In a place where your fantasy can roam free, there won't be any boundaries to what your imagination can create.
Misha’s Tech Playground
graphics, fun and code play
I'm crazy - but who cares? My ideas are constantly dwelling and this is the place for them to pour out and form into something good. Only active participation will ultimately make this place come to life.
Scripted Image Mosaics
Here’s another useful tidbit.
I already wrote a lot of posts about Javascript Sprites, how to animate them and how they perform. What I neglected so far is how they actually get on the stage or the page to use the correct term. Another fact is also that most people won’t have flashy Scripted animations all over their page – for those people utilizing one of my sprite classes is not just impractical, it’s also a waste of bandwith.
What it will do
To give those people some JavaScript love too I quickly coded a Mosaic Object this morning. It will basically look up a particular piece of your image and return:
- a canvas element which you can draw into a canvas or attach to another element
- or a div element, perfectly sized to fit the mosaic piece with background and background position set apropriately
Tags: Games, JavaScript, tile graphics
Cool Javascript Mario Games
Yesterday at work I got these links from a colleague. There really is a guy that takes JavaScript development to the top. He made a fine little Mario Land clone, having all the music and sprites coded in JavaScript. No sound files, no images, no plugins - just pure Javascript and use of Canvas. Though the script has a fallback to semantic html sprites when canvas isn’t available.
I’d say, great kudos to CupBoy.
Go check it out at his blog:
14KiB Javascript Super Mario
… and then there was this other guy 
sorry, couldn’t resist this cheesy line…
There was a response to this blog entry from Myles Eftos who had been cooking something similar with just semantic html. So these sprites are all divs and spans. Sure this is much slower than canvas but it’s impressive nonetheless.
See the blog entry here:
Swing Your Hands From Side to Side - How to Abuse Javascript
Tags: code performance, Games, JavaScript, tile graphics
Choosing the right Graphics Technique for a Browser Based Game
Whether if you are doing a puzzle game, a tricky jump ‘n run or a full fledged mmorpg, be it a simply casual or a long term persistent browser based game, you’ll certainly need one thing: images and animations.
As mentioned in last weeks article, you have the choice of implementing the right drawing technique. However, there are vast performance differences. So there is no technique that fits them all, merely you’ll need to decide on a case by case basis what you are going to use.
Since trying out everything only to realize that there were some tiny details you weren’t aware of in the first place isn’t actually fun, I am providing an in depth review of each technique.
We’ll go into detail about each techniques pro’s and con’s and you’ll learn how you would go about animating your game graphics in the technique of your choice.
At the end of this article you’ll also find a matrix containing the most important facts from this review.
A Short side-note for Those Looking to Create Flash Games:
This article won’t include information about Flash or Actionscript. There are already a lot of really great tutorials and articles on this topic out there. I don’t think I need to be making another tutorial containing the same information. Have a look at GotoAndPlay.it which is an awesome source for anyone interested in making Flash games.
Tags: code performance, game engine, Games, JavaScript Library, tile graphics
Performance comparison between HTML, SVG and Canvas
I already found out that using scroll properties is good for fast map scrolling. I extended the concept, and after posting my code to animate sprites via a containers scroll properties I thought hey, why not just check if there’s anything better. The following article provides a short overview and a sample for each technique. There is a zip file containing the full sources as well
(more…)
Tags: code performance, Firefox, Games, JavaScript, Opera, Safari, SVG
Animating with Scroll Properties, A view on Performance
Having had some time to polish up the AnimSprite Object of the game engine I had a chance to make a small performance test. I decided to give some insights on ow this style of animation works and to post the code that goes along with it for your personal joy.
The following html is generated by the script for each sprite that is placed on the stage.
Of course there is a stylesheet having defined the sprite class:
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.CGE_sprite {
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overflow: hidden;
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position: absolute;
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}
Utilizing the ScrollTop and ScrollLeft properties of the sprite box (the surrounding div) I can display 50 animated sprites @ 25fps on a page using Firefox 3 Beta 4 with a processor load of about 98% on my MBP 2.16GHz Core Duo.
Safari on the other hand is quite fast and has only 19% processor load for 50 sprites.
Having 100 sprites lets Firefox peak out at 100.9% load and slows down the animation to about 50% speed.
I'd say this is still not optimum, but it's quite a good start.
Here's my JS code for the sprites.
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var CGE = {
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// globals attributes
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LEFT: 3,
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TOP: 0,
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RIGHT: 1,
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BOTTOM: 2,
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HEIGHT: 1,
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WIDTH: 0,
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X: 0,
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Y: 1,
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Z: 2,
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STYLE_SPRITE: "CGE_sprite",
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// the game instance if needed
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game: null,
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};
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CGE.Game = new AJS.Class({
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animSprites: [],
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init: function (keys) {
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for (var i=0; i <50; i++) {
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this.animSprites[i] = new CGE.MirroredAnimSprite("_img/jumping_shadow.png", [Math.random()*300,Math.random()*250], [32,32], AJS.$("map"), true);
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};
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this.run(this);
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},
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run: function (game) {
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game.hero.move(CGE.moveDir);
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for(var i = 0; i <game.animSprites.length; ++i) {
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game.animSprites[i].next();
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}
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game.mainLoop = window.setTimeout(function(){game.run(game)}, 40); //25fps
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}
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});
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CGE.Sprite = new AJS.Class({
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box: null, // for tiles this is the tile container, pos is relative to it
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img: null,
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spriteH: 0,
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spriteW: 0,
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// get x and y directly from object, faster for anim
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z: 0,
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frames: null,
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init: function(url, pos, size, parent, useBox) {
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this.img = AJS.IMG({src: url});
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if(useBox)
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this.box = AJS.DIV({className: CGE.STYLE_SPRITE}, this.img);
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if(pos)
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this.setPos(pos);
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if(size)
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this.setSize(size);
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if(parent)
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AJS.ACN(parent, this.box);
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},
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get: function() {
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return this.img.src;
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},
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set: function(url, size) {
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this.img.src = url;
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},
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getPos: function() {
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return [this.box.offsetLeft, this.box.offsetTop];
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},
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setFrame: function(name, n) {
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this.box.scrollTop = this.frames[name][n][CGE.Y];
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this.box.scrollLeft = this.frames[name][n][CGE.X];
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},
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setPos: function(pos) {
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AJS.setLeft(this.box, pos[CGE.X]);
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AJS.setTop(this.box, pos[CGE.Y]);
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},
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setSize: function(size) {
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this.spriteH = size[CGE.HEIGHT];
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this.spriteW = size[CGE.WIDTH];
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AJS.setHeight(this.box, this.spriteH);
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AJS.setWidth(this.box, this.spriteW);
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}
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});
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CGE.AnimSprite = CGE.Sprite.extend({
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isPlaying: false,
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isMirrored: true,
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sign: true, // true=add, false = substract
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frames: null,
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key: null,
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init: function(url, pos, size, parent, isPlaying) {
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this.parent(url, pos, size, parent, true);
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this.key = {name: "base",num: 0}
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this.isPlaying = (isPlaying);
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this.frames = {base: [[0,0],[32,0],[64,0],[96,0],[128,0],[160,0]]};
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},
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getFrame: function() {
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return this.key;
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},
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setFrame: function(name, n) {
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if(n>= this.frames[name].length)
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n = 0;
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this.parent(name, n)
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this.key = {name: name, num: n};
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},
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next: function() {
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if(this.isPlaying)
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this.setFrame(this.key.name, ++this.key.num);
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},
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pause: function() {
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this.isPlaying = false;
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},
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play: function(name) {
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if(name)
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this.key.name = name;
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this.isPlaying = true;
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},
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stop: function() {
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this.pause();
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this.setFrame("base", 0);
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}
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});
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CGE.MirroredAnimSprite = CGE.AnimSprite.extend({
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sign: true, // true=add, false = substract
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setFrame: function(name, n) {
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switch(n) {
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case this.frames[name].length-1:
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this.sign = false;
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break;
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case 0:
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this.sign = true;
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};
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(this.sign) ? ++n : --n;
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this.parent(name, n);
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},
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next: function() {
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if(this.isPlaying)
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this.setFrame(this.key.name, this.key.num);
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},
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});
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function init() {
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CGE.game = new CGE.Game();
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}
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AJS.AEV(window, 'load', init);
As you can see, I make extensive use of AJS. You can get the stock version of it at the official website: AJS JavaScript Library.
The code shown here should be fully functional. I just removed the methods and members which aren't used in this example. And as a little caveat, there is no depth management as of yet.
The image I used in my code is the same as in the Javascript Sprite Animation post.
The classes to use would be:
- CGE.Sprite - which is a single not animated sprite
- CGE.AnimSprite - which is an animated sprite running in a loop
- CGE.MirroredAnimSprite - which is an animated sprite that plays in reverse when it's last/first frame is reached
- CGE.Game - which coordinates the loop in which all animations are run
Have fun 
Tags: code performance, Firefox, Games, JavaScript Library, pbbg, Safari, tile graphics
Game Engine Preview
Since the class hierarchy is almost finalized I thought I post a little sneak peek of what is to be expected.
Not everything shown here will make it into the first release, unfortunately. But be assured that development is in progress...
You might notice that this looks a lot like pseudo code, but I just don't want to throw around pieces that aren't finalized yet.
So without further ado, here's some code to stick your nose in...
Tags: code performance, Games, JavaScript Library, pbbg, tile graphics
SVG vs. XHTML
Doing a web based game without any plugin is a high-put target. I noticed this today when I tried to do my first steps with SVG. While the standard itself is certainly not in it's infancy, the browsers trying to display it certainly are. This article aims to provide some first experiences and comparisons of SVG and (X)HTML for displaying raster based graphics on a web page.
Tags: Firefox, Games, Opera, pbbg, Safari, SVG, tile graphics
Isometric vs. Top Down
Xalthorn posted an interesting article at his blog comparing isometric to top down perspective. His main focus was on the field of view each method offers when 2 players look at the same map area.
This article will focus more on the technical bits and on the pros and cons each method offers in terms of a browser based game. (more...)
Tags: Games, isometric, tile graphics
Fast map scrolling with Javascript
Chatting about moving objects around on an html page with Xalthorn the other day we came to an interesting conclusion. There is indeed a method available that works (almost) independently of the number of objects to be moved around. There are certain restrictions to this method however.
This article aims to provide a short overview over the pros and cons of using an elements scroll property rather than its children's style attribute. (more...)
Tags: code performance, Games, tile graphics
Level Editor Redux
I have dedicated more of my sparse spare time and refined my level editor quite a little bit.
I have found some very cool and useful information about tile based games on the net this week and parts of it are already directly influencing the current codebase. The latest somewhat stable version is 0.92b which rectifies some problems with Firefox 2 and implements all features listed as current. Once I have a chance to cleanup the code I'll make it available for download in a new post.
The current development milestone is 0.95a which incorporates already some of the planned features.
It still has to go a long way to be complete but the progress is going well. (more...)
Tags: Games, level editor, tile graphics
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