Huge performance drop using TMXTiledMap

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Huge performance drop using TMXTiledMap

(14 posts) (8 voices)

Started 2 years ago by parsa28
Latest reply from riq

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parsa28
Member

Hey there,
My game has 20 100x30 TMXTiledMaps (16x6 tiles) added to a ParallaxNode scrolling down the screen. I developed and tested it on iPod 2nd gen os 2.2.1 and it had a solid 60fps all the time. And now when I'm deploying the app to iPhone 2G,3G and 3GS running OS 3.0, the fps drops to ~40fps all the time.

The routine for adding maps to the ParallaxNode is as follows: add 2 first tilemaps, when reached the 2nd tilemap, release the previous and add next one and so on. So there are 2 tilemaps added to the ParallaxNode at any given moment.

When I add a single tilemap instead of 2 tilemaps, the fps gets back to 60. So the problem must be having 2 tilemaps in the node.

I'm using cocos v0.8.2 and I've tried different directors(FastDirector,DisplayLink,Projection2d).

Anyone has any idea ?

Regards,
Parsa

Posted 2 years ago #
riq
Key Master

it might be related to your second tileset (how bit is it) and the quantity of tiles that you want to render.

If you map is very big I suggest splitting it into smaller ones.

Posted 2 years ago #
MrMojo
Member
I'm experiencing the same problem. I thought that since TMXTileMap's are based on an AtlasSprite, that I could have super large tile maps... I tried it out with a Tileset that was 640 tiles x 64 tiles and it was very very sluggish.

I tried browsing through the code for how TMXTileMaps use AtlasSprites, and from what I could gather it appears that every tile in a map that isn't empty has an AtlasSprite created for it...

I would've thought that each tile in the Tileset would have an AtlasSprite created for it, and that the draw method of the layer would tell each visible tile to draw it's associated TileSet sprite in the correct location... I know this wouldn't allow each tile to be edited, so to speak, but it sounds to me like it might be way faster.

I could see that the TileMap has this in it:
```
/* Adds a quad into the texture atlas but it won't be added into the children array.
   This method should be called only when you are dealing with very big AtlasSrite and when most of the AtlasSprite won't be
   For example: a tile map (TMXMap) or a label with lots of characgers (BitmapFontAtlas)
   @since v0.8.2
   */
  -(void) addQuadFromSprite:(AtlasSprite*)sprite quadIndex:(unsigned int)index;
```
but couldn't see or understand how this directly affected how only visible sprites are being drawn, as there isn't an overridden draw method for the layer or the tilemap that would only draw the sprites that were visible onscreen...

So long story short, how could I go about optimizing this? I'm more interested in loading huge maps than making my maps editable..... Where should I start?
Posted 2 years ago #
riq
Key Master

v0.8.2 is as fast as v0.8.1 (if not faster) when rendering the tiles.
AtlasSprite is a represation of a tile but the AtlasSprite is created on demand.
There is no need to create 640x64 (40960) AtlasSprites if you are not going to use them.

As I said before, to optimize the rendering you should split the map in sub-maps.
You should create like 10 or 20 sub-maps (think of TMX layers) and enable / disable the layers that you know that are visible/invisible.

TMXMap renders all the TMXLayers that have the visible property enabled.

Posted 2 years ago #
MrMojo
Member

ahhh! by "splitting it into smaller ones" I thought you meant separate tmx files, not TMXLayers.... I'll give that a try!

Posted 2 years ago #
MrMojo
Member

i have yet to try the layer visibility approach, but was wondering 2 things:

- I assume the tilesets for all layers are always loaded into memory, regardless of whether or not the layers are visible... Is this correct?

- If I did want to try and keep my tiles all in one layer, and wanted to override the draw method of something to draw only the visible atlassprites, would I override the TMXLayer.draw method and work it from there? Or would it have to be the draw of the AtlasSpriteManager for each layer? Or is this just not a feasible idea due to the way it's currently implemented?

Posted 2 years ago #
parsa28
Member

As for your first question, we have to try it practically and checkout the instrument for the exact answer but I believe it's as you say, but being loaded into memory doesn't drop the fps, it's rendering them that drops the fps. And as for your 2nd question, I'd go with overriding draw method.

Posted 2 years ago #
bradparks
Member

I need something similar to this. It occurs to me that we could add a property to a TMXLayer thats something like "sections=10" that by default would be 1, but if set, would instead of creating that layer, would create 10 layers,

e.g. layer1.1, layer 1.2, layer 1.3 ... layer 1.10...

That way it could work for any layer without the Level author needing to break their layers into lots of smaller layers. If I implement this, I'll post it back here. I think that implementing a better draw method would be ultimately better, as at runtime you'd need to refer to the different sub layers if you wanted to do anything with the layer content, which would make your game logic more complex.

Posted 2 years ago #
blackmouth
Member

If there's anyone else struggling with loading large TMXTiledMaps, I would suggest trying Riq's suggestion of splitting the large map and making smaller submaps on their own layer within Tiled.

Something that can be easily overlooked is not saving the TMX file with the layers turned off.

Then in your game code you can turn the layer visibility ON/OFF with layer.visible=NO or layer.visible=YES;

Posted 2 years ago #
Alex_
Member

i tried following Riq's suggestion, but i'm having the following issue...
if i do this from within the tmx layer
<layer name="layer1" width="51" height="51" visible="0">
the layer does indeed not load, but layer1.visible = "YES" will not load it afterwards at all, and if i leave visible out of the layer properties in the tmx file, it loads everything up when it builds the map, so the app still crashes because of memory.
Any suggestions ?

Posted 2 years ago #
riq
Key Master

@alex: then you might need to create 2 or 3 differnt TMX maps, with some TMX layers each. Then only load the TMX map that you need. and release it as soon as you don't need it anymore.

As you have noticed, each layer should have the visible flag = true, else it won't load.

Posted 2 years ago #
arminrox
Member
I am new to this, so correct me if I am wrong but to overcome this issue of not loading the invisible layers, why can't you extend TMXTiledMap class and write your own version of the initWithTMXFile:(NSString*)tmxFile which loads all children (even the invisible ones) and then you can correctly set each layer's visibility by calling:
```
child.visible = layerInfo->visible;
```
But the real question is still remaining: will it really improve the performance (fps) if you take this approach ... I am going to try it out this weekend and will give my update after.
Posted 2 years ago #
snowmanchu
Member

So we've split the tile maps into strips. How do we delete the actual layer from the screen as we move in different directions.

Do i have to delete columns of tiles? or is there an easier way.

Posted 2 years ago #
riq
Key Master
@snowmanchu: just set the layer as invisible.
```
layer.visible = NO;
```
Posted 2 years ago #

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