Works out the percentage completed given the time passed in. This uses the formula: s = ut + 1/2at^2 We accelerate as at the rate needed (a=4) to get to 0.5 at t=0.5, and then decelerate at the same rate to end up at 1.0 at t=1.0.

public void onTimer( 
   int iTime,
   out double dPercentage,
   out bool bCompleted
)

public:
void onTimer( 
   int iTime,
   [Out] double dPercentage,
   [Out] bool bCompleted
)