b2PolygonShape Class Reference

#include <b2_polygon_shape.h>

Inheritance diagram for b2PolygonShape:

Public Member Functions
b2Shape *	Clone (b2BlockAllocator *allocator) const override
	Implement b2Shape. More...
int32	GetChildCount () const override
void	Set (const b2Vec2 *points, int32 count)
void	SetAsBox (float hx, float hy)
void	SetAsBox (float hx, float hy, const b2Vec2 &center, float angle)
bool	TestPoint (const b2Transform &transform, const b2Vec2 &p) const override
bool	RayCast (b2RayCastOutput *output, const b2RayCastInput &input, const b2Transform &transform, int32 childIndex) const override
void	ComputeAABB (b2AABB *aabb, const b2Transform &transform, int32 childIndex) const override
void	ComputeMass (b2MassData *massData, float density) const override
bool	Validate () const
Public Member Functions inherited from b2Shape
virtual b2Shape *	Clone (b2BlockAllocator *allocator) const =0
	Clone the concrete shape using the provided allocator. More...
Type	GetType () const
virtual int32	GetChildCount () const =0
	Get the number of child primitives. More...
virtual bool	TestPoint (const b2Transform &xf, const b2Vec2 &p) const =0
virtual bool	RayCast (b2RayCastOutput *output, const b2RayCastInput &input, const b2Transform &transform, int32 childIndex) const =0
virtual void	ComputeAABB (b2AABB *aabb, const b2Transform &xf, int32 childIndex) const =0
virtual void	ComputeMass (b2MassData *massData, float density) const =0

Public Attributes
b2Vec2	m_centroid
b2Vec2	m_vertices [b2_maxPolygonVertices]
b2Vec2	m_normals [b2_maxPolygonVertices]
int32	m_count
Public Attributes inherited from b2Shape
Type	m_type
float	m_radius

Additional Inherited Members
Public Types inherited from b2Shape
enum	Type {   e_circle = 0 , e_edge = 1 , e_polygon = 2 , e_chain = 3 ,   e_typeCount = 4 }

Detailed Description

A solid convex polygon. It is assumed that the interior of the polygon is to the left of each edge. Polygons have a maximum number of vertices equal to b2_maxPolygonVertices. In most cases you should not need many vertices for a convex polygon.

Member Function Documentation

Clone()

b2Shape * b2PolygonShape::Clone ( b2BlockAllocator *  allocator ) const

overridevirtual

Implement b2Shape.

Implements b2Shape.

ComputeAABB()

void b2PolygonShape::ComputeAABB ( b2AABB *  aabb, const b2Transform &  transform, int32  childIndex  ) const

overridevirtual

See also

b2Shape::ComputeAABB

Implements b2Shape.

ComputeMass()

void b2PolygonShape::ComputeMass ( b2MassData *  massData, float  density  ) const

overridevirtual

See also

b2Shape::ComputeMass

Implements b2Shape.

GetChildCount()

int32 b2PolygonShape::GetChildCount ( ) const

overridevirtual

See also

b2Shape::GetChildCount

Implements b2Shape.

RayCast()

bool b2PolygonShape::RayCast ( b2RayCastOutput *  output, const b2RayCastInput &  input, const b2Transform &  transform, int32  childIndex  ) const

overridevirtual

Implement b2Shape.

Note

because the polygon is solid, rays that start inside do not hit because the normal is not defined.

Implements b2Shape.

Set()

void b2PolygonShape::Set	(	const b2Vec2 *	points,
		int32	count
	)

Create a convex hull from the given array of local points. The count must be in the range [3, b2_maxPolygonVertices].

Warning

the points may be re-ordered, even if they form a convex polygon

collinear points are handled but not removed. Collinear points may lead to poor stacking behavior.

SetAsBox() [1/2]

void b2PolygonShape::SetAsBox	(	float	hx,
		float	hy
	)

Build vertices to represent an axis-aligned box centered on the local origin.

Parameters

hx	the half-width.
hy	the half-height.

SetAsBox() [2/2]

void b2PolygonShape::SetAsBox	(	float	hx,
		float	hy,
		const b2Vec2 &	center,
		float	angle
	)

Build vertices to represent an oriented box.

Parameters

hx	the half-width.
hy	the half-height.
center	the center of the box in local coordinates.
angle	the rotation of the box in local coordinates.

TestPoint()

bool b2PolygonShape::TestPoint ( const b2Transform &  transform, const b2Vec2 &  p  ) const

overridevirtual

See also

b2Shape::TestPoint

Implements b2Shape.

Validate()

bool b2PolygonShape::Validate

(

)

const

Validate convexity. This is a very time consuming operation.

Returns

true if valid

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

• include/box2d/b2_polygon_shape.h