100 lines
2.2 KiB
C++
Executable File
100 lines
2.2 KiB
C++
Executable File
// Vector2D.h
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//
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// Last modified: 26 May 04, Mark Thompson mot20@cam.ac.uk / mark@wildfiregames.com
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//
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// 2-dimensional vector class, primarily for use by simulation code.
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#ifndef VECTOR_2D_INCLUDED
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#define VECTOR_2D_INCLUDED
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#include "math.h"
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class CVector2D
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{
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public:
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float x;
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float y;
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CVector2D() {}
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CVector2D( float _x, float _y )
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{
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x = _x; y = _y;
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}
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static inline float dot( const CVector2D& u, const CVector2D& v )
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{
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return( u.x * v.x + u.y * v.y );
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}
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static inline float betadot( const CVector2D& u, const CVector2D& v )
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{
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// Beta-dot product. I have no idea if that's its correct name
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// but use of it tends to simplify collision formulae.
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// At the moment I think all of my code uses seperate vectors
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// and dots them together, though.
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return( u.x * v.y - u.y * v.x );
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}
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inline CVector2D beta() const
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{
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return( CVector2D( y, -x ) );
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}
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inline float dot( const CVector2D& u ) const
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{
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return( dot( *this, u ) );
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}
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inline float betadot( const CVector2D& u ) const
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{
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return( betadot( *this, u ) );
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}
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inline CVector2D operator+( const CVector2D& u ) const
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{
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return( CVector2D( x + u.x, y + u.y ) );
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}
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inline CVector2D operator-( const CVector2D& u ) const
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{
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return( CVector2D( x - u.x, y - u.y ) );
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}
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inline CVector2D& operator+=( const CVector2D& u )
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{
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x += u.x; y += u.y;
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return( *this );
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}
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inline CVector2D& operator-=( const CVector2D& u )
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{
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x -= u.x; y -= u.y;
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return( *this );
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}
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inline CVector2D operator*( const float scale ) const
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{
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return( CVector2D( x * scale, y * scale ) );
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}
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inline CVector2D operator/( const float scale ) const
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{
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return( CVector2D( x / scale, y / scale ) );
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}
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inline CVector2D& operator*=( const float scale )
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{
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x *= scale; y *= scale;
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return( *this );
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}
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inline CVector2D& operator/=( const float scale )
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{
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x /= scale; y /= scale;
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return( *this );
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}
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inline float length() const
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{
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return( sqrt( x * x + y * y ) );
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}
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CVector2D normalize() const
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{
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float l = length();
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if( l < 0.00001 ) return( CVector2D( 1.0f, 0.0f ) );
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l = 1 / l;
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return( CVector2D( x * l, y * l ) );
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}
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inline bool within( const float dist ) const
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{
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return( ( x * x + y * y ) <= ( dist * dist ) );
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}
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};
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#endif
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