/*
* Copyright (c) 2006-2009 Erin Catto http://www.gphysics.com
*
* This software is provided 'as-is', without any express or implied
* warranty. In no event will the authors be held liable for any damages
* arising from the use of this software.
* Permission is granted to anyone to use this software for any purpose,
* including commercial applications, and to alter it and redistribute it
* freely, subject to the following restrictions:
* 1. The origin of this software must not be misrepresented; you must not
* claim that you wrote the original software. If you use this software
* in a product, an acknowledgment in the product documentation would be
* appreciated but is not required.
* 2. Altered source versions must be plainly marked as such, and must not be
* misrepresented as being the original software.
* 3. This notice may not be removed or altered from any source distribution.
*/
#ifndef B2_BODY_H
#define B2_BODY_H
#include <Box2D/Common/b2Math.h>
#include <Box2D/Collision/Shapes/b2Shape.h>
#include <memory>
class b2Fixture;
class b2Joint;
class b2Contact;
class b2Controller;
class b2World;
struct b2FixtureDef;
struct b2JointEdge;
struct b2ContactEdge;
/// The body type.
/// static: zero mass, zero velocity, may be manually moved
/// kinematic: zero mass, non-zero velocity set by user, moved by solver
/// dynamic: positive mass, non-zero velocity determined by forces, moved by solver
enum b2BodyType
{
b2_staticBody = 0,
b2_kinematicBody,
b2_dynamicBody,
};
/// A body definition holds all the data needed to construct a rigid body.
/// You can safely re-use body definitions. Shapes are added to a body after construction.
struct b2BodyDef
{
/// This constructor sets the body definition default values.
b2BodyDef()
{
userData = NULL;
position.Set(0.0f, 0.0f);
angle = 0.0f;
linearVelocity.Set(0.0f, 0.0f);
angularVelocity = 0.0f;
linearDamping = 0.0f;
angularDamping = 0.0f;
allowSleep = true;
awake = true;
fixedRotation = false;
bullet = false;
type = b2_staticBody;
active = true;
inertiaScale = 1.0f;
}
/// The body type: static, kinematic, or dynamic.
/// Note: if a dynamic body would have zero mass, the mass is set to one.
b2BodyType type;
/// The world position of the body. Avoid creating bodies at the origin
/// since this can lead to many overlapping shapes.
b2Vec2 position;
/// The world angle of the body in radians.
float32 angle;
/// The linear velocity of the body's origin in world co-ordinates.
b2Vec2 linearVelocity;
/// The angular velocity of the body.
float32 angularVelocity;
/// Linear damping is use to reduce the linear velocity. The damping parameter
/// can be larger than 1.0f but the damping effect becomes sensitive to the
/// time step when the damping parameter is large.
float32 linearDamping;
/// Angular damping is use to reduce the angular velocity. The damping parameter
/// can be larger than 1.0f but the damping effect becomes sensitive to the
/// time step when the damping parameter is large.
float32 angularDamping;
/// Set this flag to false if this body should never fall asleep. Note that
/// this increases CPU usage.
bool allowSleep;
/// Is this body initially awake or sleeping?
bool awake;
/// Should this body be prevented from rotating? Useful for characters.
bool fixedRotation;
/// Is this a fast moving body that should be prevented from tunneling through
/// other moving bodies? Note that all bodies are prevented from tunneling through
/// kinematic and static bodies. This setting is only considered on dynamic bodies.
/// @warning You should use this flag sparingly since it increases processing time.
bool bullet;
/// Does this body start out active?
bool active;
/// Use this to store application specific body data.
void* userData;
/// Experimental: scales the inertia tensor.
float32 inertiaScale;
};
/// A rigid body. These are created via b2World::CreateBody.
class b2Body
{
public:
/// Creates a fixture and attach it to this body. Use this function if you need
/// to set some fixture parameters, like friction. Otherwise you can create the
/// fixture directly from a shape.
/// If the density is non-zero, this function automatically updates the mass of the body.
/// Contacts are not created until the next time step.
/// @param def the fixture definition.
/// @warning This function is locked during callbacks.
b2Fixture* CreateFixture(const b2FixtureDef* def);
/// Creates a fixture from a shape and attach it to this body.
/// This is a convenience function. Use b2FixtureDef if you need to set parameters
/// like friction, restitution, user data, or filtering.
/// If the density is non-zero, this function automatically updates the mass of the body.
/// @param shape the shape to be cloned.
/// @param density the shape density (set to zero for static bodies).
/// @warning This function is locked during callbacks.
b2Fixture* CreateFixture(const b2Shape* shape, float32 density);
/// Destroy a fixture. This removes the fixture from the broad-phase and
/// destroys all contacts associated with this fixture. This will
/// automatically adjust the mass of the body if the body is dynamic and the
/// fixture has positive density.
/// All fixtures attached to a body are implicitly destroyed when the body is destroyed.
/// @param fixture the fixture to be removed.
/// @warning This function is locked during callbacks.
void DestroyFixture(b2Fixture* fixture);
/// Set the position of the body's origin and rotation.
/// This breaks any contacts and wakes the other bodies.
/// Manipulating a body's transform may cause non-physical behavior.
/// @param position the world position of the body's local origin.
/// @param angle the world rotation in radians.
void SetTransform(const b2Vec2& position, float32 angle);
/// Get the body transform for the body's origin.
/// @return the world transform of the body's origin.
const b2Transform& GetTransform() const;
/// Get the world body origin position.
/// @return the world position of the body's origin.
const b2Vec2& GetPosition() const;
/// Get the angle in radians.
/// @return the current world rotation angle in radians.
float32 GetAngle() const;
/// Get the world position of the center of mass.
const b2Vec2& GetWorldCenter() const;
/// Get the local position of the center of mass.
const b2Vec2& GetLocalCenter() const;
/// Set the linear velocity of the center of mass.
/// @param v the new linear velocity of the center of mass.
void SetLinearVelocity(const b2Vec2& v);
/// Get the linear velocity of the center of mass.
/// @return the linear velocity of the center of mass.
b2Vec2 GetLinearVelocity() const;
/// Set the angular velocity.
/// @param omega the new angular velocity in radians/second.
void SetAngularVelocity(float32 omega);
/// Get the angular velocity.
/// @return the angular velocity in radians/second.
float32 GetAngularVelocity() const;
/// Apply a force at a world point. If the force is not
/// applied at the center of mass, it will generate a torque and
/// affect the angular velocity. This wakes up the body.
/// @param force the world force vector, usually in Newtons (N).
/// @param point the world position of the point of application.
void ApplyForce(const b2Vec2& force, const b2Vec2& point);
/// Apply a torque. This affects the angular velocity
/// without affecting the linear velocity of the center of mass.
/// This wakes up the body.
/// @param torque about the z-axis (out of the screen), usually in N-m.
void ApplyTorque(float32 torque);
/// Apply an impulse at a point. This immediately modifies the velocity.
/// It also modifies the angular velocity if the point of application
/// is not at the center of mass. This wakes up the body.
/// @param impulse the world impulse vector, usually in N-seconds or kg-m/s.
/// @param point the world position of the point of application.
void ApplyLinearImpulse(const b2Vec2& impulse, const b2Vec2& point);
/// Apply an angular impulse.
/// @param impulse the angular impulse in units of kg*m*m/s
void ApplyAngularImpulse(float32 impulse);
/// Get the total mass of the body.
/// @return the mass, usually in kilograms (kg).
float32 GetMass() const;
/// Get the rotational inertia of the body about the local origin.
/// @return the rotational inertia, usually in kg-m^2.
float32 GetInertia() const;
/// Get the mass data of the body.
/// @return a struct containing the mass, inertia and center of the body.
void GetMassData(b2MassData* data) const;
/// Set the mass properties to override the mass properties of the fixtures.
/// Note that this changes the center of mass position.
/// Note that creating or destroying fixtures can also alter the mass.
/// This function has no effect if the body isn't dynamic.
/// @param massData the mass properties.
void SetMassData(const b2MassData* data);
/// This resets the mass properties to the sum of the mass properties of the fixtures.
/// This normally does not need to be called unless you called SetMassData to override
/// the mass and you later want to reset the mass.
void ResetMassData();
/// Get the world coordinates of a point given the local coordinates.
/// @param localPoint a point on the body measured relative the the body's origin.
/// @return the same point expressed in world coordinates.
b2Vec2 GetWorldPoint(const b2Vec2& localPoint) const;
/// Get the world coordinates of a vector given the local coordinates.
/// @param localVector a vector fixed in the body.
/// @return the same vector expressed in world coordinates.
b2Vec2 GetWorldVector(const b2Vec2& localVector) const;
/// Gets a local point relative to the body's origin given a world point.
/// @param a point in world coordinates.
/// @return the corresponding local point relative to the body's origin.
b2Vec2 GetLocalPoint(const b2Vec2& worldPoint) const;
/// Gets a local vector given a world vector.
/// @param a vector in world coordinates.
/// @return the corresponding local vector.
b2Vec2 GetLocalVector(const b2Vec2& worldVector) const;
/// Get the world linear velocity of a world point attached to this body.
/// @param a point in world coordinates.
/// @return the world velocity of a point.
b2Vec2 GetLinearVelocityFromWorldPoint(const b2Vec2& worldPoint) const;
/// Get the world velocity of a local point.
/// @param a point in local coordinates.
/// @return the world velocity of a point.
b2Vec2 GetLinearVelocityFromLocalPoint(const b2Vec2& localPoint) const;
/// Get the linear damping of the body.
float32 GetLinearDamping() const;
/// Set the linear damping of the body.
void SetLinearDamping(float32 linearDamping);
/// Get the angular damping of the body.
float32 GetAngularDamping() const;
/// Set the angular damping of the body.
void SetAngularDamping(float32 angularDamping);
/// Set the type of this body. This may alter the mass and velocity.
void SetType(b2BodyType type);
/// Get the type of this body.
b2BodyType GetType() const;
/// Should this body be treated like a bullet for continuous collision detection?
void SetBullet(bool flag);
/// Is this body treated like a bullet for continuous collision detection?
bool IsBullet() const;
/// You can disable sleeping on this body. If you disable sleeping, the
/// body will be woken.
void SetSleepingAllowed(bool flag);
/// Is this body allowed to sleep
bool IsSleepingAllowed() const;
/// Set the sleep state of the body. A sleeping body has very
/// low CPU cost.
/// @param flag set to true to put body to sleep, false to wake it.
void SetAwake(bool flag);
/// Get the sleeping state of this body.
/// @return true if the body is sleeping.
bool IsAwake() const;
/// Set the active state of the body. An inactive body is not
/// simulated and cannot be collided with or woken up.
/// If you pass a flag of true, all fixtures will be added to the
/// broad-phase.
/// If you pass a flag of false, all fixtures will be removed from
/// the broad-phase and all contacts will be destroyed.
/// Fixtures and joints are otherwise unaffected. You may continue
/// to create/destroy fixtures and joints on inactive bodies.
/// Fixtures on an inactive body are implicitly inactive and will
/// not participate in collisions, ray-casts, or queries.
/// Joints connected to an inactive body are implicitly inactive.
/// An inactive body is still owned by a b2World object and remains
/// in the body list.
void SetActive(bool flag);
/// Get the active state of the body.
bool IsActive() const;
/// Set this body to have fixed rotation. This causes the mass
/// to be reset.
void SetFixedRotation(bool flag);
/// Does this body have fixed rotation?
bool IsFixedRotation() const;
/// Get the list of all fixtures attached to this body.
b2Fixture* GetFixtureList();
const b2Fixture* GetFixtureList() const;
/// Get the list of all joints attached to this body.
b2JointEdge* GetJointList();
const b2JointEdge* GetJointList() const;
/// Get the list of all contacts attached to this body.
/// @warning this list changes during the time step and you may
/// miss some collisions if you don't use b2ContactListener.
b2ContactEdge* GetContactList();
const b2ContactEdge* GetContactList() const;
/// Get the next body in the world's body list.
b2Body* GetNext();
const b2Body* GetNext() const;
/// Get the user data pointer that was provided in the body definition.
void* GetUserData() const;
/// Set the user data. Use this to store your application specific data.
void SetUserData(void* data);
/// Get the parent world of this body.
b2World* GetWorld();
const b2World* GetWorld() const;
private:
friend class b2World;
friend class b2Island;
friend class b2ContactManager;
friend class b2ContactSolver;
friend class b2TOISolver;
friend class b2DistanceJoint;
friend class b2GearJoint;
friend class b2LineJoint;
friend class b2MouseJoint;
friend class b2PrismaticJoint;
friend class b2PulleyJoint;
friend class b2RevoluteJoint;
friend class b2WeldJoint;
friend class b2FrictionJoint;
// m_flags
enum
{
e_islandFlag = 0x0001,
e_awakeFlag = 0x0002,
e_autoSleepFlag = 0x0004,
e_bulletFlag = 0x0008,
e_fixedRotationFlag = 0x0010,
e_activeFlag = 0x0020,
e_toiFlag = 0x0040,
};
b2Body(const b2BodyDef* bd, b2World* world);
~b2Body();
void SynchronizeFixtures();
void SynchronizeTransform();
// This is used to prevent connected bodies from colliding.
// It may lie, depending on the collideConnected flag.
bool ShouldCollide(const b2Body* other) const;
void Advance(float32 t);
b2BodyType m_type;
uint16 m_flags;
int32 m_islandIndex;
b2Transform m_xf; // the body origin transform
b2Sweep m_sweep; // the swept motion for CCD
b2Vec2 m_linearVelocity;
float32 m_angularVelocity;
b2Vec2 m_force;
float32 m_torque;
b2World* m_world;
b2Body* m_prev;
b2Body* m_next;
b2Fixture* m_fixtureList;
int32 m_fixtureCount;
b2JointEdge* m_jointList;
b2ContactEdge* m_contactList;
float32 m_mass, m_invMass;
// Rotational inertia about the center of mass.
float32 m_I, m_invI;
float32 m_linearDamping;
float32 m_angularDamping;
float32 m_sleepTime;
void* m_userData;
};
inline b2BodyType b2Body::GetType() const
{
return m_type;
}
inline const b2Transform& b2Body::GetTransform() const
{
return m_xf;
}
inline const b2Vec2& b2Body::GetPosition() const
{
return m_xf.position;
}
inline float32 b2Body::GetAngle() const
{
return m_sweep.a;
}
inline const b2Vec2& b2Body::GetWorldCenter() const
{
return m_sweep.c;
}
inline const b2Vec2& b2Body::GetLocalCenter() const
{
return m_sweep.localCenter;
}
inline void b2Body::SetLinearVelocity(const b2Vec2& v)
{
if (m_type == b2_staticBody)
{
return;
}
if (b2Dot(v,v) > 0.0f)
{
SetAwake(true);
}
m_linearVelocity = v;
}
inline b2Vec2 b2Body::GetLinearVelocity() const
{
return m_linearVelocity;
}
inline void b2Body::SetAngularVelocity(float32 w)
{
if (m_type == b2_staticBody)
{
return;
}
if (w * w > 0.0f)
{
SetAwake(true);
}
m_angularVelocity = w;
}
inline float32 b2Body::GetAngularVelocity() const
{
return m_angularVelocity;
}
inline float32 b2Body::GetMass() const
{
return m_mass;
}
inline float32 b2Body::GetInertia() const
{
return m_I + m_mass * b2Dot(m_sweep.localCenter, m_sweep.localCenter);
}
inline void b2Body::GetMassData(b2MassData* data) const
{
data->mass = m_mass;
data->I = m_I + m_mass * b2Dot(m_sweep.localCenter, m_sweep.localCenter);
data->center = m_sweep.localCenter;
}
inline b2Vec2 b2Body::GetWorldPoint(const b2Vec2& localPoint) const
{
return b2Mul(m_xf, localPoint);
}
inline b2Vec2 b2Body::GetWorldVector(const b2Vec2& localVector) const
{
return b2Mul(m_xf.R, localVector);
}
inline b2Vec2 b2Body::GetLocalPoint(const b2Vec2& worldPoint) const
{
return b2MulT(m_xf, worldPoint);
}
inline b2Vec2 b2Body::GetLocalVector(const b2Vec2& worldVector) const
{
return b2MulT(m_xf.R, worldVector);
}
inline b2Vec2 b2Body::GetLinearVelocityFromWorldPoint(const b2Vec2& worldPoint) const
{
return m_linearVelocity + b2Cross(m_angularVelocity, worldPoint - m_sweep.c);
}
inline b2Vec2 b2Body::GetLinearVelocityFromLocalPoint(const b2Vec2& localPoint) const
{
return GetLinearVelocityFromWorldPoint(GetWorldPoint(localPoint));
}
inline float32 b2Body::GetLinearDamping() const
{
return m_linearDamping;
}
inline void b2Body::SetLinearDamping(float32 linearDamping)
{
m_linearDamping = linearDamping;
}
inline float32 b2Body::GetAngularDamping() const
{
return m_angularDamping;
}
inline void b2Body::SetAngularDamping(float32 angularDamping)
{
m_angularDamping = angularDamping;
}
inline void b2Body::SetBullet(bool flag)
{
if (flag)
{
m_flags |= e_bulletFlag;
}
else
{
m_flags &= ~e_bulletFlag;
}
}
inline bool b2Body::IsBullet() const
{
return (m_flags & e_bulletFlag) == e_bulletFlag;
}
inline void b2Body::SetAwake(bool flag)
{
if (flag)
{
if ((m_flags & e_awakeFlag) == 0)
{
m_flags |= e_awakeFlag;
m_sleepTime = 0.0f;
}
}
else
{
m_flags &= ~e_awakeFlag;
m_sleepTime = 0.0f;
m_linearVelocity.SetZero();
m_angularVelocity = 0.0f;
m_force.SetZero();
m_torque = 0.0f;
}
}
inline bool b2Body::IsAwake() const
{
return (m_flags & e_awakeFlag) == e_awakeFlag;
}
inline bool b2Body::IsActive() const
{
return (m_flags & e_activeFlag) == e_activeFlag;
}
inline void b2Body::SetFixedRotation(bool flag)
{
if (flag)
{
m_flags |= e_fixedRotationFlag;
}
else
{
m_flags &= ~e_fixedRotationFlag;
}
ResetMassData();
}
inline bool b2Body::IsFixedRotation() const
{
return (m_flags & e_fixedRotationFlag) == e_fixedRotationFlag;
}
inline void b2Body::SetSleepingAllowed(bool flag)
{
if (flag)
{
m_flags |= e_autoSleepFlag;
}
else
{
m_flags &= ~e_autoSleepFlag;
SetAwake(true);
}
}
inline bool b2Body::IsSleepingAllowed() const
{
return (m_flags & e_autoSleepFlag) == e_autoSleepFlag;
}
inline b2Fixture* b2Body::GetFixtureList()
{
return m_fixtureList;
}
inline const b2Fixture* b2Body::GetFixtureList() const
{
return m_fixtureList;
}
inline b2JointEdge* b2Body::GetJointList()
{
return m_jointList;
}
inline const b2JointEdge* b2Body::GetJointList() const
{
return m_jointList;
}
inline b2ContactEdge* b2Body::GetContactList()
{
return m_contactList;
}
inline const b2ContactEdge* b2Body::GetContactList() const
{
return m_contactList;
}
inline b2Body* b2Body::GetNext()
{
return m_next;
}
inline const b2Body* b2Body::GetNext() const
{
return m_next;
}
inline void b2Body::SetUserData(void* data)
{
m_userData = data;
}
inline void* b2Body::GetUserData() const
{
return m_userData;
}
inline void b2Body::ApplyForce(const b2Vec2& force, const b2Vec2& point)
{
if (m_type != b2_dynamicBody)
{
return;
}
if (IsAwake() == false)
{
SetAwake(true);
}
m_force += force;
m_torque += b2Cross(point - m_sweep.c, force);
}
inline void b2Body::ApplyTorque(float32 torque)
{
if (m_type != b2_dynamicBody)
{
return;
}
if (IsAwake() == false)
{
SetAwake(true);
}
m_torque += torque;
}
inline void b2Body::ApplyLinearImpulse(const b2Vec2& impulse, const b2Vec2& point)
{
if (m_type != b2_dynamicBody)
{
return;
}
if (IsAwake() == false)
{
SetAwake(true);
}
m_linearVelocity += m_invMass * impulse;
m_angularVelocity += m_invI * b2Cross(point - m_sweep.c, impulse);
}
inline void b2Body::ApplyAngularImpulse(float32 impulse)
{
if (m_type != b2_dynamicBody)
{
return;
}
if (IsAwake() == false)
{
SetAwake(true);
}
m_angularVelocity += m_invI * impulse;
}
inline void b2Body::SynchronizeTransform()
{
m_xf.R.Set(m_sweep.a);
m_xf.position = m_sweep.c - b2Mul(m_xf.R, m_sweep.localCenter);
}
inline void b2Body::Advance(float32 t)
{
// Advance to the new safe time.
m_sweep.Advance(t);
m_sweep.c = m_sweep.c0;
m_sweep.a = m_sweep.a0;
SynchronizeTransform();
}
inline b2World* b2Body::GetWorld()
{
return m_world;
}
inline const b2World* b2Body::GetWorld() const
{
return m_world;
}
#endif