I were looking for a drawImage() alternative for fabric.js lib, so I've made a function:
function drawImage(img,sx,sy,swidth,sheight,x,y,width,height) {
return new fabric.Image(img, {
left: x,
top: y,
width: width,
height: height,
id: "rhino",
clipTo: function (ctx) {
ctx.rect(sx,sy,swidth,sheight);
}
});
}
var imgElement = new Image();
imgElement.onload = function() {
var imgInstance = drawImage(imgElement, 33, 71, 104, 124, 21, 20, 87, 104);
canvas.add(imgInstance);
};
imgElement.src = "https://mdn.mozillademos.org/files/5397/rhino.jpg";
The result needs to be:
But I don't get nothing with my custom function. Where is the problem?
Codepen: http://codepen.io/anon/pen/RaxRqZ
I do not really know what you want to achieve, but using clipTo is not my advice, both for performance and complexity reasons.
Draw on a temp canvas the portion of image you need, then use this temp canvas a source for your fabricJS image.
var canvas = new fabric.Canvas('c');
function drawImage(img,sx,sy,swidth,sheight,x,y,width,height) {
var tmpc = document.createElement('canvas');
tmpc.width = swidth;
tmpc.height = sheight;
ctx = tmpc.getContext("2d");
ctx.drawImage(img,-sx,-sy);
return new fabric.Image(tmpc, {
left: x,
top: y,
width: width,
height: height,
id: "rhino"
});
}
var imgElement = new Image();
imgElement.onload = function() {
var imgInstance = drawImage(imgElement, 33, 71, 104, 124, 21, 20, 87, 104);
canvas.add(imgInstance);
};
imgElement.src = "https://mdn.mozillademos.org/files/5397/rhino.jpg";
<script src="http://www.deltalink.it/andreab/fabric/fabric.js"></script>
<canvas id="c" width="500", height="500"></canvas>
Here you can find solution,
var canvas = ctx = '';
canvas = new fabric.Canvas('canvas');
canvas.selection = false;
ctx = canvas.getContext('2d');
function drawImage(imgPath, x, y, width, height)
{
fabric.Image.fromURL(imgPath, function(img) {
img.set({
left: x,
top: y,
width: width,
height: height,
id: "rhino",
clipTo: function (ctx) {
ctx.rect(5,5,50,50);
}
});
canvas.add(img).renderAll().setActiveObject(img);
});
}
var imgElement = new Image();
imgElement.src = "https://mdn.mozillademos.org/files/5397/rhino.jpg";
imgElement.onload = function() {
drawImage(imgElement.src, 50, 50, 100, 100);
}
https://codepen.io/mullainathan/pen/wGpzvY
Related
Below is provided a script for changing image on click, changes will be affected in canvas.
The script is working properly in Firefox and Chrome but not in Safari
What could be the reason?
<script>
$(function() {
var house = document.getElementById("house");
var ctxHouse = house.getContext("2d");
var canvas = document.getElementById("canvas");
var ctx = canvas.getContext("2d");
var canvas2 = document.getElementById("canvas2");
var ctxHand = canvas2.getContext("2d");
var FabricLink;
var imageObj = new Image();
var red = new Image();
red.onload = function() {
canvas.width = red.width;
canvas.height = red.height;
var houseImage = new Image();
houseImage.onload = function() {
house.width = houseImage.width;
house.height = houseImage.height;
ctxHouse.drawImage(houseImage, 0, 0);
}
houseImage.src = "images/img.jpg";
ctx.drawImage(red, 0, 0);
imageObj.onload = function() {
var pattern = ctx.createPattern(imageObj, 'repeat');
ctx.globalCompositeOperation = 'source-in';
ctx.rect(0, 0, canvas.width, canvas.height);
ctx.fillStyle = pattern;
ctx.fill();
};
$(imageObj).attr('src', 'images/' + FabricLink + '.png');
}
red.src = "images/img.png";
var imageObj2 = new Image();
var blue = new Image();
blue.onload = function() {
canvas2.width = blue.width;
canvas2.height = blue.height;
var houseImage = new Image();
houseImage.onload = function() {
house.width = houseImage.width;
house.height = houseImage.height;
ctxHouse.drawImage(houseImage, 0, 0);
}
houseImage.src = "images/img.jpg";
ctxHand.drawImage(blue, 0, 0);
imageObj2.onload = function() {
var pattern = ctx.createPattern(imageObj2, 'repeat');
ctxHand.globalCompositeOperation = 'source-in';
ctxHand.rect(0, 0, canvas2.width, canvas2.height);
ctxHand.fillStyle = pattern;
ctxHand.fill();
};
$(imageObj2).attr('src', 'images/' + FabricLink + '.png');
}
blue.src = "images/img.png";
$('#style li').click(
function() {
//we get our current filename and use it for the src
var linkIndex = $(this).attr("data-filename");
$(red).attr('src', 'images/' + linkIndex + '.png');
}
);
$('#Sleeves li').click(
function() {
$("#canvas2").addClass("show-z");
//we get our current filename and use it for the src
var SleevesLink = $(this).attr("data-filename");
$(blue).attr('src', 'images/' + SleevesLink + '.png');
}
);
$('#Fabric li').click(
function() {
//we get our current filename and use it for the src
FabricLink = $(this).attr("data-filename");
$(imageObj2).attr('src', 'images/' + FabricLink + '.png');
$(imageObj).attr('src', 'images/' + FabricLink + '.png');
}
);
$("#Fabric li:first-child").click();
}); // end $(function(){});
</script>
While debugging, we could see that imageObj.onload is not getting fired in the first click , only on refresh the change occurs in Safari.
jsfiddle.net/qvfx3kz7 (In the fiddle images are not loading, but the complete code is added)
I am not sure what is exactly the problem with Safari, but what I can see is that you are over-complicating everything by trying to load your assets only when requested, which leads to this callback nightmare you have set up.
Instead, prepare your assets so that you can load it only once. Since you are using patterns, I will assume that each pattern is actually a small image.
So instead of loading every little pattern images, load a single sprite-sheet, which will contain all your patterns.
From there, you'll be able to generate dynamically your CanvasPattern synchronously, without having to care for any loading callback. In order to do this, you will have to use a second, off-screen, canvas, that you will use as he source of createPattern() method:
// really dummy implementation...
function AssetsLoader() {}
AssetsLoader.prototype = Object.create({
addImage: function(objs, cb) {
if (!objs || typeof objs !== 'object') return;
if (!Array.isArray(objs)) objs = [];
var toLoad = objs.length,
imgs = objs.map(loadImage, this);
function loadImage(obj) {
if (!obj.src) return;
this.toLoad++;
var img = new Image();
img.src = obj.src;
img.onload = onimgload;
img.onerror = onimgerror;
return obj.img = img;
}
function onimgload(evt) {
if (--toLoad <= 0 && typeof cb === 'function') cb(imgs);
}
function onimgerror(evt) {
console.warn('failed to load image at ', evt.target.src);
}
}
});
// Some info about our assets, there are an infinity of ways to deal with it,
// You would have to determine yourself what's best for your own case
var dests = {
sofa: {
name: 'sofa',
src: 'https://i.stack.imgur.com/ryO42.png'
},
shirt: {
name: 'shirt',
src: 'https://i.stack.imgur.com/cPNbe.png'
}
};
var patterns = {
name: 'patterns',
src: 'https://i.stack.imgur.com/TdIAJ.png',
positions: {
orange: {
x: 0,
y: 0,
width: 173,
height: 173,
out_width: 75,
out_height: 75
},
violet: {
x: 173,
y: 0,
width: 173,
height: 173,
out_width: 35,
out_height: 35
},
psyche: {
x: 0,
y: 173,
width: 173,
height: 173,
out_width: 25,
out_height: 25
},
pink: {
x: 173,
y: 173,
width: 173,
height: 173,
out_width: 125,
out_height: 125
}
}
}
var assets = new AssetsLoader();
// first load all our images, and only then, start the whole thing
assets.addImage([dests.shirt, dests.sofa, patterns], init);
function init() {
// populate our selects
for (var key in dests) {
dest_select.appendChild(new Option(key, key));
}
for (var key in patterns.positions) {
pat_select.appendChild(new Option(key, key));
}
dest_select.onchange = pat_select.onchange = draw;
var ctx = canvas.getContext('2d');
var offscreenCtx = document.createElement('canvas').getContext('2d');
draw();
function draw() {
var dest = dests[dest_select.value].img;
ctx.canvas.width = dest.width;
ctx.canvas.height = dest.height;
ctx.globalCompositeOperation = 'source-over';
ctx.clearRect(0, 0, canvas.width, canvas.height);
ctx.drawImage(dest, 0, 0, canvas.width, canvas.height);
ctx.globalCompositeOperation = 'source-in';
// here we generate the CanvasPattern
ctx.fillStyle = getPattern(pat_select.value);
ctx.fillRect(0, 0, canvas.width, canvas.height);
ctx.globalCompositeOperation = 'luminosity';
ctx.drawImage(dest, 0, 0, canvas.width, canvas.height);
}
// now that we have our patterns loaded in a single sprite-sheet,
// we can generate the CanvasPatterns synchronously
function getPattern(key) {
var pos = patterns.positions[key]; // get our pattern's position in our dictionary
// resize the offscreen canvas so it matches our pattern
offscreenCtx.canvas.width = pos.out_width;
offscreenCtx.canvas.height = pos.out_height;
offscreenCtx.drawImage(patterns.img, pos.x, pos.y, pos.width, pos.height, 0, 0, pos.out_width, pos.out_height);
return offscreenCtx.createPattern(offscreenCtx.canvas, 'repeat');
}
}
<select id="dest_select"></select>
<select id="pat_select"></select>
<br><br><br>
<canvas id="canvas"></canvas>
I need help with fabric js
I want to create a group of clips, the group can have many clips next to each other. Each clip can have an image inside it.
similar to the grid function in canva
group of 2 clip masks with space between them
this is what I have so far it displays in a very weird shape
http://jsfiddle.net/SallyMagdyTadros/ZxYCP/1467/
<canvas id="c" width="400" height="400"></canvas>
var img01URL = 'https://www.google.com/images/srpr/logo4w.png';
(function() {
var canvas = this.__canvas = new fabric.Canvas('c');
fabric.Object.prototype.transparentCorners = false;
var img2;
fabric.Image.fromURL('http://fabricjs.com/lib/pug.jpg', function(img) {
img2 = img.scale(0.5).set({
left: 100,
top: 0,
clipTo: function(ctx) {
ctx.rect(0, 0, 100, 200);
}
});
});
fabric.Image.fromURL('https://www.google.com/images/srpr/logo4w.png',
function(img) {
img.scale(0.5).set({
left: 0,
top: 0,
clipTo: function(ctx) {
ctx.rect(0, 0, 200, 100);
}
});
var group = new fabric.Group([img, img2], {
});
group.left = 0;
group.top = 0;
canvas.add(group);
});
})();
Why next function can't find an image ( when i check with debugger i may see all other elements but not the image)
function getItemByName3(name) {
var object = null,
objects = canvas.getObjects();
objectsCount=canvas.getObjects().length;
for (var i = 0, len = objectsCount; i < len; i++) {
if (objects[i].type && objects[i].type == "image"){
if (objects[i].id && objects[i].id===name) {
object = objects[i];
break;
}
}
}
return object;
}
function backgroundSaveToJsonF(){ ////____________________________________________saveJsonF;
var backgroundImage=getItemByName3(document.getElementById("selectProject").value+"imageID");
var backgroundImageForDB=JSON.stringify(backgroundImage.toObject(['id','sendToBack','selectable']));
I am uploading image to canvas with next code:
document.getElementById('imgLoader').addEventListener("change", function(e) {
var file = e.target.files[0];
var reader = new FileReader();
reader.onload = function(f) {
var data = f.target.result;
fabric.Image.fromURL(data, function(img) {
var oImg = img.set({
left: 0,
top: 0,
angle: 00,
width: canvas.width,
height: canvas.height,
id:document.getElementById("selectProject").value+"imageID"
});
canvas.setBackgroundImage(oImg).renderAll();
var dataURL = canvas.toDataURL({
format: 'png',
quality: 0.8
});
});
};
reader.readAsDataURL(file);
});
thank you
DEMO
document.getElementById('imgLoader').addEventListener("change", function(e) {
var file = e.target.files[0];
var reader = new FileReader();
reader.onload = function(f) {
var data = f.target.result;
fabric.Image.fromURL(data, function(img) {
var oImg = img.set({
left: 0,
top: 0,
angle: 00,
width: canvas.width,
height: canvas.height
});
//canvas.setBackgroundImage(oImg).renderAll();
canvas.add(oImg);
console.log(canvas.getObjects());
var dataURL = canvas.toDataURL({
format: 'png',
quality: 0.8
});
});
};
reader.readAsDataURL(file);
});
var canvas = new fabric.Canvas('c');
canvas.add(new fabric.Rect({
left: 50,
top: 50,
height: 100,
width:100,
stroke: 'red',
fill: ''
}))
canvas.add(new fabric.Text('1',{
left: 20,
top: 50,
stroke: 'red',
fill: ''
}))
canvas.renderAll();
canvas{
border:2px dotted blue;
}
<script src="https://cdnjs.cloudflare.com/ajax/libs/fabric.js/1.7.16/fabric.min.js"></script>
<input type="file" id="imgLoader" accept="image/*"> <br>
<canvas id='c' width='400' height='400'></canvas>
Its because you are setting uploaded image as background image canvas.setBackgroundImage(oImg) you are not adding that as a object to canvas. If you want to get it in your object list then add as an object canvas.add(oImg). Check the demo.
I want to be able to run a certain function when my mouse is clicked on a certain area of the canvas but i do not understand how to do it. (I am new to programming) for example, if i wanted to click in within an area of a rectangle in the top right of the canvas, such as the coordinates of "172,58,269,166"
<!DOCTYPE HTML>
<html>
<head>
<style>
canvas{
margin-top: auto;
margin-left: auto;
margin-right: auto;
margin-bottom: auto;
/*display:block;*/
}
</style>
</head>
<body background="MANCALA-start_bg_texture.jpg">
<div class="container">
<canvas id="myCanvas" width="1141" height="479" usemap="Canvas"></canvas>
<script>
function loadImages(sources, callback) {
var images = {};
var loadedImages = 0;
var numImages = 0;
// get num of sources
for(var src in sources) {
numImages++;
}
for(var src in sources) {
images[src] = new Image();
images[src].onload = function() {
if(++loadedImages >= numImages) {
callback(images);
}
};
images[src].src = sources[src];
}
}
var canvas = document.getElementById('myCanvas');
var context = canvas.getContext('2d');
// identifies what each of the pictures
var sources = {
background: 'MANCALA-game_bg_combined3.png',
pit1marble1: 'MANCALA-game_marble.png',
pit1marble2: 'MANCALA-game_marble.png',
pit1marble3: 'MANCALA-game_marble.png',
pit1marble4: 'MANCALA-game_marble.png',
pit1marble5: 'MANCALA-game_marble.png',
pit1marble6: 'MANCALA-game_marble.png',
};
//loading the images on the canvas
loadImages(sources, function(images) {
context.drawImage(images.background, 0, 0, 1141, 479);
context.drawImage(images.pit1marble1, 200, 70, 50, 50);
context.drawImage(images.pit1marble2, 160, 85, 50, 50);
context.drawImage(images.pit1marble3, 175, 75, 50, 50);
context.drawImage(images.pit1marble4, 190, 80, 50, 50);
context.drawImage(images.pit1marble5, 200, 100, 50, 50);
context.drawImage(images.pit1marble6, 160, 100, 50, 50);
//mouse positioning
document.getElementById("myCanvas").onclick = function() {pasDiKlik()};
function pasDiKlik() {
context.beginPath();
context.arc(event.clientX-10, event.clientY-10,10, 0, 2 * Math.PI, false);
You could add a eventlistener to the canvas, get the position of the mouse on the canvas, and perform a action based on that. for example:
var canvas = document.getElementById("MyCanvas")
var canvasLeft = canvas.offsetLeft,
var canvasTop = canvas.offsetTop
canvas.addEventListener("click", function(event){
var x = event.pageX - canvasLeft
var y = event.pageY - canvasTop;
};
The variables x and y are now the pixel position on the canvas.
for example, to check on your first box(top left:200px, 70px, bottom right: 250px, 120px).
if (x >= 200 && x <= 250 && y >= 70 && y <= 120) {
//perform action here
};
How can I place a blue box between red and green one using this function?
I need to achieve this effect.
Here's a Codepen.
HTML
<canvas id="canvas">
</canvas>
JS
var canvas = document.getElementById("canvas");
var ctx = canvas.getContext('2d');
window.onload = draw;
green = new Image;
green.src = 'http://www.thebouncingbox.com/images/thumbnail/produkte/large/California-Sunbounce-meterware-green-box.jpg';
red = new Image;
red.src = 'http://www.front-porch-ideas-and-more.com/image-files/color-red.jpg';
blue = new Image;
blue.src = 'http://s3.amazonaws.com/colorcombos-images/colors/000066.png';
function draw() {
ctx.drawImage(green, 0, 0, 200, 200);
ctx.drawImage(red, 80, 50, 120, 100);
ctx.drawImage(blue, 60, 30, 100, 100);
}
You need to listen onload event of the image before drawing it. To have images over image, series operation will help!
var canvas = document.getElementById("canvas");
var ctx = canvas.getContext('2d');
window.onload = draw1;
function draw1() {
var green = new Image();
green.onload = function() {
ctx.drawImage(green, 0, 0, 200, 200);
draw2();
};
green.src = 'http://www.thebouncingbox.com/images/thumbnail/produkte/large/California-Sunbounce-meterware-green-box.jpg';
}
function draw2() {
var blue = new Image;
blue.onload = function() {
ctx.drawImage(blue, 50, 50, 100, 100);
draw3();
};
blue.src = 'http://s3.amazonaws.com/colorcombos-images/colors/000066.png';
}
function draw3() {
var red = new Image();
red.onload = function() {
ctx.drawImage(red, 100, 100, 100, 100);
};
red.src = 'http://www.front-porch-ideas-and-more.com/image-files/color-red.jpg';
}
<canvas id="canvas" width="200" height="200"></canvas>
Why not change the order you draw them?
function draw() {
ctx.drawImage(green, 0, 0, 200, 200);
ctx.drawImage(blue, 60, 30, 100, 100);
ctx.drawImage(red, 80, 50, 120, 100);
}