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

learn more… | top users | synonyms

3
votes
1answer
4k views

HTML5 - Dynamic canvas grid for scrolling a big map

I've been working on different scrolling algorithms for my JS-based game. My main problem is that I need to draw a huge map and also have it scroll smoothly. I've made a few attempts and while they're ...
5
votes
3answers
375 views

How to do a genetic algorithm's chromosome which controls movements

First I would like to inform you that I'm french and 15 so my english is not very good. I've read some articles about genetic algorithms (GA) and since I discovered the HTML5's canvas element, I can ...
10
votes
5answers
5k views

Poor performance in android when running APK, runs fine in browser

I have created a small game project in HTML5 using Phaser engine (tried both 1.1.5 and 1.1.6). Then to port it to mobile platform, used Phonegap/Cordova for Windows Phone 8, Android and iOS. In my ...
4
votes
2answers
979 views

HTML5 game fps render lag

I am currently creating a flappyBird-like HTML5 game using Proccessing.js You can see current work here: http://files.tips4design.com/flappySlothRelease/ The problem is that even though the FPS is ...
0
votes
1answer
127 views

What's the best way to time a character AI movement on android/java?

I'm creating an android game and I'm trying to figure out the best way to time a character position change, something like this: public void move() { //this.posX += 5; this.posY += 5; if ...
0
votes
1answer
393 views

2D to 3D perlin noise, I'm not sure I get it

I've been using 2d perlin noise to generate height maps for a little isometric terrain experiment. The noise value is directly related to the z-layer a tile will appear in: Math.floor(noise * 10). ...
-1
votes
2answers
596 views

How do I make a sprite blink on an HTML5 canvas?

I'm thinking of the flashing effect many games have when a character gets hit and takes damage. Something like overlaying a lighter color on visible sprite pixels for a second.
1
vote
2answers
134 views

Calculate tile ID on a Reus style world with canvas context.arc()

I need a bit of math help for my game. I'm using Javascript and the Canvas tag to create a circular world, think God Finger, and Reus. The current version of my game is here: ...
0
votes
1answer
66 views

Update function in html5 canvas game isn't working properly [closed]

Jsfiddle : http://jsfiddle.net/seekpunk/6eeKH/15/ the code : if (this.collection.length > 0) { if (((this.collection[0].blockX + this.collection[0].blockW) >= cw) || ...
2
votes
3answers
326 views

Is it more efficient to encode rotation in a spritesheet or rotate at runtime?

I'm developing a game with JavaScript and HTML5 and I'm wondering about the performance implications of sprite rotations. There are two ways that I know to rotate a sprite: Rotate the actual sprite ...
0
votes
0answers
70 views

What would be a good way to scroll a large html canvas (that contains little repetition if any)

What would be a good way to scroll the content of a huge html5 canvas so that the scroll is crisp and smooth, and memory consumption (and cpu load or battery consumption) is also reasonable? any ...
1
vote
3answers
354 views

Canvas setTransform function clarification

I'm currently building some kind of fake-3D dungeon, and I'm facing some difficulties understanding the behavior of the setTransform() function. Here's my simplified code: var can = ...
0
votes
0answers
20 views

Clicking on a canvas getting polygon [duplicate]

I'm using Canvas to create polygons like this: http://bl.ocks.org/mbostock/6675193 I want each of those polygons to represent a clickable province. How do I know which province is clicked when the ...
3
votes
1answer
890 views

How can I detect mouse events on sprites in a canvas?

I'm making an HTML 5 game. I want mouse clicks on sprites drawn in a canvas element cause events that my code can react to. At the moment, I'm doing it by checking through all of my sprites in a ...
1
vote
1answer
668 views

How to draw many identical quads in WebGL efficiently?

I have recently been trying to develop a more basic one of those 'falling sand'/'powder game' style games (See here) the past few months, and after prototyping on a plain canvas, then trying PIXI.js, ...
1
vote
1answer
454 views

Implementing fog of war on HTML5 canvas

I have been wrestling with creating fog of war for a while now. I actually did create it, but I consider the implementation too resource-heavy to be usefull. For initial information: I use createjs / ...
0
votes
2answers
477 views

translating canvas for rotating sprites that shoot

I am trying to align bullets to my different sprites guns (top down 2D for android). Right now Im using this method to draw my bullets: public void draw(Canvas canvas){ update(); ...
1
vote
2answers
2k views

HTLM5 canvas game (easeljs) slow peformance on ipad (ios7) with phonegap

I have developed a game with easeljs for HTML5 Canvas. the game is a single HTML5 page with canvas and a lot of javascript. All this time I tested the app on iOS Safari (iPad3 iOS7) with 40~50 fps ...
0
votes
1answer
2k views

Alpha Value at 0 Shows Black for Android Canvas Bitmap

There have been a few questions similar to this but none seem to give a straight answer. If I am creating a Bitmap from a .png image and want to set a color (i.e. true pink) to transparent, the color ...
1
vote
1answer
170 views

UI in Canvas-Games [closed]

I am quite new to programming with <canvas/> and WebGL, but very familiar in HTML5. So far, I have made to render some entities on the <canvas/>. Next would be to add a simple HUD to it. ...
4
votes
1answer
7k views

Is it possible to rotate an image on an HTML5 canvas, without rotating the whole canvas?

So I basically want to rotate single sprites on the canvas without rotating the whole canvas, is that someway possible. I also don't want to create a new canvas for each object I have. Also, it ...
1
vote
1answer
331 views

Replace a div (with a ball picture in it) with a 3D canvas ball [closed]

I am trying to make a game where you have to keep the ball on a green platform. At this point the ball is a div with a ball image. You can move the ball over the field, all works great. See it in ...
1
vote
0answers
97 views

Is pre-rendering Canvas graphics with ImpactJS safe? [closed]

I have several fairly complex menus I'm loading into my HTML5 game created with ImpactJS (skill trees, journal, equipment, ect). In order to draw them with a low performance impact I'm rendering them ...
2
votes
2answers
178 views

Testing HTML5 canvas games on low resource computers

I've made a game in HTML5 & JS and want to test it on varying types of user setups as I've heard it doesn't perform too well on older MacBooks. How can I accomplish this? I'm thinking of ...
1
vote
2answers
310 views

Best way to do “cutscenes” [closed]

I'm curious about the best way to display cutscenes in canvas. When I say cutscene I mean something like a static image fading from one to the other. Would it be best to use a timeout for a certain ...
2
votes
2answers
282 views

Glitch-free cross-fades in HTML5

In my HTML5 canvas game, I need to cross-fade two sprites which have some glow around them. (Glow is backed into sprites.) Initially, the first sprite is visible. During the cross-fade the first ...
1
vote
1answer
539 views

Do you need to make a tileset for a platformer?

I've been tasked to make a platformer, I've never made a tiled game before, is this necessary? I.e. can I just make different child classes of a Sprite class and add place them on the map, adding ...
2
votes
1answer
2k views

OpenGL slower than Canvas

Up to 3 days ago I used a Canvas in a SurfaceView to do all the graphics operations but now I switched to OpenGL because my game went from 60FPS to 30/45 with the increase of the sprites in some ...
0
votes
1answer
131 views

Why does my goblin only choose a walk direction once? [closed]

I'm working on a simpe 2d canvas game that has a small goblin sprite who I want to get pathing around the screen. What I originally tried was a random roll that would choose a direction, the goblin ...
1
vote
3answers
148 views

Can I use a translate function to implement a viewport?

I read this great question and its accompanying great answer about rendering a viewport in a top down 2D game: As for actually drawing the objects the camera can "see", you now draw all objects ...
0
votes
2answers
456 views

HTML5 Canvas Parsing image into tileset while preserving transparency

I'm trying to import a Tiled Map Editor JSON file into my HTML5 canvas game but I'm having trouble with separating out the tileset image into separate images while preserving the transparency. ...
1
vote
3answers
391 views

Algorithm to zoom a plotted function [closed]

I'm making a game in android and I need plot a function, my algorithm is this: @Override protected void onDraw(Canvas canvas) { float e = 0.5f; //from -x axis to +x evaluate ...
0
votes
3answers
603 views

Is there a way to create multi-resolution graphics for game with createjs?

I'm on a advanced development for a game made with createjs framework. However it's time to export it to some platforms. The graphics are made for the iPad 3 resolution. I would like to export them ...
0
votes
1answer
274 views

“Painting” elements in html5 canvas

I'm making a game in coffeescript (although for the sake of this problem that's probably not all that relevant) and html5's canvas. It's a game that involves a paint cannon, that fires circular ...
1
vote
2answers
307 views

Bullet entry Point around Player Object

I have a player rotating by the mouse and want the bullets line up with the player's gun. Right now they simply come from the point of the player and shoot in the direction of mouse. I just need the ...
1
vote
2answers
1k views

How can I create and animate 2D skeletons for HTML5 Javascript games? [closed]

I'm trying to make a 2D fighting game in HTML5(somewhat like street fighter). So basically there are two players, one AI and one Human. The players need to have animations for the body movements. ...
1
vote
2answers
279 views

Make perfect constant game animation using javascript

I tried different ways to make constant animations using JavaScript and HTML. The problem is that they are never perfect. If I want to move a square exactly 5 pixels every 50 miliseconds I would use ...
3
votes
1answer
443 views

Multilayer game HTML5 canvas

I've have a problem with HTML5 canvas and using multiple layers. I'm using 3 layers. The first layer is where the player and the collision base objects are. And the second and the third layer have ...
1
vote
0answers
59 views

Improving performance on older Androids

I'm learning to build html5 games for mobile. I'm worried about the FPS animation on older model Android... as I use a lot of setTimeouts to update certain aspects and would like some suggestions on ...
6
votes
2answers
3k views

Is using multiple canvas objects a good practice?

We're developing a jump and run game with HTML5 and JavaScript and have to build an own game framework for this. Here we have some difficulties and would like to ask you for some advice: We have a ...
2
votes
3answers
1k views

Map building - Tower Defense

Before diving too deep into my question, let it be known that I am learning as far as java script goes and figured a simple Tower Defense game would be an excellent way to learn things. So I have ...
1
vote
3answers
105 views

Move from point a, to point b, and determine the accuracy

Let's say I have a circle at point a (0,0), and I wish to move it to point b (23,58), whatever, how can I accurately do this with a speed variation if I wanted. (I'm doing this in javascript). Every ...
0
votes
3answers
515 views

how can we define dynamic Path of ViewObject(Bitmap) On Canvas

I am Currently working on One 2D Android Game, In this game One ViewObject(Bitmap) is moving Across Screen On Parabola Path Like in this Image, But this Path is Static, the Static path is getting ...
-2
votes
1answer
61 views

Error returning a value from a function? [closed]

It tells me the error is on this line: this.srcX = ShipSrcXPicker(type); However I cannot see it? I am returning the values from these methods that are being called? Is there something I am missing? ...
0
votes
2answers
240 views

Physics for space game [duplicate]

I am making a space game where you fly a ship. I am trying to work out the physics for such a game and so far came up with: var thrust; //between 1 & 100 how much the engines are pushing var ...
-4
votes
2answers
302 views

Moving Character Based on background [closed]

I want to know how can i move the following character just in predefined areas as shown in the bg.jpg file character http://s7.postimg.org/ezyaclrrb/walking.gif bg ...
0
votes
1answer
431 views

How can I draw a small bitmap on a larger bitmap at a particular position? (Canvas / SurfaceView)

I'm building a game that requires additive blending of colours for certain bitmaps. Say I have 4 different types object, there are maybe ten of each type on the screen with each type having a ...
3
votes
4answers
1k views

Why wouldn't one use Canvas for HTML 5 game development? [closed]

I'm just getting into the HTML 5 game development. I've discovered that some games seem to be created using just JS/CSS/HTML instead of the canvas. Since canvas seems to enjoy good browser ...
-1
votes
1answer
393 views

View port for my canvas game

I am developing a canvas game, and im struggling to get my head around how i can make a view port so when the character moves the world moves with it. Unlike traditional 2d maps built with arrays i ...
2
votes
1answer
547 views

JavaScript - 2D Top-down Tile Collision Detection

I am developing a small Top-down Game (Much like the old Zelda Games) and I'm having an issue in terms of Collision detection (The actual theory itself rather than assigning Tiles as solid, etc.) I ...