Combining two textures in one

I'm developing a game for iOS. I'm using cocos2d libs. I want to have an object, that have 3 parts -开发者_如何学编程 beginning, ending and the middle. I've got the image with these components. And the object can be stretched, when created. But only the middle part should be stretched, the beginning and endings should have no scaling. Because this operation is done only once i decided it's a good idea to create a new CCSprite for this object, and not to keep three (for increasing performance).

I'm using CCSPriteBatchNode for rendering, and i don't know if i really need to combine the object's parts (maybe rendering 3 parts using batch will be as fast as rendering one pre-combined object).

So there are two quastions:

1. Do i need to combine parts in one object?

2. If, yes - how can i do that?

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Instead of combining the textures you could create a node and add the three sprites as children to it. You can then work with the parent node as a single entity.

Something along the lines of:

CCNode *sprites = [CCNode node];

CCSprite *spriteA = [CCSprite spriteWithSpriteFrameName:@"spriteA.png"];
spriteA.position = ccp(-10, 0);
[sprites addChild:spriteA];

CCSprite *spriteB = [CCSprite spriteWithSpriteFrameName:@"spriteB.png"];
spriteB.position = ccp(0, 0);
[sprites addChild:spriteB];

CCSprite *spriteC = [CCSprite spriteWithSpriteFrameName:@"spriteC.png"];
spriteC.position = ccp(10, 0);
[sprites addChild:spriteC];

You can scale and position each individual sprite depending on your parameters then work with the sprites object to position/scale them as a whole.

There might be a small performance hit so I would think twice before using this for a large amount of sprites, but I've been using this method in a few situations and in my case I didn't notice any issues with performance.

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Look at the RenderTexture demo.

Instead of using the brush, you can use put your 3 parts onto it using those images instead of the brush.