cpp-game-engine/math/common.cpp

//
//  common.cpp
//  math
//
//  Created by Sam Jaffe on 8/20/16.
//

#include "common.hpp"
#include "angle.hpp"
#include "shape.hpp"
#include "vector.hpp"

namespace math {
  vec2 rotate(vec2 const & c, vec2 const & p, radian r) {
    vec2 trans = p - c;
    vec2 vcos = trans * static_cast<float>(cos(r));
    vec2 vsin = trans * static_cast<float>(sin(r));
    return {
      vcos[0] - vsin[1] + c[0],
      vsin[0] - vcos[1] + c[1]
    };
  }
  
  quad rotate(vec2 const & c, quad const & q, radian r) {
    return {
      rotate(c, q.ll, r),
      rotate(c, q.lr, r),
      rotate(c, q.ur, r),
      rotate(c, q.ul, r)
    };
  }
}