/// <summary>
/// Gets position of a car based on its lane and distance from the start in that lane.
/// </summary>
/// <param name="distance"></param>
/// <param name="lane"></param>
/// <param name="x"></param>
/// <param name="z"></param>
/// <param name="rotation">y rotation of the car, in radians.</param>
public void GetPosition(float distance, float lane, out float x, out float z, out float rotation)
{
// keep distance in [0, length)
distance -= Mathf.Floor(distance / length(lane)) * length(lane);
Vector3 pos = Vector3.zero;
Quaternion rot = Quaternion.identity;
float pieceStartDistance = 0;
float pieceEndDistance = 0;
x = 0;
z = 0;
rotation = 0;
for (int i = 0; i < 8; i++)
{
HighwayPiece piece = pieces[i];
pieceStartDistance = pieceEndDistance;
pieceEndDistance += piece.length(lane);
if (distance >= pieceEndDistance)
{
continue;
}
// inside piece i
// position and rotation local to the piece
float localX, localZ;
if (i % 2 == 0)
{
// straight piece
GetStraightPiecePosition(distance - pieceStartDistance, lane, out localX, out localZ, out rotation);
}
else
{
// curved piece
GetCurvePiecePosition(distance - pieceStartDistance, lane, out localX, out localZ, out rotation);
}
// transform
RotateAroundOrigin(localX, localZ, piece.startRotation, out x, out z);
x += piece.startX;
z += piece.startZ;
rotation += piece.startRotation;
break;
}
}
/// <summary>
/// Gets distance in another lane that appears to be the same distance in the given lane.
/// </summary>
public float GetEquivalentDistance(float distance, float lane, float otherLane)
{
// keep distance in [0, length)
distance = WrapDistance(distance, lane);
float pieceStartDistance = 0;
float pieceEndDistance = 0;
float pieceStartDistanceOtherLane = 0;
float pieceEndDistanceOtherLane = 0;
for (int i = 0; i < 8; i++)
{
HighwayPiece piece = pieces[i];
pieceStartDistance = pieceEndDistance;
pieceStartDistanceOtherLane = pieceEndDistanceOtherLane;
pieceEndDistance += piece.length(lane);
pieceEndDistanceOtherLane += piece.length(otherLane);
if (distance >= pieceEndDistance)
{
continue;
}
// inside piece i
if (i % 2 == 0)
{
// straight piece
return(pieceStartDistanceOtherLane + distance - pieceStartDistance);
}
else
{
// curved piece
float radius = curvePieceRadius(lane);
float radiusOtherLane = curvePieceRadius(otherLane);
return(pieceStartDistanceOtherLane + (distance - pieceStartDistance) * radiusOtherLane / radius);
}
}
return(0);
}
