Applying Textures and Simple Animations to Our Scene - WebGL Game Development - page 221

Concepts like these actually make your game successful. This way, even if the game
is being rendered for a long period of time without a pause, the game performance
will not deteriorate.
Let's look at the implementation of the concept closely. Open 06-Multiple-Bullets-
Action.html in your editor.
We start with the definition of our variables, a bullets[] array that will hold the pool
of bullets, and nextBulletIndex that will hold the index of the next bullet to be used.
var bullets=[];
var nextBulletIndex=0;
We just added the loadStageObjects and addStageObjects functions here.
We discussed them earlier; we added them to make the flow more intuitive.
After each object is loaded in loadStageObject , it invokes addStageObject which
in turn invokes cloneObjects . The cloneObjects function checks for the object
type and then creates its corresponding clones by invoking the clone function of the
object. For the bullet, it creates 24 clones (one was already loaded, in total 25) and
then adds them to the bullets array. Each bullet also holds the reference to the cam
object in its camera property.
function loadStageObject(url,location,rotationX,rotationY,rotationZ){
...
addStageObject(stageObject,location,rotationX,rotationY,rotationZ);
...
}
function addStageObject(stageObject,location,rotationX,rotationY,rota
tionZ){
cloneObjects(stageObject);
stageObject.location=location;
stageObject.rotationX=rotationX;
stageObject.rotationY=rotationY;
stageObject.rotationZ=rotationZ;
stage.addModel(stageObject);
}
function cloneObjects(stageObject){
...
if(stageObject.name=="bullet"){
bullets.push(stageObject);
for(var j=0;j<24;++j){
var bullet=stageObject.clone();
bullet.camera=cam;