如何在cocos2d中加载大尺寸CCTMXTiledMap？

Question

I try to design a cocos2d game that with a big world. The wolrd tiled map is very big, maybe 20 ipad screen sizes. I want to know how to load CCTMXTiledMap into screen? If I directly add it to screen, will it use too much memory? If so, is there a solution to solve this problem?

Answer 1

The memory usage of the tilemap depends on the size of the tiles and how many of the tiles need to be converted to sprites, for example if you want to run animate them.

Assuming your tiles are 32x32 pixels in size. 20 times iPad dimensions means 20.480x15.360 points. Divided by 32 gives you a tile size of the map of 640x480 tiles, or 307.200 tiles total. Assuming that each tile uses 64 Bytes memory (in an older cocos2d version it was less than 64 bytes) your map ends up using almost 19 MB of memory. That's not even counting the textures.

Now for every tile that you address via the CCSprite interface, for example by changing one of the sprite properties or running actions on it, cocos2d will convert that tile to a regular CCSprite. Each CCSprite object uses around 420 Bytes last time I checked. So if you were to change the color property of each tile thus converting all tiles to CCSprite objects, the tilemap would consume 123 MB of memory. Again, not including textures.

You could try the Tilemap renderer in KoboldTouch . It can handle very large tilemaps (millions of tiles, ie 4000x4000 tiles) and renders it at 60 fps.

Answer 2

If you try to load all the tiles at one, it will definitely occupy too much memory.

Have a look at this tutorial about CCTMXTilesMap .