Accurate BPM event listener in AS3 - actionscript-3

I'm trying to sync animation to music at a specific BPM. I've tried using the Timer but it isn't accurate when dealing with small intervals in milliseconds. I did some reading and found an alternate method that uses a small silent audio file and the SOUND_COMPLETE event as a Timer.
I used 167ms long sound file with this code.
package
{
import flash.events.Event;
import flash.events.EventDispatcher;
import flash.media.Sound;
import flash.media.SoundChannel;
import flash.net.URLRequest;
public class BetterTimer extends EventDispatcher
{
private var silentSound:Sound;
public function BetterTimer(silentSoundUrl:String):void {
super();
silentSound = new Sound( new URLRequest(silentSoundUrl) );
silentSound.addEventListener(Event.COMPLETE, start);
}
public function start():void {
this.timerFired( new Event("start") );
}
private function timerFired(e:Event):void {
dispatchEvent( new Event("fire") );
var channel:SoundChannel = silentSound.play();
channel.addEventListener(Event.SOUND_COMPLETE, timerFired, false, 0, true);
}
}
}
This still doesn't stay on beat. Is the Flash Player capable of accuracy with sound?

You can also use the new Sound API with the SampleDataEvent and basically play your MP3 manually using Sound.extract(). In that case you know the latency up front and can even count up to the sample when your (delayed) event should happen.
This is what we do in the AudioTool and it works very well.

This is very tricky to get right! There's a small lib called BeatTimer that tries to do this. I haven't tried this code myself, but if it does what it claims it should be exactly what you need.

Setting the frame rate so that the event interval is a multiple of the frame rate might help (for example, 167ms equals 6 fps; 12, 18, 24 etc. are then also ok).
If I understood correctly, better solution would be to use the enterframe event. Instead of determining the position of the animation by counting the events, calculate it using elapsed time (getTimer or sound position). This would also make the animation work on slower computers that have lag.

I was looking through the popforge library's AudioBuffer and tried using one of the approach. That's the create a sync sound. The following is what i did.
var syncSamples:ByteArray = new ByteArray();
syncSamples.length = (2646000 / _bpm) << 1; /*44100*60=2646000*/
SoundFactory.fromByteArray(syncSamples, Audio.MONO, Audio.BIT16, Audio.RATE44100, soundInit);
The ms delay is pretty close, eg: at 120 BPM, it's between 509 - 512ms. The question is, am I going in the right direction?

Related

AS3 || Using same function with different variables

I'm very new to AS3 and I'm trying to learn by experimenting in flash, by making a simple 2D farming game with very simple code.
I've made one crop field out of 6 that works, which is a movieclip with different frames for each fruit growing. For example, frame 1-5 is a strawberry growing where frame 5 is when it's ready to be picked, and then 6-10 is of carrots, etc
Is there a way for me to make it so that I don't have to write the exact same code for the next crop field, and instead change the variables in this code depending on which crop field you click on?
Here's an example of the code
if (field1.currentFrame == 1)
{
field1.nextFrame();
infoText.text = "You've watered the crop. Let's wait and see how it turns out!";
function plantStrawberry():void
{
field1.nextFrame();
if (field1.currentFrame == 5)
{
clearInterval(strawberryInterval);
}
}
var strawberryInterval = setInterval(plantStrawberry,5000);
}
pls no judgerino, as said, I'm very new to AS3, lol.
There are a few ways to go about being DRY (don't repeat yourself) with your code in this scenario. The best way, would be to learn to use classes. Classes are blueprints, and are made for these very scenarios.
Here is an example of a simple class to do what you'd like. In Flash/Animate, go to file, then new, then 'ActionScript 3.0 Class' - give it a name of Crop.
In the document that comes up, there should be some basic boilerplate code. Everything should wrapped in a package. The package tells flash where to find this class - so this example, leave it as is (just package {) and save this file in the same folder as your .fla. All functions need to be wrapped in a class declaration, this should be generated for you based off the name you put in (Crop). Next you'll see one function, that has the same name as the class. This is called a constructor, and this function runs whenever you create a new instance of this class. Since classes are blueprints, you create instances of them that are objects - those objects then get all the code you put in this class.
So, to start, you should have this:
package {
public class Crop {
public function Crop() {
// constructor code
}
}
}
Let's go ahead and put your code in. See the code comments for details:
package {
//imports should go here
import flash.display.MovieClip;
import flash.events.Event;
import flash.events.TimerEvent;
import flash.utils.Timer;
//lets make this class extend MovieClip - that means it will be a MovieClip in addition to everything else you add below
public class Crop extends MovieClip {
//instead of setInterval, use a timer - it's easier to manage and cleanup
//in class files, variables and functions have access modifiers, that's what the public and private words are about
//private means only this class can ever use the var/function
private var timer:Timer;
public function Crop() {
//initialize the timer - have it tick every 5 seconds, and repeat 4 times (to move you from frame 1 - 5)
timer = new Timer(5000, 4);
//listen for the TIMER event (which is the tick) and call the function 'grow' when the timer ticks
timer.addEventListener(TimerEvent.TIMER, grow);
}
//a function that starts the timer ticking
public function startGrowing():void {
timer.start();
}
//this function is called every timer tick.
private function grow(e:Event):void {
this.nextFrame(); //go to the next frame of your crop
}
}
}
Save the file. Now that you have this class, you need to attach it to your library assets so they all get this functionality.
In the library panel, for each of your crop objects, right click (or ctrl+click on Mac) and go to properties. In the properties, click advanced, and give it a unique class name (for instance Strawberry). Then in the base class field, put Crop (the class we just made). Repeat for the others.
Now on your timeline, when you want a crop to start growing, you can do:
field1.startGrowing(); //assuming your instance `field1` is one of the crops that you assigned the base class `Crop` to
Hopefully this gives an entry point into the power of classes. You can add more functionality into this one and it automatically apply to all the crops you attached it to.
Although BFAT's tutorial is absolutely correct, it is not the only way to do things, moreover, if you ever move from Flash and AS3 to something else, or even try Starling (a framework that allows to build fast and non-laggy mobile applications in Flash/AS3), you'll find that concept not applicable. It is very Flash-y and I applause to it though.
Instead of making each field subclass the abstract (means, it is never instantiated by itself) Crop class, you can make the Crop class take 1 of these 6 fields as an argument on creation (or later). Basically, you tell "I want to make crop field with wheat graphics". So, let me redo that class a bit.
package
{
// Imports.
import flash.display.Sprite;
import flash.display.MovieClip;
import flash.utils.Timer;
import flash.events.Event;
import flash.events.TimerEvent;
public class Crop extends Sprite
{
// I agree with the use of Timer.
private var timer:Timer;
// Visuals go here.
private var field:MovieClip;
// Class constructor.
public function Crop(FieldClass:Class)
{
// With "new" keyword you can omit ()
// if there are no mandatory arguments.
field = new FieldClass;
field.stop();
addChild(field);
}
// A function that starts the timer ticking.
public function startGrowing():void
{
timer = new Timer(5000, 4);
timer.addEventListener(TimerEvent.TIMER, grow);
timer.start();
}
// This function is called every timer tick.
private function grow(e:Event):void
{
// Command the graphics to go to the next frame.
field.nextFrame();
}
}
}
Then, the usage. When you create fields, you need to set AS3 classes to them to have access, leaving base class as is, Flash will automatically set it to non-specific MovieClip. Lessay, you have crops.Wheat field and crops.Barley field.
import Crop;
import crops.Wheat;
import crops.Barley;
var W:Crop = new Crop(Wheat);
var B:Crop = new Crop(Barley);
addChild(W);
addChild(B);
B.x = 100;
W.startGrowing();
B.startGrowing();

AS3 best way to mass crop tiles from a tilesheet?

Okay so I'm trying to create a program that reads a map from a csv file and then draw each tile using a tilesheet. Reading in the map works fine and I could draw certain tiles depending on the value read in but only if I embedded the images. Obviously this is impractical when it comes to having >20 different tiles; embedding them all just wouldn't be smart.
This is my code for drawing the tiles from the tilesheet.
package
{
import flash.display.Graphics;
import flash.display.Sprite;
import flash.display.Bitmap;
import flash.display.BitmapData;
import flash.geom.Rectangle;
import flash.geom.Point;
public class Tile extends Sprite
{
[Embed(source="../bin/lib/TileSheet.png")]
private var BitmapClass:Class;
private var tileBitmap:Bitmap = new BitmapClass();
var tileSize = 25;
var tileSheetLength = 20;
var sheetColumns:int = tileBitmap.bitmapData.width / tileSize;
var pt:Point = new Point(0, 0);
var bmp:Bitmap = new Bitmap(new BitmapData(tileSize, tileSize, true, 0));
public function Tile(collide:Boolean, id:int)
{
Draw(id);
}
private function Draw(id:int):void
{
var col:int = id % sheetColumns;
var row:int = Math.floor(id / sheetColumns);
var rect:Rectangle = new Rectangle(col * tileSize, row * tileSize, tileSize, tileSize);
bmp.bitmapData.copyPixels (tileBitmap.bitmapData, rect, pt, null, null, true);
this.addChild(bmp);
}
public function Update():void
{
}
}
}
'
So what I need help with is optimising this code so that I can run it around 1,900 times rather than the 910-911 times it can handle right now before just closing without errors. If there is a better way of doing this please let me know and any constructive criticism is always appreciated!
You have a Tile class which has a BitmapClass instance. Perhaps that should be a static property (belonging to the class, not every instance) to begin with. My guess is you're using the memory for the whole tile sheet every since time you instantiate a single tile which you probably don't want to do.
Another thing I'm noticing is you're creating a new BitmapData for each tile, when in fact you probably just need the tile data (it's id/coordinates) so you can copy pixels into the final BitmapData which gets displayed on stage. Perhaps you need to a class to manage resources(embedded bitmaps) and another to manage the different Tile instance(which should hold render data and references to pixels, but shouldn't store the actual data) and copying to the main buffer.
Also, it's a good idea to use BitmapData's lock() and unlock() functions for performance when doing multiple pixel operations on an image.
Have a look at Lee Brimelow's Sprite Sheet tutorials (part 1,2 and especially 3). They're really easy to follow and useful.
Also, it might be worth having a look at the have a look at the GPU accelerated IsoHill
library.
I've used IsoHill for a project before and it's quite fast, but it's best to get comfortable with the basics first, otherwise this might seem a bit much.

can't add an event listener to a mask AS3 Flash

New to AS3. Trying to do a simple mask exercise, but for some reason when I add event listener to 'myMask', the event doesn't trigger. I tried turning both 'myMask' and 'theMaskee' as sprites and movie clips, but no luck. It does trigger if I don't assign 'myMask' as a mask to 'theMaskee'. It also works if I add the listener directly to the stage, but eventually I want to put many things on the stage, and I'm afraid there will be conflict if it has to listen to the same event but perform several functions... especially if I need them one at a time. I looked through textbooks and the API and mask-related questions other people had, but I can't find anything relating to my specific situation.
(this code is written directly in the timeline)
import flash.display.Bitmap;
import flash.display.BitmapData;
import flash.display.MovieClip;
import flash.display.Sprite;
import flash.sampler.NewObjectSample;
import flash.events.MouseEvent;
var temp = new backGround();
var myBG:Bitmap = new Bitmap(temp);
temp = new splashMaskee();
var theMaskee:Bitmap = new Bitmap(temp);
var myMask = new MovieClip();
myMask.graphics.beginFill(0x000000, 0);
myMask.graphics.drawRect(0, 0, 800, 600);
myMask.graphics.endFill();
myMask.cacheAsBitmap = true;
theMaskee.cacheAsBitmap = true;
theMaskee.mask = myMask;
addChild(myBG);
addChild(theMaskee);
addChild(myMask);
myMask.addEventListener(MouseEvent.CLICK, myMaskClick);
//stage.addEventListener(MouseEvent.CLICK, myMaskClick);
function myMaskClick(e:MouseEvent):void
{
trace("click");
myMask.graphics.beginFill(0x000000, 1);
myMask.graphics.drawCircle(mouseX, mouseY, 30);
}
Thank you for taking the time
You need to add the listener to theMaskee instead, not your mask.
The mask in AS3 does not implement IEventDispatcher therefore can not catch and dispatch events.
Do this:
theMaskee.addEventListener(MouseEvent.CLICK, myMaskClick);
And it should work. :)
Masks dont take any mouse/keyboard events as it is just a mask and not actually present in the display list.

Ways to animate bezier curves with AS3?

I've been trying to find the best way to animate bezier curves with AS3. By this far following has been the best solution:
import flash.display.*;
import flash.display.Sprite;
import flash.geom.*;
import com.greensock.TweenMax;
import com.greensock.easing.*;
public class Waves extends MovieClip
{
public var piste:Number = stage.stageHeight;
public var piste2:Number = 0;
var a:Sprite = new Sprite();
var coord:Vector.<Number> = new Vector.<Number>();
var com:Vector.<int> = new Vector.<int>();
public function Waves()
{
addChild(a);
coord.push(0, 30);
com.push(1);
coord.push(260, piste, stage.stageWidth, 30);
com.push(3);
tweenNumbers();
}
public function tweenNumbers():void {
TweenMax.to(this, 0.45, {piste:piste2, repeat:-1, yoyo:true, immediateRender:true, ease:Expo.easeOut, onUpdate:draw});
}
public function draw():void {
coord[3] = piste;
a.graphics.clear();
a.graphics.lineStyle(1,0x990000,1);
a.graphics.drawPath(com, coord);
}
}
Do I really have to use graphics.clear to animate curves? Is there more efficient way? If I tween faster than 1 second, rendering lags and you can see the previous line, is there way to get rid of it?
Hmm. Perhaps you should post your used version of TweenMax to properly debug the issue. There seem to be several of them, some use asynchronusly dispatched "update" events, some employ an enterframe listener, thus making sure each update routine is called each frame. So, graphics jittering can occur in an asynchronus scenario.
On the other questions:
Yes, you have to redraw the graphics object in question, this involves calling graphics.clear(). See, the Graphics object is a blackbox entity, you can't directly reach a control point of a curve to tween it somehow. So, in order to change a point on a curve, you have to redraw it.
A more efficient way would be emulating a tween on your Sprite directly, via an enterframe listener and a function similar to Strong.easeOut used in tweening to interpolate coordinates. You will then get rid of the all extra framework included in TweenMax library and will get full control of the event and code flow. This, however, is some work to both emulate yoyo behavior, time setting behavior, framerate behavior (you can switch to "time=frame" approach, eliminating one of the issues) and easing behavior. The tweenNumbers will look like this:
var isYoyo:Boolean=false;
var currentFrame:int;
var maxFrame:int;
function easingFunction(frame:int,maxframe:int,a:Number,b:Number):Number {
var x:Number=Number(frame)/maxframe;
return a+(b-a)*(x*x*(3-2*x)); // 3x^2-2x^3, a double-easing Perlin function
// recreate your needed function here!
}
var piste1:Number=0; // storing start coordinate
private function tweenNumbers():void {
maxFrame=Math.round(0.45*stage.frameRate); // from seconds to frames
currentFrame=0;
isYoyo=false;
a.addEventListener(Event.ENTER_FRAME,onUpdate);
}
private function onUpdate(e:Event):void {
if (!isYoyo) {
currentFrame++;
if (currentFrame==maxFrame) isYoyo=true;
} else {
currentFrame--;
if (currentFrame==0) isYoyo=false;
} // advance time
coords[3]=easingFunction(currentFrame,maxFrame,piste1,piste2);
// tween the coords[3] manually
a.graphics.clear();
a.graphics.lineStyle(1,0x990000,1);
a.graphics.drawPath(com, coord);
// draw updated path
}
No guarantee of desynching, though, but will normally work. Also a desynch (seeing previous line) can possibly happen if you have set stage framerate too high, so the video subsystem of a target device can't draw as many frames at once.

Actionscript 3.0 sounds accounting

I have an Array of SoundChannels actively playing.
When new sound is going to play, I append its SoundChannel to this array.
I have to maintain such an array in order to be able to stop all sounds at once.
I would like to remove sound channel from array when it finishes to prevent inifinite growing of my array. But when I catch e=Event.SOUND_COMPLETE, I have no information on sound channel. It is only possible to get Sound as e.target.
Actually, I can maintain Array of pairs (Sound, SoundChannel).
But maybe there exists more light-weight solution?
you don't need that array :) you can just use SoundMixer.StopAll(); to stop every sound that is playing.
edit: since you want to stop all special sounds, i have a new solution.
first, you create a new actionscript class and you add this code to it.
package
{
import flash.display.DisplayObject;
import flash.events.Event;
import flash.media.SoundChannel;
public class SpecialSoundChannel extends SoundChannel
{
var _parent:DisplayObject;
public function SpecialSoundChannel(Parent:DisplayObject)
{
super();
_parent = Parent;
_parent.addEventListener("StopSpecialSound", stopChannel);
}
public function stopChannel(e:Event):void
{
//DO SOME OTHER STUFF YOU WANT DONE.
stop();
}
}
}
every time you want to have a special sound added that is not music, you just do it like this:
var _sound:SpecialSoundChannel = new SpecialSoundChannel(this);
"this" is the class where you play and stop your soundchannel, which i am assuming is the same as where you create your soundchannel and therefore can call it "this". You add the following function to that class.
public function stopSpecialSounds():void
{
var _e:Event = new Event("StopSpecialSound");
dispatchEvent(_e);
}
if you want to stop all special sounds, you just call for this last function.