www.pudn.com > Fog_D3D.zip > vector.cpp

#include  
#include  
#include "vector.h" 
 
// Checks for two floats to be equal within a certain tolerance 
inline bool TEqual(float a, float b, float t) 
{ 
	return ((a > b - t) && (a < b + t)); 
} 
 
// Assignment operator 
CVector& CVector::operator =(const CVector &vec) 
{ 
	x = vec.x; 
	y = vec.y; 
	z = vec.z; 
		return *this; 
} 
 
// Addition operator 
CVector CVector::operator +(const CVector &vec) const 
{ 
	return CVector(x + vec.x, y + vec.y, z + vec.z); 
} 
 
// Subtraction operator 
CVector CVector::operator -(const CVector &vec) const 
{ 
	return CVector(x - vec.x, y - vec.y, z - vec.z); 
} 
 
// Negative sign operator 
CVector CVector::operator -() const 
{ 
	return CVector(-x, -y, -z); 
} 
 
// Plus/Equals operator 
void CVector::operator +=(const CVector &vec) 
{ 
	x += vec.x; 
	y += vec.y; 
	z += vec.z; 
} 
 
// Subtract/Equals operator 
void CVector::operator -=(const CVector &vec) 
{ 
	x -= vec.x; 
	y -= vec.y; 
	z -= vec.z; 
} 
 
// Equality operator 
bool CVector::operator ==(const CVector &vec) const 
{ 
	return (TEqual(x, vec.x, .001f) && 
		    TEqual(y, vec.y, .001f) && 
		    TEqual(z, vec.z, .001f)); 
} 
 
// Not equal operator 
bool CVector::operator !=(const CVector &vec) const 
{ 
	return !(*this == vec); 
} 
 
// Dot product 
float CVector::operator *(const CVector &vec) const 
{ 
	return (x * vec.x + y * vec.y + z * vec.z); 
} 
 
// Set the CVector to the (x,y,z) passed in 
void CVector::set(float xxx, float yyy, float zzz) 
{ 
	x = xxx; 
	y = yyy; 
	z = zzz; 
} 
 
// Set the CVector to the CVector passed in 
void CVector::set(const CVector &vec) 
{ 
	x = vec.x; 
	y = vec.y; 
	z = vec.z; 
} 
 
// Negate the CVector 
void CVector::negate() 
{ 
	x = -x; 
	y = -y; 
	z = -z; 
} 
 
// Normalizes the CVector (ie makes it a unit vector) 
void CVector::normalize() 
{ 
	assert(!TEqual(magnitude(), 0.0f, .001f)); // Make sure length isn't zero 
	 
	float oneOverLen = 1.0f / magnitude(); 
	 
	x *= oneOverLen; 
	y *= oneOverLen; 
	z *= oneOverLen; 
} 
 
// Scales the vector by the amount passed in 
void CVector::scale(float amt) 
{ 
	x *= amt; 
	y *= amt; 
	z *= amt; 
} 
 
// Returns the magnitude (ie length or norm) of the CVector 
float CVector::magnitude() const 
{ 
	return sqrtf((x * x) + (y * y) + (z * z)); 
} 
 
// Crosses "this" vector with "vec" -- Stores the cross product in "result" 
void CVector::crossProduct(const CVector &vec, CVector &result) const 
{ 
	result.x = (y * vec.z) - (vec.y * z); 
	result.y = (z * vec.x) - (vec.z * x); 
	result.z = (x * vec.y) - (vec.x * y); 
} 
 
// Crosses "this" vector with "vec" and returns the resulting CVector 
CVector CVector::crossProduct(const CVector &vec) const 
{ 
	return CVector((y * vec.z) - (vec.y * z),  
				   (z * vec.x) - (vec.z * x), 
				   (x * vec.y) - (vec.x * y)); 
}