Making Javascript and HTML5 games - html

A long time ago (Netscape 4-era), I wrote Javascript-based games: Pong, Minesweeper, and John Conway's Life among them. I'm getting back into it, and want to get my hands even dirtier.
I have a few games in mind:
Axis & Allies clone, with rugged maps and complex rules.
Tetris clone, possibly with real-time player-vs-player or player-vs-computer mode
Breakout clone, with a couple weapons and particle velocities
In all of these, I have only a few objectives:
Use JavaScript and HTML 5 - it should run on Chrome, Safari, or maybe an iPad.
Start small and simple, then build-up features.
Learn something new about game design and implementation.
So my questions are:
How would you implement these games?
Do you have any technology recommendations?
If you've written these games, what was the hardest part?
N.B.
I also want to start from first-principles - if you recommend a framework/library, I would appreciate some theory or implementation details behind it. These games are different enough that I should learn something new from each one.

Depends how much you want to start from scratch. To answer your direct questions:
1) How would you implement these games?
A: JavaScript + Canvas. Canvas is the 2D drawing surface from HTML5. Performance is pretty good on desktop machines, not so great on iOS and Android devices (as of the date of this post). If mobile is your utmost concern, you need to use the DOM and CSS3 3D transforms which trigger the GPU on those devices.
2) Do you have any technology recommendations?
A: This is sort of answered by the first question. JavaScript is a must, but I would ignore jQuery. You are targeting HTML5 devices, so no need to compensate for legacy browsers. As you are probably using Canvas, no need to smooth over the DOM interaction, either. There are some higher level libraries which make interacting with Canvas easier, such as Easel.js. WebSockets are useful for bi-directional streaming communication. And Box2D is useful for a physics engine. Local Storage is simple key/value string data for things like level progress, but for anything complex, you'll want WebSQL DB. For large binary assets you'll want to look at the File System API. Finally, don't be afraid of WebGL, as it is extremely fast and useful for 2D games.
3) What is the hardest part?
A: Almost certainly the hardest part is the debugging. WebKit's Developer Tools can make this easier, so don't leave home without them.

Put simply use Canvas for moving lots of stuff around the screen and SVG for prettier, slower, vector graphics.
One of the first things you should do is write a speed test program to see what can be done with Canvas and then play with it.
I wrote a blog post about Canvas & writing HTML5 games

edit 2019-02: processing.js is old and not well supported. Instead, try p5.js, which is equivalent and up to date.
Don't forget processing.js, which is a pretty well tested full-stack graphics and interactivity javascript framework, which has substantial (if not comprehensive) support for most I/O, sounds, graphics, and even WebGL. If you write vanilla Processing code, which is basically Java syntax compiled to JavaScript, you can use many open-source debuggers out there, including the native Processing environment. Other than that, you can integrate any other JavaScript code you have a mind to include.
Here is a guide for the JavaScript developer, explaining much of what you might want to know.
Check it out. Good stuff.

The hardest part, for me, was that there were no tools to help make the graphics, as there is no Maya export to canvas, for example, so, everything is done manually, with primitives, unless you want to take bitmaps that you will modify as though they are sprites.
At the time there was no real support for text in canvas, so my solution didn't work using excanvas, but worked fine on Safari and Firefox.
So, you may want to look at what HTML5 features you want to support, such as a built-in database, and then decide which browsers you are willing to work on.
How to implement these will largely depend on how you want to create the graphics, and if you want to do 3D graphics, as then the bitmapped sprites would not work.

Tom here from Scirra (Construct 2 game maker). We make an HTML5 games engine called Construct 2, it exports purely to HTML5 no Flash in sight!
Construct 2 uses an event based system to add logic to your games and does tons of the repetitive/difficult legwork for you. For example adding polygon collision to objects without some visual editor is a difficult task to undertake sometimes.
Anyway we think it's worth a look and you can get results very quickly from it as well. It's an alternative to coding the entire game you might want to take into consideration when developing HTML5 games.

Take a look at ChromeExperiments The examples are from around the world using the latest open standards, including HTML5, Canvas, SVG, and javascript.

Maybe this is not what you wanted to hear, but have you thought of starting with a good book?
http://www.amazon.com/s/ref=nb_sb_noss_2?url=search-alias%3Daps&field-keywords=html5%20game
A good book will save you a lot of time, and start you off right at the basics.

A good question when I also started to learn HTML5 I also came across this question, finally after lot of research I found best way to do is by using some engine or framework. I learned canvas and made my own game but that took hours of logic and 100+ lines of code.
Better go with scirra, it might reduce your work.

I'm currently working on a series of blog posts explaining how to build a Javascript game using EaselJS and Box2D for physics. Here's Part 1.

Related

Sample Code for site -> the expressive web from Adobe

I have been following the expressive web site. I have done some R&D of the site on the google but did n't get the satisfactory link that explains the concept that how the site is being made.
Although i know that it is made in html5, css3 but i was looking for some sample code that will help me to do some coding stuff of it.
Can anyone help me into this?
"the expressive web" was made to impress developers with the new amazing creative possibilities of the HTML5 and CSS3. But it is a toy example. Underlying technology is as simple as bunch of divs animated and transformed with the css. It's all about tedious production and impressive artistic effort.
The most suitable technology for this kind of tasks is WebGL. And it's, actually, will be easier to implement.
Here some reasons to consider:
At this moment HTML5 + CSS realisation, probably, has large coverage. But still you can't run it on older browsers or use shims because it's too heavy and it even don't work properly in all modern browsers. So you will end up with flash\html5 video fallback anyway.
It's really bad for the DOM render time.
This way you are stuck with the simple geometry and no lighting effects or shaders.
You can implement it with the simple particle system or morphing and almost all of your code will be executed on the GPU so it will have pereformence really close to native code and will save battery for the handhelds.
It's really inextensible. You can't just scale up for desktops and scale down for handheld. But with WebGL it's trivial including simplifying of the geometry.
CSS + HTML has performance overhead because every side of an object is part of the DOM.
There is no tools(as far as i know) to work with assets for this kind of graphic effects. But you can find plenty of software(including free ones) to work with such frameworks as three.js or other common 3D pipeline tools including really simple to use declarative frameworks like http://www.x3dom.org/

Create HTML5 game using CreateJS and Canvas Boilerplate

I've pretty much set my mind on using CreateJS to create an HTML5 game, but I also came across H5CGB, a boilerplate created specifically for creating HTML5 canvas games. It looks very thorough and I believe the developer when he says it would save me heaps of time writing code I would have had to write anyway.
However, looking at tutorials for both CreateJS and H5CGB, they seem to conflict quite a bit, at least in terms of how these specific tutorials implement their respective tools:
http://hub.tutsplus.com/tutorials/learn-createjs-by-building-an-html5-pong-game--active-11845
http://icecreamyou.github.io/HTML5-Canvas-Game-Boilerplate/docs/#!/guide/walkthrough
I'm basically just trying to understand how to integrate these two systems. For example, both come with their own preloader utility, so I'm not sure which to use and if they would cause issues or if it's just a redundancy resulting in unnecessarily longer loading times.
Has anyone had any experience working with these two tools together?
I believe you should probably just stick to using createJS because the two frameworks do have a lot of overlapping functionality. It wouldn't make sense to use both.
I think you should also check out other game specific frameworks like Crafty.js and possibly watch Google I/O Canvas to get a good idea on the total range of your options!
Crafty
http://craftyjs.com/
Google I/O
http://blog.sethladd.com/2011/05/source-code-slides-and-video-for-html5.html
Hope this helps and good luck learning canvas!
Shalom
I created H5CGB. (Just found this question today via the newly-released Github traffic stats.)
The biggest two reasons to use H5CGB are:
You do not have to learn any new APIs to start developing. H5CGB provides a bunch of scaffolding you can use to skip the boring stuff, but you won't get into trouble if you want to implement any part of your app yourself, and you probably can get going immediately just by editing main.js without even reading the documentation.
The code base is intended to be boilerplate, so you can use all the utilities and scaffolding H5CGB provides as a starting point and edit it if you want things to work differently.
This is in contrast to most other canvas libraries, which tend to be monolithic black boxes of no-touchiness with sparsely documented APIs.

HTML5 canvas alternatives for d3.js, graph visualization library

Is there any Canvas library that is like d3.js (is svg library). I have a website here and I coded a graph with svg elements however it is not efficient on smart phone's browsers and works so slow. I now, want to change it with a 2d canvas type of it and see whether it is better or not. Can you suggest a canvas library that is useful for this purpose?
Thanks...
D3 is not necessarily an svg only library - svg is used in many cases, but the library can do any kind of representations that you would like to make. See this example of parallel coordinates using canvas in D3, by Kai Chang: http://bl.ocks.org/2409451
Also see here for some discussion on performance issues, etc, that might be helpful: https://groups.google.com/d/topic/d3-js/mtlTsGCULVQ/discussion
I know I am late to the party, but times have changed, and I believe this question deserves an updated answer. SVG performance has improved a lot over the years and especially for the non-trivial graph-like visualizations it often gives superior performance; but it really depends on the exact use-case: If the visualization is simple and consists of thousands of elements, especially on mobile, Canvas may be the faster option. If the visualization is almost trivial, WebGL gives the best performance and beats Canvas hands-down - especially on mobile!
However WebGL especially and also Canvas are a bit harder to use than the declarative approach that SVG uses. Things like CSS animations and transitions are easy to do with SVG and give good performance due to being hardware accelerated and totally independent of JavaScript performance. Canvas and WebGL always require JavaScript.
If you take a look at the commercial graph drawing library yFiles for HTML you will see that it offers all three technologies at the same time. This is because all three can be the best choice, depending on the exact use-case.
There is a blog entry that compares the performance of SVG, Canvas, and WebGL especially in the context of graph visualization. It compares various graph sizes and categories of devices. The "conclusion" is that there is not a clear winner. Often times the combination of all three technologies gives the best results. For smaller graphs, though, SVG most of the time gives very good results and is a pleasure to work with. That's also the reason why d3.js has its focus on SVG, rather than Canvas and WebGL, I would say.
There is an interactive demo linked from that blog entry that let's you play with the various technologies and see their strengths and weaknesses. Of course the demo mainly compares the three technologies used in that specific library so your results may vary, but they spent a lot of time optimizing all three technologies in that library, so I think the results are not too biased.
Disclaimer: I work for the company that creates the above mentioned library, but I do not represent my employer here on SO. I think what I said should be valid not just for that library.
For the Samsung Olympic Genome Project facebook app, we used http://thejit.org to make the force directed graph style animation for the app. It's heavily modified by me and others on my team of course, and only plays a very small part in the app, but it's quite a powerful framework.
Chart.js is a javascript library that just came out that creates charts using HTML5 for rendering. Its not as feature inclusive as D3, but it is working to become exactly that in the future. http://www.chartjs.org/
Take a look at Cytoscape.JS which uses a HTML5 canvas for rendering. At the time of writing this it's in its infancy but the project seems promising. According to its wiki the library supports both desktop and mobile browsers:
Cytoscape.js is easily integrated into your webapp, especially since
Cytoscape.js supports both desktop browsers, like Chrome, and mobile
browsers, like on the iPad.

HTML vs ActionScript3 in Game Development?

I have developed a casual game that has become a modest hit on a few flash gaming sites and
I'm weighing the pros and cons of adding it to facebook. I don't have a strong coding background - I learned AS3 as I was developing the game- so I'm not sure if embedding a flash file is a good idea for facebook games. If I want to eventually enable in-app purchases, are there any reasons I might not want to use Flash? Does Flash make the game more susceptible to cheating? Are there any other reasons that I might want to go with HTML5 or another coding language?
HTM5 isn't a coding language, but JavaScript is used for programming the HTML5 Canvas element, which is what your consideration would be.
There are a lot of Canvas vs. Flash posts on the internet and I suggest you search for them and read them. There's no reason for me to reiterate what's been said a hundred times.
There isn't anything wrong with embedding Flash on Facebook, though the usual iOS crowd won't be able to see it.
Personally I'd recommend learning Canvas, which is a lot lower level than Flash but totally doable. The future of flash is probably going to get a lot smaller, and you're already boxing out at least one demographic (iPad/Phone/Pod/iOS) by using it.
So the bottom line is that Flash is easier, at least for now, but HTML5 Canvas is the future here.
There are a number of Canvas books that cover simple game development and there are already several libraries that make game creation easier (ImpactJS, Game Closure, etc. I'd suggest searching and taking a good look at the currently most popular ones)
If you already actually have the game all coded up and working in AS3, it's pretty much a waste of time to switch it over to another language. A lot of Facebook games are Flash, and if you want to target iOS you can always package it as an AIR app.
For future projects though, I'd agree that taking a look at HTML5 technologies would be prudent.

What is the fastest way to pick up simple 3D rendering for HTML5 canvas?

I've got a good amount of experience with 2D rendering on <canvas>, however there is a project coming up where I need to have a 3D object rotating left along its centre (I believe z-axis). Luckily this is all I need to achieve. The page will run on iPads at an upcoming event.
I'm not experienced with any 3D software/libraries aside from minimal playing around with Papervision 3D in Flash.
I can pick things up pretty easily, so:
Are there any frameworks I can use to take care of the initial stuff?
Are there any open-source projects that include the code to do the above? If not, tutorials to do it are fine.
How do I create the 3D object? Is this the same as a BitmapMaterial in Papervision?
Threejs can be a good library to start with too.
Their "getting started" article is awesome.
There's a GLGE, for example.
GLGE is a javascript library intended to ease the use of WebGL; which is basically a native browser javascript API giving direct access to openGL ES2, allowing for the use of hardware accelerated 2D/3D applications without having to download any plugins.
The aim of GLGE is to mask the involved nature of WebGL from the web developer, who can then spend his/her time creating richer content for the web.
Three.js is pretty awesome, just wanted to point you to this github repo as well
http://lamberta.github.com/html5-animation/ check out the examples in part 4.
Billy Lamberta authored Foundation HTML5 Animation with JavaScript, which is a great book teaching you the math/etc. behind doing things like this if you are interesting in getting a little deeper understanding.