AS3 tile map rendering (with 1000's of tiles)

问题:

Just first off I'll say that the context here is Actionscript 3.0 (IDE: Flashbuilder) along with the Starling Framework.

So, I want to create a Tile Map that could be used for a platformer or something similar.

I want to use 8x8 pixel tiles on an 800x600 pixel stage, and the problem I am having is that I don't know how to add these 7500+ tile objects to the stage without dramatically reducing the framerate.

I've found that the drop in performance comes from adding each tile to the stage, not from initializing each Tile object.

I know I'm not giving much specific information, but what I'm asking for is if there is a standardized way to draw thousands of static objects onto the stage without a loss of performance. I feel like there is a way, and I just have yet to find it.

Update:

After all of your kind help, I have found what seems to be a great solution. At first I wanted to implement Amy's solution, using copyPixels() and draw() to make one large bitmap data for the whole map and then render that to the screen. Then, though, I wanted to know if there was a Starling equivalent to this, because everything would be so much simpler if I didn't have to mix Starling with Native Flash.

Thanks to Amy again, I looked into Starling's RenderTexture class a bit more, and found that using it's "drawBundled()" and "draw()" methods, I could easily draw all of the tiles into a RenderTexture, and then put the RenderTexture into an Image (Starling's Image Class) and then just add that Image to the screen.

That solution is a million times faster than the silly slow solutions I tried before, with flattening sprites and such. Its faster both in it's initialization time and there seems to be no drop in framerate while the renderTexture's Image is on the screen.

The one thing I want to test with this is if it is easy to update the graphics of a tile during the gameplay. Say, if water spreads from a source (or something) and a "Grass" tile had to become a "Water" tile, would the RenderTexture and it's image be able to change their appearance without some sort of lag spike or performance hiccup. I will test this out soon.

Thank you all for your help!

回答1:

Don't add that many objects to the stage. Instead, create a BitmpaData the size of your stage and use copyPixels() or draw() to draw onto it. Here's an article that should get you started. You can then take the concepts you learned in that post and learn anything specific you need to do that's not covered (flashandmath.com has a lot of good tutorials about pixel manipulation)

回答2:

You need to manage the tiles that need to be added and removed as you move around the game. Only add to stage tiles that are with in 800 px of the center of the screen. Once the tile is beyond 800 px from center remove it. That should keep everything moving smoothly. Good luck.

or look into drawing/coping your tiles into one bitmap. You would be basically stamping your tiles onto the new bitmap. Here is an example from adobe:

import flash.display.Bitmap; import flash.display.BitmapData; import flash.geom.Rectangle; import flash.geom.Point;  var bmd1:BitmapData = new BitmapData(40, 40, false, 0x000000FF); var bmd2:BitmapData = new BitmapData(80, 40, false, 0x0000CC44);  var rect:Rectangle = new Rectangle(0, 0, 20, 20); var pt:Point = new Point(10, 10); bmd2.copyPixels(bmd1, rect, pt);  var bm1:Bitmap = new Bitmap(bmd1); this.addChild(bm1); var bm2:Bitmap = new Bitmap(bmd2); this.addChild(bm2); bm2.x = 50; 

More Info on the bitmapData class. I think copyPixels is what you are after.

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