Function vm_GetMagnitudeFast

vecmat/vector.cpp:421–449

}

float vm_GetMagnitudeFast(vector *v) {
  float a, b, c, bc;

  a = fabs(v->x);
  b = fabs(v->y);
  c = fabs(v->z);

  if (a < b) {
    float t = a;
    a = b;
    b = t;
  }

  if (b < c) {
    float t = b;
    b = c;
    c = t;

    if (a < b) {
      float t = a;
      a = b;
      b = t;
    }
  }

  bc = (b / 4) + (c / 8);

  return a + bc + (bc / 2);
}

// Normalize a vector using an approximation of the magnitude
// Returns:  the magnitude before normalization