float variableOscillator::updateVariableOscillator(float deltaTime)
{
float returnVal;
float halfRange;
mCumTime += deltaTime;
// has the function crossed a max or a min?
if ((mGoingUp && (mCumTime > (mPeriod / 2.0f))) ||
(!mGoingUp && (mCumTime > mPeriod)))
{
mStartVal = mLastVal;
if (mGoingUp)
{
mEndVal = computeEndVal(mStartVal, mMin);
}
else
{
mEndVal = computeEndVal(mStartVal, mMax);
mCumTime = mCumTime - mPeriod;
}
mGoingUp = !mGoingUp;
}
halfRange = 0.5f * PxAbs(mEndVal - mStartVal);
returnVal = -halfRange * PxCos(mCumTime * PxTwoPi / mPeriod) + halfRange + PxMin(mStartVal, mEndVal);
mLastVal = returnVal;
return(returnVal);
}
variableOscillator::variableOscillator(float min, float max, float initial, float period) :
mMin(min),
mMax(max),
mPeriod(period),
mStartVal(initial),
mLastVal(initial)
{
mCumTime = 0.0f;
mGoingUp = true;
mEndVal = computeEndVal(mMin, mMax);
}
variableOscillator::variableOscillator(physx::PxF32 min, physx::PxF32 max, physx::PxF32 initial, physx::PxF32 period) :
mMin(min),
mMax(max),
mPeriod(period),
mStartVal(initial),
mLastVal(initial)
{
mCumTime = 0.0f;
mGoingUp = true;
mEndVal = computeEndVal(mMin, mMax);
}
