Function ConvertEulerToAxisAmount

physics/collide.cpp:1523–1568

}

void ConvertEulerToAxisAmount(vector *e, vector *n, float *w) {
  float rotspeed = vm_GetMagnitude(e);
  matrix rotmat;
  vector e_n;
  float scale = rotspeed / .0001f;

  // If there isn't a rotation, return something valid
  if (rotspeed == 0.0f || scale == 0.0f) {
    *n = Zero_vector;
    n->y = 1.0f;
    *w = 0.0f;

    return;
  }

  e_n = *e / scale;

  CollideAnglesToMatrix(&rotmat, e_n.x, e_n.y, e_n.z);

  // This is from Graphics Gems 1 p.467  I am converting from a angle vector
  // to the normal of that rotation (you can also get the angle about that normal, but
  // we don't need it)
  n->x = rotmat.uvec.z - rotmat.fvec.y;
  n->y = rotmat.fvec.x - rotmat.rvec.z;
  n->z = rotmat.rvec.y - rotmat.uvec.x;

  if (*n != Zero_vector) {
    vm_NormalizeVector(n);

    float ct = (rotmat.rvec.x + rotmat.uvec.y + rotmat.fvec.z - 1.0f) / 2.0f;
    if (ct < -1.0f)
      ct = -1.0f;
    else if (ct > 1.0f)
      ct = 1.0f;

    float v = acos(ct);
    float z = sin(v);

    *w = rotspeed * ((2.0f * PI) / (65535.0f));

    if (z >= 0.0f)
      *n *= -1.0f;
  } else {
    *w = 0.0f;
  }
}

void ConvertAxisAmountToEuler(vector *n, float *w, vector *e) {
  float s;