener may be registered to this event, subsequent event listeners overwrite the current one. Pass nullptr to remove the current event listener

Note: The callback is only invoked for non-sensor contacts. That is, if one of the two colliders in contact is a sensor, the on stay event will not be triggered. The event is also not triggered if the body the collider is attached to is not awake

Warning: Don't keep the pointers passed to the callback, they are invalidated when the callback execution terminates

See also: onContactBegin, onContactEnd and setSensor

◆ 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 unique id of the destruction listener

The destruction listener is called when the object reaches the end of its lifetime. Note that an object may have multiple destruction listeners registered to it

Warning: It's not advised to call virtual functions in the destruction callback as some parts of the object may have already been destroyed by the time the callback is invoked. In such an event, the behavior is undefined

See also: removeEventListener

◆ onPropertyChange() [1/2]

int ime::Object::onPropertyChange	(	const Callback< Property > &	callback,
		bool	oneTime = `false`
	)

inherited

Add an event listener to any property change event.

Parameters

callback	The function to be executed when any property changes
oneTime	True to execute the callback one-time or false to execute it every time the event is triggered

Returns: The unique id of the event listener

When unsubscribing the any property change event handler, you must pass "propertyChange" as the name of the event

See also: onPropertyChange(const std::string&, const ime::Callback<ime::Property>&)

◆ onPropertyChange() [2/2]

int ime::Object::onPropertyChange	(	const std::string &	property,
		const Callback< Property > &	callback,
		bool	oneTime = `false`
	)

inherited

Add an event listener to a specific property change event.

Parameters

property	The name of the property to add an event listener to
oneTime	True to execute the callback one-time or false to execute it every time the event is triggered
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, the setTag() function, modifies the tag property of the object, thus will generate a "tag" change event each time it is called

Note that multiple event listeners may be registered to the same property change event. In addition, 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");

See also: unsubscribe and onPropertyChange(const ime::Callback<ime::Property>&)

◆ operator=()

EdgeCollider & ime::EdgeCollider::operator= ( EdgeCollider && )

noexcept

Move assignment operator.

◆ removeEventListener() [1/2]

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

inherited

Remove an event listener from an event.

Parameters

event	The name of the event to remove an 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 tag of the object to console every time it changes
auto tagChangeId = object.onPropertyChange("tag", [](ime::Property tag) {
     std::cout << name.getValue<std::string>() << std::endl;
});
 
// Stop displaying the tag of the object when it changes
object.removeEventListener("tag", tagChangeId);

◆ removeEventListener() [2/2]

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

inherited

Remove an event listener.

Parameters

id	The id of the event listener to be removed

Returns: True if the event listener was removed or false if no such handler exists

◆ resetCollisionFilterData()

void ime::Collider::resetCollisionFilterData ( )

inherited

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 )

inherited

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 )

inherited

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 )

inherited

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 )

inherited

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

◆ setOneSided()

void ime::EdgeCollider::setOneSided	(	const Vector2f &	v0,
		const Vector2f &	v1,
		const Vector2f &	v2,
		const Vector2f &	v3
	)

Create a one sided collision edge.

Parameters

v0	A ghost vertex adjacent to the first edge vertex
v1	The first edge vertex
v2	The second edge vertex
v3	A ghost vertex adjacent to the second edge vertex

In many cases a game environment is constructed by connecting several edge shapes end-to-end. This can give rise to an unexpected artifact when a polygon slides along the chain of edges (ghost collisions). Ghost collisions occur when the polygon collides with an internal vertex generating an internal collision normal. This function provides a mechanism for eliminating ghost collisions by storing the adjacent ghost vertices (v0 and v3) and using them internally to prevent internal collisions that lead to ghost collision.

v1 and v2 are the edge vertices whilst v0 and v3 are the adjacent ghost vertices. The extra ghost vertices are used to provide smooth movement across junctions.

The edge normal points to the right looking from v1 to v2

See also: setTwoSided

◆ setRestitution()

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

inherited

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 )

inherited

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 )

inherited

Set whether or not the collider acts as a sensor.

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. However, sensors only form contacts when at least one body is dynamic, therefore, 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

tag	The alias of the object

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

By default, the tag is an empty string

See also: getObjectId

◆ setTwoSided()

void ime::EdgeCollider::setTwoSided	(	const Vector2f &	v1,
		const Vector2f &	v2
	)

Create a two sided collision edge.

Parameters

v1	The first edge vertex
v2	The second edge vertex

This function is more suited for edge colliders that are not chained to other edge colliders. If edge colliders are chained, ghost collision may occur when a polygon collider such as the BoxCollider slides across the chain. To counteract this effect, use the setOneSided function to construct the collider. However, if you don't care about ghost collisions, then this function is the preferred function to create an edge collider

The edge normal points to the right looking from v1 to v2.

See also: setOneSided

◆ suspendedEventListener()

void ime::Object::suspendedEventListener	(	int	id,
		bool	suspend
	)

inherited

Pause or resume execution of an event listener.

Parameters

id	The event listeners unique identification number
suspend	True to suspend/pause or false to unsuspend/resume

See also: isEventListenerSuspended

Member Data Documentation

◆ eventEmitter_

EventEmitter ime::Object::eventEmitter_

protectedinherited

Event dispatcher.

Definition at line 289 of file Object.h.

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

EdgeCollider.h

Public Types

Public Member Functions

Static Public Member Functions

Protected Member Functions

Protected Attributes

Detailed Description

Member Typedef Documentation

◆ CollisionCallback

◆ Ptr

Member Enumeration Documentation

◆ Type

Constructor & Destructor Documentation

◆ EdgeCollider() [1/2]

◆ EdgeCollider() [2/2]

◆ ~EdgeCollider()

Member Function Documentation

◆ clone()

◆ containsPoint()

◆ copy()

◆ create()

◆ emitChange()

◆ emitDestruction()

◆ getBody()

◆ getClassName()

◆ getClassType()

◆ getCollisionFilterData()

◆ getDensity()

◆ getEdgeVertices()

◆ getFirstVertex()

◆ getFriction()

◆ getGhostVertices()

◆ getObjectId()

◆ getRestitution()

◆ getRestitutionThreshold()

◆ getSecondVertex()

◆ getTag()

◆ getType()

◆ getUserData()

◆ isAttachedToBody()

◆ isEventListenerSuspended()

◆ isOneSided()

◆ isSameObjectAs()

◆ isSensor()

◆ onContactBegin()

◆ onContactEnd()

◆ onContactStay()

◆ onDestruction()

◆ onPropertyChange() [1/2]

◆ onPropertyChange() [2/2]

◆ operator=()

◆ removeEventListener() [1/2]

◆ removeEventListener() [2/2]

◆ resetCollisionFilterData()

◆ setCollisionFilter()

◆ setDensity()

◆ setEnable()

◆ setFriction()

◆ setOneSided()

◆ setRestitution()

◆ setRestitutionThreshold()

◆ setSensor()

◆ setTag()

◆ setTwoSided()

◆ suspendedEventListener()

Member Data Documentation

◆ eventEmitter_