Tagged:Code

Bloggle

My wife and I recently made the move from Glasgow, UK to her home province of Beautiful British Columbia™, Canada. While we’re getting set up over here, we’ve been graciously hosted by my parents-in-law. And as a direct consequence, we have all been playing a veritable butt-ton of board games – foremost of which has been Boggle.



When stumped for a gift…

It’s a fun game, and one variant is to sit around without any timer running and openly shout out words (of 4+ or 5+ letters, to keep it interesting) as you see them. After a while, you get the impression that there cannot possibly be any words left to find – but is that really the case? I wanted to find out…

…And I also wanted to avoid using one of the innumerable free solvers available out there, for the sake of – erm, fun?

So, as a weekend project, I wrote the above Boggle solver, publishing for Flash, (and courtesy AIR) Android and iOS, and uploaded the source code to GitHub: https://github.com/hanenbro/BoggleSolver. Please feel free to do what you like with it; the licence is MIT.



Here it is running on a Nexus 7 tablet and iPhone 4S

For anyone looking just to install the app on mobile (for those crucial on-the-go Boggle scuffles), the APK will install for any device set to allow 3rd party apps, but the IPA will only work for jailbroken iOS devices, unless you recompile with your own provisioning profile.

The app is using a modified word list from InfoChimps, with the words shorter than 3 and longer than 16 letters removed (per the rules and limitations of game). That still leaves around 100,000 words, so at least in my usage, it tends to come up with a high percentage of never-before-seen lexical wonders. Educational tool or ego-deflating depression fuel? You decide!

Replacing the buttonMode hand cursor icon in FP 10.2+

Thought I’d share a little snippet from a project I worked on a month or so back – it takes advantage of the Mouse.cursor property introduced in Flash Player 10.2. MouseCursor, as you may know, beats the ass of previous cursor replacement solutions because it modifies the OS pointer, and thus is not at the whim of slow stage framerates or the various other painful snags that come with faking it; hiding the system cursor and manually positioning a graphic in its place.

There’s a decent amount of documentation out there on how to use it, but my specific requirement was to replace the cursor only when mousing over buttons and other clickable items. I wanted it to show up wherever the hand cursor would normally appear, across a whole project.

This is the kind of behaviour I needed:

catswitch
Click to run the example. The buttons show a custom mouse-over cursor only when they’re enabled.

Now, if you look at the Adobe docs on the topic, you can register a cursor by passing in a String constant and a MouseCursorData object like so:

Mouse.registerCursor("PointerCursor", mouseCursorData);

Additionally, you can spy a number of static String constants inside the MouseCursor class – such as IBEAM and HAND – which certainly made me wonder whether I could do something like the following:

Mouse.registerCursor(MouseCursor.HAND, mouseCursorData);

But as you may have guessed, this does not work as hoped; it’s not possible just to override the graphic used for the hand cursor.

So here’s my workaround for achieving this kind of behaviour, which I opt to keep inside a centralised class (the filthy singleton). I’ve set up a git repository for the full example, but here’s the crux (a few extra functions aren’t shown here):

public function buttonMode_set(target:Sprite, buttonMode:Boolean):void {
	
	//If the dictionary hasn't been initialised, do so and set up the custom mouse cursor//
	if (! _buttonModeDictionary) {
		_buttonModeDictionary = new Dictionary();
		var pointerCursor = new MouseCursorData();
		pointerCursor.data = new <BitmapData>[new Cursor32Shadow()];
		pointerCursor.frameRate = 0;
		pointerCursor.hotSpot = new Point(3, 1);
		Mouse.registerCursor("PointerCursor", pointerCursor);
	}
	
	//Check whether the Sprite has already been registered for use//
	if (target in _buttonModeDictionary) {
		
		//Only add/remove listeners if the buttonMode state is actually changing//
		if (_buttonModeDictionary[target] != buttonMode) {
			_buttonModeDictionary[target] = buttonMode;
			if (buttonMode) {
				target.addEventListener(MouseEvent.ROLL_OVER, pointerCursor_show);
				target.addEventListener(MouseEvent.ROLL_OUT, pointerCursor_hide);
				mouseOver_check(target, true);
			} else {
				target.removeEventListener(MouseEvent.ROLL_OVER, pointerCursor_show);
				target.removeEventListener(MouseEvent.ROLL_OUT, pointerCursor_hide);
				mouseOver_check(target, false);
			}
		}
		
	//Only add the new entry if pseudo-buttonMode is being turned on//
	} else if (buttonMode) {
		
		_buttonModeDictionary[target] = true;
		target.addEventListener(MouseEvent.ROLL_OVER, pointerCursor_show);
		target.addEventListener(MouseEvent.ROLL_OUT, pointerCursor_hide);
		mouseOver_check(target, true);
	}
}

And then it can be turned on and off for each object like this:

buttonMode_set(button1, true);	//button1.buttonMode = true;
buttonMode_set(button2, false);	//button2.buttonMode = false;

The full example can be downloaded from github here: https://github.com/hanenbro/CursorDemo

A poor man’s particle system

For a recent Flash job, I was required to add a particle system on top of an application already very CPU heavy. The project involved a large stage size, AR marker detection from a webcam feed, and a 3D-orientated plane displaying a running video, attached to the marker. This video plane then had to spew out various flavours of 3D particle at appropriate moments in the FLV.

The idea of plugging in a sexy particle engine like Flint, when the SWF was struggling even to maintain its target framerate of 25fps, made me uncomfortable. Bespoke seemed the only way to go, and hey! it worked out. Here’s what one of the particle types ended up resembling:

(It’s worth mentioning that fewer particles than can be made in the above demo were needed for the project itself. Maxing out the version here gets my CPU usage up to around 40%, which would not have left enough room for the marker tracking and FLV playback.)

To briefly cover the tricks used here, I faked 3D z-positioning by scaling clips as a function of their bespoke ‘zPosition’ value. The formula: focalLength / (focalLength + zPosition) gives the scale factor used to set the scaleX and scaleY properties of each MovieClip. The scaleX parameter was also adjusted to spoof motion blur, by overriding the x position property, and repeatedly comparing it to its value at the last update. The greater the change, the larger the scaleX multiplier, and the more stretched/blurred the particle would appear.

Rotation of the whole particle field was done by avoiding setting the x or z properties directly, depending instead on ‘radius’ and ‘rotational offset’ values. All the particles reside inside an imagined cylinder (the particle field), with its central spindle aligned with the y-axis. Each particle has its x and z location calculated on the basis of this rotation and distance from the central axis, as they move in their orbits. Channelling Mr McCallum, my secondary school maths teacher, the formulae to do this kind of positioning are, for the x axis: cos(angle) * radius; and for the z axis: sin(angle) * radius. (These can be used instead with the x and y properties to show rotation around a flat circle as opposed to the cylinder.)

In addition to rotary motion, the particles were required to ‘wander’ of their own accord. To achieve this, a large bitmap of Perlin noise is generated at the beginning of the simulation, with a reference to it passed to each particle instance. Going from pixel to pixel each frame, the RGB value is sampled and used to increment the y-velocity and radius-velocity of each particle. Over time, the Perlin noise is traversed completely, resulting in a wide range of even motion. Each particle begins sampling from a randomised row/column too, so that the movement is staggered.

Thanks Ken Perlin!
Setting the Perlin noise generation to tile allows the bitmap to be traversed from side to side and top to bottom without any sudden changes in value.

With all said and done, there may indeed have been a package out there that was equally lightweight and flexible enough for the nuances of the project. But, hard deadlines being as they are, it sometimes pays just to go from the ground up, omitting any chaff on the way – rather than hunt for elusive wheat through sprawling, multifaceted libraries.

If the source code happens to be of use to anyone I’d be very happy to clean it up and post it here. Until then… indolence wins out. Sorry!

Dinoglyphs

Been feeling at all out of touch lately? Wondered what the next big thing’s going to be? You came to the right blog post friend, because I’ll tell you what it is for free:

ANAGLYPHS

ANAGLYPHS

And what would be the perfect companion to this timely tech? Extinct animals. Namely:

DINOSAURS

DINOSAURS

Over the past few weeks at work, I got the chance to develop an educational Papervision3D/FLARToolKit application for the the BBC’s Learning Development site. I wrote up some nerdy/whiney information on the process here, and the page itself can be found at the picture-link below.

SpinARsaurus Challenge

Moving images containing terrible lizards are all very well; Steven Spielberg gave us those in 1993 – more than fifty years ago! But what that documentary promised to be the simple matter of drilling into amber and injecting mosquito blood into a frog, still hasn’t yielded any dino fun parks. What gives?

In order to fill this void (over the next couple of months, before one of the parks is complete and we’re busy petting T-rexes), I’ve made a dinosaur that looks so real you could touch it.

Dinoglyph
It will take a minute or two to load up, so please be patient! (You can’t rush virtual reality.) Moving the mouse around alters the spin speed and direction, and zooms in and out.

For the demo, I loaded in a second skeleton model, iterated over the texture files and ColorTransform-ed the red / green+blue out of them, respectively, then set their BlendModes to DIFFERENCE. After that, I moved the red copy a little left, the blue copy a little right, and applied all other movement relative to those locations.

The eventual colours work out well to be mutually invisible in the corresponding panes of the paper glasses that were bundled with the copy of Ben 10 Magazine I bought in shame. (FYI, decent journalism, but the word searches were MUCH too difficult for the recommended age bracket.) More sophisticated glasses will probably result in uneven colouring.

FUTURE
And you wont look as cool.

Hello

I'm Adam Vernon: front-end developer, free-time photographer, small-hours musician and general-purpose humanoid.