In my document I'm referring jQuery version 3.1.0, as well as oCanvas version 2.8.1. This is how I have my scripts represented in my document:
<script src="//cdnjs.cloudflare.com/ajax/libs/jquery/3.1.0/jquery.min.js"></script>
<script src="//cdnjs.cloudflare.com/ajax/libs/ocanvas/2.8.1/ocanvas.min.js"></script>
My code creates fading circles within the canvas element as such:
jQuery(document).ready(function($) {
var windowXArray = [],
windowYArray = [];
for (var i = 0; i < $(window).innerWidth(); i++) {
windowXArray.push(i);
}
for (var i = 0; i < $(window).innerHeight(); i++) {
windowYArray.push(i);
}
function randomPlacement(array) {
var placement = array[Math.floor(Math.random() * array.length)];
return placement;
}
var canvas = oCanvas.create({
canvas: '#connect',
//background: '#131417',
fps: 60
});
setInterval(function() {
var rectangle = canvas.display.ellipse({
x: randomPlacement(windowXArray),
y: randomPlacement(windowYArray),
origin: {
x: 'center',
y: 'center'
},
radius: 0,
fill: '#fff',
opacity: 1
});
canvas.addChild(rectangle);
rectangle.animate({
radius: 10,
opacity: 0
}, {
duration: '1000',
easing: 'linear',
callback: function() {
this.remove();
}
});
}, 100);
$(window).resize(function() {
canvas.width = $(window).innerWidth();
canvas.height = $(window).innerHeight();
});
$(window).resize();
});
The full error I receive is:
TypeError: this.canvasElement.getContext is not a function. (In 'this.canvasElement.getContext("2d")', 'this.canvasElement.getContext' is undefined)
and it complains within the actual jQuery document which is very odd. I have this same exact setup on a another project and it works with no issue. A screenshot of where the error occurs is below:
What could possibly be going on here?
Related
See Fiddle: I am trying to render a background image on a FabricJS polygon, but for some reason the scale of the pattern is different on different devices / browsers for no obvious reason.
Here is the code:
HTML:
<canvas id="tcanvas" width="200" height="200" />
JavaScript:
function testPattern(id) {
var url = 'https://dummyimage.com/200x200/aff/000',
tCanvas = new fabric.Canvas(id);
new fabric.Image.fromURL(url, function(img) {
var tPoints = [{
x: 0,
y: 0
},
{
x: 0,
y: 200
},
{
x: 200,
y: 200
},
{
x: 200,
y: 0
}
];
var tPatternWidth = 200;
var tPatternHeight = 200;
var tImgXScale = tPatternWidth / img.width;
var tImgYScale = tPatternHeight / img.height;
img.set({
left: 0,
top: 0,
scaleX: tImgXScale,
scaleY: tImgYScale
});
var tPatternSourceCanvas = new fabric.StaticCanvas();
tPatternSourceCanvas.add(img);
tPatternSourceCanvas.renderAll();
var tPattern = new fabric.Pattern({
offsetX: 0,
offsetY: 0,
source: function() {
tPatternSourceCanvas.setDimensions({
width: tPatternWidth,
height: tPatternHeight
});
tPatternSourceCanvas.renderAll();
return tPatternSourceCanvas.getElement();
},
repeat: 'no-repeat'
});
var tImgPoly = new fabric.Polygon(tPoints, {
left: 100,
top: 100,
originX: 'center',
originY: 'center',
fill: tPattern,
objectCaching: false,
selectable: false,
stroke: 'red',
strokeWidth: 1
});
tCanvas.add(tImgPoly);
tCanvas.renderAll();
});
}
testPattern('tcanvas');
This is what I see on my desktop Chrome:
... and this what I see on a (Samsung) tablet Chrome:
How can I fix the code so that the both patterns look the same, i.e., like the first one?
It s a retina support side effect.
When initializing the canvas for the Pattern, please pass as option:
enableRetinaScaling: false
var tPatternSourceCanvas = new fabric.StaticCanvas(null, {enableRetinaScaling: false});
This will avoid fabric trying to enhance the canvas twice.
I am trying to draw grid on canvas with custom attribute. After that trying to remove that grid using those added custom attribute.
So Grid is showing on canvas, but when i am trying to remove the grid. it's not working.
Code
//Draw Grid
function draw_grid(){
var grid = 50;
canvas.getObjects().forEach(function(o) {
if(o.custom_class == 'canvas_grid') {
console.log(o.custom_class);
canvas.remove(o);
}
});
for (var i = 0; i < (600 / grid); i++) {
var grid_line1 = new fabric.Line([i * grid, 0, i * grid, 600], {
stroke: '#ccc',
selectable: false,
'custom_class' : 'canvas_grid'
});
canvas.add(grid_line1);
var grid_line2 = new fabric.Line([0, i * grid, 600, i * grid], {
stroke: '#ccc',
selectable: false,
'custom_class' : 'canvas_grid'
});
canvas.add(grid_line2);
}
}
draw_grid();
/* Hide/Show Grid */
$(document).on('change','#show_grid',function(){
if($(this).is(':checked'))
{
draw_grid();
}
else
{
canvas.getObjects().forEach(function(o) {
if(o.custom_class === 'canvas_grid') {
canvas.remove(o);
}
});
}
});
Codepen
https://codepen.io/dhavalsisodiya/pen/OQEzVE
Just change the visible property, no need to add and remove all time.
DEMO
var canvas = new fabric.Canvas('canvas1');
//Draw Grid
function draw_grid() {
var grid = 50;
var lines = [];
for (var i = 0; i <= 600; i += grid) {
lines.push(new fabric.Line([i, 0, i, 300],{stroke:'#000',strokeWidth: 2}));
}
for (var i = 0; i <= 300; i += grid) {
lines.push(new fabric.Line([0, i, 600, i],{stroke:'#000',strokeWidth: 2}));
}
gridObj = new fabric.Group(lines, {
selectable:false,
evented:false,
hoverCursor: 'auto',
left: -2,
top: -2,
visible:false
});
canvas.add(gridObj);
canvas.renderAll();
console.log(gridObj.toJSON())
}
draw_grid();
/* Hide/Show Grid */
$(document).on('change', '#show_grid', function() {
gridObj.visible = $(this).is(':checked');
gridObj.dirty = true;
canvas.renderAll();
});
<script src="https://rawgit.com/kangax/fabric.js/master/dist/fabric.js"></script>
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
Show Grid: <input type="checkbox" id="show_grid" />
<canvas id="canvas1" width="600" height="300" style="border:1px solid #000000;"></canvas>
Here is codepen.
Or
Get all the objects having custom_class = canvas_grid property and remove them using canvas.remove(). Here is codepen.
I am using this function to define my fabricJS canvas background image:
$scope.bgImage = function () {
const {
ipcRenderer
} = require('electron')
ipcRenderer.send('openFile', () => {
})
ipcRenderer.once('fileData', (event, filepath) => {
fabric.Image.fromURL(filepath, function (image) {
var hCent = canvas.getHeight / 2;
var wCent = canvas.getWidth / 2;
canvas.setBackgroundColor({
source: filepath,
top: hCent,
left: wCent,
originX: 'center',
originY: 'middle',
repeat: 'no-repeat',
scaleX: 10,
scaleY: 10
}, canvas.renderAll.bind(canvas));
})
})
};
All the parameters shoulkd be change on the fly with some html inputs. Setting the repeat is working fine and i can change it dynamically.
But I am simply not able to change the scale of my background image. Using the above function I would expect that my background image would be:
would be not repeated (ok. is working)
positioned in the middle/center of my canvas (it is not)
would be scaled by a factor of 10 (it is not)
I am making again a newbish mistake? Or ist this realted to some changes in image handling in FabricJS v.2
canvas.setBackgroundImage() Use this function to add Image as a background.
To get Height/Width of canvas use canvas.getHeight()/canvas.getWidth(),these are functions. Or else you can use the properties > canvas.height/canvas.width respectively.
DEMO
// initialize fabric canvas and assign to global windows object for debug
var canvas = window._canvas = new fabric.Canvas('c');
var hCent = canvas.getHeight() / 2;
var wCent = canvas.getWidth() / 2;
canvas.setBackgroundImage('http://fabricjs.com/assets/jail_cell_bars.png', canvas.renderAll.bind(canvas), {
originX: 'center',
originY: 'center',
left: wCent,
top: hCent,
scaleX: 1,
scaleY: 1
});
fabric.util.addListener(document.getElementById('toggle-scaleX'), 'click', function () {
if (!canvas.backgroundImage) return;
canvas.backgroundImage.scaleX = canvas.backgroundImage.scaleX < 1 ? 1 : fabric.util.toFixed(Math.random(), 2);
canvas.renderAll();
});
fabric.util.addListener(document.getElementById('toggle-scaleY'), 'click', function () {
if (!canvas.backgroundImage) return;
canvas.backgroundImage.scaleY = canvas.backgroundImage.scaleY < 1 ? 1 : fabric.util.toFixed(Math.random(), 2);
canvas.renderAll();
});
canvas {
border: 1px solid #999;
}
button {
margin-top: 20px;
}
<script src="https://rawgithub.com/kangax/fabric.js/master/dist/fabric.js"></script>
<canvas id="c" width="600" height="600"></canvas>
<button id="toggle-scaleX">Toggle scaleX</button>
<button id="toggle-scaleY">Toggle scaleY</button>
I am creating a little app with KineticJS which creates multiple nodes (RegularPolygons). After the stage is loaded (triggered with play(); ) I fill each node sequentially with an (pattern)image (triggered with loadImages(urls);.
This works fine, but now I want to add a nice fade-in effect with a Tween, like:
set all nodes > load single image > set node patternImage > tween to opacity 0.8 > on tween complete, load next image (repeat).
For some reason the tweens won't play, they just appear in complete state (opacity 1) ;(
var stage = new Kinetic.Stage({
container: 'canvas',
width: $(window).width(),
height: $(window).height()
});
var layer = new Kinetic.Layer()
var layer2 = new Kinetic.Layer()
var urls =
[
'http://lorempixel.com/300/300/sports/1',
'http://lorempixel.com/300/300/sports/2',
'http://lorempixel.com/300/300/sports/3',
'http://lorempixel.com/300/300/sports/4',
'http://lorempixel.com/300/300/sports/5',
'http://lorempixel.com/300/300/sports/6',
'http://lorempixel.com/300/300/sports/7',
'http://lorempixel.com/300/300/sports/8',
'http://lorempixel.com/300/300/sports/9',
'http://lorempixel.com/300/300/sports/10',
'http://lorempixel.com/300/300/business/1',
'http://lorempixel.com/300/300/business/2',
'http://lorempixel.com/300/300/business/3',
'http://lorempixel.com/300/300/business/4',
'http://lorempixel.com/300/300/business/5',
'http://lorempixel.com/300/300/business/6',
'http://lorempixel.com/300/300/business/7',
'http://lorempixel.com/300/300/business/8',
'http://lorempixel.com/300/300/business/9',
'http://lorempixel.com/300/300/business/10'/*,
'http://lorempixel.com/300/300/cats/1',
'http://lorempixel.com/300/300/cats/2',
'http://lorempixel.com/300/300/cats/3',
'http://lorempixel.com/300/300/cats/4',
'http://lorempixel.com/300/300/cats/5',
'http://lorempixel.com/300/300/cats/6',
'http://lorempixel.com/300/300/cats/7',
'http://lorempixel.com/300/300/cats/8',
'http://lorempixel.com/300/300/cats/9',
'http://lorempixel.com/300/300/cats/10',
'http://lorempixel.com/300/300/nature/1',
'http://lorempixel.com/300/300/nature/2',
'http://lorempixel.com/300/300/nature/3',
'http://lorempixel.com/300/300/nature/4',
'http://lorempixel.com/300/300/nature/5',
'http://lorempixel.com/300/300/nature/6',
'http://lorempixel.com/300/300/nature/7',
'http://lorempixel.com/300/300/nature/8',
'http://lorempixel.com/300/300/nature/9',
'http://lorempixel.com/300/300/nature/10',
'http://lorempixel.com/300/300/people/1',
'http://lorempixel.com/300/300/people/2',
'http://lorempixel.com/300/300/people/3',
'http://lorempixel.com/300/300/people/4',
'http://lorempixel.com/300/300/people/5'*/
];
// LOAD IMAGES
function loadImages(arrayOfImages, index) {
index = index || 0;
if (arrayOfImages && arrayOfImages.length && arrayOfImages.length > index) {
var img = new Image();
img.onload = function() {
var pane = layer2.get('#pane_' + index );
pane.fill('').fillPatternImage(img);
stage.draw(); // <<< THIS WORKS
var tween = new Kinetic.Tween({
node: pane,
duration: 1,
opacity: 0.8,
easing: Kinetic.Easings.BackEaseOut,
onFinish: function() {
loadImages(arrayOfImages, index + 1
}
}).play; // <<< NOT WORKING
//setTimeout(function(){ loadImages(arrayOfImages, index + 1); }, 200);
};
img.src = arrayOfImages[index];
}
}
function start() {
console.log("numOfPanes: " +urls.length);
for (i = 0; i <= urls.length; i++) {
var shape0 = new Kinetic.RegularPolygon({
x: i * 15,
y: i * 15,
sides: 5,
rotation: i * 10,
radius: 70,
fill: 'Red'
});
var shape1 = new Kinetic.RegularPolygon({
x: i * 15,
y: i * 15,
sides: 5,
rotation: i * 10,
radius: 70,
opacity: 0,
fillPatternOffset: {x:-220, y:70},
id: 'pane_' + i,
name: 'pane',
fill: 'Green'
});
layer.add(shape0);
layer2.add(shape1);
}
stage.add(layer,layer2);
}
// INIT
start();
// trigger loadimages() with console
loadImages(urls);
play is a function. So you should call it.
var tween = new Kinetic.Tween({
node: pane,
duration: 1,
opacity: 0.8,
easing: Kinetic.Easings.BackEaseOut,
onFinish: function() {
loadImages(arrayOfImages, index + 1
}
}).play();
Also: when you are finding node with get function it returns Collection. So if you need just node use:
var pane = layer2.get('#pane_' + index )[0];
I am trying to recreate the game http://www.sinuousgame.com/ and studying html5 canvas and kineticJS.
This is my fiddle:
http://jsfiddle.net/2WRwY/7/
My problem:
The tail part of the player in the fiddle doesn't seem to retract back.
The red ball objects should appear over the player objects.
(Try running the fiddle with layer.removeChildren(); and without it.)
Right now,I have commented "layer.removeChildren();" on the fiddle.. (basically which causes the problem for me)
Here's my html:
<!DOCTYPE html>
<html>
<head>
<title>Collision Detection-player</title>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<meta name="viewport" content="width=device-width">
<link rel="stylesheet" href="../css/style.css"/>
</head>
<body>
<div id="container" style="width: auto; height: auto; background:#000; margin:auto; float:left;"></div>
<script src="../js/jquery.min.js"></script>
<script src="../js/kinetic-v5.0.0.min.js"></script>
<script src="../js/main_kinetic_combined.js"></script>
</body>
</html>
Here's my javascript:
//The working player code
var LimitedArray = function(upperLimit) {
var storage = [];
// default limit on length if none/invalid supplied;
upperLimit = +upperLimit > 0 ? upperLimit : 100;
this.push = function(item) {
storage.push(item);
if (storage.length > upperLimit) {
storage.shift();
}
return storage.length;
};
this.get = function(flag) {
return storage[flag];
};
this.iterateItems = function(iterator) {
var flag, l = storage.length;
if (typeof iterator !== 'function') {
return;
}
for (flag = 0; flag < l; flag++) {
iterator(storage[flag]);
}
};
};
var tail = new LimitedArray(50);
var flag = 0, jincr = 0;
var stage = new Kinetic.Stage({
container: 'container',
width: window.innerWidth,
height: window.innerHeight,
listening: true
});
var layer = new Kinetic.Layer({
listening: true
});
stage.add(layer);
var player = new Kinetic.Circle({
x: 20,
y: 20,
radius: 6,
fill: 'cyan',
stroke: 'black',
draggable: true
});
layer.add(player);
// move the circle with the mouse
stage.getContent().addEventListener('mousemove', function() {
<!--layer.removeChildren(); -->
layer.add(player);
player.setPosition(stage.getPointerPosition());
var obj = {
x: stage.getPointerPosition().x,
y: stage.getPointerPosition().y
};
tail.push(obj);
var arr = [];
tail.iterateItems(function(p) {
arr.push(p.x, p.y);
});
var line = new Kinetic.Line({
points: arr,
stroke: 'white',
strokeWidth: 2,
lineCap: 'round',
lineJoin: 'round'
});
layer.add(line);
// layer.draw();
});
var x = 0;
var y = 0;
var noOfEnemies = 150;
var enemyArmada = new Array();
createEnemy();
function createEnemy() {
for (var i = 0; i < noOfEnemies; i++) {
var enemy = new Kinetic.Circle({
x: Math.random() * window.innerWidth,
y: Math.random() * window.innerHeight,
radius: 4.5 + 1.5 * Math.random(),
fill: 'red',
stroke: 'black',
});
enemy.speedX = enemy.speedY = (0.3 + Math.random() * 50);
enemyArmada.push(enemy);
layer.add(enemy);
}
}
var anim = new Kinetic.Animation(function(frame) {
for (var i = 0; i < noOfEnemies; i++) {
var e = enemyArmada[i];
e.position({
x: e.position().x - e.speedX * frame.timeDiff / 500,
y: e.position().y + e.speedY * frame.timeDiff / 500
});
if (e.position().y < 0 || e.position().x < 0) {
e.position({
x: (Math.random() * (window.innerWidth + 600)),
y: -(Math.random() * window.innerHeight)
});
}
}
}, layer);
anim.start();
Any suggestions?
The problem is that after you've added the enemies, you're adding the player and the line to the layer again, so they'll be on top. Also, on each mouse move, you're creating the line over and over again.
So, instead, you should just update the line points (and you don't need the layer.removeChildren(); line at all), like this:
var line = new Kinetic.Line({
points: [],
stroke: 'white',
strokeWidth: 2,
lineCap: 'round',
lineJoin: 'round'
});
layer.add(line);
layer.add(player);
// move the circle with the mouse
stage.getContent().addEventListener('mousemove', function() {
player.position(stage.getPointerPosition());
var obj = {
x: stage.getPointerPosition().x,
y: stage.getPointerPosition().y
};
tail.push(obj);
var arr = [];
tail.iterateItems(function(p) {
arr.push(p.x, p.y);
});
line.points(arr);
});
See fiddle: http://jsfiddle.net/Kunstmord/p9fnq/2/
This way, you're only creating the line once. This also seems to fix the non-disappearing trail.
Also, please note:
1) use position instead of setPosition and getPosition (see KineticJS 5.0 docs)
2) adding <!-- --> does not comment out a line in Javascript (layer.removeChildren(); line).