void Fluid::dens_temp_step(float dt)
{
add_source(sd, d, dt);
add_source(sT, T, dt);
SWAPFPTR(d0, d);
diffuse(0, d0, d, diffusion, dt);
SWAPFPTR(d0, d);
SWAPFPTR(T0, T);
advect_cool(0, d0, d, T0, T, u, v, w, dt);
}
void Fluid::dens_step(float dt)
{
add_source(sd, d, dt);
#ifdef DIFFUSE
SWAPFPTR(d0, d);
diffuse(0, d0, d, diffusion, dt);
#endif
#ifdef ADVECT
SWAPFPTR(d0, d);
advect(0, d0, d, u, v, w, dt);
#endif
}
/* order perm[i0..i1-1] such that *perm[i] <= *perm[j]
forall i0<=i<q and q<=j<i1 */
static void hoare_selectp (const float **perm, int i0, int i1, int q)
{
float pivot = PERM(i0);
int j0, j1, lim;
assert (i1 - i0 > 1 && q > i0 && q < i1);
for (j0 = i0, j1 = i1 ; 1 ; ) {
while (j0 < j1 - 1) {
j0++;
if (PERM(j0) > pivot)
goto endseginf;
}
lim = j1;
break;
endseginf:
while (j1 - 1 > j0) {
j1--;
if (PERM(j1) <= pivot)
goto endsegsup;
}
lim = j0;
break;
endsegsup:
SWAPFPTR (j0, j1);
}
assert (lim > i0);
if (lim == i1) {
SWAPFPTR (i0, i1 - 1);
lim = i1 - 1;
}
if (lim == q)
return;
else if (q < lim)
hoare_selectp (perm, i0, lim, q);
else
hoare_selectp (perm, lim, i1, q);
}
void Fluid::vel_step(float dt)
{
add_source(su, u, dt);
add_source(sv, v, dt);
add_source(sw, w, dt);
add_buoyancy(dt);
vorticity_confinement(dt);
#ifdef DIFFUSE
SWAPFPTR(u0, u); SWAPFPTR(v0, v); SWAPFPTR(w0, w);
diffuse(1, u0, u, viscosity, dt);
diffuse(2, v0, v, viscosity, dt);
diffuse(3, w0, w, viscosity, dt);
project();
#endif
#ifdef ADVECT
SWAPFPTR(u0, u); SWAPFPTR(v0, v); SWAPFPTR(w0, w);
advect(1, u0, u, u0, v0, w0, dt);
advect(2, v0, v, u0, v0, w0, dt);
advect(3, w0, w, u0, v0, w0, dt);
project();
#endif
}
