Flint Particle System Forum - Use a class file with ImageClasses to generate particles?

Use a class file with ImageClasses to generate particles?

ed — Tue, 20 Oct 2009 20:37:15 +0100

I've learned from the tutorial that the emitters must create the particles to be rendered using either the DisplayObjectRenderer or BitmapRenderer. But I haven't seen an example much discussion about defining an image from a separate class file for use with the ImageClass when passing the emitter your image. For example, I have a class called Box.as that extends a MovieClip and generates a black box whose height and width are linked to the length of a sentence that is stored in a database. After the data has been loaded, the length of the sentence is passed to each Box as a parameter; within each Box are various MouseEvents.

I'm trying to use ImageClasses to "load" an array of MovieClips.


//PHP loaded, XML nodes converted to object properties...

private function dataLoaded(e:DataEvent):void {
	_itemArray = e.items;
			
	for (var i:uint = 0; i < _itemArray.length; i++) {
		var box:Box = new Box(_itemArray[i].sentence.length);
		_boxArray.push(box);
	}
			
	images = new ImageClasses(_boxArray);
	emitter.counter = new Blast(_boxArray.length);
	emitter.addInitializer(images);
	emitter.addInitializer(new Position(zone));
			
	renderer.addEmitter(emitter);
	renderer.mouseChildren = true;
	addChild(renderer);
}

But I keep getting this error:

Error #1034: Type Coercion failed: cannot convert Box@35537451 to Class.

I've compared my code to the snippet seen here: http://flintparticles.org/forum/comments.php?DiscussionID=242&page=1 but I still get the error...any ideas?

Use a class file with ImageClasses to generate particles?

ed — Tue, 20 Oct 2009 22:50:51 +0100

Solution found :)
Took a hint from this post: http://flintparticles.org/forum/comments.php?DiscussionID=155. I placed the particle first, then added them to the emitter...I'm guessing I could have placed the particles after adding them as well, but this seemed the most straightforward to me.


private function dataLoaded(e:DataEvent):void {
	_itemArray = e.items;
	
	for (var i in _itemArray) {
		var l:uint = _itemArray[i].sentence.length;
		var box:Box = new Box(l);
		box.x = 900 * Math.random() + 50;
		box.y = 550 * Math.random() + 25;
		addChild(box);
		
		box.setData(_itemArray[i]);
		_boxArray.push(box);
		
		var particle = Particle2DUtils.createParticle2DFromDisplayObject(box, renderer, emitter.particleFactory);
		emitter.addExistingParticles([particle], true);
	}
	
	emitter.addInitializer(new Position(zone));
		
	emitter.addAction(new MutualGravity(5, 500, 3));
	emitter.addAction(new TurnTowardsMouse(.25, renderer));
	emitter.addAction(new BoundingBox(0, 0, 1000, 600));
	emitter.addAction(new SpeedLimit(150));
	emitter.addAction(new Move());
	
	renderer.addEmitter(emitter);
	renderer.mouseChildren = true;
	addChild(renderer);

	emitter.start();
	emitter.runAhead(10);
}

BTW, Richard, thank you for this remarkable system. You've really made particle simulation accessible to everyone. Amazing documentation as well. Hats off to you!

Use a class file with ImageClasses to generate particles?

Richard — Mon, 02 Nov 2009 08:01:05 +0000

Hi Ed

I'm pleased you found the solution. It is possible to pass the image directly to the particle -

particle.image = box

but because the emitter works with behaviours, you'd have to wrap this up as an Initializer.

I intend to add a tutorial about writing custom Initializers and Actions soon, but there's a few bits of work I have to get out the way first.

Richard