void SemiLagrangeMAC(FlagGrid& flags, MACGrid& vel, MACGrid& dst, MACGrid& src, Real dt)
{
if (flags.isObstacle(i,j,k)) {
dst(i,j,k) = 0;
return;
}
// std::cout << " Don't worry, I MADE IT till here " << std::endl ;
if ( isNotFluidMAC(flags,i,j,k) ) {
dst(i,j,k) = src(i,j,k);
return;
}
// std::cout << " Don't worry, I REACHED till here " << std::endl ;
// get currect velocity at MAC position
// no need to shift xpos etc. as lookup field is also shifted
Vec3 xpos = Vec3(i+0.5f,j+0.5f,k+0.5f) - vel.getAtMACX(i,j,k) * dt;
Real vx = src.getInterpolatedComponent<0>(xpos);
Vec3 ypos = Vec3(i+0.5f,j+0.5f,k+0.5f) - vel.getAtMACY(i,j,k) * dt;
Real vy = src.getInterpolatedComponent<1>(ypos);
Vec3 zpos = Vec3(i+0.5f,j+0.5f,k+0.5f) - vel.getAtMACZ(i,j,k) * dt;
Real vz = src.getInterpolatedComponent<2>(zpos);
// std::cout << " Don't worry, I CAN till here " << std::endl ;
dst(i,j,k) = Vec3(vx,vy,vz);
// std::cout << " Don't worry, I COULD till here " << std::endl ;
}
void MacCormackClampMAC (FlagGrid& flags, MACGrid& vel, MACGrid& dst, MACGrid& orig, MACGrid& fwd, Real dt)
{
if (flags.isObstacle(i,j,k))
return;
if ( isNotFluidMAC(flags,i,j,k) ) {
dst(i,j,k) = fwd(i,j,k);
return;
}
Vec3 pos(i,j,k);
Vec3 dval = dst(i,j,k);
Vec3i upperClamp = flags.getSize() - 1;
// get total fwd lookup
Vec3i posFwd = toVec3i( Vec3(i,j,k) - vel.getCentered(i,j,k) * dt );
Vec3i posBwd = toVec3i( Vec3(i,j,k) + vel.getCentered(i,j,k) * dt );
// clamp individual components
dval.x = doClampComponentMAC<0>(upperClamp, orig, dval.x, toVec3i( pos - vel.getAtMACX(i,j,k) * dt) );
dval.y = doClampComponentMAC<1>(upperClamp, orig, dval.y, toVec3i( pos - vel.getAtMACY(i,j,k) * dt) );
dval.z = doClampComponentMAC<2>(upperClamp, orig, dval.z, toVec3i( pos - vel.getAtMACZ(i,j,k) * dt) );
// test if lookups point out of grid or into obstacle
if (posFwd.x < 0 || posFwd.y < 0 || posFwd.z < 0 ||
posBwd.x < 0 || posBwd.y < 0 || posBwd.z < 0 ||
posFwd.x > upperClamp.x || posFwd.y > upperClamp.y || ((posFwd.z > upperClamp.z)&&flags.is3D()) ||
posBwd.x > upperClamp.x || posBwd.y > upperClamp.y || ((posBwd.z > upperClamp.z)&&flags.is3D())
//|| flags.isObstacle(posFwd) || flags.isObstacle(posBwd) // note - this unfortunately introduces asymmetry... TODO update
)
{
dval = fwd(i,j,k);
}
// writeback
dst(i,j,k) = dval;
}