/// <summary>
/// Calculates the LinearEquation of a line given two points
/// </summary>
/// <param name="_pointA">The first point</param>
/// <param name="_pointB">The second point</param>
/// <returns>The LinearEquation of the line</returns>
/// <returntype>LinearEquation</returntype>
public static LinearEquation GetLinearEquationFromPoints(Vector2f _pointA, Vector2f _pointB)
{
LinearEquation equation = new LinearEquation();
// Calculate the gradient
equation.Gradient = (_pointB.Y - _pointA.Y) / (_pointB.X - _pointA.X);
// Calculate the y-intercept using the values if _pointA. The values of _pointB can also be used, the answer will be the same
equation.YIntercept = _pointA.Y - (equation.Gradient * _pointA.X);
return(equation);
}
/// <summary>
/// Finds the intersection point of two lines
/// </summary>
/// <param name="_lineA">The linear equation of the first line</param>
/// <param name="_lineB">The linear equation of the second line</param>
/// <param name="_intersectPoint">The point at which these two lines intersect. (0, 0) if lines do not intersect</param>
/// <returns>True if the lines intersect at a point, false if lines do not intersect</returns>
/// <returntype>bool</returntype>
public static bool GetLinearIntersectionPoint(LinearEquation _lineA, LinearEquation _lineB, out Vector2f _intersectPoint)
{
// Get X value from equations.
float xValue = (_lineB.YIntercept - _lineA.YIntercept) / (_lineA.Gradient - _lineB.Gradient);
// Calculate intersection point on the Y axis, using both equations
float yPointLineA = _lineA.Gradient * xValue + _lineA.YIntercept;
float yPointLineB = _lineB.Gradient * xValue + _lineB.YIntercept;
// See if both Y points are equal, if so, _lineA and _lineB intersect. If not equal, lines do not intersect
if (yPointLineA == yPointLineB)
{
_intersectPoint = new Vector2f(xValue, yPointLineA);
return(true);
}
else
{
_intersectPoint = new Vector2f(-1, -1);
return(false);
}
}
