Yes a vector is probably appropriate. On Wed, Jul 20, 2011 at 10:20 AM, Nathan BIAGINI <nathan.o...@gmail.com>wrote:
> Ok. But all the calcul of how long the bullet will take to reach the target > etc... will be made byn using vector? I mean, using a vector still viable? > > > 2011/7/20 Joe Ranalli <jrana...@gmail.com> > >> It depends what you're trying to do. >> >> If you draw the straight line between the tower and the enemy and use that >> vector to translate a bullet each tick, the bullets might miss the enemy. >> Think about it this way, the bullet moves 2 steps toward the enemy, then the >> enemy moves 1 step, then the bullet moves 2, etc. Because the enemy moves >> the bullet will have to change its direction through the flight. So you >> could calculate the direction vector between the bullet and the enemy every >> tick and have the bullet move that direction. That would make the bullets >> kind of arc to the target. >> >> If you want to have the bullet go straight to the right spot, you need to: >> 1) calculate how long the bullet will take to get to the enemy >> 2) calculate where the enemy will be at that time (newposition) >> 3) calculate how long it will take the bullet to get to newposition >> 4) recalculate newposition based on the new time >> >> Technically you could iterate that repeatedly until newposition >> converges. Practically, iterating once probably gets you close enough >> unless the movement is extremely complicated. >> >> >> On Wed, Jul 20, 2011 at 9:14 AM, Nathan BIAGINI <nathan.o...@gmail.com>wrote: >> >>> Hi everyone, >>> >>> i would like to know what are the common way to handle "trajectory" in a >>> 2d game. In fact, i think of writing a tower defense game and i wonder how >>> to handle the trajectory of the missile launch by the towers. I though of >>> getting the pos of the tower and the target and create a vector between this >>> two entitites to make a sprite translation of this vector but there is maybe >>> some tricky stuff to do it. >>> >>> Thanks in advance and happy game making all :-) >>> >> >> >
