GameMaker - Collision Line Point

/// @function                   collision_line_point(_x1, _y1, _x2, _y2, _object, _precision, _notme)
/// @param {real} _x1           The x coordinate of the start of the line
/// @param {real} _y1           The y coordinate of the start of the line
/// @param {real} _x2           The x coordinate of the end of the line
/// @param {real} _y2           The y coordinate of the end of the line
/// @param {index} _object      The object to check for instance collisions
/// @param {bool} _precision    Whether or not to use precise collision checking (slower)
/// @param {bool} _notme        Whether or not to check for collision with the calling instance
/// @description                A collision line function which returns an array with the instance and impact point of collision

function collision_line_point(_x1, _y1, _x2, _y2, _object, _precision, _notme)
{
    var _inst = collision_line(_x1, _y1, _x2, _y2, _object, _precision, _notme),
        _rx = _x1,
        _ry = _y1;

    if (_inst != noone) {

        var _count = ceil(log2(point_distance(_x1, _y1, _x2, _y2))) + 1,
            _p0 = 0,
            _p1 = 1;

        _x2 -= _x1;
        _y2 -= _y1;

        repeat (_count) {

            var _np = _p0 + (_p1 - _p0) * 0.5,
                _nx = _x1 + _x2 * _np,
                _ny = _y1 + _y2 * _np,
                _px = _x1 + _x2 * _p0,
                _py = _y1 + _y2 * _p0,
                _inst2 = collision_line(_px, _py, _nx, _ny, _object, _precision, _notme);

            if (_inst2 != noone) {
                _inst = _inst2;
                _rx = _nx;
                _ry = _ny;
                _p1 = _np;
            } else _p0 = _np;

        }
    }

    // Returns instance id (or noone), and the impact x/y
    return [_inst, _rx, _ry];
}