/// <summary>
/// This is a coroutine for walking a spline section at constant speed in a defined time duration.
/// </summary>
/// <remarks>
/// Based on the specified duration and the length of the specified spline section it calculates the required speed and then calls WalkAtSpeed.
/// </remarks>
/// <param name="startIndex">The start index of the spline section. Use start index greater than end index to invert the direction of motion.</param>
/// <param name="endIndex">The end index of the spline section. Use end index lesser than start index to invert the direction of motion.</param>
/// <param name="duration">The desired duration to cover the spline section.</param>
/// <param name="transform">An optional transform object where to apply motion.</param>
/// <param name="mode">The SplineWalkerMode: once, loop or ping pong.</param>
/// <param name="lookForward">If set to <c>true</c> the transform rotation is set to curve direction.</param>
/// <param name="completeFunction">This function will be called upon motion completion (only form SplineWalkerMode.Once).</param>
/// <param name="updateFunction">This function will be called every frame.</param>
/// <seealso cref="WalkAtSpeed"/>
public IEnumerator WalkDuration(
int startIndex, int endIndex,
float duration, Transform transform, SplineWalkerMode mode = SplineWalkerMode.Once, Boolean lookForward = true,
WalkCompleteFunction completeFunction = null, WalkUpdateFunction updateFunction = null)
{
_UpdateLengths();
// Calculate length from startPoint to endPoint
int a = startIndex, b = endIndex;
if (a > b)
{
int tmp = a;
a = b;
b = tmp;
}
float l = _arcLengths[b] - _arcLengths[a];
return(WalkAtSpeed(startIndex, endIndex, l / duration, transform, mode, lookForward, completeFunction, updateFunction));
}
/// <summary>
/// This is a coroutine for walking a spline section at constant speed.
/// </summary>
/// <remarks>
/// It uses the function GetProgressAtSpeed in order to update the curve parameter at each frame mantaining a constant speed.
/// </remarks>
/// <param name="startIndex">The start index of the spline section. Use start index greater than end index to invert the direction of motion.</param>
/// <param name="endIndex">The end index of the spline section. Use end index lesser than start index to invert the direction of motion.</param>
/// <param name="velocity">The desired velocity.</param>
/// <param name="transform">An optional transform object where to apply motion.</param>
/// <param name="mode">The SplineWalkerMode: once, loop or ping pong.</param>
/// <param name="lookForward">If set to <c>true</c> the transform rotation is set to curve direction.</param>
/// <param name="completeFunction">This function will be called upon motion completion (only form SplineWalkerMode.Once).</param>
/// <param name="updateFunction">This function will be called every frame.</param>
/// <seealso cref="WalkDuration"/>
public IEnumerator WalkAtSpeed(
int startIndex, int endIndex,
float velocity, Transform transform = null, SplineWalkerMode mode = SplineWalkerMode.Once, Boolean lookForward = true,
WalkCompleteFunction completeFunction = null, WalkUpdateFunction updateFunction = null)
{
float progress = startIndex / (float)curveCount;
float limit = endIndex / (float)curveCount;
yield return(GetPoint(progress));
int direction = endIndex > startIndex ? 1 : -1;
while (true)
{
progress = GetProgressAtSpeed(progress, velocity, direction);
if ((direction == 1 && progress >= limit) ||
(direction == -1 && progress <= limit))
{
if (mode == SplineWalkerMode.Once)
{
break;
}
else if (mode == SplineWalkerMode.PingPong)
{
direction *= -1;
if (direction * (endIndex - startIndex) > 0)
{
limit = endIndex / (float)curveCount;
}
else
{
limit = startIndex / (float)curveCount;
}
continue;
}
else if (mode == SplineWalkerMode.Loop)
{
progress -= limit - startIndex / (float)curveCount;
continue;
}
}
Vector3 position = GetPoint(progress);
if (transform != null)
{
transform.position = position;
if (lookForward)
{
transform.LookAt(transform.position + GetDirection(progress));
}
}
if (updateFunction != null)
{
updateFunction(position, progress);
}
yield return(null);
}
if (completeFunction != null)
{
completeFunction();
}
}
