batches and text

[Nitneroc]

As I said in another thread, I'm a newbie, so I hope my question isn't totally stupid.

I have Sprite objects, with a name displayed above them. This name is a cocos2d Label. For speed-ups, I wanted to put the Sprites in a batch, so I just tried to add them as children to the BatchNode. This raised an error because the Label isn't a BatchableNode. I knew things couldn't be that easy, but I tried to create my own Label class that inherited from BatchableNode, and the exception disappeared, but there is only one of my labels displayed, and I don't really understand how to make it work...

In fact I don't know a thing about how batches manage to speed-up drawing operations, I guess it's by calling draw for objects with the same graphics. So I guess putting text inside a batch is meaningless (looking through cocos.text.TextElement, I think I understood that pyglet uses a specific batch for each label).

How can I add such a Sprite to a BatchNode ?

Thanks for reading

[claudio canepa]

On Mon, Apr 16, 2012 at 3:50 PM, Nitneroc <corent...@gmail.com> wrote:

As I said in another thread, I'm a newbie, so I hope my question isn't totally stupid.

I have Sprite objects, with a name displayed above them. This name is a cocos2d Label. For speed-ups, I wanted to put the Sprites in a batch, so I just tried to add them as children to the BatchNode. This raised an error because the Label isn't a BatchableNode. I knew things couldn't be that easy, but I tried to create my own Label class that inherited from BatchableNode, and the exception disappeared, but there is only one of my labels displayed, and I don't really understand how to make it work...

In fact I don't know a thing about how batches manage to speed-up drawing operations, I guess it's by calling draw for objects with the same graphics.

No, batches speed-up comes from drawing as many vertexs in as few calls to openGL as possible, and minimizing the number of openGL state changes.

For a 10000ft overview see

http://www.pyglet.org/doc/programming_guide/batched_rendering.html

 

To know more you will need to read the related pyglet code and be familiar with  

openGL.

So I guess putting text inside a batch is meaningless (looking through cocos.text.TextElement, I think I understood that pyglet uses a specific batch for each label).

How can I add such a Sprite to a BatchNode ?

Forget batches while being new to cocos-pyglet.

Make a simple NamedSprite, beginning with something like

class NamedSprite(cocos.cocosnode.CocosNode):

    def __init__(self, name, *args, **kwargs):

        self.figure = cocos.sprite.Sprite(*args, **kwargs)

        self.label = cocos.text.Label(name)

        # adjust label position

        self.add(self.figure)

        self.add(self.label)

 

hth

claudio

--

[Nitneroc]

OK I looked at this pyglet documentation and I didn't understand much of it... So I'll follow your advice and stick to the no-batch option, with a class pretty similar to yours.

Thanks for the kind explanations