include/crbn/solver/quadratic.hpp

#ifndef __quadratic_hpp__
#define __quadratic_hpp__

#include <crbn/basic/scalar.hpp>

// Solve a quadratic equation. It only returns real roots.
inline int quadratic_r(const float& a, const float& b, const float& c, float& x0, float& x1) {
  float delta = (b * b) - (4.0 * a * c);
  
  if(delta < 0) return 0;

  if(delta > 0) {
    delta = sqrt(delta);
    x0 = (-b - delta) / (2.0 * a);
    x1 = (-b + delta) / (2.0 * a);
    
    return 2;
  }

  x0 = x1 = - b / (2.0 * a);
  return 1;
}

#endif

---