/// <summary>
/// Initialize the solver with parameters
/// </summary>
/// <param name="param"></param>
public void Init(SolverParams param)
{
NX = param.Width;
NY = param.Height;
NZ = param.Depth;
dims = new IntPos(NX, NY, NZ);
array_size = NX * NY * NZ;
dt = param.Dt;
dt_inv = -dt * NX;
force = param.Force;
source = param.Source;
tAmb = param.Tamb;
temperature = param.Temperature;
vorticity = param.Vorticity;
vel_x = new float[array_size];
vel_y = new float[array_size];
vel_z = new float[array_size];
vel_x_prev = new float[array_size];
vel_y_prev = new float[array_size];
vel_z_prev = new float[array_size];
density = new float[array_size];
density_prev = new float[array_size];
heat = new float[array_size];
heat_prev = new float[array_size];
pressure = new float[array_size];
pressure_prev = new float[array_size];
curl = new float[array_size];
compressibility = new float[array_size];
divergence = new float[array_size];
obstacles = new int[array_size];
}
private float get_interpolated_val_with_obs(float[] x, int[] obs, Vector3 pos, float h, IntPos n)
{
//The grid world pos is 0-1.
int i0 = (int)(pos.X / h);
int j0 = (int)(pos.Y / h);
int k0 = (int)(pos.Z / h);
int i1 = Clamp(i0 + 1, 0, n.X - 1); // returns 1??
int j1 = Clamp(j0 + 1, 0, n.Y - 1);
int k1 = Clamp(k0 + 1, 0, n.Z - 1);
//Calculate t per component
float it = (pos.X - i0 * h);
float jt = (pos.Y - j0 * h);
float kt = (pos.Z - k0 * h);
// Assume a cube with 8 points
//Front face
//Top Front MIX
float xFrontLeftTop = x[IX(i0, j1, k0)] * (1 - obs[IX(i0, j1, k0)]);
float xFrontRightTop = x[IX(i1, j1, k0)] * (1 - obs[IX(i1, j1, k0)]);
float xFrontTopInterp = MIX(xFrontLeftTop, xFrontRightTop, it);
//Bottom Front MIX
float xFrontLeftBottom = x[IX(i0, j0, k0)] * (1 - obs[IX(i0, j0, k0)]);
float xFrontRightBottom = x[IX(i1, j0, k0)] * (1 - obs[IX(i1, j0, k0)]);
float xFrontBottomInterp = MIX(xFrontLeftBottom, xFrontRightBottom, it);
//Back face
//Top Back MIX
float xBackLeftTop = x[IX(i0, j1, k1)] * (1 - obs[IX(i0, j1, k1)]);
float xBackRightTop = x[IX(i1, j1, k1)] * (1 - obs[IX(i1, j1, k1)]);
float xBackTopInterp = MIX(xBackLeftTop, xBackRightTop, it);
//Bottom Back MIX
float xBackLeftBottom = x[IX(i0, j0, k1)] * (1 - obs[IX(i0, j0, k1)]);
float xBackRightBottom = x[IX(i1, j0, k1)] * (1 - obs[IX(i1, j0, k1)]);
float xBackBottomInterp = MIX(xBackLeftBottom, xBackRightBottom, it);
//Now get middle of front -The bilinear interp of the front face
float xBiLerpFront = MIX(xFrontBottomInterp, xFrontTopInterp, jt);
//Now get middle of back -The bilinear interp of the back face
float xBiLerpBack = MIX(xBackBottomInterp, xBackTopInterp, jt);
//Now get the interpolated point between the points calculated in the front and back faces - The trilinear interp part
float xTriLerp = MIX(xBiLerpFront, xBiLerpBack, kt);
return(xTriLerp);
}