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How to export Canva Render has GIF with CSS modification

I'm using p5.js to make a GIF animation but I have an issue when I want to export it.
I did a pixelased effect on my animation by adding these css properties to the Canva (140*140) :
image-rendering: pixelated;
width:500px;
height:500px;
My problem is that I can't export this Canva with the properties I added. (I'm using CCapture)
My gif is in 140x140 without the pixelated effect.
How can I get the rendering I need?

There is a difference between the width & height you can set for a HTML element e.g. <canvas width='140' height='140'> and the CSS width & height properties.
The former defines the actual size of the canvas - 140x 140in this case.
If we now set the CSS width & height to something deviating from the HTML element's width & height e.g. <canvas width='140' height='140' style='width: 500px; height:500px;'> the actual size in pixels of the canvas does not change - it stays 140 x 140 pixels. The CSS properties just control the displayed size of the element inside the browser, meaning the 140 x 140 are simply stretched to 500 x 500.
So if you get actual pixel data of the canvas - for exporting to gif/png - the final image will have the original dimensions of the canvas - not the rendered.
The fix is quite simple though. Instead of directly using the source canvas for exporting, draw it's content on a second canvas, the size of your desired resolution.
To force the 'export' canvas to not use any filtering/smoothing, you need to set the imageSmoothingEnabled property of it's context to false.
Here's an example (you can right-click and save both images to see the difference):
var ctx = document.getElementById('canvas').getContext('2d');
var image = new Image();
image.onload = function() {
ctx.drawImage(image, 0, 0);
let sourceCanvas = document.getElementById("canvas");
let virtualWidth = parseInt(getComputedStyle(sourceCanvas).width);
let virtualHeight = parseInt(getComputedStyle(sourceCanvas).height);
var canvas = document.getElementById("exportCanvas");
canvas.width = virtualWidth;
canvas.height = virtualHeight;
canvas.getContext('2d').imageSmoothingEnabled = false;
canvas.getContext('2d').drawImage(sourceCanvas, 0, 0, virtualWidth, virtualHeight);
}
image.src = 'https://mdn.mozillademos.org/files/12640/cat.png';
canvas {
width: 500px;
height: 500px;
}
<span>Rendered canvas</span><br>
<canvas id="canvas" width="140" height="140"></canvas><br>
<span>Export canvas</span><br>
<canvas id="exportCanvas"></canvas>

Adding canvas inside another canvas: obj.setCoords is not a function( fabric js)

Started using fabric.js and trying to add a canvas inside another canvas, so that the top canvas stays constant and I'll add objects to inner canvas.
Here is the snippet of adding a canvas to another canvas.
canvas = new fabric.Canvas('artcanvas');
innerCanvas = new fabric.Canvas("innerCanvas");
canvas.add(innerCanvas);
and my html looks like this
<canvas id="artcanvas" width="500" height="500"></canvas>
<canvas id="innerCanvas" width="200" height="200" ></canvas>
Once adding these successfully, what I am going to do is , add the coordinates to the inner canvas, so that it looks like one on another to the end user.
However, ran into the below error for the tried code
Uncaught TypeError: obj.setCoords is not a function
at klass._onObjectAdded (fabric.js:6894)
at klass.add (fabric.js:231)
at main.js:60
at fabric.js:19435
at HTMLImageElement.fabric.util.loadImage.img.onload (fabric.js:754)
_onObjectAdded # fabric.js:6894
add # fabric.js:231
(anonymous) # main.js:60
(anonymous) # fabric.js:19435
fabric.util.loadImage.img.onload # fabric.js:754
Looking at the error message, just went to the line of error and here is what I found in chrome console
Can someone point the mistake in my codes ?

After going through no.of discussions and internet solutions, for time being I am using Fabric Rectangle as a clipper and setting it's boundaries so user can be able to drop/play with in that particular clipper.
Dotted red(image below) is my clipper and now I can bound the dropping and below is the code to add an image with a clipper.
function addImageToCanvas(imgSrc) {
fabric.Object.prototype.transparentCorners = false;
fabric.Image.fromURL(imgSrc, function(myImg) {
var img1 = myImg.set({
left: 20,
top: 20,
width: 460,
height: 460
});
img1.selectable = false;
canvas.add(img1);
var clipRectangle = new fabric.Rect({
originX: 'left',
originY: 'top',
left: 150,
top: 150,
width: 200,
height: 200,
fill: 'transparent',
/* use transparent for no fill */
strokeDashArray: [10, 10],
stroke: 'red',
selectable: false
});
clipRectangle.set({
clipFor: 'layer'
});
canvas.add(clipRectangle);
});
}
Now while appending any image/layer to the canvas, I bind that image/layer/text to the clipper I created.
function addLayerToCanvas(laImg) {
var height = $(laImg).height();
var width = $(laImg).width();
var clickedImage = new Image();
clickedImage.onload = function(img) {
var pug = new fabric.Image(clickedImage, {
width: width,
height: height,
left: 150,
top: 150,
clipName: 'layer',
clipTo: function(ctx) {
return _.bind(clipByName, pug)(ctx)
}
});
canvas.add(pug);
};
clickedImage.src = $(laImg).attr("src");
}
And the looks like, after restriction of bounds,
Here is the fiddle I have created with some static image url.
https://jsfiddle.net/sureshatta/yxuoav39/
So I am staying with this solution for now and I really feel like this is hacky and dirty. Looking for some other clean solutions.

As far as I know you can't add a canvas to another canvas - you're getting that error as it tries to call setCoords() on the object you've added, but in this case it's another canvas and fabric.Canvas doesn't contain that method (see docs). I think a better approach would be to have two canvases and position them relatively using CSS - see this simple fiddle
HTML
<div class="parent">
<div class="artcanvas">
<canvas id="artcanvas" width="500" height="500"></canvas>
</div>
<div class="innerCanvas">
<canvas id="innerCanvas" width="200" height="200" ></canvas>
</div>
</div>
CSS
.parent {
position: relative;
background: black;
}
.artcanvas {
position: absolute;
left: 0;
top: 0;
}
.innerCanvas {
position: absolute;
left: 150px;
top: 150px;
}
JS
$(document).ready(function() {
canvas = new fabric.Canvas('artcanvas');
innerCanvas = new fabric.Canvas("innerCanvas");
var rect = new fabric.Rect({
fill: 'grey',
width: 500,
height: 500
});
canvas.add(rect);
var rect2 = new fabric.Rect({
fill: 'green',
width: 200,
height: 200
});
innerCanvas.add(rect2);
})
To handle the object serialization, you can do something like this:
var innerObjs = innerCanvas.toObject();
console.dir(innerObjs);
var outerObjs = canvas.toObject();
innerObjs.objects.forEach(function (obj) {
obj.left += leftOffset; // offset of inner canvas
obj.top += topOffset;
outerObjs.objects.push(obj);
});
var json = JSON.stringify(outerObjs);
This will then give you the JSON for all objects on both canvases

I have no understanding why you want to do this thing, but to put a canvas inside another canvas, you have one simple way:
canvas = new fabric.Canvas('artcanvas');
innerCanvas = new fabric.Canvas("innerCanvas");
imageContainer = new fabric.Image(innerCanvas.lowerCanvasEl);
canvas.add(imageContainer);
Then depending what you want to do, you may need additional tweaks, but this should work out of the box.

Don't create a canvas
Most objects in fabric (from my limited experience) are at some point converted to a canvas. Creating an additional fabric canvas to manage a group of objects is kind of pointless as you are just adding overhead and mimicking fabrics built in groups object.
Fabric objects are basically DOM canvases wrappers.
The following example shows how fabric uses a canvas to store the content of a group. The demo creates a group and adds it to the fabric canvas, then gets the groups canvas and adds it to the DOM. Clicking on the group's canvas will add a circle. Note how it grows to accommodate the new circles.
const radius = 50;
const fill = "#0F0";
var pos = 60;
const canvas = new fabric.Canvas('fCanvas');
// create a fabric group and add two circles
const group = new fabric.Group([
new fabric.Circle({radius, top : 5, fill, left : 20 }),
new fabric.Circle({radius, top : 5, fill, left : 120 })
], { left: 0, top: 0 });
// add group to the fabric canvas;
canvas.add(group);
// get the groups canvas and add it to the DOM
document.body.appendChild(group._cacheContext.canvas);
// add event listener to add circles to the group
group._cacheContext.canvas.addEventListener("click",(e)=>{
group.addWithUpdate(
new fabric.Circle({radius, top : pos, fill : "blue", left : 60 })
);
canvas.renderAll();
pos += 60;
});
canvas {
border : 2px solid black;
}
div {
margin : 10px;
}
<script src="https://cdnjs.cloudflare.com/ajax/libs/fabric.js/1.7.13/fabric.min.js"></script>
<div>Fabric's canvas "canvas = new fabric.Canvas('fCanvas');"</div>
<canvas id="fCanvas" width="256" height="140"></canvas>
<div>Fabric group canvas below. Click on it to add a circle.</div>
Use a group rather than a new instance of a fabric canvas.
As you can see a canvas is generated for you. Adding another fabric canvas (Note that a fabric canvas is not the same as a DOM canvas) will only add more work for fabric to do, which already has a lot of work to do.
You are best of to use a group and have that hold the content of the other fabric object you wish to shadow. That would also contain its content in a group.
Just an image
And just a side not, a DOM canvas is an image and can be used by fabric just as any other image. It is sometimes better to do the rendering directly to the canvas rather than via fabric so you can avoid rendering overheads that fabric needs to operate.
To add a DOM canvas to fabric just add it as an image. The border and text are not fabric object, and apart from the code to render them take up no memory, and no additional CPU overhead that would be incurred if you used a fabric canvas and objects.
const canvas = new fabric.Canvas('fCanvas');
// create a standard DOM canvas
const myImage = document.createElement("canvas");
// size it add borders and text
myImage.width = myImage.height = 256;
const ctx = myImage.getContext("2d");
ctx.fillRect(0,0,256,256);
ctx.fillStyle = "white";
ctx.fillRect(4,4,248,248);
ctx.fillStyle = "black";
ctx.font = "32px arial";
ctx.textAlign = "center";
ctx.textBaseline = "middle";
ctx.fillText("The DOM canvas!",128,128);
// use the canvas to create a fabric image and add it to fabrics canvas.
canvas.add( new fabric.Image(myImage, {
left: (400 - 256) / 2,
top: (400 - 256) / 2,
}));
canvas {
border : 2px solid black;
}
<script src="https://cdnjs.cloudflare.com/ajax/libs/fabric.js/1.7.13/fabric.min.js"></script>
<canvas id="fCanvas" width="400" height="400"></canvas>

innerCanvas.setCoords(); ìs a function, but you need it only after you set the coordinates. Or more precise, set these four elements:
innerCanvas.scaleX = 1;
innerCanvas.scaleY = 1;
innerCanvas.left = 150;
innerCanvas.top = 150;
innerCanvas.setCoords();
canvas.renderAll();

Creating new fabric canvas changes canvas position

I am trying to learn about fabricjs and noticed that when i create a new fabric.Canvas object it changes the position of my canvas.
HTML
<canvas id="c"></canvas>
Css
#c {
border: thin red solid;
position: absolute;
top: 50px;
left: 100px;
}
Javascript
var c = document.getElementById("c");
var ctx = c.getContext("2d");
var img = new Image();
img.src = 'cheese.jpg';
img.onload = function() {
ctx.drawImage(img, 0, 0);
};
// applying the below line shifts the canvas element back to 0,0 position
var cFabric = new fabric.Canvas('c');
Hoping you guys know what i am doing wrong.

You are not doing anything wrong. Calling the fabric.Canvas constructor on your native canvas element will result in your native canvas getting wrapped by a .canvas-container div. The original canvas gets an added .lower-canvas class and its left, right css styles are set to 0px. Other then that, a sibling canvas is added below your original canvas, with a class of upper-canvas. These two canvases act like layers, managed by the inner workings of Fabric.js (magic :O).
If you need to position and style your canvas, I recommend you wrap your html canvas with a wrapper div.
<div id="canvas-wrapper">
<canvas id="c"></canvas>
</div>
Next transfer your css rules to the wrapper
#canvas-wrapper {
position: absolute;
top: 50px;
left: 100px;
}
Here's a simple fiddle that I made by updating #Mullainathan's sample fiddle: https://jsfiddle.net/eo7vdg1t/1/

Changing width and height in angular-chart.js module

I'm using the angular module angular-chart.js. It is simple to work with and very smart. But I've noticed that I can't change the width and height of the charts. Somewhere I've read that I have to define the size of the chart as follows:
var vm = $scope;
vm.labels = [];
vm.data = [];
CrudService.getData(selDate).$promise.then(
function (response) {
angular.forEach(response, function (val) {
val.datum = $filter('date')(val.datum, 'dd.MM.yyyy');
vm.labels.push(val.datum);
vm.data.push(val.grade);
});
vm.dataChart = [vm.data];
/* This is the important part to define the size */
vm.options = [
{
size: {
height: 200,
width: 400
}
}
];
/************************************************/
});
The view:
<canvas id="bar"
class="chart chart-bar"
chart-data="dataChart"
chart-labels="labels"
chart-click="onClick"
chart-options="options">
</canvas>
Do anyone knows how to define the width and height in angular-chart.js ?

Ok I have tried this solution and it works.
<canvas id="bar"
height="100"
width="100"
class="chart chart-bar"
chart-data="dataChart"
chart-labels="labels"
chart-click="onClick"
chart-options="options">
</canvas>
Or defining the size as like a style in a CSS-class.

You can also wrap the <canvas> into a <div>, like so:
<div style="height:300px;width:300px;">
<canvas
class="chart chart-radar"
chart-data="$ctrl.data"
chart-options="options"
chart-labels="$ctrl.labels"></canvas>
</div>
Setting the width and height like in the other answers did not work for me.

To define height of charts according to the screen size, I use this code :
In controllers
$scope.height_chart = window.innerHeight*0.7;
In template
<canvas height="{{height_chart}}" class="chart chart-line" data="weight.data" labels="weight.labels" series="weight.series"></canvas>
I hope these codes will help.

The problem is that the height and width attribute values are stored in the chart and are not updated in the same way that the other attributes are. To fix this you have to add a listener to the create event and manually change the height in the chart object
HTML:
<canvas
id="chart"
class="chart chart-horizontal-bar"
chart-data="chart.data"
chart-labels="chart.data.labels"
chart-series="chart.series"
chart-options="chart.options"
chart-colors="chart.colors"
height="{{ compareChart.height }}"
width="{{ compareChart.width }}"
></canvas>
JS:
$scope.$on('chart-create', function (event, chart) {
chart.chart.height = $scope.chart.height;
});
You would expect $scope.chart.height to change during an AJAX lookup or something that will bring in new data.

Chart uses its parent container to update the canvas render and display sizes. However, this method requires the container to be relatively positioned and dedicated to the chart canvas only. Responsiveness can then be achieved by setting relative values for the container size

Get screen coordinates of an Kinetic image in Javascript?

I'm writing an app and using Kinetic JS library to load image from client's computer. The image is contained in a photo object and is initialised as below
var photoObj = new Image();
photoObj.onload = function() {
var photoImage = new Kinetic.Image({
x: 0,
y: 0,
image: photoObj,
width: photoObj.width,
height: photoObj.height,
name: "photo",
id: "photo"
});
photoGroup.removeChildren();
photoGroup.add(photoImage);
The object is included in a Kinetic Group object, named photoGroup, which is created earlier.
photoGroup = new Kinetic.Group({
x : 0,
y : 0,
draggable : true,
id : "photoGroup"
});
photoLayer = new Kinetic.Layer({
drawBorder: true
});
photoLayer.add(photoGroup);
stage = new Kinetic.Stage({
container : "kinetic-kard-preview",
width : 320,
height : 480
});
stage.add(photoLayer);
stage.draw();
The group object is included in a Kinetic Layer object, named photoLayer, which is included in a Kinetic Stage object, named stage.
Anyway, my question is, now I would like to get the screen coordinates of the image. I successfully got the coordinates of the stage by
var containerOffset=$("#kinetic-kard-preview").offset();
var offsetX=containerOffset.left;
var offsetY=containerOffset.top;
console.log(offsetX);//455.859375
console.log(offsetY);//218
but I can't seem to do the same thing for the image. When I viewed source code of the web page, I've noticed that the generated html code of the canvas that contains the image is something like this.
<canvas width="320" height="480" style="padding: 0px; margin: 0px; border: 0px; background-color: transparent; width: 320px; height: 480px; position: absolute; background-position: initial initial; background-repeat: initial initial;"></canvas>
How can I get the screen coordinates of the image after it's loaded from client's pc to the canvas? Please help!!! Thank you.
thanks for your answer but it can't seem to get what I need. I just added the link of the screenshot here:
As you can see in the picture, the coordinates of the image are not the same as the coordinates of the stage that contains it. I wrote a mousemove event and calculated
- the distance between the x screen coordinate of the stage (ie. offsetX) and x screen coordinate of the image.
- the distance between the y screen coordinate of the stage (ie. offsetY) and y screen coordinate of the image.
They all have the same number....24 (as shown on the screen). By using the mousemove event, I manually got the values of offsetX, offsetY and the x and y screen coordinates of the image are 455, 218, 479 and 242.
However, my problem is how to get those numbers automatically, especially the screen coordinates of the image, after the image is loaded from my pc. I printed the values of gPos to console.log and got (0,0) values. So when I added offsetX and offsetY to these values, they are the same (455,218), not (479,242). Please let me know what should I do now? Thanks again for your help.

Your Kinetic.Image is at position [0,0] in a draggable Kinetic.Group.
So you can get your image position by adding:
The #kinetic-kard-preview offsets
Plus the current group position: group.position()
[ Added code for KineticJS version 4.5.1 ]
Here is example code for v4.5.1 and a Demo: http://jsfiddle.net/m1erickson/NXH9X/
<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<title>Prototype</title>
<script type="text/javascript" src="http://code.jquery.com/jquery.min.js"></script>
<script src="http://d3lp1msu2r81bx.cloudfront.net/kjs/js/lib/kinetic-v4.5.1.min.js"></script>
<style>
body{padding:20px; background:ivory;}
#kinetic-kard-preview{
margin-top: 10px;
width:350px;
height:350px;
border:1px solid gray;
}
#target{position:absolute;top:200px;left:150px;opacity:0.50;}
</style>
<script>
$(function(){
//
$pos=$("#results");
//
var containerOffset=$("#kinetic-kard-preview").offset();
var offsetX=containerOffset.left;
var offsetY=containerOffset.top;
//
var stage = new Kinetic.Stage({
container: 'kinetic-kard-preview',
width: 350,
height: 350
});
//
photoLayer = new Kinetic.Layer({
drawBorder: true
});
stage.add(photoLayer);
//
photoGroup = new Kinetic.Group({
x : 0,
y : 0,
draggable : true,
id : "photoGroup"
});
photoGroup.on("dragmove",function(){
var gPos=photoGroup.getPosition();
var x=parseInt(offsetX+gPos.x);
var y=parseInt(offsetY+gPos.y);
$pos.text("photoImage: screenX="+x+", screenY="+y);
});
photoLayer.add(photoGroup);
//
var photoObj = new Image();
photoObj.onload = function() {
var photoImage = new Kinetic.Image({
x: 0,
y: 0,
image: photoObj,
width: photoObj.width,
height: photoObj.height,
name: "photo",
id: "photo"
});
photoGroup.add(photoImage);
photoLayer.draw();
}
photoObj.src="https://dl.dropboxusercontent.com/u/139992952/multple/norwayFlag.jpg";
}); // end $(function(){});
</script>
</head>
<body>
<h4>Semi-transparent flag is at screen position 150,200</h4>
<p id=results>Drag the opaque flag and see screen position</p>
<img id=target src='https://dl.dropboxusercontent.com/u/139992952/multple/norwayFlag.jpg'>
<div id="kinetic-kard-preview"></div>
</body>
</html>