Box2D.h

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#ifndef G3D_Box2D_h
#define G3D_Box2D_h

#include "G3D/platform.h"
#include "G3D/Vector2.h"

namespace G3D {

class CoordinateFrame;
typedef class CoordinateFrame CFrame;
class Rect2D;
typedef class Rect2D AABox2D;

class Box2D {
private:
 Vector2 m_corner[4];

 Vector2 m_axisin[2];

 Vector2 m_axis[2];

 Vector2 m_center;

 float origin[2];

 float m_area;

 Vector2 m_extent;

 bool overlaps1Way(const Box2D& other) const;


 void computeAxes();

public:

 Box2D(const Vector2& center = Vector2(0, 0), float w = 0, float h = 0, float angle = 0);

 Box2D(const AABox2D& b);

 Box2D(const Vector2& min, const Vector2& max);

 Box2D(const CFrame& frame, Box2D& b);
 
 inline bool contains(const Vector2& v) const {
 // Take to object space:
 const Vector2& p = v - m_center;
 float x = p.dot(m_axisin[0]);
 float y = p.dot(m_axisin[1]);

 // Must be within extent/2 on both axes in object space
 return (abs(x) <= 0.5f) && (abs(y) <= 0.5f); 
 }

 inline const Vector2& extent() const {
 return m_extent;
 }

 inline const Vector2& axis(int a) const {
 debugAssert(a == 0 || a == 1);
 return m_axis[a];
 }

 inline float area() const {
 return m_area;
 }

 inline const Vector2& corner(int i) const {
 debugAssert(i >=0 && i <= 3);
 return m_corner[i];
 }

 inline const Vector2& center() const {
 return m_center;
 }

 inline bool overlaps(const Box2D& other) const {
 return overlaps1Way(other) && other.overlaps1Way(*this);
 }
};

} // G3D
#endif