A new feature of HTML5, allowing Javascript apps to have a drawing surface in the browser.

learn more… | top users | synonyms

2
votes
2answers
1k views

HTML5 clicking objects in canvas

I have a function in my JS that gets the user's mouse click on the canvas. Now lets say I have a random shape on my canvas (really its a PNG image which is rectangular) but i don't want to include ...
3
votes
1answer
2k views

Canvas tile grid, hover effects, single tilesheet, etc

I'm currently in the process of building both the client and server side of an HTML5, canvas, and WebSocket game. This is what I have thus far for the client: http://jsfiddle.net/dDmTf/20/ Current ...
1
vote
2answers
987 views

Matrix rotation of a rectangle to “face” a given point in 2d

Suppose you have a rectangle centered at point (0, 0) and now I want to rotate it such that it is facing the point (100, 100), how would I do this purely with matrix math? To give some more specifics ...
1
vote
2answers
2k views

Creating several instances of the same object, and selecting only one

I'm playing around with making a puzzle game, haven't done that much before I run into my first problem. I want to create a certain amount of the same object/function. But without hardcoding the ...
10
votes
2answers
613 views

Dirty 2D map rendering

I keep hearing people talk about "dirty rendering" when it comes to map rendering for HTML5. I've Googled and searched the GameDev about it but there isn't much about it. What exactly is it? How to ...
3
votes
0answers
258 views

Choosing a (browser) game environment [closed]

I apologise in advance if this post is something you've heard a million times already or seems like a trolling attempt. I just want some advice and I'm coming up short with my own Google searches. ...
5
votes
4answers
2k views

Making a startscreen for an HTML5 game?

How would I make a start screen for a game using HTML5 canvas? I'm not looking for something advanced, just the new game button and highscore link etc. The question might be stupid, but I've never ...
2
votes
2answers
1k views

Drawing isometric map in canvas / javascript

I have a problem with my map design for my tiles. I set player position which is meant to be the middle tile that the canvas is looking at. How ever the calculation to put them in x:y pixel location ...
3
votes
1answer
306 views

How do I show the current view from the viewport on my map?

I'm doing HTML5 Canvas development and currently have a large viewport (on the left) and a map (on the right). Like this: I need to show on the map what is currently being viewed in the left. And ...
2
votes
2answers
461 views

Collision Detection doesnt work because some things move more than 1px at a time

I'm writing a 2d scrolling game in javascript using canvas and since I'm limited to setInterval running at minimum once every ms, I need to have some objects moving at greater than 1 pixel a second. I ...
1
vote
1answer
276 views

Isometric Optimization in javascript

I'm having some issues with my optimization of my game. I have a simple tile map looped like this in my case the images are 64 by 64 pixels: for (i=0; i < 50; i++){ //horizontal for (j=0; ...
4
votes
2answers
666 views

HTML5 multi-player game data/event validation best practices

I'll start by saying that I am fully aware that this question might seem subjective at first, but I'll try and provide a specific test case scenario for it to be a clear question about validating the ...
1
vote
1answer
1k views

Android-Handling screen clicks for dynamically moving objects in a view

I have a kind of broad question to ask but I have to start some where so.....What is the best way to handle onscreen clicks for moving objects being drawn on a canvas in a view. Im registering the ...
2
votes
1answer
2k views

Collision detection between a sprite and rectangle in canvas

I'm building a Javascript + canvas game which is essentially a platformer. I have the player all set up and he's running, jumping and falling, but I'm having trouble with the collision detection ...
3
votes
2answers
3k views

HTML5 canvas screen to isometric coordinate conversion

I am trying to create an isometric game using HTML5 canvas, but don't know how to convert HTML5 canvas screen coordinates to isometric coordinates. My code now is: var mouseX = 0; var mouseY = 0; ...
3
votes
3answers
416 views

Commonizing cycle time across different browsers for HTML5

Is there a good (accepted) method for "fixing" the cycle time within an HTML5 canvas game implementation? The game that I have been working on runs far quicker in Google Chrome than in other browsers ...
10
votes
2answers
1k views

How should I handling clipping vertices that are closer to the eye than the near clip plane?

I'm rolling my own 3D engine in Javascript and using only canvas drawing, no WebGL. This is another Minecraft clone, I love boxes, don't judge me. So far everything works wonderfully, except for one ...
3
votes
1answer
2k views

Optimizing HTML5 canvas transformed drawing in Javascript

I am trying to optimize my HTML5 game engine and have noticed that currently a majority of the time taken in the game loop can be taken when drawing transformed tiles. I think this is because each ...
2
votes
2answers
1k views

Canvas Rotation collision detection on a sprite

I am using this code to detect collisions between two rectangular sprites. intersect: function(other) { return this.x < other.x + other.width && other.x < this.x + this.width ...
1
vote
1answer
4k views

How to rotate a moving canvas in Android

I am developing an Android game. In this game some trains are moving on tracks. I am able to move trains horizontally and vertically using two train images for horizontal train and vertical train ...
3
votes
1answer
610 views

Best resources for Canvas Html 5 development

I am at a competition at work for who can make the best canvas game. Theme is a top down shooter... Winner gets dinner for free. Anyways I have been looking around looking for some good resources on ...
7
votes
2answers
1k views

How to scroll hex tiles?

I don't seem to be able to find an answer to this one. I have a map of hex tiles. I wish to implement scrolling. Code at present: drawTilemap = function() { actualX = Math.floor(viewportX / ...
1
vote
1answer
659 views

Calculating bullet travel knowing coordinates and radian

I have a player sprite that has a x and y coordinate and also a radian. The radian determines which way the sprite faces in a top-down game interface. In this case, the radian points from the player ...
8
votes
1answer
1k views

Set sprite to face direction of mouse

I'm building a html5 canvas game and I need a way to get my sprite to face the mouse cursor. I have the X and Y co-ordinates for the sprite, and also the X and Y co-ordinates of the pointer. All I'm ...
7
votes
2answers
2k views

How to efficiently store and display a tile map on the web?

About These are actually two questions in one. First of all I am looking for a way to efficiently store large amounts of tile data. The other aspect deals with querying the data set and displaying ...
2
votes
2answers
372 views

How to draw objects that have a smaller Y axis first?

In my game there is a large 2D map of various objects. Example. As you see, upon creation objects of the same type (trees for example) are placed correctly, but objects of another type (enemies) are ...
3
votes
1answer
6k views

How do I make magenta in my PNG transparent in HTML5/Canvas/JS?

I'm putting together a simple hex map to use within an HTML5 / Canvas / JS game and before I get round to sorting any custom graphics, I was wondering if anybody knew how to make the pink/magenta ...
2
votes
2answers
609 views

Animating sprites at different speed than what the game runs at

I am building a Javascript/canvas platformer game, and it's coming along nicely. The only problem I've really run into where I can think of any solution at all is the animation of my player sprite. ...
5
votes
1answer
3k views

How do I implement side scrolling in a javascript platformer?

I'm building a side scrolling platformer with Javascript and the canvas element for a school project. I have the character all sorted out. He runs left and right, and has a different sprite set for ...
1
vote
1answer
1k views

Has anyone used PhoneGap to make 2D games for the iPhone? [closed]

I love simple casual games. I've been riding the bus a lot recently and so simple, no-brainer games are great fun and well worth the small price I pay on the App Store. It got me thinking... I know ...
5
votes
2answers
2k views

Calculating the angular direction from velocity

I'm trying to calculate the angular direction of a projectile, knowing it's X and Y velocity I can find the magnitude of its movement, but I'm having a hard time wrapping my mind around getting the ...
0
votes
1answer
336 views

Drawing slope lines in a confined space

This isn't a game development question per se, but here goes... I have a 50x50 pixel space in which I need to draw five lines: X and Y axes, and one line for each of a steepest, average, and flattest ...
5
votes
3answers
2k views

Chrome Angry Birds engine?

Was Chrome AngryBirds game made using html5 canvas? And if yes: what kind of engine did they use?
1
vote
3answers
1k views

Where to start, to develop an online Backgammon game?

I would like to develop a backgammon game to play against other players online, as a way of learning more Javascript/jQuery and a little game development. I'm a web developer and most of my experience ...
0
votes
1answer
840 views

HTML Canvas drawing - Firefox error

I am getting the following error ONLY when running my game in Firefox (3.6) Component returned failure code: 0x80040111 (NS_ERROR_NOT_AVAILABLE) [nsIDOMCanvasRenderingContext2D.drawImage] ...