I have a similar slideshow displayed a few times here! It works fine but I don't get the right mapping on an a-sky. I am not a coder but I guess drawImage is just made for rectangular objects instead of spherical? Is there an alternative to drawImage which works for spherical?
Here are my codes:
AFRAME.registerComponent('draw-canvas', {
schema: {
type: 'selector'
},
init: function() {
var canvas = this.canvas = this.data;
var ctx = this.ctx = canvas.getContext('2d');
var i = 0; // Start Point
var images = []; // Images Array
var time = 3000; // Time Between Switch
// Image List
images[0] = "Tulips.jpg";
images[1] = "Tulips2.jpg";
images[2] = "Tulips3.jpg";
// Change Image
function changeImg() {
document.getElementById('pic01').src = images[i];
ctx.drawImage(document.getElementById('pic01'), 0, 0, 300, 300);
// Check If Index Is Under Max
if (i < images.length - 1) {
// Add 1 to Index
i++;
} else {
// Reset Back To O
i = 0;
}
// Run function every x seconds
setTimeout(function() {
changeImg()
}, time);
}
// Run function when page loads
window.onload = changeImg;
console.log("Hello World!");
}
});
<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<title>Canvas Texture</title>
<meta name="description" content="Canvas Texture - A-Frame">
<script src="./components/aframe-v0.6.0.js"></script>
<script src="./components/slideshow.js"></script>
</head>
<body>
<a-scene>
<a-assets>
<img id="pic01" src="Tulips.jpg">
<img id="pic02" src="Tulips2.jpg">
<img id="pic03" src="Tulips3.jpg">
<canvas id="slide" name="slide" crossOrigin="anonymous"> </canvas>
</a-assets>
<a-sky material="shader: flat; src: #slide" draw-canvas="#slide">
<a-sky/>
</a-scene>
</body>
</html>
And if anybody knows how to nicely fade over the pictures, please feel free to share! I bet a lot of people would be happy about a nice A-Frame Slideshow.
I've got a solution, but I've altered quite a lot of Your stuff.
I've got rid of the canvas, You already have three image assets, no need to rewrite, or buffer them on each other.
Just store the asset id's and use setAttribute("material", "src", picID)
Furthermore I've added the a-animation component, so Your slideshow will have a nice smooth transition. You need to set the animation duration to the slideshow's time / 2, for it goes back and forth.
This said, check out my fiddle.
As for the drawImage part of the question, drawImage draws (writes) an image onto a canvas element. The mapping is fine, since You only need to make sure You have a spherical photo, otherwise it will get stretched all over the model.
Related
I have been practicing using sprites for a game I am going to make and have watched and read a few tutorials, I thought I was close to getting my sprite to appear so I could finally start my game but while practicing I cant get it to work, I have dont 2 seperate tutorials where I can get the sprite and the background to appear by themselfs but cannot get them to work together, I have been using EaselJS too. some of the sprite animation code has been copied from tutorials too.
<!DOCTYPE HTML>
<html>
<head>
<meta charset="UTF-8">
<title>sprite prac<title>
<!-- EaselJS library -->
<script src="lib/easel.js"></script>
<script>
// Initialize on start up so game runs smoothly
function init() {
canvas = document.getElementById("canvas");
stage = new Stage(canvas);
bg = new Image();
bg.src = "img/grassbg.jpg";
bg.onload = setBG;
stage.addChild(background);
imgMonsterARun = new Image();
imgMonsterARun.onload = handleImageLoad;
imgMonsterARun.onerror = handleImageError;
imgMonsterARun.src = "img/MonsterARun.png";
stage.update();
}
function handleImageLoad(e) {
startGame();
}
// Simple function for setting up the background
function setBG(event){
var bgrnd = new Bitmap(bg);
stage.addChild(bgrnd);
stage.update();
}
function startGame() {
// create a new stage and point it at our canvas:
stage = new createjs.Stage(canvas);
// grab canvas width and height for later calculations:
screen_width = canvas.width;
screen_height = canvas.height;
// create spritesheet and assign the associated data.
var spriteSheet = new createjs.SpriteSheet({
// image to use
images: [imgMonsterARun],
// width, height & registration point of each sprite
frames: {width: 64, height: 64, regX: 32, regY: 32},
animations: {
walk: [0, 9, "walk"]
}
});
// create a BitmapAnimation instance to display and play back the sprite sheet:
bmpAnimation = new createjs.BitmapAnimation(spriteSheet);
// start playing the first sequence:
bmpAnimation.gotoAndPlay("walk"); //animate
// set up a shadow. Note that shadows are ridiculously expensive. You could display hundreds
// of animated rats if you disabled the shadow.
bmpAnimation.shadow = new createjs.Shadow("#454", 0, 5, 4);
bmpAnimation.name = "monster1";
bmpAnimation.direction = 90;
bmpAnimation.vX = 4;
bmpAnimation.x = 16;
bmpAnimation.y = 32;
// have each monster start at a specific frame
bmpAnimation.currentFrame = 0;
stage.addChild(bmpAnimation);
// we want to do some work before we update the canvas,
// otherwise we could use Ticker.addListener(stage);
createjs.Ticker.addListener(window);
createjs.Ticker.useRAF = true;
createjs.Ticker.setFPS(60);
}
//called if there is an error loading the image (usually due to a 404)
function handleImageError(e) {
console.log("Error Loading Image : " + e.target.src);
}
function tick() {
// Hit testing the screen width, otherwise our sprite would disappear
if (bmpAnimation.x >= screen_width - 16) {
// We've reached the right side of our screen
// We need to walk left now to go back to our initial position
bmpAnimation.direction = -90;
}
if (bmpAnimation.x < 16) {
// We've reached the left side of our screen
// We need to walk right now
bmpAnimation.direction = 90;
}
// Moving the sprite based on the direction & the speed
if (bmpAnimation.direction == 90) {
bmpAnimation.x += bmpAnimation.vX;
}
else {
bmpAnimation.x -= bmpAnimation.vX;
}
// update the stage:
stage.update();
}
</script>
</head>
<body onload="init();">
<canvas id="canvas" width="500" height="500" style="border: thin black solid;" ></canvas>
</body>
</html>
There are a few places where you are using some really old APIs, which may or may not be supported depending on your version of EaselJS. Where did you get the easel.js script you reference?
Assuming you have a version of EaselJS that matches the APIs you are using, there are a few issues:
You add background to the stage. There is no background, so you are probably getting an error when you add it. You already add bgrnd in the setBackground method, which should be fine. If you get an error here, then this could be your main issue.
You don't need to update the stage any time you add something, just when you want the stage to "refresh". In your code, you update after setting the background, and again immediately at the end of your init(). These will fire one after the other.
Are you getting errors in your console? That would be a good place to start debugging. I would also recommend posting code if you can to show an actual demo if you continue to have issues, which will help identify what is happening.
If you have a newer version of EaselJS:
BitmapAnimation is now Sprite, and doesn't support direction. To flip Sprites, use scaleX=-1
Ticker no longer uses addListener. Instead it uses the EventDispatcher. createjs.Ticker.addEventListener("tick", tickFunction);
You can get new versions of the CreateJS libraries at http://code.createjs.com, and you can get updated examples and code on the website and GitHub.
Good day!
I have a problem with merging canvas images. This questions will be mark as reply I think but I didn't find solution for my problem.
So this the deal:
Get 3 canvas - 1 and 2 are images(must be hidden i think), 3 - merged canvas. 1 is a frame, 2 is a photo, photo must be under frame (at css I could make it with z-index).
Html:
<div class="container">
<canvas id="first" width="400" height="400"></canvas>
<canvas id="second" width="200" height="200"></canvas>
<canvas id="third" width="400" height="400"></canvas>
</div>
JS:
var imgFirst = document.getElementById("first");
ctx1 = imgFirst.getContext('2d');
pic1 = new Image();
pic1.src = "http://www.deftune.com/wp-content/uploads/2010/10/thexx-400x400.jpg";
var imgSecond = document.getElementById("second");
ctx2 = imgSecond.getContext('2d');
pic2 = new Image();
pic2.src = "http://tech21info.com/admin/wp-content/uploads/2013/03/chrome-logo-200x200.png";
var imgThird = document.getElementById('third');
ctx3 = imgThird.getContext('2d');
pic1.onload = function() {
pic2.onload = function() {
ctx3.drawImage(pic1, 0, 0, 400, 400);
ctx3.drawImage(pic2, 100, 100, 200, 200);
};
};
I've got jsfiddle example: http://jsfiddle.net/hh6ovneq/3/ but it not works
There are a couple of things that could simplify your code a lot. First of, since you are only loading image resources, use the img tag instead. Then create a callback function and trigger it when both images have loaded.
Since I am unclear what your photo is and what your frame is I currently use the inversed order that you had, but just switching the two drawImage functions should switch their order (or z-index, hopwever you want to describe it). Because your top image doesn't have transparent values, though, it will hide the bottom image as the pixels are overwritten with new colors.
The result would look something like this, which looks a lot cleaner and more readable:
// Get all your images.
var first = document.getElementById('first');
var second = document.getElementById('second');
// get canvas and context
var result = document.getElementById('result');
var context = result.getContext('2d');
// create a counter to make sure all images are loaded before drawing
var loaded = 0;
// something to execute when loading of images has completed
function combine(){
// The order of drawing will be the order of layers
// The final two arguments define the size of what you want to draw
context.drawImage(second, 0, 0, 400, 400);
context.drawImage(first, 100, 100, 200, 200);
}
// Add event listeners to the images
first.addEventListener('load', function(){
// increase the loaded number
loaded++;
// hide the image
first.style.display = 'none';
// if loaded hits the total number of images, use the completion function
if(loaded === 2) combine();
}, false);
// (wrince, repeat for image 2)
second.addEventListener('load', function(){
loaded++;
second.style.display = 'none';
if(loaded === 2) combine();
}, false);
<div class="container">
<img id="first" width="400" height="400" src="http://www.deftune.com/wp-content/uploads/2010/10/thexx-400x400.jpg" />
<img id="second" width="200" height="200" src="http://tech21info.com/admin/wp-content/uploads/2013/03/chrome-logo-200x200.png" />
<canvas id="result" width="400" height="400"></canvas>
</div>
Lastly I would like to add that your nested onload function could backfire on you when the second image is loaded before the first, which would mean that the load event does not get triggered anymore. Use separate onloads and count them in order to be sure the outcome is correct.
I am looking for a way to wrap a bitmap image around the canvas, for an infinite scrolling effect. I'm looking at EaselJS but clean javascript code will also suffice.
Right now I am displacing an image to the left, and when it reaches a certain mark, it resets itself.
Coming from actionscript, there was an option to "wrap" the pixels of a bitmap around to the other side, thereby never really displacing the image, instead you were wrapping the pixels inside the image. Is this possible in javascript with canvas?
My current code:
this.update = function() {
// super large graphic
_roadContainer.x -= 9;
if(_roadContainer.x < -291) _roadContainer.x = 0;
}
Start with a good landscape image.
Flip the image horizontally using context.scale(-1,1).
Combine the flipped image to the right side of the original image.
Because we have exactly mirrored the images, the far left and right sides of the combined image are exactly the same.
Therefore, as we pan across the combined image and “run out of image”, we can just add another copy of the combined image to the right side and we have infinite + seamless panning.
Here's code and a Fiddle: http://jsfiddle.net/m1erickson/ywDp5/
<!doctype html>
<html>
<head>
<link rel="stylesheet" type="text/css" media="all" href="css/reset.css" /> <!-- reset css -->
<script type="text/javascript" src="http://code.jquery.com/jquery.min.js"></script>
<style>
body{ background-color: ivory; }
canvas{border:1px solid red;}
</style>
<script>
$(function(){
// thanks Paul Irish for this RAF fallback shim
window.requestAnimFrame = (function(callback) {
return window.requestAnimationFrame || window.webkitRequestAnimationFrame || window.mozRequestAnimationFrame || window.oRequestAnimationFrame || window.msRequestAnimationFrame ||
function(callback) {
window.setTimeout(callback, 1000 / 60);
};
})();
var canvas=document.getElementById("canvas");
var ctx=canvas.getContext("2d");
var infiniteImage;
var infiniteImageWidth;
var img=document.createElement("img");
img.onload=function(){
// use a tempCanvas to create a horizontal mirror image
// This makes the panning appear seamless when
// transitioning to a new image on the right
var tempCanvas=document.createElement("canvas");
var tempCtx=tempCanvas.getContext("2d");
tempCanvas.width=img.width*2;
tempCanvas.height=img.height;
tempCtx.drawImage(img,0,0);
tempCtx.save();
tempCtx.translate(tempCanvas.width,0);
tempCtx.scale(-1,1);
tempCtx.drawImage(img,0,0);
tempCtx.restore();
infiniteImageWidth=img.width*2;
infiniteImage=document.createElement("img");
infiniteImage.onload=function(){
pan();
}
infiniteImage.src=tempCanvas.toDataURL();
}
img.crossOrigin="anonymous";
img.src="https://dl.dropboxusercontent.com/u/139992952/stackoverflow/mountain.jpg";
var fps = 60;
var offsetLeft=0;
function pan() {
// increase the left offset
offsetLeft+=1;
if(offsetLeft>infiniteImageWidth){ offsetLeft=0; }
ctx.drawImage(infiniteImage,-offsetLeft,0);
ctx.drawImage(infiniteImage,infiniteImage.width-offsetLeft,0);
setTimeout(function() {
requestAnimFrame(pan);
}, 1000 / fps);
}
}); // end $(function(){});
</script>
</head>
<body>
<canvas id="canvas" width=500 height=143></canvas><br>
</body>
</html>
You can achieve this quite easily with the html5 canvas.
Look at the drawImage specification here :
http://www.whatwg.org/specs/web-apps/current-work/multipage/the-canvas-element.html#drawing-images
drawImage comes in 3 flavors, the first being a simple copy of the image, the second allowing to scale the image, and the third is the one you seek, it allows to perform clipping in a single call.
What you have to do :
- have a counter that will move from zero to the width of your image, then loop to zero again.
- each frame, draw the maximum of the image that you can on the canvas.
- If there is still some part of the canvas not drawn, draw again the image starting from zero to fill the canvas.
i made a fiddle, the only part that matters is in the animate function (other things are tools i often use in my fiddles).
(Rq : I assumed in this example that two images would be enough to fill the canvas.)
http://jsfiddle.net/gamealchemist/5VJhp/
var startx = Math.round(startPos);
var clippedWidth = Math.min(landscape.width - startx, canvasWidth);
// fill left part of canvas with (clipped) image.
ctx.drawImage(landscape, startx, 0, clippedWidth, landscape.height,
0, 0, clippedWidth, landscape.height);
if (clippedWidth < canvasWidth) {
// if we do not fill the canvas
var remaining = canvasWidth - clippedWidth;
ctx.drawImage(landscape, 0, 0, remaining, landscape.height,
clippedWidth, 0, remaining, landscape.height);
}
// have the start position move and loop
startPos += dt * rotSpeed;
startPos %= landscape.width;
To answer my own question: I found a way to achieve this effect with EaselJS. The great benefit of this method is that you don't have to check for the position of your bitmap. It will scroll infinitely - without ever resetting the position to 0.
The trick is to fill a shape with a bitmapfill. You can set a bitmapfill to repeat infinitely. Then you use a Matrix2D to decide the offset of the bitmapfill. Since it repeats automatically, this will generate a scrolling effect.
function.createRoad() {
// road has a matrix, shape and image
_m = new createjs.Matrix2D();
// this gets the image from the preloader - but this can be any image
_r = queue.getResult("road");
// this creates a shape that will hold the repeating bitmap
_roadshape = new createjs.Shape();
// put the shape on the canvas
addChild(_roadshape);
}
//
// the draw code gets repeatedly called, for example by requestanimationframe
//
function.drawRoad() {
// var _speed = 4;
_m.translate(-_speed, 0);
_roadshape.graphics.clear().beginBitmapFill(_r, "repeat", _m).rect(0, 0, 900, 400);
}
I'm creating a HTML5 game which can be made to run on Android also. I went through few articles and didn't get the solution yet. I have a image which i'm generating through javascript and I want to move this image using touchmove so that I can run it in my Android device. This is the code:
gameCanvas.addEventListener("touchmove", touchXY, true);
function touchXY(e) {
if (!e)
var e = event;
e.preventDefault();
avatarX = e.targetTouches[0].pageX - gameCanvas.offsetLeft;
avatarY = e.targetTouches[0].pageY - gameCanvas.offsetTop;
}
This is not working. I got this code from https://developer.apple.com/library/archive/documentation/AudioVideo/Conceptual/HTML-canvas-guide/AddingMouseandTouchControlstoCanvas/AddingMouseandTouchControlstoCanvas.html
And this is my canvas:
<canvas id="gameCanvas" onclick="setUpGame();" width="400" height="300"></canvas>
This is my image:
avatarImage.src = "img/avatar.png";
gameCanvas.getContext("2d").drawImage(avatarImage, Math.random() * 100, Math.random() * 100);
I just want to move the image inside the canvas.
I wrote a full example, hopefully it's not too verbose.
<!DOCTYPE html>
<html>
<head>
<meta charset='UTF-8'>
</head>
<body>
<canvas id='canvas' width='512' height='512'></canvas>
<script>
var c=document.getElementById('canvas'),
ctx=c.getContext('2d'),
activeBox='none',
//populate the map with objects
box=[
{
x:256,
y:128,
width:32,
height:64
},
{
x:128,
y:64,
width:64,
height:64
},
{
x:32,
y:32,
width:32,
height:32
},
];
function draw(){
//clear the screen, draw population
ctx.clearRect(0,0,c.width,c.height);
for(var i=0;i<box.length;i++){
ctx.fillRect(box[i].x,box[i].y,box[i].width,box[i].height);
}
//repeat at 60fps if possible, pause if window looses focus
requestAnimationFrame(draw);
}
function startTouch(e){
//this makes it easier to write control flow later and keeps XY relative to canvas
var xTouch=e.touches[0].pageX-c.offsetLeft,
yTouch=e.touches[0].pageY-c.offsetTop;
//its best to go through this loop in touchstart, because it only happens once per touch
for(var i=0;i<box.length;i++){
if(xTouch>box[i].x&&xTouch<box[i].x+box[i].width){
if(yTouch>box[i].y&&yTouch<box[i].y+box[i].height){
activeBox=i;
}
}
}
}
function moveTouch(e){
//grab a box by the center
if(activeBox!='none'){
box[activeBox].x=e.changedTouches[0].pageX-box[activeBox].width/2;
box[activeBox].y=e.changedTouches[0].pageY-box[activeBox].height/2;
}
}
function endTouch(){
//clear active so that dragging empty space wont move the last active box
activeBox='none';
}
canvas.addEventListener('touchstart',startTouch);
canvas.addEventListener('touchmove',moveTouch);
canvas.addEventListener('touchend',endTouch);
window.addEventListener('load',draw);
</script>
</body>
</html>
I used fillRect for simplicity, but if you want to replace it with drawImage you'll need to create a new element for each and add a source property to the box object array. Here's a partial example.
//you need a new one of these for every image
var img=new Image();
img.src='http://www.w3schools.com/images/w3logotest2.png';
var box={
source:img,
x:Math.floor((Math.random()*256)+1),
y:Math.floor((Math.random()*256)+1)
};
//make sure the image doesnt load before the script
window.onload=function(){
ctx.drawImage(img,box.x,box.y);
}
<html>
<head>
<meta charset="utf-8">
<title>Game</title>
<script src="http://code.createjs.com/easeljs-0.4.2.min.js"></script>
</head>
<body>
<div id ="beeld">
<canvas id ="stageCanvas" width="1024" height="576">
<script src ="javascript.js"></script>
</canvas>
</div>
</body>
</html>
This is my Html
//Javascript Document
var canvas = document.getElementById('stageCanvas');
var stage = new Stage(canvas);
var Background;
var imgBackground = new Image();
imgBackground.src ="images/bg.png";
Background = new Bitmap(imgBackground);
Background.x = 0
Background.y = 0
stage.addChild(Background);
stage.update();
And that's my js.
The image is 1024 by 576, so it should be fullscreen. The original is 2048 by 576. I was planning to do like the background would slide to left and repeat it self when it gets to the end.
So my question is, why doesnt the image show up on the canvas.
I'm a very new to this, so I'm sorry if I'm asking such an easy question.
PS: If I inspect the HTML, it DOESN'T show any errors and it DOES show that the image is being loaded. It's just not.. drawn.. I guess.
I'm getting frustrated, because I'm stuck here for a couple hours already.
I FOUND A WORKING CODE
<!DOCTYPE HTML>
<html>
<head>
<meta charset="UTF-8">
<title>Easel simple game</title>
<script src="http://code.createjs.com/easeljs-0.4.2.min.js"></script>
<script>
var canvas;
var stage;
var bg;
var score;
var ghost;
function init() {
canvas = document.getElementById("StageCanvas");
stage = new Stage(canvas);
score = 0;
bg = new Image();
bg.src = "img/bg.png";
bg.onload = setBG;
}
function setBG(event){
var bgrnd = new Bitmap(bg);
stage.addChild(bgrnd);
stage.update();
}
</script>
</head>
<body onload="init();">
<canvas id="StageCanvas" width="1240" height="576"></canvas>
</body>
</html>
By the way this code is the work for someone else, so I don't take any credit.
This seems to work perfectly. But once I remove the
bg = new Image();
bg.src = "img/bg.png";
bg.onload = setBG;
it stops working.
Background = new Bitmap(imgBackground);
In HTML:
Try to move the script-tag of your javascript.js to right before the </body> or at least not into the <canvas>...</canvas>.
And another thing is: You have a space between src and = and id and =, that might cause problems in some browsers.
In JavaScript:
You need to execute the update-method with () otherwise that line will just be a listed reference to the update function.
stage.update();
And a second thing, that I noticed(though not part of the issue): You are using EaselJS 0.4.2, but 0.5.0 is already released, just in case you want to be up-to-date: http://code.createjs.com/easeljs-0.5.0.min.js ;-)
I'm having the same issue with EaselJS at the moment. While it might work for you, you can try and add a ticker which will automatically update the canvas:
createjs.Ticker.addListener(stage);
I was able to get the image to paint on the canvas after adding this, but as soon as I add any transforms to the image (scale, positioning, height, width) they are not applied prior to the image being drawn.
I've been scratching my head over this too.