public void Update(float turnRate)
{
// continuously adjust the car's forward direction and speed
mTurnRate = turnRate;
/// Two distinct states to be concerned with
///
/// 1. There are next road segment to move towards
/// 2. Within the bounds of current road segment
///
if (mCurrentRoadSegment < mRoad.NumDefinedSegments())
{
Vector2 travelled = Center - mRoad.RoadSegmentStartPos(mCurrentRoadSegment);
if (travelled.Length() >= mRoad.RoadSegmentLength(mCurrentRoadSegment))
{
mCurrentRoadSegment++;
if (mCurrentRoadSegment >= mRoad.NumDefinedSegments())
{
ResetCarPosition();
}
}
}
else
{
ResetCarPosition();
}
UpdateCarDirAndSpeed();
}
private void UpdateBallDirAndSpeed(float ticksToTravel)
{
if (mNumTicksLeft <= 0) // beginning of a new road
{
mNumTicksLeft = ticksToTravel;
}
// use num ticks to determine how far we have travelled
float percentTravelled = (ticksToTravel - mNumTicksLeft) / ticksToTravel;
// ball's center position should be percentTravelled along the road's entire length
float roadLength = mRoad.RoadSegmentLength(mCurrentRoadSegment);
Vector2 v = mRoad.RoadSegmentDir(mCurrentRoadSegment);
Vector2 startPos = mRoad.RoadSegmentStartPos(mCurrentRoadSegment);
Center = startPos + percentTravelled * roadLength * v;
VelocityDirection = v;
// speed will be a function of what is remaining length and remaining ticks left.
float totalLength = mRoad.RoadSegmentLength(mCurrentRoadSegment);
float travelled = (Center - startPos).Length();
float remainLength = totalLength - travelled;
Speed = remainLength / mNumTicksLeft;
}
public bool Update(float ticksToTravel)
{
// continuously adjust the ball's forward direction and speed
bool newState = false;
/// distinct states to be concerned with
///
/// 1. Has a valide next state (road segment)
/// 1a. continues to be valid (within the bounds of road segment)
/// 1b. if not, trasition to next state
/// 2. No more valid next state: reset
///
if (mCurrentRoadSegment < mRoad.NumDefinedSegments())
{
Vector2 travelled = Center - mRoad.RoadSegmentStartPos(mCurrentRoadSegment);
if (travelled.Length() >= mRoad.RoadSegmentLength(mCurrentRoadSegment))
{
mCurrentRoadSegment++;
newState = true;
if (mCurrentRoadSegment >= mRoad.NumDefinedSegments())
{
ResetBallPosition();
}
}
}
else
{
ResetBallPosition();
newState = true;
}
// **** set dir and velocity only during state trasition ***
// CONSEQUENCE?: Last state/setment (under user control) may be
// wrong if user changes the state (Road Size/Dir)
// while we are in the segment
if (newState ||
(mCurrentRoadSegment == (mRoad.NumDefinedSegments() - 1))
)
{
UpdateBallDirAndSpeed(ticksToTravel);
}
// SOLUTION? Call UpdateBallDirAndSpeed() during _EVERY_ Update
// for LAST SEGMENT only.
return(newState);
}
