/// <summary>
/// Gets the path directions.
/// </summary>
/// <returns>The path directions.</returns>
/// <param name="_path">Path data.</param>
/// <param name="_accuracy">Accuracy in decimals, lower value improves accuracy.</param>
public static Vector3[] GetPathDirections(PathData _path, float _accuracy)
{
/// <summary>
/// Get angle difference between routes.
/// Negative value, turns to left. Positive value, turns to right.
/// </summary>
///
/// Research on angle between world direction and curve direction.
///
/// If both values are negative...
/// -7f - -5f = -2f Expected value
/// -5f - -7f = 2f Expected value
///
/// If first value is positive...
/// 7f - -5f = 12f Opposite direction of Expected value
/// 5f - -7f = 12f Opposite direction of Expected value
///
/// If second value is positive...
/// -7f - 5f = -12f Opposite direction of Expected value
/// -5f - 7f = -12f Opposite direction of Expected value
///
/// First value should be the value turned in this equation.
/// Second value is to help with the turn to right direction.
/// If both values are negative, resulting angle is in right direction.
/// If values are in opposite directions, resulting angle is also opposite.
///
/// Direction should be changed when only other value is negative.
/// Repeating calculation is curve angle - direction angle.
/// If there's pair of different directions, turn the resulting angle aswell.
///
/// If statement explanation: Option 1 OR Option 2
/// 1: Curve angle is larger or same as 0f which is larger or same as direction angle
/// 2: Curve angle is smaller than 0f which is smaller than direction angle
/// Alternative: NOT (Option 1 OR Option 2)
/// 1: both curve and direction angles are smaller than 0f
/// 2: both curve and direction angles are larger or same as 0f
///
/// Programmatically alternative statement has extra NOT.
///
/// Result, true when values are in different ends of 0f, positive and negative sides.
/// In math 0f is considered positive value.
///
/// Great usage of 3 hours... Study © Juha-Matti Kokkonen 11.02.2019
// Get path direction
Vector3 pathDirection = _path.endPosition - _path.startPosition;
pathDirection = new Vector3(pathDirection.x, 0f, pathDirection.z);
// Get curve direction
Vector3 curveDirection = new Vector3(
_path.curve.keys[_path.curve.keys.Length].time, 0f,
_path.curve.keys[_path.curve.keys.Length].value
);
float
curveAngle = Vector3.Angle(Vector3.forward, curveDirection),
directionAngle = Vector3.Angle(Vector3.forward, pathDirection),
angle = curveAngle - directionAngle;
if ((curveAngle >= 0f && 0f > directionAngle) || (curveAngle < 0f && 0f <= directionAngle))
{
angle = -angle;
}
// Create Quaternion which turns all vectors with the angle.
Quaternion turner = Quaternion.AngleAxis(angle, Vector3.up);
// Get curve directions.
Vector2[] points = AnimationCurveParser.GetCurveDirections(_path.curve, _accuracy);
// Get distance between points
float distance = Vector3.Distance(_path.startPosition, _path.endPosition);
// Change curve directions to represent 3D world directions
List <Vector3> directions = new List <Vector3>();
foreach (Vector2 point in points)
{
// Use Quaternion to rotate curve closer to 3D world direction.
directions.Add(turner * new Vector3(point.x, 0f, point.y) * distance);
}
return(directions.ToArray());
}
/// <summary>
/// Gets the accurate length of the path.
/// </summary>
/// <returns>The accurate path length.</returns>
/// <param name="_path">Path data.</param>
/// <param name="_accuracy">Accuracy.</param>
public static float GetAccuratePathLength(PathData _path, float _accuracy)
{
return(AnimationCurveParser.GetAccurateCurveLength(_path.curve, _accuracy)
* Vector3.Distance(_path.startPosition, _path.endPosition));
}
