static void mPower (double *A, int eA, double *V, int *eV, int m, int n)
{
double *B;
int eB, i;
if (n == 1) {
for (i = 0; i < m * m; i++)
V[i] = A[i];
*eV = eA;
return;
}
mPower (A, eA, V, eV, m, n / 2);
B = (double *) malloc ((m * m) * sizeof (double));
mMultiply (V, V, B, m);
eB = 2 * (*eV);
if (B[(m / 2) * m + (m / 2)] > NORM)
renormalize (B, m, &eB);
if (n % 2 == 0) {
for (i = 0; i < m * m; i++)
V[i] = B[i];
*eV = eB;
} else {
mMultiply (A, B, V, m);
*eV = eA + eB;
}
if (V[(m / 2) * m + (m / 2)] > NORM)
renormalize (V, m, eV);
free (B);
}
// pow(10, *eV) * V := (pow(10, eA) * A) ^ n
// where dim(A) = (m,m)
void mPower(double *A,int eA,double *V,int *eV,int m,int n) {
double *B;
int eB,i;
// Base case (n = 1): copy A to V and eA to eV
if(n==1) {
for(i=0;i<m*m;i++)
V[i]=A[i];
*eV=eA;
return;
}
// Recursive step:
// pow(10, *eV) * V := (pow(10,eA) * A) ^ floor(n/2))
mPower(A,eA,V,eV,m,n/2);
B=(double*)malloc((m*m)*sizeof(double));
// pow(10, eB) * B := (pow(10, *eV) * V) ^ 2
mMultiply(V,V,B,m);
eB=2*(*eV);
if(n%2==0) {
// if original N was even, finish by copying B to V and eB to eV
for(i=0;i<m*m;i++)
V[i]=B[i];
*eV=eB;
} else {
// if original N was odd, finish by multiplying:
// pow(10, *eV) * V := (pow(10, eA) * A) * (pow(10, eB) * B)
mMultiply(A,B,V,m);
*eV = eA + eB;
}
// Finally, if center element of V is too big, move some of its exponent into *eV
if (V[(m/2)*m+(m/2)] > 1e140) {
for (i=0; i<m*m; i++)
V[i] = V[i] * 1e-140;
*eV += 140;
}
free(B);
}
void QuaternionManipulator::qtest2()
{
HEADER("TEST 2 : Rotation of 90 degrees about the y-axis with matrix")
Vector axis = {0.0f, 1.0f, 0.0f, 1.0f};
Quaternion q = qFromAngleAxis(90.0f, axis);
qPrint(" q", q);
Vector vi = {7.0f, 0.0f, 0.0f, 1.0f};
vPrint("vi", vi);
Vector ve = {0.0f, 0.0f, -7.0f, 1.0f};
vPrint("ve", ve);
Matrix m;
qGLMatrix(q,m);
Vector vf = mMultiply(m, vi);
vPrint("vf", vf);
assert(vEqual(vf, ve));
}