public static EriSinCos[] CreateRevolveParameter(int nDegreeDCT)
{
int nDegreeNum = 1 << nDegreeDCT;
int lc = 1;
for (int n = nDegreeNum / 2; n >= 8; n /= 8)
{
++lc;
}
EriSinCos[] ptrRevolve = new EriSinCos[lc * 8];
double k = Math.PI / (nDegreeNum * 2);
int ptrNextRev = 0;
int nStep = 2;
do
{
for (int i = 0; i < 7; i++)
{
double ws = 1.0;
double a = 0.0;
for (int j = 0; j < i; j++)
{
a += nStep;
ws = ws * ptrRevolve[ptrNextRev + j].rSin + ptrRevolve[ptrNextRev + j].rCos * Math.Cos(a * k);
}
double r = Math.Atan2(ws, Math.Cos((a + nStep) * k));
ptrRevolve[ptrNextRev + i].rSin = (float)Math.Sin(r);
ptrRevolve[ptrNextRev + i].rCos = (float)Math.Cos(r);
}
ptrNextRev += 7;
nStep *= 8;
}while (nStep < nDegreeNum);
return(ptrRevolve);
}
public static void OddGivensInverseMatrix(float[] ptrSrc, int src, EriSinCos[] ptrRevolve, int nDegreeDCT)
{
int nDegreeNum = 1 << nDegreeDCT;
int index = 1;
int nStep = 2;
int lc = (nDegreeNum / 2) / 8;
int resolve_idx = 0;
for (;;)
{
resolve_idx += 7;
index += nStep * 7;
nStep *= 8;
if (lc <= 8)
break;
lc /= 8;
}
int k = index + nStep * (lc - 2);
int j;
float r1, r2;
for (j = lc - 2; j >= 0; j--)
{
r1 = ptrSrc[src + k];
r2 = ptrSrc[src + k + nStep];
ptrSrc[src + k] = r1 * ptrRevolve[resolve_idx+j].rCos + r2 * ptrRevolve[resolve_idx+j].rSin;
ptrSrc[src + k + nStep] = r2 * ptrRevolve[resolve_idx+j].rCos - r1 * ptrRevolve[resolve_idx+j].rSin;
k -= nStep;
}
for (; lc <= (nDegreeNum / 2) / 8; lc *= 8)
{
resolve_idx -= 7;
nStep /= 8;
index -= nStep * 7;
for (int i = 0; i < lc; i++)
{
k = i * (nStep * 8) + index + nStep * 6;
for ( j = 6; j >= 0; j -- )
{
r1 = ptrSrc[src + k];
r2 = ptrSrc[src + k + nStep];
ptrSrc[src + k] =
r1 * ptrRevolve[resolve_idx+j].rCos + r2 * ptrRevolve[resolve_idx+j].rSin;
ptrSrc[src + k + nStep] =
r2 * ptrRevolve[resolve_idx+j].rCos - r1 * ptrRevolve[resolve_idx+j].rSin;
k -= nStep;
}
}
}
}
public static EriSinCos[] CreateRevolveParameter(int nDegreeDCT)
{
int nDegreeNum = 1 << nDegreeDCT;
int lc = 1;
for (int n = nDegreeNum / 2; n >= 8; n /= 8)
{
++lc;
}
EriSinCos[] ptrRevolve = new EriSinCos[lc*8];
double k = Math.PI / (nDegreeNum * 2);
int ptrNextRev = 0;
int nStep = 2;
do
{
for (int i = 0; i < 7; i++)
{
double ws = 1.0;
double a = 0.0;
for (int j = 0; j < i; j++)
{
a += nStep;
ws = ws * ptrRevolve[ptrNextRev+j].rSin + ptrRevolve[ptrNextRev+j].rCos * Math.Cos (a * k);
}
double r = Math.Atan2 (ws, Math.Cos ((a + nStep) * k));
ptrRevolve[ptrNextRev+i].rSin = (float)Math.Sin (r);
ptrRevolve[ptrNextRev+i].rCos = (float)Math.Cos (r);
}
ptrNextRev += 7;
nStep *= 8;
}
while (nStep < nDegreeNum);
return ptrRevolve;
}