www.pudn.com > QuadTreeLOD4cs.rar > VECTOR.CPP, change:2003-08-05,size:3132b

#include "vector.h" 
//#include <gl\gl.h>	 
 
 
//------------------------------------------------------------------// 
//- float ComputeDotProduct(CVector3*, CVector3*) ----------------------// 
//------------------------------------------------------------------// 
//- Description: Returns the dot product of two vectors (this stuff-// 
//-              is pretty self explanatory, eh?).				   -// 
//------------------------------------------------------------------// 
float DotProduct(const CVector3 &v1, const CVector3 &v2) 
{ 
	return (v1.x*v2.x)+(v1.y*v2.y)+(v1.z*v2.z); 
}; 
 
//------------------------------------------------------------------// 
//- CVector3 ComputeCrossProduct(CVector3*, CVector3*) -------------------// 
//------------------------------------------------------------------// 
//- Description: Returns the cross product of two vectors.		   -// 
//------------------------------------------------------------------// 
CVector3 CrossProduct(const CVector3 &v1, const CVector3 &v2) 
{ 
	CVector3 result(0.0f, 0.0f, 0.0f); 
 
	result.x= (v1.y*v2.z) - (v1.z*v2.y); 
	result.y= (v1.z*v2.x) - (v1.x*v2.z); 
	result.z= (v1.x*v2.y) - (v1.y*v2.x); 
 
	return result; 
}; 
 
 
 
/////////////////////////////////////// MAGNITUDE \\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\* 
///// 
/////	This returns the magnitude of a vector 
///// 
/////////////////////////////////////// MAGNITUDE \\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\* 
 
float Magnitude(CVector3 vNormal) 
{ 
	// Here is the equation:  magnitude = sqrt(V.x^2 + V.y^2 + V.z^2) : Where V is the vector 
	return (float)sqrt( (vNormal.x * vNormal.x) +  
						(vNormal.y * vNormal.y) +  
						(vNormal.z * vNormal.z) ); 
} 
 
 
/////////////////////////////////////// NORMALIZE \\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\* 
///// 
/////	This returns a normalize vector (A vector exactly of length 1) 
///// 
/////////////////////////////////////// NORMALIZE \\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\* 
 
CVector3 Normalize(CVector3 vVector) 
{ 
	// Get the magnitude of our normal 
	float magnitude = Magnitude(vVector);				 
 
	// Now that we have the magnitude, we can divide our vector by that magnitude. 
	// That will make our vector a total length of 1.   
	vVector = vVector / magnitude;		 
	 
	// Finally, return our normalized vector 
	return vVector;										 
} 
bool SameSign(float f1,float f2) 
{ 
	return f1<0&&f2<0||f1>0&&f2>0||f1==0&&f2==0?true:false; 
} 
//判断点vPnt是否在射线(起点是vPtStart,方向是vDrct)上 
bool PntFrontOrBack(const CVector3 &vPnt,const CVector3 &vPtStart,const CVector3 &vDrct) 
{ 
	return SameSign(vPnt.x-vPtStart.x,vDrct.x)&& 
		SameSign(vPnt.y-vPtStart.y,vDrct.y)&& 
		SameSign(vPnt.z-vPtStart.z,vDrct.z)?true:false; 
} 
bool PntFrontOrBack2(const CVector3 &vPnt,const CVector3 &vPtStart,const CVector3 &vDrct) 
{ 
	return SameSign(vPnt.x-vPtStart.x,vDrct.x)&& 
	//	SameSign(vPnt.y-vPtStart.y,vDrct.y)&& 
		SameSign(vPnt.z-vPtStart.z,vDrct.z)?true:false; 
} 
float Dist(const CVector3 &v1,const CVector3 &v2) 
{ 
	return float(sqrt((v1.x-v2.x)*(v1.x-v2.x)+(v1.y-v2.y)*(v1.y-v2.y)+(v1.z-v2.z)*(v1.z-v2.z))); 
}