87 lines
2.6 KiB
C++
87 lines
2.6 KiB
C++
|
#include "stroid/topology/mapping.h"
|
||
|
|
#include <cmath>
|
||
|
|
#include <algorithm>
|
||
|
|
|
||
|
|
namespace stroid::topology {
|
||
|
|
void ApplyEquiangular(mfem::Vector &pos) {
|
||
|
|
const double x = pos(0);
|
||
|
|
const double y = pos(1);
|
||
|
|
const double z = pos(2);
|
||
|
|
|
||
|
|
const double absX = std::abs(x);
|
||
|
|
const double absY = std::abs(y);
|
||
|
|
const double absZ = std::abs(z);
|
||
|
|
|
||
|
|
const double maxAbs = std::max({absX, absY, absZ});
|
||
|
|
|
||
|
|
if (maxAbs < 1e-14) return;
|
||
|
|
|
||
|
|
if (absX == maxAbs) {
|
||
|
|
pos(1) = x * std::tan(M_PI / 4.0 * (y/x));
|
||
|
|
pos(2) = x * std::tan(M_PI / 4.0 * (z/x));
|
||
|
|
} else if (absY == maxAbs) {
|
||
|
|
pos(0) = y * std::tan(M_PI / 4.0 * (x/y));
|
||
|
|
pos(2) = y * std::tan(M_PI / 4.0 * (z/y));
|
||
|
|
} else { // absZ == maxAbs
|
||
|
|
pos(0) = z * std::tan(M_PI / 4.0 * (x/z));
|
||
|
|
pos(1) = z * std::tan(M_PI / 4.0 * (y/z));
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
void ApplySpheroidal(mfem::Vector &pos, const fourdst::config::Config<config::MeshConfig> &config) {
|
||
|
|
pos(2) *= (1.0 - config->flattening);
|
||
|
|
}
|
||
|
|
|
||
|
|
void TransformPoint(mfem::Vector &pos, const fourdst::config::Config<config::MeshConfig> &config, int attribute_id) {
|
||
|
|
double l_inf = 0.0;
|
||
|
|
for (int i = 0; i < pos.Size(); ++i) {
|
||
|
|
l_inf = std::max(l_inf, std::abs(pos(i)));
|
||
|
|
}
|
||
|
|
|
||
|
|
if (l_inf < config->r_instability) return;
|
||
|
|
|
||
|
|
// Gnomonic projection
|
||
|
|
const double r_log = pos.Norml2();
|
||
|
|
mfem::Vector unit_dir = pos;
|
||
|
|
unit_dir /= r_log;
|
||
|
|
|
||
|
|
ApplyEquiangular(unit_dir);
|
||
|
|
unit_dir /= unit_dir.Norml2(); // Re-normalize
|
||
|
|
|
||
|
|
if (l_inf <= config->r_core) {
|
||
|
|
const double t = l_inf / config->r_core;
|
||
|
|
double alpha = std::pow(t, config->core_steepness);
|
||
|
|
|
||
|
|
// Smoothstep function to apply C1 continuity
|
||
|
|
alpha = alpha * alpha * (3.0 - 2.0 * alpha);
|
||
|
|
|
||
|
|
mfem::Vector pos_cartesian = pos;
|
||
|
|
mfem::Vector pos_spherical = unit_dir;
|
||
|
|
|
||
|
|
pos_spherical *= l_inf;
|
||
|
|
|
||
|
|
|
||
|
|
for (int d = 0; d < pos.Size(); ++d) {
|
||
|
|
pos(d) = (1.0 - alpha) * pos_cartesian(d) + alpha * pos_spherical(d);
|
||
|
|
}
|
||
|
|
|
||
|
|
ApplySpheroidal(pos, config);
|
||
|
|
return;
|
||
|
|
}
|
||
|
|
if (l_inf <= config->r_star) {
|
||
|
|
const double xi = (l_inf - config->r_core) / (config->r_star - config->r_core);
|
||
|
|
const double r_phys = config->r_core + xi * (config->r_star - config->r_core);
|
||
|
|
|
||
|
|
pos = unit_dir;
|
||
|
|
pos *= r_phys;
|
||
|
|
|
||
|
|
ApplySpheroidal(pos, config);
|
||
|
|
} else {
|
||
|
|
pos = unit_dir;
|
||
|
|
pos *= l_inf;
|
||
|
|
|
||
|
|
ApplySpheroidal(pos, config);
|
||
|
|
}
|
||
|
|
}
|
||
|
|
}
|