1 | Entity->tBob += 0.5*ddtBob*dt*dt + Entity->dtBob*dt; |
instead of
1 | Entity->tBob += ddtBob*dt*dt + Entity->dtBob*dt; |
since f(x)=ax integrates to F(x)=(a/2)x^2.
Also, polynomial expressions are often calculated in the form (...(a_n x + a_{n-1})x ... + a_1)x + a_0 for efficiency. Though it isn't much, maybe the line should say
1 | Entity->tBob += (0.5*ddtBob*dt + Entity->dtBob)*dt; |