Colliding Shapes
Ian Parberry's "Introduction to Game Physics"
Public Member Functions | Private Member Functions | Private Attributes | List of all members
CDynamicCircle Class Reference

Dynamic circle. More...

#include <DynamicCircle.h>

Inheritance diagram for CDynamicCircle:
CCircle CShape CShapeCommon

Public Member Functions

 CDynamicCircle (const CDynamicCircleDesc &)
 Constructor. More...
 
void move ()
 Move using Euler integration. More...
 
bool AABBCollide (CDynamicCircle *)
 Collide detection using AABBs. More...
 
void PostCollide (const CContactDesc &)
 Collision response. More...
 
Vector2 GetVel ()
 Get velocity. More...
 
void SetVel (const Vector2 &)
 Set velocity. More...
 
- Public Member Functions inherited from CCircle
 CCircle (const CCircleDesc &)
 Constructor. More...
 
bool PreCollide (CContactDesc &)
 Collision detection. More...
 
bool PtInCircle (const Vector2 &)
 Point in circle test. More...
 
Vector2 ClosestPt (const Vector2 &)
 Closest point on circle. More...
 
bool Tangents (const Vector2 &, Vector2 &, Vector2 &)
 Tangents through external point. More...
 
bool Tangents (CCircle *, CLineSegDesc &, CLineSegDesc &)
 Common tangents. More...
 
bool Tangent (CCircle *, CLineSegDesc &)
 Common tangent. More...
 
float GetRadius ()
 Get radius. More...
 
- Public Member Functions inherited from CShape
 CShape (const CShapeDesc &)
 Constructor. More...
 
virtual ~CShape ()
 Destructor. More...
 
const eShape GetShapeType () const
 Get shape type. More...
 
const eMotion GetMotionType () const
 Get motion type. More...
 
const CAabb2DGetAABB () const
 Get AABB. More...
 
const bool GetSensor () const
 Is this shape a sensor? More...
 
const Vector2 & GetPos () const
 Get position. More...
 
void SetPos (const Vector2 &)
 Set position. More...
 
void SetAABBPoint (const Vector2 &)
 Set AABB point. More...
 
void AddAABBPoint (const Vector2 &)
 Add AABB point. More...
 
void SetCanCollide (bool=true)
 Turn collisions on or off. More...
 
const bool GetCanCollide () const
 Get whether shape can collide. More...
 
virtual void Rotate (const Vector2 &, float)
 Rotate. More...
 
virtual void Reset ()
 Reset orientation. More...
 
const bool GetRotating () const
 Get whether rotating. More...
 
void SetRotating (bool)
 Start or stop rotating. More...
 
const float GetOrientation () const
 Get orientation. More...
 
const float GetRotSpeed () const
 Get rotation speed. More...
 
const Vector2 & GetRotCenter () const
 Get rotation speed. More...
 
const float GetElasticity () const
 Get elasticity. More...
 
void SetOrientation (float)
 Set orientation. More...
 
void SetRotSpeed (float)
 Set rotation speed. More...
 
void SetRotCenter (const Vector2 &)
 Set center of rotation. More...
 
void * GetUserPtr () const
 Get user pointer. More...
 
void SetUserPtr (void *)
 Set user pointer. More...
 

Private Member Functions

void PostCollideStatic (const CContactDesc &)
 Collision response for static shape. More...
 
void PostCollideKinematic (const CContactDesc &)
 Collision response for kinematic shape. More...
 
void PostCollideDynamic (const CContactDesc &)
 Collision response for dynamic shape. More...
 

Private Attributes

Vector2 m_vVel
 Velocity. Speed is measured in pixels per second.
 
float m_fMass = 0.0f
 Mass.
 

Additional Inherited Members

- Protected Attributes inherited from CCircle
float m_fRadius = 0.0f
 Radius.
 
float m_fRadiusSq = 0.0f
 Radius squared, used for faster distance calculations.
 
- Protected Attributes inherited from CShape
eShape m_eShapeType = eShape::Unknown
 Type of shape.
 
eMotion m_eMotionType = eMotion::Static
 How shape moves.
 
float m_fElasticity = 1.0f
 Elasticity, aka restitution, bounciness.
 
bool m_bIsSensor = false
 Sensor only, no rebound on collision.
 
CAabb2D m_cAABB
 Axially aligned bounding box in World Space.
 
bool m_bCanCollide = true
 Can collide with other shapes.
 
float m_fOrientation = 0.0f
 Orientation angle.
 
void * m_pUser
 Spare pointer for user in case they might need one.
 
Vector2 m_vRotCenter
 Center of rotation.
 
float m_fRotSpeed = 0.0f
 Rotation speed.
 
bool m_bRotating = false
 Whether rotating.
 
- Static Protected Attributes inherited from CShapeCommon
static float m_fGravity = 0.0f
 Gravitational constant.
 
static float m_fTimeStep = 0.0f
 Time step per animation frame (fictional).
 

Detailed Description

A dynamic circle is a circle shape that moves and can collide with static, kinematic, and dynamic shapes.

Constructor & Destructor Documentation

◆ CDynamicCircle()

CDynamicCircle::CDynamicCircle ( const CDynamicCircleDesc r)

Constructs a dynamic circle described by a dynamic circle descriptor.

Parameters
rDynamic circle descriptor.

Member Function Documentation

◆ AABBCollide()

bool CDynamicCircle::AABBCollide ( CDynamicCircle pCirc)

Does the AABB for this dynamic circle overlap the AABB for another dynamic circle?

Parameters
pCircPointer to a dynamic circle.
Returns
true if their AABBs overlap.

◆ GetVel()

Vector2 CDynamicCircle::GetVel ( )

Reader function for the velocity.

Returns
The velocity.

◆ move()

void CDynamicCircle::move ( )
virtual

Move the shape using Euler integration, depending on the physics time step and the gravity constant.

Reimplemented from CShape.

◆ PostCollide()

void CDynamicCircle::PostCollide ( const CContactDesc cd)

Collision response for a dynamic circle colliding with a shape.

Parameters
cdContact descriptor which has been filled in by collision detection.

◆ PostCollideDynamic()

void CDynamicCircle::PostCollideDynamic ( const CContactDesc cd)
private

Collision response for a dynamic circle colliding with a dynamic shape.

Parameters
cdContact descriptor which has been filled in by collision detection.

◆ PostCollideKinematic()

void CDynamicCircle::PostCollideKinematic ( const CContactDesc cd)
private

Collision response for a dynamic circle colliding with a kinematic shape. This circle's velocity is affected by the kinematic shape's rotation. This code assumes that all elasticities are less than unity.

Parameters
cdContact descriptor that has been filled in by collision detection.

◆ PostCollideStatic()

void CDynamicCircle::PostCollideStatic ( const CContactDesc cd)
private

Collision response for a dynamic circle colliding with a static shape.

Parameters
cdContact descriptor which has been filled in by collision detection.

◆ SetVel()

void CDynamicCircle::SetVel ( const Vector2 &  v)

Set the velocity to a new value.

Parameters
vNew velocity.