Beginner help w. AtlasSpriteMangher and TextureAtlas

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Beginner help w. AtlasSpriteMangher and TextureAtlas

(4 posts) (4 voices)

Started 2 years ago by mikejstein
Latest reply from Steve Oldmeadow

Tags:

AtalsSpriteManager TextureAtlas

mikejstein
Member

Hi all,

I'm moving from following Cocos2D tutorials, to coding my own game, and I'm having trouble trying to sort out how all the various sprite elements work together.

I get that AtlasSprite is more efficient than regular sprite.

What confuses me is AtlasSpriteManager, TextureAtlas. I'm just not sure what they're for, and how to use them.

I would have thought that the AtlasSpriteManager was for managing groups of sprites, but I'm confused as to why I can create an ASM with an image - I didn't think the ASM was a visible object.

As for TextureAtlas, am I correct in thinking that a textureAtlas is used to reduce the memory issues associated with loading many textures, by loading them all at once. And, when I need to change the texture on an existing AtlasSprite, I pull that texture from the already loaded TextureAtals?

Posted 2 years ago #
Cypher
Member

Another newbie here, been reading and learning..

From my understanding, the AtlasSpriteManager is fed a single image which happens to be a sprite sheet. You can then carve out the individual images to create your animations and things of the like. Since only a single image is loaded, the memory footprint is constant..

Haven't figured out TextureAtlas yet..:)

Posted 2 years ago #
OldJames
Member

Hi Mike,
For beginning purposes, it's easy to think of the AtlasSpriteManager as your texture image and an acapsulating object for all the sprites you wan't use from that image.

You'll want to set up your Manager with the image you have, and the add the manager as a child to you layer or whatever. (Note that this won't show/draw anything).
AtlasSpriteManager *mgrForMySprites = [AtlasSpriteManager spriteManagerWithFile:@"image.png" capacity:3];
[self addChild:mgrForMySprites z:0 tag:123];

The next step is to actually initialize some sprites from that manager. Basically taking square cuts from your managers image. To do this:
AtlasSprite *mySpriteFromAtlasManager = [AtlasSprite spriteWithRect:CGRectMake(0,0,20,50) spriteManager:mgrForMySprites];
*Here your creating a new sprite and telling it to acquire its image from the manager you've already set up.
Next, ad the sprite you created as a child of your MANAGER:
[mgrForMySprites addChild:mySpriteFromAtlasManager z:0 tag:555];

That's the coles notes and getting it to work. You can do lots with it, so be sure to spend some time in the examples for AtlasSprite and the class documentation.

Posted 2 years ago #
Steve Oldmeadow
Administrator

@mikejstein, TextureManager actually does the job you think TextureAtlas is doing. TextureAtlas is designed to draw a bunch of rectangles (often called quads) that are in reality made up of triangles and also map sub sections of a texture to those rectangles. The important part is that it can draw a lot of rectangles at once and the sub section of the texture can be altered to any rectangular sub section of the texture image.

TextureAtlas gives us some powerful functionality that can be used in many ways. For example the texture can contain characters/glyphs and TextureAtlas can be used to draw a lot of those in one hit - useful for drawing text (see LabelAtlas and BitmapFontAtlas) or the texture could contain images for sprites and we can easily animate the sprites by changing which rectangular sub section of the texture it maps to (see AtlasSpriteManager).

Posted 2 years ago #

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