Efficient maths algorithm to calculate intersections

Question

For a game I am developing I need an algorithm that can calculate intersections. I have solved the problem, but the way I have done it is really nasty and I am hoping someon

Answer 1

float x12 = x1 - x2;
float x34 = x3 - x4;
float y12 = y1 - y2;
float y34 = y3 - y4;

float c = x12 * y34 - y12 * x34;

if (fabs(c) < 0.01)
{
  // No intersection
  return false;
}
else
{
  // Intersection
  float a = x1 * y2 - y1 * x2;
  float b = x3 * y4 - y3 * x4;

  float x = (a * x34 - b * x12) / c;
  float y = (a * y34 - b * y12) / c;

  return true;
}

Formulas taken from:
Line-line intersection - Wikipedia