Christmas Hurl

I recommend going to the large version here and saving the .swf to your desktop.

The holidays are here! In celebration, I've whipped up the above. It's a simple little tree decoration thing that showcases a few concepts. First off, we have gravity and physics. As each ornament falls, it picks up speed, giving the illusion of gravity pulling. Surprisingly, faking gravity is INCREDIBLY easy! You see, each movie clip is moving a set amount every frame (shown as _y+=dy where dy is a number). The trick here is that the "dy" constantly increases by a set amount. So let's say dy starts at 0 but increases by 1 every time.

Frame1:
dy = 1
old _y = 0
new _y = 1

Frame 2:
dy = 2
old_y = 1
new _y = 3

Frame 3:
dy = 3
old_y = 3
new _y = 6

and so on...but remember, you're likely running around 24 -31 fps, so your change in dy should probably be tiny (experiment with this to simulate different gravities! I tend to use .1 as a baseline, but it changes depending on how I want something to move).

Speaking of dy, the bouncing effect is a neat little trick, too. When the movie clip hits the bottom, it is first moved to the bottom edge of the screen (if something is moving fast enough it goes PAST the bottom of the screen, so this rights it) and then it's dy is multiplied by -.7. Why not -1? In the real world, some energy is lost to the ground when a ball bounces (ever have a really heavy box fall beside you? Even if you didn't get hit, you definitely felt the box thud! That's the dissipated energy...some of it, anyway).

The last little bit I'll share with you is how to calculate the speed of the thrown object. To be honest, this was an experiment that I really didn't expect to work. But surprise! Work it did. Essentially, we're keeping track of two values. Where the mouse is NOW and where the mouse was a frame ago. These values are updated every time the mouse moves, and the difference between the two is stored as a number. When you release the ornament, that difference is used to determine the speed of the the thrown object. Nifty, eh?

Well, that's it for now. Merry Christmas!

Feelin' Lucky?

Larger version here.

In a departure from the stuff I normally do, I decided to make an actual game. Here you have a 4-reeled slot machine. You place your bet (top 3 red buttons) and your risk of the spin (bottom 3 red buttons). Then click the purple "roll" button and you're off!

Your winnings are determined by how many of the rings line up once the spin is completed.
No Matches: 0
One Match: (your bet) x (risk/2)
Two Matches or 3 of-a-kind: (your bet) x (risk)
All Four: (your bet) x (risk) x 5

This isn't an absolutely crazy to program game. I use modulus (%) to determine when or if one of the rings should stop. Each ring is simple a tweened animation, and every 1, 2, or 5 frames (based on risk 1, risk 5, or risk 10 respectively) it rolls a counter to see if it should stop or not.

Once all four rings are stopped, the frame number of each is pushed into an array. Each value in the array is compared to the rest of the values to see if they match. Different numbers of matches indicate what the winnings should be. I wasn't quite able to compare a single value against everything else and then exclude it from the array (probably could, but not worth the headache), so a non-match actually shows up as 4 matches (the checked value in the array checks against itself as well).

Oh, and the little "$" button in the corner refills your credits to 100 if you are below 100 credits.