Using Quaternions

void	Quaternion::InitFromRadians(float	Xrad,float	Yrad,float	Zrad){	float	cosX	=	cosf(Xrad*.5);	float	sinX	=	sinf(Xrad*.5);	float	cosY	=	cosf(Yrad*.5);	float	sinY	=	sinf(Yrad*.5);		float	cosZ	=	cosf(Zrad*.5);	float	sinZ	=	sinf(Zrad*.5);	Quaternion	X,Y,Z;		X.w	=	cosX;		X.x	=	sinX;		X.y = 0;		X.z = 0;	Y.w	=	cosY;	Y.x	=	0;	Y.y = sinY;	Y.z = 0;	Z.w =	cosZ;	Z.x	=	0;	Z.y = 0;	Z.z = sinZ;	*this	=	X*Y*Z;	}..and to multiply quaternions:Quaternion &	Quaternion::operator *(Quaternion & B){  Quaternion C;  C.x = w*B.x + x*B.w + y*B.z - z*B.y;  C.y = w*B.y - x*B.z + y*B.w + z*B.x;  C.z = w*B.z + x*B.y - y*B.x + z*B.w;   C.w = w*B.w - x*B.x - y*B.y - z*B.z;  return C;}

Matrix3x3 &	Quaternion::ToMatrix(){	Matrix3x3	Output;	float	wx, wy, wz;	float	xx, yy, yz;	float	xy, xz, zz;	float	x2, y2, z2;	x2 = x + x;	y2 = y + y;	z2 = z + z;	xx = x * x2;	xy = x * y2;	xz = x * z2;	yy = y * y2;	yz = y * z2;	zz = z * z2;	wx = w * x2;	wy = w * y2;	wz = w * z2;	Output.mat[0][0] = 1.0f-(yy+zz);	Output.mat[0][1] = xy-wz;	Output.mat[0][2] = xz+wy;	Output.mat[1][0] = xy+wz;	Output.mat[1][1] = 1.0f-(xx+zz);	Output.mat[1][2] = yz-wx;	Output.mat[2][0] = xz-wy;	Output.mat[2][1] = yz+wx;	Output.mat[2][2] = 1.0f-(xx+yy);	return	Output;}

void		Quaternion32RotateVector3Radians(Vector3	*ToRotate,float	xradians,float yradians,float zradians){	float	CosX = cosf((xradians)*.5);	float	SinX = sinf((xradians)*.5);	float	CosY = cosf((yradians)*.5);	float	SinY = sinf((yradians)*.5);	float	CosZ = cosf((zradians)*.5);	float	SinZ = sinf((zradians)*.5);	Quaternion	XAxisRot(CosX,SinX,0,0);	Quaternion YAxisRot(CosY,0,SinY,0);	Quaternion ZAxisRot(CosZ,0,0,SinZ);	//Am I doing anything incorrect about the order of multiplications here?	//EDIT:	yes, I had to reverse the order here! Now it works (Update this in FPS_CheckMouse as well)	Quaternion temp = ZAxisRot * YAxisRot * XAxisRot;	Quaternion temp_view(0,ToRotate->x,ToRotate->y,ToRotate->z);	Quaternion NewView = FastHomoMorphism(&temp,&temp_view);	ToRotate->x = NewView.x;	ToRotate->y = NewView.y;	ToRotate->z = NewView.z;}Quaternion	FastHomoMorphism(Quaternion *A, Quaternion *B){	//Multiply A by B in the fastest method possible	//12 mults (13 if you count negating a multiplication by negative 1)	//8 adds	//You can do this because B represents view and has a w component of 0, so you can skip those operations	float NewX = A->w*B->x + A->y*B->z - A->z*B->y;	float NewY = A->w*B->y - A->x*B->z + A->z*B->x;	float NewZ = A->w*B->z + A->x*B->y - A->y*B->x;	float NewW = - A->x*B->x - A->y*B->y - A->z*B->z; //notice that you need this in the calculations below, so don't ignore		Quaternion	rslt(NewW, NewX, NewY, NewZ);	Quaternion	conj(A->w, -A->x, -A->y, -A->z);	//Now we need to multiply rsl by conj in the fastest way possible	  Quaternion	Final;  //12 mults  //9 adds  Final.x = rslt.w*conj.x + rslt.x*conj.w + rslt.y*conj.z - rslt.z*conj.y;  Final.y = rslt.w*conj.y - rslt.x*conj.z + rslt.y*conj.w + rslt.z*conj.x;  Final.z = rslt.w*conj.z + rslt.x*conj.y - rslt.y*conj.x + rslt.z*conj.w;   Final.w = 0;//w*conj.w - x*conj.x - y*conj.y - z*conj.z;  return Final;}