axmol/thirdparty/box2d-optimized/include/box2d/b2_fixture.h

399 lines
10 KiB
C++

// MIT License
// Copyright (c) 2019 Erin Catto
// Permission is hereby granted, free of charge, to any person obtaining a copy
// of this software and associated documentation files (the "Software"), to deal
// in the Software without restriction, including without limitation the rights
// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
// copies of the Software, and to permit persons to whom the Software is
// furnished to do so, subject to the following conditions:
// The above copyright notice and this permission notice shall be included in all
// copies or substantial portions of the Software.
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
// SOFTWARE.
#ifndef B2_FIXTURE_H
#define B2_FIXTURE_H
#include "b2_api.h"
#include "b2_body.h"
#include "b2_collision.h"
#include "b2_shape.h"
class b2BlockAllocator;
class b2Body;
class b2BroadPhase;
class b2Fixture;
/// This holds contact filtering data.
struct B2_API b2Filter
{
b2Filter()
{
categoryBits = 0x0001;
maskBits = 0xFFFF;
groupIndex = 0;
}
/// The collision category bits. Normally you would just set one bit.
uint16 categoryBits;
/// The collision mask bits. This states the categories that this
/// shape would accept for collision.
uint16 maskBits;
/// Collision groups allow a certain group of objects to never collide (negative)
/// or always collide (positive). Zero means no collision group. Non-zero group
/// filtering always wins against the mask bits.
int16 groupIndex;
};
/// A fixture definition is used to create a fixture. This class defines an
/// abstract fixture definition. You can reuse fixture definitions safely.
struct B2_API b2FixtureDef
{
/// The constructor sets the default fixture definition values.
b2FixtureDef()
{
shape = nullptr;
#ifdef ENABLE_FRICTION
friction = 0.2f;
#endif // ENABLE_FRICTION
#ifdef ENABLE_RESTITUTION
restitution = 0.0f;
restitutionThreshold = 1.0f * b2_lengthUnitsPerMeter;
#endif // ENABLE_RESTITUTION
density = 0.0f;
isSensor = false;
}
/// The shape, this must be set. The shape will be cloned, so you
/// can create the shape on the stack.
const b2Shape* shape;
#ifdef ENABLE_USER_DATA
/// Use this to store application specific fixture data.
b2FixtureUserData userData;
#endif // ENABLE_USER_DATA
#ifdef ENABLE_FRICTION
/// The friction coefficient, usually in the range [0,1].
float friction;
#endif // ENABLE_FRICTION
#ifdef ENABLE_RESTITUTION
/// The restitution (elasticity) usually in the range [0,1].
float restitution;
#endif // ENABLE_RESTITUTION
/// Restitution velocity threshold, usually in m/s. Collisions above this
/// speed have restitution applied (will bounce).
float restitutionThreshold;
/// The density, usually in kg/m^2.
float density;
/// A sensor shape collects contact information but never generates a collision
/// response.
bool isSensor;
/// Contact filtering data.
b2Filter filter;
};
/// A fixture is used to attach a shape to a body for collision detection. A fixture
/// inherits its transform from its parent. Fixtures hold additional non-geometric data
/// such as friction, collision filters, etc.
/// Fixtures are created via b2Body::CreateFixture.
/// @warning you cannot reuse fixtures.
class B2_API b2Fixture
{
public:
/// Get the type of the child shape. You can use this to down cast to the concrete shape.
/// @return the shape type.
b2Shape::Type GetType() const;
/// Get the child shape. You can modify the child shape, however you should not change the
/// number of vertices because this will crash some collision caching mechanisms.
/// Manipulating the shape may lead to non-physical behavior.
b2Shape* GetShape();
const b2Shape* GetShape() const;
/// Set if this fixture is a sensor.
void SetSensor(bool sensor);
/// Is this fixture a sensor (non-solid)?
/// @return the true if the shape is a sensor.
bool IsSensor() const;
/// Set the contact filtering data. This will not update contacts until the next time
/// step when either parent body is active and awake.
/// This automatically calls Refilter.
void SetFilterData(const b2Filter& filter);
/// Get the contact filtering data.
const b2Filter& GetFilterData() const;
/// Call this if you want to establish collision that was previously disabled by b2ContactFilter::ShouldCollide.
void Refilter();
/// Get the parent body of this fixture. This is nullptr if the fixture is not attached.
/// @return the parent body.
b2Body* GetBody();
const b2Body* GetBody() const;
/// Get the next fixture in the parent body's fixture list.
/// @return the next shape.
b2Fixture* GetNext();
const b2Fixture* GetNext() const;
#ifdef ENABLE_USER_DATA
/// Get the user data that was assigned in the fixture definition. Use this to
/// store your application specific data.
b2FixtureUserData& GetUserData();
#endif // ENABLE_USER_DATA
uint32 GetId();
/// Test a point for containment in this fixture.
/// @param p a point in world coordinates.
bool TestPoint(const b2Vec2& p) const;
/// Compute the distance from this fixture.
/// @param p a point in world coordinates.
void ComputeDistance(const b2Vec2& p, float32* distance, b2Vec2* normal) const;
/// Cast a ray against this shape.
/// @param output the ray-cast results.
/// @param input the ray-cast input parameters.
bool RayCast(b2RayCastOutput* output, const b2RayCastInput& input) const;
/// Get the mass data for this fixture. The mass data is based on the density and
/// the shape. The rotational inertia is about the shape's origin. This operation
/// may be expensive.
void GetMassData(b2MassData* massData) const;
/// Set the density of this fixture. This will _not_ automatically adjust the mass
/// of the body. You must call b2Body::ResetMassData to update the body's mass.
void SetDensity(float density);
/// Get the density of this fixture.
float GetDensity() const;
#ifdef ENABLE_FRICTION
/// Get the coefficient of friction.
float GetFriction() const;
/// Set the coefficient of friction. This will _not_ change the friction of
/// existing contacts.
void SetFriction(float friction);
#endif // ENABLE_FRICTION
#ifdef ENABLE_RESTITUTION
/// Get the coefficient of restitution.
float GetRestitution() const;
/// Set the coefficient of restitution. This will _not_ change the restitution of
/// existing contacts.
void SetRestitution(float restitution);
/// Get the restitution velocity threshold.
float GetRestitutionThreshold() const;
/// Set the restitution threshold. This will _not_ change the restitution threshold of
/// existing contacts.
void SetRestitutionThreshold(float threshold);
#endif // ENABLE_RESTITUTION
void UpdateAABB();
/// Get the fixture's AABB. This AABB may be enlarge and/or stale.
/// If you need a more accurate AABB, compute it using the shape and
/// the body transform.
const b2AABB& GetAABB() const;
/// Dump this fixture to the log file.
void Dump(int32 bodyIndex);
protected:
friend class b2Body;
friend class b2World;
friend class b2Contact;
friend class b2ContactManager;
b2Fixture();
// We need separation create/destroy functions from the constructor/destructor because
// the destructor cannot access the allocator (no destructor arguments allowed by C++).
void Create(b2BlockAllocator* allocator, b2Body* body, const b2FixtureDef* def);
void Destroy(b2BlockAllocator* allocator);
float m_density;
b2Fixture* m_next;
b2Body* m_body;
b2Shape* m_shape;
b2AABB m_aabb;
#ifdef ENABLE_FRICTION
float m_friction;
#endif // ENABLE_FRICTION
#ifdef ENABLE_RESTITUTION
float m_restitution;
float m_restitutionThreshold;
#endif // ENABLE_RESTITUTION
b2Filter m_filter;
bool m_isSensor;
#ifdef ENABLE_USER_DATA
b2FixtureUserData m_userData;
#endif // ENABLE_USER_DATA
uint32 m_id;
};
inline b2Shape::Type b2Fixture::GetType() const
{
return m_shape->GetType();
}
inline b2Shape* b2Fixture::GetShape()
{
return m_shape;
}
inline const b2Shape* b2Fixture::GetShape() const
{
return m_shape;
}
inline bool b2Fixture::IsSensor() const
{
return m_isSensor;
}
inline const b2Filter& b2Fixture::GetFilterData() const
{
return m_filter;
}
#ifdef ENABLE_USER_DATA
inline b2FixtureUserData& b2Fixture::GetUserData()
{
return m_userData;
}
#endif // ENABLE_USER_DATA
inline uint32 b2Fixture::GetId()
{
return m_id;
}
inline b2Body* b2Fixture::GetBody()
{
return m_body;
}
inline const b2Body* b2Fixture::GetBody() const
{
return m_body;
}
inline b2Fixture* b2Fixture::GetNext()
{
return m_next;
}
inline const b2Fixture* b2Fixture::GetNext() const
{
return m_next;
}
inline void b2Fixture::SetDensity(float density)
{
b2Assert(b2IsValid(density) && density >= 0.0f);
m_density = density;
}
inline float b2Fixture::GetDensity() const
{
return m_density;
}
#ifdef ENABLE_FRICTION
inline float b2Fixture::GetFriction() const
{
return m_friction;
}
inline void b2Fixture::SetFriction(float friction)
{
m_friction = friction;
}
#endif // ENABLE_FRICTION
#ifdef ENABLE_RESTITUTION
inline float b2Fixture::GetRestitution() const
{
return m_restitution;
}
inline void b2Fixture::SetRestitution(float restitution)
{
m_restitution = restitution;
}
#endif // ENABLE_RESTITUTION
inline float b2Fixture::GetRestitutionThreshold() const
{
return m_restitutionThreshold;
}
inline void b2Fixture::SetRestitutionThreshold(float threshold)
{
m_restitutionThreshold = threshold;
}
inline bool b2Fixture::TestPoint(const b2Vec2& p) const
{
return m_shape->TestPoint(m_body->GetTransform(), p);
}
inline void b2Fixture::ComputeDistance(const b2Vec2& p, float32* d, b2Vec2* n) const
{
m_shape->ComputeDistance(m_body->GetTransform(), p, d, n);
}
inline bool b2Fixture::RayCast(b2RayCastOutput* output, const b2RayCastInput& input) const
{
return m_shape->RayCast(output, input, m_body->GetTransform());
}
inline void b2Fixture::GetMassData(b2MassData* massData) const
{
m_shape->ComputeMass(massData, m_density);
}
inline const b2AABB& b2Fixture::GetAABB() const
{
return m_aabb;
}
#endif