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/*
* Copyright (c) 2006-2007 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_POLYGON_SHAPE_H
#define B2_POLYGON_SHAPE_H
#include "b2Shape.h"
/// Convex polygon. The vertices must be in CCW order for a right-handed
/// coordinate system with the z-axis coming out of the screen.
struct b2PolygonDef : public b2ShapeDef
{
b2PolygonDef()
{
type = e_polygonShape;
vertexCount = 0;
}
/// Build vertices to represent an axis-aligned box.
/// @param hx the half-width.
/// @param hy the half-height.
void SetAsBox(float32 hx, float32 hy);
/// Build vertices to represent an oriented box.
/// @param hx the half-width.
/// @param hy the half-height.
/// @param center the center of the box in local coordinates.
/// @param angle the rotation of the box in local coordinates.
void SetAsBox(float32 hx, float32 hy, const b2Vec2& center, float32 angle);
/// The polygon vertices in local coordinates.
b2Vec2 vertices[b2_maxPolygonVertices];
/// The number of polygon vertices.
int32 vertexCount;
};
/// A convex polygon.
class b2PolygonShape : public b2Shape
{
public:
/// @see b2Shape::TestPoint
bool TestPoint(const b2XForm& transform, const b2Vec2& p) const;
/// @see b2Shape::TestSegment
b2SegmentCollide TestSegment( const b2XForm& transform,
float32* lambda,
b2Vec2* normal,
const b2Segment& segment,
float32 maxLambda) const;
/// @see b2Shape::ComputeAABB
void ComputeAABB(b2AABB* aabb, const b2XForm& transform) const;
/// @see b2Shape::ComputeSweptAABB
void ComputeSweptAABB( b2AABB* aabb,
const b2XForm& transform1,
const b2XForm& transform2) const;
/// @see b2Shape::ComputeMass
void ComputeMass(b2MassData* massData) const;
/// @see b2Shape::ComputeSubmergedArea
float32 ComputeSubmergedArea( const b2Vec2& normal,
float32 offset,
const b2XForm& xf,
b2Vec2* c) const;
/// Get the oriented bounding box relative to the parent body.
const b2OBB& GetOBB() const;
/// Get local centroid relative to the parent body.
const b2Vec2& GetCentroid() const;
/// Get the vertex count.
int32 GetVertexCount() const;
/// Get the vertices in local coordinates.
const b2Vec2* GetVertices() const;
/// Get the core vertices in local coordinates. These vertices
/// represent a smaller polygon that is used for time of impact
/// computations.
const b2Vec2* GetCoreVertices() const;
/// Get the edge normal vectors. There is one for each vertex.
const b2Vec2* GetNormals() const;
/// Get the first vertex and apply the supplied transform.
b2Vec2 GetFirstVertex(const b2XForm& xf) const;
/// Get the centroid and apply the supplied transform.
b2Vec2 Centroid(const b2XForm& xf) const;
/// Get the support point in the given world direction.
/// Use the supplied transform.
b2Vec2 Support(const b2XForm& xf, const b2Vec2& d) const;
private:
friend class b2Shape;
b2PolygonShape(const b2ShapeDef* def);
void UpdateSweepRadius(const b2Vec2& center);
// Local position of the polygon centroid.
b2Vec2 m_centroid;
b2OBB m_obb;
b2Vec2 m_vertices[b2_maxPolygonVertices];
b2Vec2 m_normals[b2_maxPolygonVertices];
b2Vec2 m_coreVertices[b2_maxPolygonVertices];
int32 m_vertexCount;
};
inline b2Vec2 b2PolygonShape::GetFirstVertex(const b2XForm& xf) const
{
return b2Mul(xf, m_coreVertices[0]);
}
inline const b2OBB& b2PolygonShape::GetOBB() const
{
return m_obb;
}
inline const b2Vec2& b2PolygonShape::GetCentroid() const
{
return m_centroid;
}
inline int32 b2PolygonShape::GetVertexCount() const
{
return m_vertexCount;
}
inline const b2Vec2* b2PolygonShape::GetVertices() const
{
return m_vertices;
}
inline const b2Vec2* b2PolygonShape::GetCoreVertices() const
{
return m_coreVertices;
}
inline const b2Vec2* b2PolygonShape::GetNormals() const
{
return m_normals;
}
#endif
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