Monday, May 16, 2016

CSS3 Smoke Animation Effect

The comic today uses quite a bit of CSS3 animation. This is a rather new thing for me - I've been using mostly JavaScript-powered animations on Amphibian.com since it started. But after I did the rain animation using CSS back in March (see the comic here), I've been warming up to the idea of more CSS and less JavaScript to move things around.

For this task, I wanted to make some animated smoke come out of the frogs' rocket ship before the launch. My style is mostly just simple geometric shapes arranged to look like things, so using circular DIV elements to look like puffs of smoke was fine with me. I found a great starting point by Andrea Verlicchi on CodePen, and then modified it for my comic.

Here's the basic idea - puffs of smoke emanate from a given source element. They move downward and off to the side while fading away.

The puffs of smoke will be represented by rounded SPAN elements, with this CSS applied to them:

span.smokepuff {
    display: block;
    position: absolute;
    bottom: -35px;
    left: 50%;
    margin-left: -20px;
    height: 0px;
    width: 0px;
    border: 35px solid #4b4b4b;
    border-radius: 35px;
    left: -14px;
    opacity: 0;
    transform: scale(0.2);
}

The above styling just makes them round, grey, and positioned absolutely in their container. I also have two animation keyframes defined, one for the down-and-left movement and one for the down-and-right movement:

@keyframes smokeL {
    0% {
        transform: scale(0.2) translate(0, 0);
    }
    10% {
        opacity: 1;
        transform: scale(0.2) translate(0, 5px);
    }
    100% {
        opacity: 0;
        transform: scale(1) translate(-50px, 80px);
    }
}

@keyframes smokeR {
    0% {
        transform: scale(0.2) translate(0, 0);
    }
    10% {
        opacity: 1;
        transform: scale(0.2) translate(0, 5px);
    }
    100% {
        opacity: 0;
        transform: scale(1) translate(50px, 80px);
    }
}

The above keyframe definitions define an animation that will move the smoke puffs lower by 80 pixels and 50 pixels to either side while at the same time scaling them up and fading them out. It defines 3 steps: 0% (the start), 10% (moved a little down), and 100% (moved completely down and over). There's one for the left, smokeL, and one for the right, smokeR.

Note: if you care about being compatible with slightly older browsers, you would want copies of these with @-moz-keyframes and @-webkit-keyframes as the names as well as adding -moz-transform and -webkit-transform to them all! I left that out here to keep the example simpler!

I said this was pure CSS3 animation, but there's still a little JavaScript involved. It doesn't really do the animating, but I use some code to generate the puffs in the first place. Something like this:

function createSmoke(time, num) {

    var timeGap = (time / num); 

    for( var i = 0; i < num; i++) {

        var delay = (timeGap * i) + 's';

        var aniName = "smokeL";
        if (((i+1) % 2) == 0) {
            aniName = "smokeR";
        }

        var aniStyle = "animation: " + aniName + " " + duration + " " + delay + " infinite";
        $('#smoker').append('<span class="smokepuff" style="' + aniStyle + '"></span>');

    }

}

When this function is called, you give it the length of the animation and the number of puffs of smoke you want. It figures out how much of a delay there should be between each puff's animation starting based on those two values. For example, if you want the animation to run 5 seconds and have 10 puffs of smoke, the first puff would have no delay, the second would have a delay of ( 5 / 10 ) * 1, the third a delay of (5 / 10 ) * 2, and so on. In this example, that just means add a half-second delay for each puff you generate. Also, each time through the loop, it alternates between the smokeL and smokeR animations so that every other puff moves in the opposite direction. One final piece of the total animation style is to set the repeat-count to infinite, so the puffs keep on coming! The function generates new SPAN tags with these animation styles applied and appends them to the parent element, which here is named smoker. It's just a DIV somewhere on the page - all the puffs of smoke will appear to come out of it.

The finished animation. Don't miss it!

I think the effect turned out great. Even though I used a little JavaScript to create the elements, doing all the animation with JavaScript would have been much, much more complicated. I may consider replacing all the old JavaScript-powered animation on Amphibian.com with CSS animation, and fix up my animation editor to go with it!

Now don't miss the smoke effect in today's comic! If you're reading this on the publication day (16 May 2016) the countdown to launch will be live! That means the last frame of the comic will change and do different things right up to the launch time! Keep watching it!

Amphibian.com comic for 16 May 2016

Monday, May 9, 2016

Add Gamepad Support to a Phaser Game

It seems like I haven't written a blog post in forever! It's actually been less than 2 weeks. Right before I took a break, I wrote a little about my new NES-style Bluetooth gamepad. I've been trying off-and-on ever since then to get my 8-bit style platformer to work with it, and today I finally had some success!

First of all, it needs to be said that support for gamepads in the browser is very inconsistent. The W3C's Gamepad API document is still a working draft after all these years (I first read about it and tried it out in 2013). It seems as though Mozilla and Google have some different opinions on how it should work, because the way you interact with the devices varies significantly between Firefox and Chrome. Phaser provides gamepad support through the Gamepad object, but the documentation carries a warning about the volatility of the specification.

Here's what I learned when I tried to use it...

I started with some of the examples on Phaser's site. They worked, most of the time. Let me explain. In theory, working with a gamepad in Phaser is simple. You get a gamepad object, setup a callback to handle the detection of a gamepad device, and bind to buttons in that callback. Then you start the gamepad polling.

function create() {

    // ... setup stuff ...

    var jumpButton = null;

    controller = game.input.gamepad.pad1;

    controller.addCallbacks(this, {
        onConnect: function() {
            // you could use a different button here if you want...
            jumpButton = controller.getButton(Phaser.Gamepad.BUTTON_1);
        }
    });

    game.input.gamepad.start();

    // ... other stuff ...

}

function update() {

    // ... other stuff ...

    if (jumpButton.isDown) {
        // jump code goes here!
    }

    // ... other stuff ...

}

Much like you do for keyboard input, you can set up the buttons you want to listen for in create and then perform actions based on their state in update. And this works pretty well - in Firefox. Chrome, on the other hand, has some issues. Phaser's example code, much like my example above, works most of the time in Chrome when the code gets executed very quickly after the page loads. But if you put enough setup code in front of your gamepad initialization you'll be wondering, like I was, why your gamepad never connects.

I had to dig into the Phaser code in order to figure this out. It works consistently in Firefox because Firefox waits until the first time a button is pressed on a gamepad before it emits a gamepadconnected event from the window object. Phaser catches that and sets everything up, calling the onConnect function when complete. In Chrome, however, gamepads just show up magically at some point after the page is loaded, in an array-like object accessed by calling navigator.getGamepads(). Phaser checks this list constantly, and when things appear for the first time, it makes all the internal setup calls. And right there's the problem! If the gamepads appear BEFORE my onConnect callback function is set up, I missed the boat. A default, no-op callback got executed instead and my gamepad buttons never get set up!

There was no work-around for this that I felt was acceptable, so I actually forked Phaser and fixed the problem in the Gamepad object's code. It was a fairly simple fix - I just don't start polling for those gamepad objects until after the call has been made to game.input.gamepad.start().

I forked off of version 2.4.7 and submitted a pull request, so hopefully my fix makes it in to the next Phaser release and the rest of you won't have to deal with this problem like I had to! If you can't wait, try using my fork and gamepad branch.

If you're just interesting in playing the game I've been working on, you can do that here: http://amphibian.com/eight-bit. The full source code is available on GitHub. If you're just interested in viewing today's comic, you can do that here:

Amphibian.com comic for 9 May 2016

Wednesday, April 27, 2016

The Most Awesome Thing on the Internet

Here it is, people. The most awesome thing on the Internet (besides my frog comics) - a
Mariachi Cover of the Dark World theme from The Legend of Zelda: A Link to the Past.




You can thank me later (by viewing and sharing today's comic!). Oh look, here it is...

Amphibian.com comic for 27 April 2016

Monday, April 25, 2016

Review of Xgaming's NES-style Wireless Gamepad

Late last week I received my new Bluetooth wireless gamepad from Xgaming. I was really excited about this new product. I've had one of their arcade joysticks for years and found it to be an excellent piece of hardware that fully lives up to the high expectations set for it on their web site. I was certain that this new wireless gamepad, a bit of a departure from their existing product line, would not disappoint me.


So, what do I think now that I've had a few days to play with it?

Let's start with my initial impressions. It was a little smaller than I had expected it to be. It doesn't really give dimensions anywhere on Xgaming's site (as far as I could tell) but the unit is only 5.125 inches wide and 2.5 inches tall. It's slightly over half an inch thick (not counting the sticks and buttons). For me, the small size makes hitting both sets of top trigger buttons awkward but maybe I just need to get used to it. Most games I play only need one set of top triggers anyway. Besides that, the position of all the buttons and sticks is excellent. It weighs only 3 ounces, but feels very solid. The buttons and D-pad are very firm and have a wonderful feel to them.

Technically, it has been functioning very well. I had no problems pairing it to my Windows 10 PC as a Bluetooth game controller, but it did seem to lose its pairing once (there are colored LED lights on the bottom which indicate things like that - flashing blue means ready to pair). I'm not sure if it was the device's fault or mine - I may have been holding down one of the settings buttons inadvertently while powering it on. I'll withhold judgement on that issue until I see if it repeats. There were no issues setting up button mappings in my emulator software either. It all worked very well.

Playing games with it has been very enjoyable so far. The button response is much better than my old SNES-style USB game controller. I honestly haven't liked a PC game controller this much since my Gavis PC GamePad.

The device is currently selling for about $45. If you love playing emulated NES and SNES games as much as I do, I believe you'll find it to be well-worth the money.

The only question left might be, does it work in web-based HTML5 games such as the 8-bit style platformer I've been working on? The answer is...maybe. Web browser gamepad support is still weird. Phaser has an API for it, but so far I've found it difficult to work with. I'll keep trying and maybe have something to report next week.

Until then, I've got more comics for you to enjoy!

Amphibian.com comic for 25 April 2015

Friday, April 22, 2016

Answering Questions

Tonight I'm working on answering interview questions. Yes, I'm being interviewed by Best WebComics, a site that promotes the discovery of new webcomics. Their questions are rather unique so the finished interview should be a good read. I also get Amphibian.com promoted on their site for a week next month.

I've been working on the comics for over 2 years now. The first comic was published in August of 2014 but I actually started working on it in January of that year. It took almost 8 months to get things ready. I had to develop the web page stuff, the back-end application that runs everything, make the editor for the comics, and write a bunch of comics. Looking back on some of my early work, I think I've gotten a lot better.

So when you view today's comic, why don't you click the link to go back to the first comic too? Even if you've been reading them from the beginning, you've probably forgotten the early ones.

Amphibian.com comic for 22 April 2016

Wednesday, April 20, 2016

Read Another Blog Today

As I said last week, I'm not spending as much time writing this blog as I normally have been. I need a few weeks off from it due to the demands of the real world. But that doesn't mean that you, the reader, have to suffer. Please take the time you would have normally spent reading my inane ramblings to read someone else's.

Here are some excellent options:

Smoke in the Cinderhaze
I'm not exactly sure what a "Cinderhaze" is, but I suspect that it's a word used to describe Cinderella's mental state before she has her first cup of coffee in the morning. Either that or some kind of sailor thing. This tech blog is written by my friend Daryl Wiest, and he doesn't update it often enough. Go leave him some comments about that.
David Walsh Blog
An excellent tech blog that covers a variety of topics, but often covers JavaScript and front-end stuff. Also some excellent career advice sometimes. This David Walsh guy is fairly famous so you might have heard of him already. If not, you should.

While you wander off to read those, don't forget to read today's comic! It's #314, which is a lower number than Monday's comic (#315). That kind of thing hasn't happened in a while. I move the publish dates around from time to time after I make them. I hope it doesn't bother anyone.

Amphibian.com comic for 20 April 2016

Monday, April 18, 2016

Better Static Images for Amphibian.com

The new, improved version of the image for a recent comic.
As I mentioned last week, I have been working to close Issue #7 on my webcomic. Basically, Amphibian.com is not a normal webcomic. It's not an image, which is great until someone wants to share a link to a comic on social media. I auto-generate static images of the comic just for sharing. But the comics which contain embedded games and stuff haven't looked right in the static captures. I wanted to at least put a warning in the image that explains why they often look weird, but as an added bonus I actually made them look better (most of the time).

As you can see in the picture on the right, I was able to add some warning text to the top of dynamic comics. I generally share this version on TopWebcomics.com but you may see it other places as well. When people see comics like this in the future, they'll know that they should view it on Amphibian.com to get the full effect.

Also, when this comic was originally published, the third frame was black. The game was not captured as part of the image. This was due to two things - the URL of the page used for the image capture was such that the game's image assets could not be loaded, and the fact that the capture was taken before the game initialized asynchronously. I fixed the URL issue by changing the static image comic path from /basic/[comic-number] to /[comic-number]&b=1. There wasn't really a generic way to ensure the comic will be rendered before the capture in all cases, but I added a 500 millisecond delay which should be good enough the majority of the time.

Finally, I also locked-down the ability to see the basic versions of the comic. It was the case that you could view a future comic if you asked for the basic rendering. I changed the rules so that only authenticated users or requests coming from the server itself can see them. I use PhantomJS to perform the image capture and it runs on the server, so that was a simpler fix than I initially thought that it would be.

It always feels good to resolve an issue. It also feels good to read one of my comics. Here's the link so you can feel good too.

Amphibian.com comic for 18 April 2016