I'm developing a canvas game that happens to have several scenes. Each scene might end up being a static final frame after having finished. The circumstances are that the ticker and the listener for the "tick" event are still running and keep on rendering full speed - which is asking for cpu usage.
I have tried to remove the listeners at the end of scene and add them back wenn the user interacts and starts the next scene.
I wonder what would be the "createJS" way of doing this.
I see some other options but am a bit lost how to proceed:
Caching the "whole" last frame. Will it make the ticker do "absolutely nothing" performance-wise?
Pause the ticker and check for the paused attribute in the handleTick method: Seems to not take the CPU usage completely down.
Can somebody recommend a way?
On a side note: I need my real "this" object inside the tick function that is bound to the ticker. How can I achieve this? Right now I use this code:
createjs.Ticker.addEventListener("tick", handleTick);
function handleTick(event) {
// Actions carried out each tick (aka frame)
if (!event.paused) {
// Actions carried out when the Ticker is not paused.
}
}
Inside handleTick "this" is not my object that added the listener.
A simple createjs.Ticker.removeEventListener("tick", handleTick); should do just fine as long as handleTick exists in your current scope. See this example.
There are a couple ways to access the scope of the object that assigned the tick listener. For example, you could simply assign this to a local variable like so:
var _this = this;
function handleTick(){
//"_this" now refers to the scope that defined handleTick.
}
Or you can use a delegate. In this example I'm using jQuery's proxy function to scope handleTick to this.
var handleTick = $.proxy(function(){
//"this" refers to the scope that defined handleTick.
}, this);
createjs.Ticker.addEventListener("tick", tickHandler);
Related
I'm working on an interactive map in Actionscript-3 (Adobe Flash CS6).
What I'm trying to do is, with a single button, to show multiple objects (movieclips) with each mouse click.
I'm currently working with this code, but I can't manage to find out how to show multiple movieclips, I can only show ONE:
btn_ally_unit.addEventListener(MouseEvent.CLICK, mostrar_ally_unit2);
function mostrar_ally_unit2(event:MouseEvent):void
{
map_editor.ally_unit.visible = true;
}
How do I extend this to apply to any number of movieclips?
I'm sure by infinite you mean indefinite.
Target the unit clicked by using the target property of the Event class. Looks something like this:
btn_ally_unit.addEventListener(MouseEvent.CLICK, mostrar_ally_unit2);
function mostrar_ally_unit2(event:MouseEvent):void
{
event.target.visible = true;
}
You see? (event:MouseEvent) is saying that this function expects one argument (a MouseEvent) which you are giving the variable name of event. That's a convention but I like to use me as an abbreviation for mouse event. Others just use the letter e. Ok. Now event has a property, target, which is the thing receiving the event. In this case it will be one of your units. Your units have a property of visible which you can toggle off like you have been doing but by using the relative mouse event target, you can use the same line of code for all units.
note
Of course you must add the event listener to each unit. You could make it part of the class or just add it when a new unit is instantiated.
note
Using the event flow in actionscript 3 can be tricky. Seek out a tutorial on this. Here is one link related to event flow from Adobe.
I've created a few buttons in Flash. I'm trying to make it so that if you click one button, the audio starts playing for that button. If you click another button, the active audio stops and the new audio of the button you clicked last start playing.
Any help please?
What you're describing is actually quite easy to do.
First things first, I recommend importing the audio into your Flash project. Alternatively, there is a way to play it directly from an external file. This is beyond the scope of my answer, so if you need help on that, you should post a question specifically covering it.
Assuming you have imported the audio file into your Flash project's library, make an as3 instance of it. (Right click the file in the library, click Properties --> ActionScript [tab] --> [Check] Export for ActionScript & [Enter name in] Class)
Now, create a definition of the sound in your code. (Assuming your two sounds were named "mySound1" and "mySound2" in the Class field of the previous step.)
var mySound1:Sound = new mySound1();
var mySound2:Sound = new mySound2();
Now, define your sound channel.
var mySoundChannel:SoundChannel = new SoundChannel();
There are two alternate ways of stopping one sound and playing another. The first is to create one function that does both every time. The second method is to create two formulas, one for "play" and one for "stop". You will need to decide which method works best for you. I'll use the two-function method below:
function stopSound():void
{
//This stops all sound in the sound channel.
//If there is nothing playing, nothing happens.
mySoundChannel.stop();
}
//In this function, we create an argument that allows us to tell the function
//what sound to we want it to play.
function playSound(soundname:String):void
{
mySoundChannel = this[soundname].play(0, 0);
}
[Note, you can tweak the play() properties to meet your needs, doing things like starting in the middle of the song, or looping it forever. 0,0 starts at the beginning, and doesn't loop. See the documentation for this.]
Now you hook up the event listeners for the buttons. (If you need help with event listeners, read the documentation.)
myButton1.addEventListener(Mouse.CLICK, btn1Click);
myButton2.addEventListener(Mouse.CLICK, btn2Click);
function btn1Click(evt:Event):void
{
stopSound();
playSound(mySound1);
}
function btn2Click(evt:Event):void
{
stopSound();
playSound(mySound2);
}
This should be enough information to get you started. In my game core, I actually have a custom class for dealing with sound playback that gives me the ability to repeat sounds, change volume, and keep sounds from conflicting with each other. I say that to emphasize that you can do quite a bit with the sound class. Do some digging in that documentation for ideas and help.
You may also consider putting a try-catch statement in the playSound function, since it will throw an reference error if you pass a name for a sound that doesn't exist.
I'm loading multiple swf files from the main menu which is never unloaded. I've done this with the following code... Only issue is that instead of unloading to the main menu I just see a white screen as if nothing is loaded.
function BackToMenu(i:MouseEvent):void
{
var BaseMovie:MovieClip = parent.parent as MovieClip;
BaseMovie.parent.removeChild(BaseMovie);
}
EDIT: I'll explain from the start I have a MainMenu.swf. The games are loaded from MainMenu.swf when the button relating to the game is clicked. When a game button is clicked on MainMenu.swf the game loads. When the player completes a game they are presented with the exit button which unloads the current game and shows the MainMenu.swf without having to re-load it.
First, you should remove one parent to make sure you are actually removing only the game:
function BackToMenu(i:MouseEvent):void
{
var BaseMovie:MovieClip = parent as MovieClip;
BaseMovie.parent.removeChild(BaseMovie);
}
This should take care of your most pressing problem, and allow you to return to the menu. You have, however, not really unloaded the game, but only removed it from the display list. This often means, that there are still sounds running, active key and/or mouse listeners, etc. - these must all be taken care of!
And, like I said, this will only fix your immediate problem. It is, however, neither a permanent solution, nor a good one: Since the main SWF is responsible for loading the games, it should also be responsible for disposing of them. You should put cleanup code into your game, but it should only be concerned with stopping any running scripts, sounds, etc. - simple rule: anything that is started within the game, should be stopped within the game. But it should not try to access objects further up in the display hierarchy, or try to unload itself.
The much better way to do this is by replacing all the above code, and letting the main SWF take care of removing the game, as well as unloading it from memory. For this, you have to do three things:
Instead of writing actual removeChild calls, etc., let your button dispatch a custom event to notify the main SWF that it should now be removed:
function onBackButtonClicked( event:MouseEvent ):void {
destroyGame(); // this would be the function that stops all the scripts
dispatchEvent( new Event( "FINISH_GAME", true ) );
}
Note that "FINISH_GAME" is now a "bubbling" event, i.e. it travels downward in the display hierarchy. We can now listen for this event in any ancestor display object containing the game.
In your main SWF, add an event listener to the Loader when the game was successfully loaded. This is done in the event listener that is called when the load process completes:
function onLoadComplete( event:Event ):void {
var loader:Loader = event.target.loader;
loader.addEventListener( "FINISH_GAME", onFinishGame, true );
}
Use the corresponding event handler to remove the game clip:
function onFinishGame( event:Event ):void {
var loader:loader = event.currentTarget;
loader.parent.removeChild( loader );
loader.unloadAndStop();
}
A few more things to consider:
The naming conventions in ActionScript advise us to use lower case names for methods and variables, and upper case only for types.
The same naming conventions suggest we use either "on" or "handle" as a prefix for event listeners, along with the name of the event. Thus, it should be onBackToMenu or rather, onBackButtonClicked, etc.
Since I don't know anything about the code you use for loading, I just assumed you have a complete listener, and you don't keep references to the loader. If you use a member variable, you can use that instead of event.target, resp. event.currentTarget.
I'm creating a GUI, but only if things go ok, so can i
addEventListener(Event.Complete, go) to something and in the go function create my GUI (grafical elements such as labels, lists, squares)?
Is it ok to do that?
Technically it's fine. crooksy88 gives a good example of supplying a default value for the event parameter to make the function more versatile.
However, for the sake of semantics, clarity, and maintenance I would usually prefer to separate things more. So mine might be set up more like this:
protected function onLoadComplete(e:Event):void {
initAppSettings();
createUI();
startApp();
}
It makes it much easier to understand the flow of the app and what each part does just by reading the function names. When I come back to this later, I'll know that my UI is created in the function named createUI and not have to figure out that it gets created in an event handler with a cryptic name like go or handleEvent.
Also, if I want to change the flow of my app, say to pop up a dialog once the load is complete before the UI is created, I just have to move around some function calls, instead of moving around large chunks of code.
Yes that is perfectly fine. The go function isn't part of the event listener.
function go(e:Event):void {
// do something
}
The sample above requires the event parameter from the listener (e:Event).
But you can modify the function so that the parameter is optional so you can call the go function any time you want
function go(e:Event = null):void {
// do something
}
The example above will be triggered by the listener and also by typing
go();
I have a function that states when movieclip1 is dragged and hits a line then it stops the drag, however it seems to stop the entire drag function in the swf on the other movieclips even though they arent called in the function. Can somebody please help me with this.
Regards
T
Here is the code:
function hitTest(event:Event):void
{
if (movieclip1.hitTestObject(line))
{
movieclip1.stopDrag();
}
else
{
}
}
Are you absolutely positive you only have one instance of movieclip1 on your stage? Definitely double check. Are you creating them dynamically, or are they preloaded when your SWF loads?
If they're preloaded:
Perhaps during testing you made some quick copies of it, and now those copies have the same name and they're all responding the same. That's my first guess.
If they're loaded dynamically:
Check the function where they're being created. If you're naming them in a loop (with a number on the end like the above), be sure that you're properly increasing the numeric value used on the end.