vec2 line_intersection(vec2 a1, vec2 a2,
                       vec2 b1, vec2 b2)
{
  float x1 = a1.x;
  float y1 = a1.y;
  float x2 = a2.x;
  float y2 = a2.y;

  float x3 = b1.x;
  float y3 = b1.y;
  float x4 = b2.x;
  float y4 = b2.y;

  float x1x2 = x1 - x2;
  float x1x3 = x1 - x3;
  float x3x4 = x3 - x4;
  float y1y2 = y1 - y2;
  float y1y3 = y1 - y3;
  float y3y4 = y3 - y4;

  float div = 1.0f / (x1x2 * y3y4 - y1y2 * x3x4);

  float t = (x1x3 * y3y4 - y1y3 * x3x4) * div;
  float u = (x1x2 * y1y3 - y1y2 * x1x3) * div;

  return {t, u};
}