#include <CUObstacle.h>

Inheritance diagram for cugl::physics2::Obstacle:

Public Member Functions
	Obstacle (void)

virtual	~Obstacle ()

virtual bool	init ()

virtual bool	init (const Vec2 vec)

virtual b2BodyType	getBodyType () const

virtual void	setBodyType (b2BodyType value)

virtual Vec2	getPosition () const

virtual void	setPosition (const Vec2 value)

virtual void	setPosition (float x, float y)

virtual float	getX () const

virtual void	setX (float value)

virtual float	getY () const

virtual void	setY (float value)

virtual float	getAngle () const

virtual void	setAngle (float value)

virtual Vec2	getLinearVelocity () const

virtual void	setLinearVelocity (const Vec2 value)

virtual void	setLinearVelocity (float x, float y)

virtual float	getVX () const

virtual void	setVX (float value)

virtual float	getVY () const

virtual void	setVY (float value)

virtual float	getAngularVelocity () const

virtual void	setAngularVelocity (float value)

virtual bool	isEnabled () const

virtual void	setEnabled (bool value)

virtual bool	isAwake () const

virtual void	setAwake (bool value)

virtual bool	isSleepingAllowed () const

virtual void	setSleepingAllowed (bool value)

virtual bool	isBullet () const

virtual void	setBullet (bool value)

virtual bool	isFixedRotation () const

virtual void	setFixedRotation (bool value)

virtual float	getGravityScale () const

virtual void	setGravityScale (float value)

virtual float	getLinearDamping () const

virtual void	setLinearDamping (float value)

virtual float	getAngularDamping () const

virtual void	setAngularDamping (float value)

void	setBodyState (const b2Body &body)

float	getDensity () const

virtual void	setDensity (float value)

float	getFriction () const

virtual void	setFriction (float value)

float	getRestitution () const

virtual void	setRestitution (float value)

bool	isSensor () const

virtual void	setSensor (bool value)

b2Filter	getFilterData () const

virtual void	setFilterData (b2Filter value)

virtual Vec2	getCentroid () const

virtual void	setCentroid (const Vec2 value)

virtual void	setCentroid (float x, float y)

virtual float	getInertia () const

virtual void	setInertia (float value)

virtual float	getMass () const

virtual void	setMass (float value)

virtual void	resetMass ()

bool	isRemoved () const

void	markRemoved (bool value)

bool	isDirty () const

void	markDirty (bool value)

void	setShared (bool shared)

bool	isShared () const

void	clearSharingDirtyBits ()

bool	hasDirtyType () const

bool	hasDirtyPosition () const

bool	hasDirtyVelocity () const

bool	hasDirtyAngle () const

bool	hasDirtyAngularVelocity () const

bool	hasDirtyBool () const

bool	hasDirtyFloat () const

virtual b2Body *	getBody ()

virtual bool	activatePhysics (b2World &world)

virtual void	deactivatePhysics (b2World &world)

virtual void	createFixtures ()

virtual void	releaseFixtures ()

virtual void	update (float delta)

const std::function< void(Obstacle *obstacle)> &	getListener () const

void	setListener (const std::function< void(Obstacle *obstacle)> &listener)

int	getPositionSnap ()

void	setPositionSnap (unsigned int snap)

int	getAngleSnap ()

void	setAngleSnap (unsigned int snap)

std::string	getName () const

void	setName (std::string value)

std::string	toString () const

Color4	getDebugColor () const

virtual void	setDebugColor (Color4 color)

scene2::SceneNode *	getDebugScene () const

scene2::WireNode *	getDebugNode () const

virtual void	setDebugScene (const std::shared_ptr< scene2::SceneNode > &node)

bool	hasDebug ()

Protected Member Functions
virtual void	resetDebug ()

virtual void	updateDebug ()

Protected Attributes
b2BodyDef	_bodyinfo

b2FixtureDef	_fixture

b2MassData	_massdata

bool	_masseffect

std::shared_ptr< scene2::SceneNode >	_scene

std::shared_ptr< scene2::WireNode >	_debug

Color4	_dcolor

std::string	_tag

std::function< void(Obstacle *obstacle)>	_listener

b2Body *	_body

int	_posSnap

unsigned long	_posFact

int	_angSnap

unsigned long	_angFact

bool	_shared

Friends
std::ostream &	operator<< (std::ostream &os, const Obstacle &obj)

Detailed Description

Base model class to support collisions.

Instances of this class represent a body. There should be NO game controlling logic code in a physics objects. That should reside in the Controllers.

This is an instance of a Physics object with just one body. It does not have any joints. It is the primary type of physics object. This class does not provide Shape information, and should not be instantiated directly.

In addition to combining body and fixture information, this class provides some basic primitives for synchronizing bodies between multiple physics worlds. See setShared.

Many of the method comments in this class are taken from the Box2d manual by Erin Catto (2011).

Constructor & Destructor Documentation

◆ Obstacle()

cugl::physics2::Obstacle::Obstacle ( void )

Creates a new physics object at the origin.

NEVER USE A CONSTRUCTOR WITH NEW. If you want to allocate an object on the heap, use one of the static constructors instead (in this case, in one of the subclasses).

◆ ~Obstacle()

virtual cugl::physics2::Obstacle::~Obstacle ( )

virtual

Deletes this physics object and all of its resources.

We have to make the destructor public so that we can polymorphically delete physics objects. Note that we do not allow an obstacle to be deleted while physics is still active. Doing so will result in an error.

A non-default destructor is necessary since we must release all claims on scene graph nodes.

Member Function Documentation

◆ activatePhysics()

virtual bool cugl::physics2::Obstacle::activatePhysics ( b2World & world )

virtual

Creates the physics Body(s) for this object, adding them to the world.

Implementations of this method should NOT retain ownership of the Box2D world. That is a tight coupling that we should avoid.

Parameters

world Box2D world to store body

Returns: true if object allocation succeeded

◆ clearSharingDirtyBits()

void cugl::physics2::Obstacle::clearSharingDirtyBits ( )

inline

Clears all of the bits tracking the shared state.

This is done after a physics object has been synchronized across the appropriate worlds.

◆ createFixtures()

virtual void cugl::physics2::Obstacle::createFixtures ( )

inlinevirtual

Create new fixtures for this body, defining the shape

This is the primary method to override for custom physics objects.

Reimplemented in cugl::physics2::BoxObstacle, cugl::physics2::CapsuleObstacle, cugl::physics2::PolygonObstacle, and cugl::physics2::WheelObstacle.

◆ deactivatePhysics()

virtual void cugl::physics2::Obstacle::deactivatePhysics ( b2World & world )

virtual

Destroys the physics Body(s) of this object if applicable.

This removes the body from the Box2D world.

Parameters

world Box2D world that stores body

◆ getAngle()

virtual float cugl::physics2::Obstacle::getAngle ( ) const

inlinevirtual

Returns the angle of rotation for this body (about the center).

The value returned is in radians

Returns: the angle of rotation for this body

◆ getAngleSnap()

int cugl::physics2::Obstacle::getAngleSnap ( )

inline

Returns the number of decimal places to snap rotation to the physics body

Physics bodies will have very precise angles, but these fractional angles may not be ideal for drawing, and may produce artifacts. When the value of snap is nonnegative, CUGL will round the rotation (measured in degrees, as that is the value used by images) of the image to snap decimal places.

For example, if the snap is 0, it will always round the angle to the nearest degree. If it is 1, it will round it to the nearest 10th of a degree. If it is -1 (or any negative value) it will not snap at all.

Returns: the number of decimal places to snap rotation to the physics body

◆ getAngularDamping()

virtual float cugl::physics2::Obstacle::getAngularDamping ( ) const

inlinevirtual

Returns the angular damping for this body.

Angular damping is use to reduce the angular velocity. Damping is different than friction because friction only occurs with contact. Damping is not a replacement for friction and the two effects should be used together.

Damping parameters should be between 0 and infinity, with 0 meaning no damping, and infinity meaning full damping. Normally you will use a damping value between 0 and 0.1.

Returns: the angular damping for this body.

◆ getAngularVelocity()

virtual float cugl::physics2::Obstacle::getAngularVelocity ( ) const

inlinevirtual

Returns the angular velocity for this physics body

The rate of change is measured in radians per step

Returns: the angular velocity for this physics body

◆ getBody()

virtual b2Body * cugl::physics2::Obstacle::getBody ( )

inlinevirtual

Returns a (weak) reference to Box2D body for this obstacle.

You use this body to add joints and apply forces. As a weak reference, this physics obstacle does not transfer ownership of this body. In addition, the value may be a nullptr.

Returns: a (weak) reference to Box2D body for this obstacle.

◆ getBodyType()

virtual b2BodyType cugl::physics2::Obstacle::getBodyType ( ) const

inlinevirtual

Returns the body type for Box2D physics

If you want to lock a body in place (e.g. a platform) set this value to STATIC. KINEMATIC allows the object to move (and some limited collisions), but ignores external forces (e.g. gravity). DYNAMIC makes this is a full-blown physics object.

Returns: the body type for Box2D physics

◆ getCentroid()

virtual Vec2 cugl::physics2::Obstacle::getCentroid ( ) const

inlinevirtual

Returns the center of mass of this body

This method converts from a Box2D vector type to a CUGL vector type. This cuts down on the confusion between vector types. It also means that changes to the returned vector will have no effect on this object.

Returns: the center of mass for this physics body

◆ getDebugColor()

Color4 cugl::physics2::Obstacle::getDebugColor ( ) const

inline

Returns the color of the debug wireframe.

The default color is white, which means that the objects will be shown with a white wireframe.

Returns: the color of the debug wireframe.

◆ getDebugNode()

scene2::WireNode * cugl::physics2::Obstacle::getDebugNode ( ) const

inline

Returns the scene graph node for the debug wireframe

The returned node draws a wireframe of the physics body. The wireframe consists of the physics fixtures adjusted by the drawing scale. The debug node is positioned in the coordinate space of the parent scene.

The wireframe will be drawn using physics coordinates, which is possibly much smaller than your drawing coordinates (e.g. 1 Box2D unit = 1 pixel). If you want the wireframes to be larger, you should scale the parent parent coordinate space to match the rest of the application.

This scene graph node is intended for debugging purposes only. If you want a physics body to update a proper texture image, you should either use the method update(float) for subclasses or setListener for decoupled classes.

Returns: the scene graph node for the debug wireframe

◆ getDebugScene()

scene2::SceneNode * cugl::physics2::Obstacle::getDebugScene ( ) const

inline

Returns the parent scene graph node for the debug wireframe

The returned node is the parent coordinate space for drawing physics. All debug nodes for physics objects are drawn within this coordinate space. Setting the visibility of this node to false will disable any debugging.

The wireframe will be drawn using physics coordinates, which is possibly much smaller than your drawing coordinates (e.g. 1 Box2D unit = 1 pixel). If you want the wireframes to be larger, you should scale the parent parent coordinate space to match the rest of the application.

This scene graph node is intended for debugging purposes only. If you want a physics body to update a proper texture image, you should either use the method update(float) for subclasses or setListener for decoupled classes.

Returns: the scene graph node for the debug wireframe

◆ getDensity()

float cugl::physics2::Obstacle::getDensity ( ) const

inline

Returns the density of this body

The density is typically measured in usually in kg/m^2. The density can be zero or positive. You should generally use similar densities for all your fixtures. This will improve stacking stability.

Returns: the density of this body

◆ getFilterData()

b2Filter cugl::physics2::Obstacle::getFilterData ( ) const

inline

Returns the filter data for this object (or null if there is none)

Collision filtering allows you to prevent collision between fixtures. For example, say you make a character that rides a bicycle. You want the bicycle to collide with the terrain and the character to collide with the terrain, but you don't want the character to collide with the bicycle (because they must overlap). Box2D supports such collision filtering using categories and groups.

Returns: the filter data for this object (or null if there is none)

◆ getFriction()

float cugl::physics2::Obstacle::getFriction ( ) const

inline

Returns the friction coefficient of this body

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. When the friction force is computed between two shapes, Box2D must combine the friction parameters of the two parent fixtures. This is done with the geometric mean.

Returns: the friction coefficient of this body

◆ getGravityScale()

virtual float cugl::physics2::Obstacle::getGravityScale ( ) const

inlinevirtual

Returns the gravity scale to apply to this body

This allows isolated objects to float. Be careful with this, since increased gravity can decrease stability.

Returns: the gravity scale to apply to this body

◆ getInertia()

virtual float cugl::physics2::Obstacle::getInertia ( ) const

inlinevirtual

Returns the rotational inertia of this body

For static bodies, the mass and rotational inertia are set to zero. When a body has fixed rotation, its rotational inertia is zero.

Returns: the rotational inertia of this body

◆ getLinearDamping()

virtual float cugl::physics2::Obstacle::getLinearDamping ( ) const

inlinevirtual

Returns the linear damping for this body.

Linear damping is use to reduce the linear velocity. Damping is different than friction because friction only occurs with contact. Damping is not a replacement for friction and the two effects should be used together.

Damping parameters should be between 0 and infinity, with 0 meaning no damping, and infinity meaning full damping. Normally you will use a damping value between 0 and 0.1. Most people avoid linear damping because it makes bodies look floaty.

Returns: the linear damping for this body.

◆ getLinearVelocity()

virtual Vec2 cugl::physics2::Obstacle::getLinearVelocity ( ) const

inlinevirtual

Returns the linear velocity for this physics body

This method converts from a Box2D vector type to a CUGL vector type. This cuts down on the confusion between vector types. It also means that changes to the returned vector will have no effect on this object.

Returns: the linear velocity for this physics body

◆ getListener()

const std::function< void(Obstacle *obstacle)> & cugl::physics2::Obstacle::getListener ( ) const

inline

Returns the active listener to this object.

Listeners are called after every physics update, to notify them of any changes in this object state. For performance reasons, a physics obstacle can have only one listener. If you need multiple objects listening to a single physics obstacle, the listener should handle the dispatch to other objects.

Returns: the active listener to this object.

◆ getMass()

virtual float cugl::physics2::Obstacle::getMass ( ) const

inlinevirtual

Returns the mass of this body

The value is usually in kilograms.

Returns: the mass of this body

◆ getName()

std::string cugl::physics2::Obstacle::getName ( ) const

inline

Returns the physics object tag.

A tag is a string attached to an object, in order to identify it in debugging.

Returns: the physics object tag.

◆ getPosition()

virtual Vec2 cugl::physics2::Obstacle::getPosition ( ) const

inlinevirtual

Returns the current position for this physics body

This method converts from a Box2D vector type to a CUGL vector type. This cuts down on the confusion between vector types. It also means that changes to the returned vector will have no effect on this obstacle.

Returns: the current position for this physics body

◆ getPositionSnap()

int cugl::physics2::Obstacle::getPositionSnap ( )

inline

Returns the number of decimal places to snap the node to the physics body

Physics bodies will have very precise positions, but these fractional positions may not be ideal for drawing, and may produce artifacts. When the value of snap is nonnegative, CUGL will round the position of the node to snap decimal places.

For example, if the snap is 0, it will always round position to the nearest integer. If it is 1, it will round it to the nearest 10th of a point. If it is -1 (or any negative value) it will not snap at all.

Returns: the number of decimal places to snap the node to the physics body

◆ getRestitution()

float cugl::physics2::Obstacle::getRestitution ( ) const

inline

Returns the restitution of this body

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.

Returns: the restitution of this body

◆ getVX()

virtual float cugl::physics2::Obstacle::getVX ( ) const

inlinevirtual

Returns the x-velocity for this physics body

Returns: the x-velocity for this physics body

◆ getVY()

virtual float cugl::physics2::Obstacle::getVY ( ) const

inlinevirtual

Returns the y-velocity for this physics body

Returns: the y-velocity for this physics body

◆ getX()

virtual float cugl::physics2::Obstacle::getX ( ) const

inlinevirtual

Returns the x-coordinate for this physics body

Returns: the x-coordinate for this physics body

◆ getY()

virtual float cugl::physics2::Obstacle::getY ( ) const

inlinevirtual

Returns the y-coordinate for this physics body

Returns: the y-coordinate for this physics body

◆ hasDebug()

bool cugl::physics2::Obstacle::hasDebug ( )

inline

Returns true if the obstacle has a wireframe for debugging.

This method will return false if there is no active parent scene for the wireframe.

Returns: true if the obstacle has a wireframe for debugging.

◆ hasDirtyAngle()

bool cugl::physics2::Obstacle::hasDirtyAngle ( ) const

inline

Returns true if the angle of this obstacle is dirty

This happens if the angle is modified outside of the physics simulation.

Returns: true if the angle of this obstacle is dirty

◆ hasDirtyAngularVelocity()

bool cugl::physics2::Obstacle::hasDirtyAngularVelocity ( ) const

inline

Returns true if the angular velocity of this obstacle is dirty

This happens if the angular velocity is modified outside of the physics simulation.

Returns: true if the angular velocity of this obstacle is dirty

◆ hasDirtyBool()

bool cugl::physics2::Obstacle::hasDirtyBool ( ) const

inline

Returns true if any boolean attribute of this obstacle is dirty

This happens if the attribute is modified outside of the physics simulation.

Returns: true if the boolean attribute of this obstacle is dirty

◆ hasDirtyFloat()

bool cugl::physics2::Obstacle::hasDirtyFloat ( ) const

inline

Returns true if any float attribute of this obstacle is dirty

This happens if the attribute is modified outside of the physics simulation.

Returns: true if the float attribute of this obstacle is dirty

◆ hasDirtyPosition()

bool cugl::physics2::Obstacle::hasDirtyPosition ( ) const

inline

Returns true if the positional data of this obstacle is dirty

This happens if the position is modified outside of the physics simulation.

Returns: true if the positional data of this obstacle is dirty

◆ hasDirtyType()

bool cugl::physics2::Obstacle::hasDirtyType ( ) const

inline

Returns true if the body type of this obstacle is dirty

This happens if the body type is modified outside of the physics simulation.

Returns: true if the body type of this obstacle is dirty

◆ hasDirtyVelocity()

bool cugl::physics2::Obstacle::hasDirtyVelocity ( ) const

inline

Returns true if the velocity data of this obstacle is dirty

This happens if the velocity is modified outside of the physics simulation.

Returns: true if the velocity data of this obstacle is dirty

◆ init() [1/2]

virtual bool cugl::physics2::Obstacle::init ( )

inlinevirtual

Initializes a new physics object at the origin.

Returns: true if the obstacle is initialized properly, false otherwise.

Reimplemented in cugl::physics2::PolygonObstacle, cugl::physics2::BoxObstacle, cugl::physics2::CapsuleObstacle, and cugl::physics2::WheelObstacle.

◆ init() [2/2]

virtual bool cugl::physics2::Obstacle::init ( const Vec2 vec )

virtual

Initializes a new physics object at the given point

Parameters

vec	Initial position in world coordinates

Returns: true if the obstacle is initialized properly, false otherwise.

Reimplemented in cugl::physics2::BoxObstacle, cugl::physics2::CapsuleObstacle, cugl::physics2::WheelObstacle, and cugl::physics2::PolygonObstacle.

◆ isAwake()

virtual bool cugl::physics2::Obstacle::isAwake ( ) const

inlinevirtual

Returns true if the body is awake

An sleeping body is one that has come to rest and the physics engine has decided to stop simulating it to save CPU cycles. If a body is awake and collides with a sleeping body, then the sleeping body wakes up. Bodies will also wake up if a joint or contact attached to them is destroyed.
You can also wake a body manually.

Returns: true if the body is awake

◆ isBullet()

virtual bool cugl::physics2::Obstacle::isBullet ( ) const

inlinevirtual

Returns true if this body is a bullet

By default, Box2D uses continuous collision detection (CCD) to prevent dynamic bodies from tunneling through static bodies. Normally CCD is not used between dynamic bodies. This is done to keep performance reasonable. In some game scenarios you need dynamic bodies to use CCD. For example, you may want to shoot a high speed bullet at a stack of dynamic bricks. Without CCD, the bullet might tunnel through the bricks.

Fast moving objects in Box2D can be labeled as bullets. Bullets will perform CCD with both static and dynamic bodies. You should decide what bodies should be bullets based on your game design.

Returns: true if this body is a bullet

◆ isDirty()

bool cugl::physics2::Obstacle::isDirty ( ) const

inline

Returns true if the shape information must be updated.

Attributes tied to the geometry (and not just forces/position) must wait for collisions to complete before they are reset. Shapes (and their properties) are reset in the update method.

Returns: true if the shape information must be updated.

◆ isEnabled()

virtual bool cugl::physics2::Obstacle::isEnabled ( ) const

inlinevirtual

Returns true if the body is enabled

A disabled body not participate in collision or dynamics. This state is similar to sleeping except the body will not be woken by other bodies and the body's fixtures will not be placed in the broad-phase. This means the body will not participate in collisions, ray casts, etc.

Returns: true if the body is enabled

◆ isFixedRotation()

virtual bool cugl::physics2::Obstacle::isFixedRotation ( ) const

inlinevirtual

Returns true if this body be prevented from rotating

This is very useful for characters that should remain upright.

Returns: true if this body be prevented from rotating

◆ isRemoved()

bool cugl::physics2::Obstacle::isRemoved ( ) const

inline

Returns true if our object has been flagged for garbage collection

A garbage collected object will be removed from the physics world at the next time step.

Returns: true if our object has been flagged for garbage collection

◆ isSensor()

bool cugl::physics2::Obstacle::isSensor ( ) const

inline

Returns true if this object is a sensor.

Sometimes game logic needs to know when two entities overlap yet there should be no collision response. This is done by using sensors. A sensor is an entity that detects collision but does not produce a response.

Returns: true if this object is a sensor.

◆ isShared()

bool cugl::physics2::Obstacle::isShared ( ) const

inline

Returns whether this object is shared across multiple physics worlds.

If true, this object will keep additional information about it's state changes. In particular, we track any change to a physics object that is not a result of the physics simulation itself.

Returns: whether this object is shared across multiple physics worlds.

◆ isSleepingAllowed()

virtual bool cugl::physics2::Obstacle::isSleepingAllowed ( ) const

inlinevirtual

Returns false if this body should never fall asleep

An sleeping body is one that has come to rest and the physics engine has decided to stop simulating it to save CPU cycles. If a body is awake and collides with a sleeping body, then the sleeping body wakes up. Bodies will also wake up if a joint or contact attached to them is destroyed. You can also wake a body manually.

Returns: false if this body should never fall asleep

◆ markDirty()

void cugl::physics2::Obstacle::markDirty ( bool value )

inline

Sets whether the shape information must be updated.

Attributes tied to the geometry (and not just forces/position) must wait for collisions to complete before they are reset. Shapes (and their properties) are reset in the update method.

Parameters

value whether the shape information must be updated.

◆ markRemoved()

void cugl::physics2::Obstacle::markRemoved ( bool value )

inline

Sets whether our object has been flagged for garbage collection

A garbage collected object will be removed from the physics world at the next time step.

Parameters

value whether our object has been flagged for garbage collection

◆ releaseFixtures()

virtual void cugl::physics2::Obstacle::releaseFixtures ( )

inlinevirtual

Release the fixtures for this body, reseting the shape

This is the primary method to override for custom physics objects.

Reimplemented in cugl::physics2::BoxObstacle, cugl::physics2::CapsuleObstacle, cugl::physics2::PolygonObstacle, and cugl::physics2::WheelObstacle.

◆ resetDebug()

virtual void cugl::physics2::Obstacle::resetDebug ( )

inlineprotectedvirtual

Creates the outline of the physics fixtures in the debug wireframe

The debug wireframe is use to outline the fixtures attached to this object. This is very useful when the fixtures have a very different shape than the texture (e.g. a circular shape attached to a square texture).

Reimplemented in cugl::physics2::BoxObstacle, cugl::physics2::CapsuleObstacle, cugl::physics2::PolygonObstacle, and cugl::physics2::WheelObstacle.

◆ resetMass()

virtual void cugl::physics2::Obstacle::resetMass ( )

inlinevirtual

Resets this body to use the mass computed from the its shape and density

◆ setAngle()

virtual void cugl::physics2::Obstacle::setAngle ( float value )

inlinevirtual

Sets the angle of rotation for this body (about the center).

Parameters

value the angle of rotation for this body (in radians)

◆ setAngleSnap()

void cugl::physics2::Obstacle::setAngleSnap ( unsigned int snap )

inline

Sets the number of decimal places to snap rotation to the physics body

Physics bodies will have very precise angles, but these fractional angles may not be ideal for drawing, and may produce artifacts. When the value of snap is nonnegative, CUGL will round the rotation (measured in degrees, as that is the value used by images) of the image to snap decimal places.

For example, if the snap is 0, it will always round the angle to the nearest degree. If it is 1, it will round it to the nearest 10th of a degree. If it is -1 (or any negative value) it will not snap at all.

Parameters

snap	the number of decimal places to snap rotation to the physics body

◆ setAngularDamping()

virtual void cugl::physics2::Obstacle::setAngularDamping ( float value )

inlinevirtual

Sets the angular damping for this body.

Angular damping is use to reduce the angular velocity. Damping is different than friction because friction only occurs with contact. Damping is not a replacement for friction and the two effects should be used together.

Damping parameters should be between 0 and infinity, with 0 meaning no damping, and infinity meaning full damping. Normally you will use a damping value between 0 and 0.1.

Parameters

value the angular damping for this body.

◆ setAngularVelocity()

virtual void cugl::physics2::Obstacle::setAngularVelocity ( float value )

inlinevirtual

Sets the angular velocity for this physics body

Parameters

value the angular velocity for this physics body (in radians)

◆ setAwake()

virtual void cugl::physics2::Obstacle::setAwake ( bool value )

inlinevirtual

Sets whether the body is awake

An sleeping body is one that has come to rest and the physics engine has decided to stop simulating it to save CPU cycles. If a body is awake and collides with a sleeping body, then the sleeping body wakes up. Bodies will also wake up if a joint or contact attached to them is destroyed. You can also wake a body manually.

Parameters

value whether the body is awake

◆ setBodyState()

void cugl::physics2::Obstacle::setBodyState ( const b2Body & body )

Copies the state from the given body to the body def.

This is important if you want to save the state of the body before removing it from the world.

◆ setBodyType()

virtual void cugl::physics2::Obstacle::setBodyType ( b2BodyType value )

inlinevirtual

Sets the body type for Box2D physics

If you want to lock a body in place (e.g. a platform) set this value to STATIC. KINEMATIC allows the object to move (and some limited collisions), but ignores external forces (e.g. gravity). DYNAMIC makes this is a full-blown physics object.

Parameters

value the body type for Box2D physics

◆ setBullet()

virtual void cugl::physics2::Obstacle::setBullet ( bool value )

inlinevirtual

Sets whether this body is a bullet

By default, Box2D uses continuous collision detection (CCD) to prevent dynamic bodies from tunneling through static bodies. Normally CCD is not used between dynamic bodies. This is done to keep performance reasonable. In some game scenarios you need dynamic bodies to use CCD. For example, you may want to shoot a high speed bullet at a stack of dynamic bricks. Without CCD, the bullet might tunnel through the bricks.

Fast moving objects in Box2D can be labeled as bullets. Bullets will perform CCD with both static and dynamic bodies. You should decide what bodies should be bullets based on your game design.

Parameters

value whether this body is a bullet

◆ setCentroid() [1/2]

virtual void cugl::physics2::Obstacle::setCentroid ( const Vec2 value )

inlinevirtual

Sets the center of mass for this physics body

This method converts from a CUGL vector type to a Box2D vector type. This cuts down on the confusion between vector types.

Parameters

value the center of mass for this physics body

◆ setCentroid() [2/2]

virtual void cugl::physics2::Obstacle::setCentroid	(	float	x,
		float	y
	)

virtual

Sets the center of mass for this physics body

Parameters

x	the x-coordinate of the center of mass for this physics body
y	the y-coordinate of the center of mass for this physics body

◆ setDebugColor()

virtual void cugl::physics2::Obstacle::setDebugColor ( Color4 color )

virtual

Sets the color of the debug wireframe.

The default color is white, which means that the objects will be shown with a white wireframe.

Parameters

color the color of the debug wireframe.

◆ setDebugScene()

virtual void cugl::physics2::Obstacle::setDebugScene ( const std::shared_ptr< scene2::SceneNode > & node )

virtual

Sets the parent scene graph node for the debug wireframe

The given node is the parent coordinate space for drawing physics. All debug nodes for physics objects are drawn within this coordinate space. Setting the visibility of this node to false will disable any debugging. Similarly, setting this value to nullptr will disable any debugging.

The wireframe will be drawn using physics coordinates, which is possibly much smaller than your drawing coordinates (e.g. 1 Box2D unit = 1 pixel). If you want the wireframes to be larger, you should scale the parent parent coordinate space to match the rest of the application.

This scene graph node is intended for debugging purposes only. If you want a physics body to update a proper texture image, you should either use the method update(float) for subclasses or setListener for decoupled classes.

Parameters

node	he parent scene graph node for the debug wireframe

◆ setDensity()

virtual void cugl::physics2::Obstacle::setDensity ( float value )

virtual

Sets the density of this body

The density is typically measured in usually in kg/m^2. The density can be zero or positive. You should generally use similar densities for all your fixtures. This will improve stacking stability.

Parameters

value the density of this body

Reimplemented in cugl::physics2::CapsuleObstacle.

◆ setEnabled()

virtual void cugl::physics2::Obstacle::setEnabled ( bool value )

inlinevirtual

Sets whether the body is enabled

A disabled body not participate in collision or dynamics. This state is similar to sleeping except the body will not be woken by other bodies and the body's fixtures will not be placed in the broad-phase. This means the body will not participate in collisions, ray casts, etc.

Parameters

value whether the body is enabled

◆ setFilterData()

virtual void cugl::physics2::Obstacle::setFilterData ( b2Filter value )

virtual

Sets the filter data for this object

Collision filtering allows you to prevent collision between fixtures. For example, say you make a character that rides a bicycle. You want the bicycle to collide with the terrain and the character to collide with the terrain, but you don't want the character to collide with the bicycle (because they must overlap). Box2D supports such collision filtering using categories and groups.

A value of null removes all collision filters.

Parameters

value the filter data for this object

◆ setFixedRotation()

virtual void cugl::physics2::Obstacle::setFixedRotation ( bool value )

inlinevirtual

Sets whether this body be prevented from rotating

This is very useful for characters that should remain upright.

Parameters

value whether this body be prevented from rotating

◆ setFriction()

virtual void cugl::physics2::Obstacle::setFriction ( float value )

virtual

Sets the friction coefficient of this body

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. When the friction force is computed between two shapes, Box2D must combine the friction parameters of the two parent fixtures. This is done with the geometric mean.

Parameters

value the friction coefficient of this body

◆ setGravityScale()

virtual void cugl::physics2::Obstacle::setGravityScale ( float value )

inlinevirtual

Sets the gravity scale to apply to this body

This allows isolated objects to float. Be careful with this, since increased gravity can decrease stability.

Parameters

value the gravity scale to apply to this body

◆ setInertia()

virtual void cugl::physics2::Obstacle::setInertia ( float value )

virtual

Sets the rotational inertia of this body

For static bodies, the mass and rotational inertia are set to zero. When a body has fixed rotation, its rotational inertia is zero.

Parameters

value the rotational inertia of this body

◆ setLinearDamping()

virtual void cugl::physics2::Obstacle::setLinearDamping ( float value )

inlinevirtual

Sets the linear damping for this body.

Linear damping is use to reduce the linear velocity. Damping is different than friction because friction only occurs with contact. Damping is not a replacement for friction and the two effects should be used together.

Damping parameters should be between 0 and infinity, with 0 meaning no damping, and infinity meaning full damping. Normally you will use a damping value between 0 and 0.1. Most people avoid linear damping because it makes bodies look floaty.

Parameters

value the linear damping for this body.

◆ setLinearVelocity() [1/2]

virtual void cugl::physics2::Obstacle::setLinearVelocity ( const Vec2 value )

inlinevirtual

Sets the linear velocity for this physics body

This method converts from a CUGL vector type to a Box2D vector type. This cuts down on the confusion between vector types.

Parameters

value the linear velocity for this physics body

◆ setLinearVelocity() [2/2]

virtual void cugl::physics2::Obstacle::setLinearVelocity	(	float	x,
		float	y
	)

inlinevirtual

Sets the linear velocity for this physics body

Parameters

x	the x-coordinate of the linear velocity
y	the y-coordinate of the linear velocity

◆ setListener()

void cugl::physics2::Obstacle::setListener ( const std::function< void(Obstacle *obstacle)> & listener )

inline

Sets the active listener to this object.

Listeners are called after every physics update, to notify them of any changes in this object state. For performance reasons, a physics obstacle can have only one listener. If you need multiple objects listening to a single physics obstacle, the listener should handle the dispatch to other objects.

Parameters

listener the active listener to this object.

◆ setMass()

virtual void cugl::physics2::Obstacle::setMass ( float value )

virtual

Sets the mass of this body

The value is usually in kilograms.

Parameters

value the mass of this body

◆ setName()

void cugl::physics2::Obstacle::setName ( std::string value )

inline

Sets the physics object tag.

A tag is a string attached to an object, in order to identify it in debugging.

Parameters

value the physics object tag

◆ setPosition() [1/2]

virtual void cugl::physics2::Obstacle::setPosition ( const Vec2 value )

inlinevirtual

Sets the current position for this physics body

This method converts from a CUGL vector type to a Box2D vector type. This cuts down on the confusion between vector types.

Parameters

value the current position for this physics body

◆ setPosition() [2/2]

virtual void cugl::physics2::Obstacle::setPosition	(	float	x,
		float	y
	)

inlinevirtual

Sets the current position for this physics body

Parameters

x	the current x-coordinate for this physics body
y	the current y-coordinate for this physics body

◆ setPositionSnap()

void cugl::physics2::Obstacle::setPositionSnap ( unsigned int snap )

inline

Sets the number of decimal places to snap the node to the physics body

Physics bodies will have very precise positions, but these fractional positions may not be ideal for drawing, and may produce artifacts. When the value of snap is nonnegative, CUGL will round the position of the node to snap decimal places.

For example, if the snap is 0, it will always round position to the nearest integer. If it is 1, it will round it to the nearest 10th of a point. If it is -1 (or any negative value) it will not snap at all.

Parameters

snap	the number of decimal places to snap the node to the physics body

◆ setRestitution()

virtual void cugl::physics2::Obstacle::setRestitution ( float value )

virtual

Sets the restitution of this body

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.

Parameters

value the restitution of this body

◆ setSensor()

virtual void cugl::physics2::Obstacle::setSensor ( bool value )

virtual

Sets whether this object is a sensor.

Sometimes game logic needs to know when two entities overlap yet there should be no collision response. This is done by using sensors. A sensor is an entity that detects collision but does not produce a response.

Parameters

value whether this object is a sensor.

◆ setShared()

void cugl::physics2::Obstacle::setShared ( bool shared )

inline

Sets whether this object is shared across multiple physics worlds.

If true, this object will keep additional information about it's state changes. In particular, we track any change to a physics object that is not a result of the physics simulation itself.

Parameters

shared Whether this object is shared across multiple worlds.

◆ setSleepingAllowed()

virtual void cugl::physics2::Obstacle::setSleepingAllowed ( bool value )

inlinevirtual

Sets whether the body should ever fall asleep

An sleeping body is one that has come to rest and the physics engine has decided to stop simulating it to save CPU cycles. If a body is awake and collides with a sleeping body, then the sleeping body wakes up. Bodies will also wake up if a joint or contact attached to them is destroyed. You can also wake a body manually.

Parameters

value whether the body should ever fall asleep

◆ setVX()

virtual void cugl::physics2::Obstacle::setVX ( float value )

inlinevirtual

Sets the x-velocity for this physics body

Parameters

value the x-velocity for this physics body

◆ setVY()

virtual void cugl::physics2::Obstacle::setVY ( float value )

inlinevirtual

Sets the y-velocity for this physics body

Parameters

value the y-velocity for this physics body

◆ setX()

virtual void cugl::physics2::Obstacle::setX ( float value )

inlinevirtual

Sets the x-coordinate for this physics body

Parameters

value the x-coordinate for this physics body

◆ setY()

virtual void cugl::physics2::Obstacle::setY ( float value )

inlinevirtual

Sets the y-coordinate for this physics body

Parameters

value the y-coordinate for this physics body

◆ toString()

std::string cugl::physics2::Obstacle::toString ( ) const

Returns a string representation of this physics object.

This method converts the physics object into a string for debugging. By default it shows the tag and position. Other physics objects may want to override this method for more detailed information.

Returns: a string representation of this physics object

◆ update()

virtual void cugl::physics2::Obstacle::update ( float delta )

inlinevirtual

Updates the object's physics state (NOT GAME LOGIC).

This method is called AFTER the collision resolution state. Therefore, it should not be used to process actions or any other gameplay information.
Its primary purpose is to adjust changes to the fixture, which have to take place after collision.

In other words, this is the method that updates the scene graph. If you forget to call it, it will not draw your changes.

Parameters

delta Timing values from parent loop

◆ updateDebug()

virtual void cugl::physics2::Obstacle::updateDebug ( )

protectedvirtual

Repositions the debug wireframe so that it agrees with the physics object.

The debug wireframe is use to outline the fixtures attached to this object. This is very useful when the fixtures have a very different shape than the texture (e.g. a circular shape attached to a square texture).

Friends And Related Symbol Documentation

◆ operator<<

std::ostream & operator<<	(	std::ostream &	os,
		const Obstacle &	obj
	)

friend

Outputs this physics object to the given output stream.

This function uses the toString() method to convert the physics object into a string

Parameters

os	the output stream
obj	the physics object to ouput

Returns: the output stream

Member Data Documentation

◆ _angFact

unsigned long cugl::physics2::Obstacle::_angFact

protected

Cache of factor to snap rotation of image to physics body

◆ _angSnap

int cugl::physics2::Obstacle::_angSnap

protected

Number of decimal places to snap rotation of image to physics body

◆ _body

b2Body* cugl::physics2::Obstacle::_body

protected

The physics body for Box2D.

◆ _bodyinfo

b2BodyDef cugl::physics2::Obstacle::_bodyinfo

protected

Stores the body information for this shape

◆ _dcolor

Color4 cugl::physics2::Obstacle::_dcolor

protected

The wireframe color for debugging

◆ _debug

std::shared_ptr<scene2::WireNode> cugl::physics2::Obstacle::_debug

protected

The wireframe node for debugging.

◆ _fixture

b2FixtureDef cugl::physics2::Obstacle::_fixture

protected

Stores the fixture information for this shape

◆ _listener

std::function<void(Obstacle* obstacle)> cugl::physics2::Obstacle::_listener

protected

(Singular) callback function for state updates

◆ _massdata

b2MassData cugl::physics2::Obstacle::_massdata

protected

The mass data of this shape (which may override the fixture)

◆ _masseffect

bool cugl::physics2::Obstacle::_masseffect

protected

Whether or not to use the custom mass data

◆ _posFact

unsigned long cugl::physics2::Obstacle::_posFact

protected

Cache of factor to snap position of image to physics body

◆ _posSnap

int cugl::physics2::Obstacle::_posSnap

protected

Number of decimal places to snap position of image to physics body

◆ _scene

std::shared_ptr<scene2::SceneNode> cugl::physics2::Obstacle::_scene

protected

The wireframe parent for debugging.

◆ _shared

bool cugl::physics2::Obstacle::_shared

protected

Whether or not this obstacle is shared across multiple obstacle worlds

◆ _tag

std::string cugl::physics2::Obstacle::_tag

protected

A tag for debugging purposes

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

/Users/wmwhite/Developer/CUGL/include/cugl/physics2/CUObstacle.h

Public Member Functions

Protected Member Functions

Protected Attributes

Friends

Detailed Description

Constructor & Destructor Documentation

◆ Obstacle()

◆ ~Obstacle()

Member Function Documentation

◆ activatePhysics()

◆ clearSharingDirtyBits()

◆ createFixtures()

◆ deactivatePhysics()

◆ getAngle()

◆ getAngleSnap()

◆ getAngularDamping()

◆ getAngularVelocity()

◆ getBody()

◆ getBodyType()

◆ getCentroid()

◆ getDebugColor()

◆ getDebugNode()

◆ getDebugScene()

◆ getDensity()

◆ getFilterData()

◆ getFriction()

◆ getGravityScale()

◆ getInertia()

◆ getLinearDamping()

◆ getLinearVelocity()

◆ getListener()

◆ getMass()

◆ getName()

◆ getPosition()

◆ getPositionSnap()

◆ getRestitution()

◆ getVX()

◆ getVY()

◆ getX()

◆ getY()

◆ hasDebug()

◆ hasDirtyAngle()

◆ hasDirtyAngularVelocity()

◆ hasDirtyBool()

◆ hasDirtyFloat()

◆ hasDirtyPosition()

◆ hasDirtyType()

◆ hasDirtyVelocity()

◆ init() [1/2]

◆ init() [2/2]

◆ isAwake()

◆ isBullet()

◆ isDirty()

◆ isEnabled()

◆ isFixedRotation()

◆ isRemoved()

◆ isSensor()

◆ isShared()

◆ isSleepingAllowed()

◆ markDirty()

◆ markRemoved()

◆ releaseFixtures()

◆ resetDebug()

◆ resetMass()

◆ setAngle()

◆ setAngleSnap()

◆ setAngularDamping()

◆ setAngularVelocity()

◆ setAwake()

◆ setBodyState()

◆ setBodyType()

◆ setBullet()

◆ setCentroid() [1/2]

◆ setCentroid() [2/2]

◆ setDebugColor()

◆ setDebugScene()

◆ setDensity()

◆ setEnabled()

◆ setFilterData()

◆ setFixedRotation()