//////////////////////////////////////////////////////////////////////
// Advect using the MacCormack method from the Selle paper
//////////////////////////////////////////////////////////////////////
void FLUID_3D::advectMacCormack()
{
Vec3Int res = Vec3Int(_xRes,_yRes,_zRes);
if(DOMAIN_BC_LEFT == 0) copyBorderX(_xVelocity, res);
else setZeroX(_xVelocity, res);
if(DOMAIN_BC_TOP == 0) copyBorderY(_yVelocity, res);
else setZeroY(_yVelocity, res);
if(DOMAIN_BC_FRONT == 0) copyBorderZ(_zVelocity, res);
else setZeroZ(_zVelocity, res);
SWAP_POINTERS(_xVelocity, _xVelocityOld);
SWAP_POINTERS(_yVelocity, _yVelocityOld);
SWAP_POINTERS(_zVelocity, _zVelocityOld);
SWAP_POINTERS(_density, _densityOld);
SWAP_POINTERS(_heat, _heatOld);
const float dt0 = _dt / _dx;
// use force arrays as temp arrays
for (int x = 0; x < _totalCells; x++)
_xForce[x] = _yForce[x] = 0.0;
float* t1 = _xForce;
float* t2 = _yForce;
advectFieldMacCormack(dt0, _xVelocityOld, _yVelocityOld, _zVelocityOld, _densityOld, _density, t1,t2, res, _obstacles);
advectFieldMacCormack(dt0, _xVelocityOld, _yVelocityOld, _zVelocityOld, _heatOld, _heat, t1,t2, res, _obstacles);
advectFieldMacCormack(dt0, _xVelocityOld, _yVelocityOld, _zVelocityOld, _xVelocityOld, _xVelocity, t1,t2, res, _obstacles);
advectFieldMacCormack(dt0, _xVelocityOld, _yVelocityOld, _zVelocityOld, _yVelocityOld, _yVelocity, t1,t2, res, _obstacles);
advectFieldMacCormack(dt0, _xVelocityOld, _yVelocityOld, _zVelocityOld, _zVelocityOld, _zVelocity, t1,t2, res, _obstacles);
if(DOMAIN_BC_LEFT == 0) copyBorderX(_xVelocity, res);
else setZeroX(_xVelocity, res);
if(DOMAIN_BC_TOP == 0) copyBorderY(_yVelocity, res);
else setZeroY(_yVelocity, res);
if(DOMAIN_BC_FRONT == 0) copyBorderZ(_zVelocity, res);
else setZeroZ(_zVelocity, res);
setZeroBorder(_density, res);
setZeroBorder(_heat, res);
for (int x = 0; x < _totalCells; x++)
t1[x] = t2[x] = 0.0;
}
//////////////////////////////////////////////////////////////////////
// Advect using the MacCormack method from the Selle paper
//////////////////////////////////////////////////////////////////////
void FLUID_3D::advectMacCormackEnd2(int zBegin, int zEnd)
{
const float dt0 = _dt / _dx;
Vec3Int res = Vec3Int(_xRes,_yRes,_zRes);
// use force array as temp arrays
float* t1 = _xForce;
// advectFieldMacCormack2(dt, xVelocity, yVelocity, zVelocity, oldField, newField, tempfield, temp, res, obstacles)
advectFieldMacCormack2(dt0, _xVelocityOld, _yVelocityOld, _zVelocityOld, _densityOld, _density, _densityTemp, t1, res, _obstacles, zBegin, zEnd);
advectFieldMacCormack2(dt0, _xVelocityOld, _yVelocityOld, _zVelocityOld, _heatOld, _heat, _heatTemp, t1, res, _obstacles, zBegin, zEnd);
advectFieldMacCormack2(dt0, _xVelocityOld, _yVelocityOld, _zVelocityOld, _xVelocityOld, _xVelocityTemp, _xVelocity, t1, res, _obstacles, zBegin, zEnd);
advectFieldMacCormack2(dt0, _xVelocityOld, _yVelocityOld, _zVelocityOld, _yVelocityOld, _yVelocityTemp, _yVelocity, t1, res, _obstacles, zBegin, zEnd);
advectFieldMacCormack2(dt0, _xVelocityOld, _yVelocityOld, _zVelocityOld, _zVelocityOld, _zVelocityTemp, _zVelocity, t1, res, _obstacles, zBegin, zEnd);
if(_domainBcLeft == 0) copyBorderX(_xVelocityTemp, res, zBegin, zEnd);
else setZeroX(_xVelocityTemp, res, zBegin, zEnd);
if(_domainBcFront == 0) copyBorderY(_yVelocityTemp, res, zBegin, zEnd);
else setZeroY(_yVelocityTemp, res, zBegin, zEnd);
if(_domainBcTop == 0) copyBorderZ(_zVelocityTemp, res, zBegin, zEnd);
else setZeroZ(_zVelocityTemp, res, zBegin, zEnd);
setZeroBorder(_density, res, zBegin, zEnd);
setZeroBorder(_heat, res, zBegin, zEnd);
/*int begin=zBegin * _slabSize;
int end=begin + (zEnd - zBegin) * _slabSize;
for (int x = begin; x < end; x++)
_xForce[x] = _yForce[x] = 0.0f;*/
}
void FLUID_3D::advectMacCormackBegin(int zBegin, int zEnd)
{
Vec3Int res = Vec3Int(_xRes,_yRes,_zRes);
if(_domainBcLeft == 0) copyBorderX(_xVelocityOld, res, zBegin, zEnd);
else setZeroX(_xVelocityOld, res, zBegin, zEnd);
if(_domainBcFront == 0) copyBorderY(_yVelocityOld, res, zBegin, zEnd);
else setZeroY(_yVelocityOld, res, zBegin, zEnd);
if(_domainBcTop == 0) copyBorderZ(_zVelocityOld, res, zBegin, zEnd);
else setZeroZ(_zVelocityOld, res, zBegin, zEnd);
}
void FLUID_3D::advectFieldMacCormack2(const float dt, const float* xVelocity, const float* yVelocity, const float* zVelocity,
float* oldField, float* newField, float* tempResult, float* temp1, Vec3Int res, const unsigned char* obstacles, int zBegin, int zEnd)
{
float* phiHatN = tempResult;
float* t1 = temp1;
const int sx= res[0];
const int sy= res[1];
float*& phiN = oldField;
float*& phiN1 = newField;
// phiHatN = A^R(phiHatN1)
advectFieldSemiLagrange( -1.0*dt, xVelocity, yVelocity, zVelocity, phiHatN, t1, res, zBegin, zEnd); // uses wide data from old field and velocities (both are whole)
// phiN1 = phiHatN1 + (phiN - phiHatN) / 2
const int border = 0;
for (int z = zBegin+border; z < zEnd-border; z++)
for (int y = border; y < sy-border; y++)
for (int x = border; x < sx-border; x++) {
int index = x + y * sx + z * sx*sy;
phiN1[index] = phiHatN[index] + (phiN[index] - t1[index]) * 0.50f;
//phiN1[index] = phiHatN1[index]; // debug, correction off
}
copyBorderX(phiN1, res, zBegin, zEnd);
copyBorderY(phiN1, res, zBegin, zEnd);
copyBorderZ(phiN1, res, zBegin, zEnd);
// clamp any newly created extrema
clampExtrema(dt, xVelocity, yVelocity, zVelocity, oldField, newField, res, zBegin, zEnd); // uses wide data from old field and velocities (both are whole)
// if the error estimate was bad, revert to first order
clampOutsideRays(dt, xVelocity, yVelocity, zVelocity, oldField, newField, res, obstacles, phiHatN, zBegin, zEnd); // phiHatN is only used at cells within thread range, so its ok
}