Unlike the iPad, the BlackBerry PlayBook has rather poor international keyboard support, with no method for entering chinese characters. I like the way iOS achieves this, so went about building my own version in ActionScript. Continue reading Chinese Handwriting Recognition App
Category Archives: AIR
Posts related to Adobe Integrated Runtime.
iPad smoothness for iPad
I’d recently been playing around with packaging AIR for iOS, to run on my iPad. While the performance has been improved massively since CS5 Packager, it’s still not great in AIR 2.6. It seems that AIR 2.7 brings with it some great performance enhancements – though I’ll reserve judgement until I’ve tried it myself – check out the article and video here.
ActionScript performance tips
Here are a few simple tricks that may help the performance of your code/graphics intensive Flash movies. This is not an exhaustive list, by any means, rather some of the more effective performance tweaks to try out on your projects. There are the usual sensible coding tricks, like using local variables for oft-used references within functions, or planning your code loops carefully and breaking out of loops whenever feasible – but you should be doing these already. I’ll be adding to this post as and when I feel necessary, but will generally avoid the more granular tricks, such as bytecode optimisation. Some of those methods are too complex to explain in simple terms here and generally have a low effort-to-benefit ratio anyway:
Use scrollRect in conjunction with cacheAsBitmap. The cacheAsBitmap parameter of a movieclip can improve performance dramatically, but will cause problems if the render area of the movieclip gets too large (e.g. larger than 2880 in width or height), regardless of whether it is cropped by the viewable area of the Flash Player. The solution is to use scrollRect to constrain the rendering area to desired limits, in this example, the stage width/height:
import flash.geom.Rectangle; scrollRect = new Rectangle(0, 0, Stage.width, Stage.height); cacheAsBitmap = true;
Create bitmap snapshots of complex movieclips. Where you may have a movieclip full of layered graphical effects that isn’t animated, you can save a lot of rendering time by creating a snapshot of the movie. Similar to the cacheAsBitmap parameter, but will improve performance further if your movieclip comprises many lines or alphas. The following function shows a quick and dirty way of duplicating a movieclip as a snapshot of the original:
import flash.geom.*; function createSnapshot (base:MovieClip, mc:MovieClip):MovieClip { var bounds = mc.getBounds(base); var bmpWidth = bounds.xMax-bounds.xMin; var bmpHeight = bounds.yMax-bounds.yMin; var bmp1 = new BitmapData(bmpWidth, bmpHeight, true, 0x00000000); var snapshot = base.createEmptyMovieClip("snapshot"+base.getNextHighestDepth(), base.getNextHighestDepth()); snapshot._x = mc._x; snapshot._y = mc._y; var rect = new Rectangle(0, 0, bmpWidth, bmpHeight); var pos = new Point(0, 0); bmp1.draw(mc, new Matrix(mc._xscale/100, 0, 0, mc._yscale/100, mc._x-bounds.xMin, mc._y-bounds.yMin)); snapshot.attachBitmap(bmp1, 1, "auto", true); snapshot._x = bounds.xMin; snapshot._y = bounds.yMin; mc.unloadMovie(); return snapshot; }
Use the opaque window mode trick – sparingly! Setting the wmode=opaque HTML parameter of your Flash object can improve rendering performance, but at a potential cost. Not only does it make the rendering order of movieclips and frames more ‘lazy’, but will effect keyboard interaction adversely in some browsers (especially FireFox). Use with caution.
I’ll be updating and tracking back to this post occasionally, so stay tuned…