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Basic Fabric.js Image Selection with Mask

I have a unique (but hopefully simple) issue to fix with Fabric.js to fix.
I have this very simple example below:
I have
2 Images
Both have an absolutePositioned mask via clipPath property on the fabric.Image instance
My issue is:
I want the image to only be selectable (and hoverable) whenever the selection happens within the bounds of the mask, not anywhere on image (even outside of the bounds of its mask).
This image shows the mouse hovering over the red door picture (even though the mouse is outside of the mask bounds, but not outside the image bounds:
Here's a code snippet of the door image snippet:
fabric.Image.fromURL(url1, function(img){
canvas.add(img.set({
left: 0,
top: 0,
clipPath: rect1,
hasControls: false,
}));
img.on('mouseover', () => {
const filter = new fabric.Image.filters.BlendColor({
color: 'white',
alpha: 0.7,
mode: 'tint'
})
img.filters.push(filter)
img.applyFilters()
canvas.renderAll()
})
img.on('mouseout', () => {
img.filters.pop()
img.applyFilters()
canvas.renderAll()
})
}, {crossOrigin: "Anonymous"});
JS Fiddle Example showing the current behavior that I'm trying to change.

A possible solution is to listen to the mouse event in the canvas and toggle the activeObject based on the mouse position:
canvas.observe('mouse:move', function(options) {
const pos = canvas.getPointer(options.e);
if (!imageRight || !imageLeft) return
if (pos.x > 200) {
activeImage = imageRight
} else {
activeImage = imageLeft
}
const activeObj = canvas.getActiveObject();
if (activeImage !== activeObj) {
canvas.setActiveObject(activeImage);
canvas.renderAll()
}
});
This is a very simplified way to detect if the mouse is over the image. It checks if the x > 200 since that is where the line between both images is positioned. This could be improved to be more accurate, but it works just to illustrate the idea.
var canvas = window._canvas = new fabric.Canvas('c');
const url1 = 'https://picsum.photos/300/200'
const url2 = 'https://picsum.photos/320'
let imageRight
let imageLeft
let activeImage
canvas.observe('mouse:move', function(options) {
const pos = canvas.getPointer(options.e);
if (!imageRight || !imageLeft) return
if (pos.x > 200) {
activeImage = imageRight
} else {
activeImage = imageLeft
}
const activeObj = canvas.getActiveObject();
if (activeImage !== activeObj) {
canvas.setActiveObject(activeImage);
canvas.renderAll()
}
});
const baseProps = {
width: 200,
height: 200,
top: 0,
fill: '#000',
absolutePositioned: true,
hasControls: false,
evented: false,
selectable: false
}
const rect1 = new fabric.Rect({
...baseProps,
left: 0,
})
const rect2 = new fabric.Rect({
...baseProps,
left: 200,
})
canvas.add(rect1)
canvas.add(rect2)
fabric.Image.fromURL(url2, function(img) {
imageRight = img
canvas.add(img.set({
left: 200,
top: 0,
clipPath: rect2,
hasControls: false
}))
}, {
crossOrigin: "Anonymouse"
})
fabric.Image.fromURL(url1, function(img) {
imageLeft = img
canvas.add(img.set({
left: 0,
top: 0,
clipPath: rect1,
hasControls: false,
}));
}, {
crossOrigin: "Anonymous"
});
canvas {
border: 2px red solid;
}
<script src="https://cdnjs.cloudflare.com/ajax/libs/fabric.js/2.6.0/fabric.min.js"></script>
<canvas id="c" width="420" height="220"></canvas>

Why I cannot draw multiple curved arrows with sceneFunc() in Shape object using KonvaJS?

I am inspired with KonvaJS tutorial Modify Curves with Anchor Points to make my own example which is to create multiple custom arrows.
on click on the selectionBox create an anchor.
on the creation of the third anchor create the curved arrow.
on the fourth click reset all variables in order to draw a new curved arrow.
var width = window.innerWidth;
var height = window.innerHeight;
// globals
var selectionBoxLayer, curveLayer, lineLayer, anchorLayer, quad, bezier;
function updateDottedLines() {
var q = quad;
var quadLine = lineLayer.get('#quadLine')[0];
quadLine.setPoints([q.start.attrs.x, q.start.attrs.y, q.control.attrs.x, q.control.attrs.y, q.end.attrs.x, q.end.attrs.y]);
lineLayer.draw();
}
function buildAnchor(x, y) {
var anchor = new Konva.Circle({
x: x,
y: y,
radius: 20,
stroke: '#666',
fill: '#ddd',
strokeWidth: 2,
draggable: true
});
// add hover styling
anchor.on('mouseover', function() {
document.body.style.cursor = 'pointer';
this.setStrokeWidth(4);
anchorLayer.draw();
});
anchor.on('mouseout', function() {
document.body.style.cursor = 'default';
this.setStrokeWidth(2);
anchorLayer.draw();
});
anchor.on('dragend', function() {
drawCurves();
updateDottedLines();
});
anchorLayer.add(anchor);
anchorLayer.draw();
return anchor;
}
function drawCurves() {
var context = curveLayer.getContext();
var arrowLine = new Konva.Shape({
sceneFunc: function(context){
debugger;
// draw quad
context.beginPath();
context.moveTo(quad.start.attrs.x, quad.start.attrs.y);
context.quadraticCurveTo(quad.control.attrs.x, quad.control.attrs.y, quad.end.attrs.x, quad.end.attrs.y);
//Draw Arrow Head
var headlen = 10; // length of head in pixels
var angle = Math.atan2(quad.end.attrs.y - quad.control.attrs.y, quad.end.attrs.x - quad.control.attrs.x);
context.lineTo(quad.end.attrs.x-headlen*Math.cos(angle-Math.PI/6), quad.end.attrs.y-headlen*Math.sin(angle-Math.PI/6));
context.moveTo(quad.end.attrs.x, quad.end.attrs.y);
context.lineTo(quad.end.attrs.x- headlen*Math.cos(angle+Math.PI/6), quad.end.attrs.y-headlen*Math.sin(angle+Math.PI/6));
context.fillStrokeShape(this);
},
stroke: 'black',
strokeWidth: 4
});
curveLayer.add(arrowLine);
curveLayer.draw();
}
var stage = new Konva.Stage({
container: 'container',
width: width,
height: height
});
selectionBoxLayer = new Konva.Layer();
anchorLayer = new Konva.Layer();
lineLayer = new Konva.Layer();
// curveLayer just contains a canvas which is drawn
// onto with the existing canvas API
curveLayer = new Konva.Layer();
var quadLine = new Konva.Line({
dash: [10, 10, 0, 10],
strokeWidth: 3,
stroke: 'black',
lineCap: 'round',
id: 'quadLine',
opacity: 0.3,
points: [0, 0]
});
// add dotted line connectors
lineLayer.add(quadLine);
quad = {};
// keep curves insync with the lines
anchorLayer.on('beforeDraw', function() {
if(quad.start && quad.control && quad.end){
drawCurves();
updateDottedLines();
}
});
var selectionBoxBackground = new Konva.Rect({
x: 0,
y: 0,
height:stage.height(),
width: stage.width(),
fill: 'transparent',
draggable: false,
name: 'selectionBoxBackground'
});
selectionBoxLayer.add(selectionBoxBackground);
var clickCounter = 0;
selectionBoxBackground.on("click", function(){
clickCounter +=1;
var mousePos = {};
switch(clickCounter){
case 1:
mousePos = stage.getPointerPosition();
quad.start = buildAnchor(mousePos.x, mousePos.y);
break;
case 2:
mousePos = stage.getPointerPosition();
quad.control = buildAnchor(mousePos.x, mousePos.y);
break;
case 3:
mousePos = stage.getPointerPosition();
quad.end = buildAnchor(mousePos.x, mousePos.y);
drawCurves();
updateDottedLines();
break;
default:
clickCounter = 0;
quad = {};
anchorLayer.destroyChildren();
anchorLayer.draw();
}
});
stage.add(curveLayer);
stage.add(lineLayer);
stage.add(selectionBoxLayer);
stage.add(anchorLayer);
body {
margin: 0;
padding: 0;
overflow: hidden;
background-color: #F0F0F0;
}
<script src="https://cdn.rawgit.com/konvajs/konva/0.11.1/konva.min.js"></script>
<body>
<div id="container"></div>
</body>
P.S Please note when I write in the browser console curveLayer.children, it will bring all created curved arrows.
Hint: I think on the creation of new Shape() the values of all created shapes will be changed to the new one.
I don't know what I am missing.

How to free draw circle using Fabric.js?

I am using FabricJS to draw circle in canvas:
var circle = new fabric.Circle({radius: 100,
fill: '',
stroke: 'red',
strokeWidth: 3,
originX: 'center',
originY: 'center'
});
var text = new fabric.Text('HELLO WORLD.',
{ fontSize: 30,
originX: 'center',
originY: 'center',
fill : 'red'
});
var group = new fabric.Group([ circle, text ], {
left: 150, top: 100
});
canvas.add(group);
This code draws a normal circle but I need to freely draw circle with mouse.
Any code help will be appreciated.

According to your previous code for drawing rectangle http://jsfiddle.net/Subhasish2015/8u1cqasa/2/ Here is the code for drawing circle:
$(document).ready(function(){
//Getting the canvas
var canvas1 = new fabric.Canvas("canvas2");
var freeDrawing = true;
var divPos = {};
var offset = $("#canvas2").offset();
$(document).mousemove(function(e){
divPos = {
left: e.pageX - offset.left,
top: e.pageY - offset.top
};
});
$('#2').click(function(){
//Declaring the variables
var isMouseDown=false;
var refCircle;
//Setting the mouse events
canvas1.on('mouse:down',function(event){
isMouseDown=true;
if(freeDrawing) {
var circle=new fabric.Circle({
left:divPos.left,
top:divPos.top,
radius:0,
stroke:'red',
strokeWidth:3,
fill:''
});
canvas1.add(circle);
refCircle=circle; //**Reference of rectangle object
}
});
canvas1.on('mouse:move', function(event){
if(!isMouseDown)
{
return;
}
//Getting yhe mouse Co-ordinates
if(freeDrawing) {
var posX=divPos.left;
var posY=divPos.top;
refCircle.set('radius',Math.abs((posX-refCircle.get('left'))));
canvas1.renderAll();
}
});
canvas1.on('mouse:up',function(){
canvas1.add(refCircle);
//alert("mouse up!");
isMouseDown=false;
//freeDrawing=false; // **Disables line drawing
});
});
});

var Circle = (function() {
function Circle(canvas) {
this.canvas = canvas;
this.className = 'Circle';
this.isDrawing = false;
this.bindEvents();
}
Circle.prototype.bindEvents = function() {
var inst = this;
inst.canvas.on('mouse:down', function(o) {
inst.onMouseDown(o);
});
inst.canvas.on('mouse:move', function(o) {
inst.onMouseMove(o);
});
inst.canvas.on('mouse:up', function(o) {
inst.onMouseUp(o);
});
inst.canvas.on('object:moving', function(o) {
inst.disable();
})
}
Circle.prototype.onMouseUp = function(o) {
var inst = this;
inst.disable();
};
Circle.prototype.onMouseMove = function(o) {
var inst = this;
if (!inst.isEnable()) {
return;
}
var pointer = inst.canvas.getPointer(o.e);
var activeObj = inst.canvas.getActiveObject();
activeObj.stroke = 'red',
activeObj.strokeWidth = 5;
activeObj.fill = 'red';
if (origX > pointer.x) {
activeObj.set({
left: Math.abs(pointer.x)
});
}
if (origY > pointer.y) {
activeObj.set({
top: Math.abs(pointer.y)
});
}
activeObj.set({
rx: Math.abs(origX - pointer.x) / 2
});
activeObj.set({
ry: Math.abs(origY - pointer.y) / 2
});
activeObj.setCoords();
inst.canvas.renderAll();
};
Circle.prototype.onMouseDown = function(o) {
var inst = this;
inst.enable();
var pointer = inst.canvas.getPointer(o.e);
origX = pointer.x;
origY = pointer.y;
var ellipse = new fabric.Ellipse({
top: origY,
left: origX,
rx: 0,
ry: 0,
transparentCorners: false,
hasBorders: false,
hasControls: false
});
inst.canvas.add(ellipse).setActiveObject(ellipse);
};
Circle.prototype.isEnable = function() {
return this.isDrawing;
}
Circle.prototype.enable = function() {
this.isDrawing = true;
}
Circle.prototype.disable = function() {
this.isDrawing = false;
}
return Circle;
}());
var canvas = new fabric.Canvas('canvas');
var circle = new Circle(canvas);
<script src="https://cdnjs.cloudflare.com/ajax/libs/fabric.js/1.7.17/fabric.min.js"></script>
Please draw circle here
<div id="canvasContainer">
<canvas id="canvas" width="400" height="400" style="border: solid 1px"></canvas>
</div>
Here is the detail blog with jsfiddle - https://blog.thirdrocktechkno.com/sketching-circle-of-a-html5-canvas-using-the-fabricjs-f7dbfa20cf2d

Here is an example of drawing a rectangle which I carefully made and works for latest versions. Krunan example seems to work OK- just in case this is a rectangle free drawing implementation that doesn't use DOM apis like e.clientX, offsetLeft, etc to track the coords, but fabric.js APIs only which I think is safer. Also unregister event listeners - I'm still trying to refine it since I need free drawing support for my project - Since there is no official support for this I wanted to reference the example here for others.
https://cancerberosgx.github.io/demos/misc/fabricRectangleFreeDrawing.html

An easy way to add a Circle to a canvas:
canvas.add(new fabric.Circle({ radius: 30, fill: "green", top: 100, left: 100 }));

Collision detection using kineticJS (getIntersection function not working)

I am trying to recreate the game http://www.sinuousgame.com/ and started studying html5 canvas and kineticJS.
Recently i came across the getIntersection function and coudnt find much details regarding it.But with what i had ,i did make a code to get the Collision detection done using getIntersection() function.
But it doesnt seem to be working.
As you can see, My Fiddle: http://jsfiddle.net/p9fnq/8/
//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
});
var line = new Kinetic.Line({
points: [],
stroke: 'cyan',
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);
});
var x = 0;
var y = 0;
var noOfEnemies = 200;
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 = (0.5 + Math.random() * 50);
enemyArmada.push(enemy);
layer.add(enemy);
}
}
var checkCollide = function() {
var position = stage.getPointerPosition();
if(position == null)
position = player.position();
if(position == null)
position = {x:0,y:0};
var collided = stage.getIntersection(position);
console.log(position);
if (typeof collided !== 'Kinetic.Shape') {
console.log("not shape");
}
else {
console.log("BOOOM!!!");
}
};
var anim = new Kinetic.Animation(function(frame) {
checkCollide();
for (var i = 0; i < noOfEnemies; i++) {
var e = enemyArmada[i];
e.position({
x: e.position().x - e.speedX * (frame.timeDiff / 400),
y: e.position().y + e.speedY * (frame.timeDiff / 400)
});
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();
I need the collision to be detected. The function i have written here is checkCollide and its called within the kinetic.Animation function.
Can anyone help me out with this??
(If you don't know the solution,please do like the post,i need the solution badly)

The source of the problem
getIntersection(point) means "is any object at this point".
Since the point you're using is the player's position, getIntersection will always return true because player is always at its own position !
One solution
Put your player on one layer and all enemies on a separate layer.
That way you can hit test the enemy layer without the interference of the player object.
Code and a Demo: http://jsfiddle.net/m1erickson/JCfW8/
<!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-v5.0.1.min.js"></script>
<style>
body{padding:20px;}
#container{
border:solid 1px #ccc;
margin-top: 10px;
width:350px;
height:350px;
}
</style>
<script>
$(function(){
var stage = new Kinetic.Stage({
container: 'container',
width: 350,
height: 350
});
var enemyLayer = new Kinetic.Layer();
stage.add(enemyLayer);
var playerLayer = new Kinetic.Layer();
stage.add(playerLayer);
var player = new Kinetic.Circle({
x:100,
y:100,
radius: 10,
fill: 'green',
draggable: true
});
player.on("dragmove",function(){
if(enemyLayer.getIntersection(player.position())){
this.fill("red");
playerLayer.draw();
}
});
playerLayer.add(player);
playerLayer.draw();
var enemy = new Kinetic.Circle({
x:200,
y:100,
radius: 20,
fill: 'blue',
draggable: true
});
enemyLayer.add(enemy);
enemyLayer.draw();
}); // end $(function(){});
</script>
</head>
<body>
<h4>Drag the green player<br>Player will turn red if it collides<br>with the blue enemy</h4>
<div id="container"></div>
</body>
</html>
Another solution
Mathematically test the player against every enemy:
Warning: untested code--some tweaking might be required
function playerEnemyCollide(){
var playerX=player.x();
var playerY=player.y();
var playerRadius=player.radius();
for(var i=0;i<enemyArmada.length;i++){
var e=enemyArmada[i];
if(circlesColliding(playerX,playerY,playerRadius,e.x,e.y,e.radius)){
return(true);
}
}
return(false);
}
function circlesColliding(cx1,cy1,radius1,cx2,cy2,radius2){
var dx=cx2-cx1;
var dy=cy2-cy1;
return(dx*dx+dy*dy<(radius1*2+radius2*2);
}

Anchor points should only visible when mouse goes over them

The code below creates a scalable and draggable triangle with anchor points at its vertices. i want that the anchor points should only visible when mouse goes over them??
and also, how collision detection can be implemented to avoid drawing of other spaces inside the triangle?
<html>
<head>
<script src="http://www.html5canvastutorials.com/libraries/kinetic-v3.10.0.js"></script>
<script type="text/javascript">
// the circle anchor points
function buildAnchor(layer, x, y, name) {
var anchor = new Kinetic.Circle({
x: x,
y: y,
radius: 6,
stroke: "#666",
fill: "#ddd",
strokeWidth: 2,
draggable: true,
name : name
});
// add hover styling
anchor.on("mouseover", function() {
document.body.style.cursor = "pointer";
this.setStrokeWidth(4);
layer.draw();
});
anchor.on("mouseout", function() {
document.body.style.cursor = "default";
this.setStrokeWidth(2);
layer.draw();
});
layer.add(anchor);
return anchor;
}
function buildTriangle(layer, points, name) {
var triangle = new Kinetic.Polygon({
stroke : "red",
strokeWidth : 4,
name : name,
draggable : true
});
triangle.a = buildAnchor(layer, points[0], points[1], "anchor");
triangle.b = buildAnchor(layer, points[2], points[3], "anchor");
triangle.c = buildAnchor(layer, points[4], points[5], "anchor");
triangle.was = { x : 0, y : 0 };
layer.add(triangle);
return triangle;
}
function drawTriangle() {
var triangle = this.get(".triangle")[0];
if ( !triangle.isDragging() ) {
triangle.setPoints([ triangle.a.attrs.x - triangle.was.x,
triangle.a.attrs.y - triangle.was.y,
triangle.b.attrs.x - triangle.was.x,
triangle.b.attrs.y - triangle.was.y,
triangle.c.attrs.x - triangle.was.x,
triangle.c.attrs.y - triangle.was.y ]);
} else {
var anchors = this.get(".anchor");
for ( var i = 0; i < anchors.length; i ++ ) {
anchors[i].setX(anchors[i].getX() + (triangle.getX() - triangle.was.x));
anchors[i].setY(anchors[i].getY() + (triangle.getY() - triangle.was.y));
}
triangle.was.x = triangle.getX();
triangle.was.y = triangle.getY();
}
}
window.onload = function() {
var stage = new Kinetic.Stage({
container: "container",
height: 200
});
var layer = new Kinetic.Layer({
drawFunc : drawTriangle
});
var triangle = buildTriangle(layer, [60, 100, 90, 100, 90, 140], "triangle");
triangle.moveToBottom();
// add the layer to the stage
stage.add(layer);
}
</script>
<style>
#container {
border: 1px solid black;
}
</style>
</head>
<body onmousedown="return false;">
<div id="container"></div>
</body>
</html>
jsFiddle: http://jsfiddle.net/Y9AtR/

I like #Tomalak's solution, here is mine:
http://jsfiddle.net/Y9AtR/2/
triangle.on('mouseover', function(){
triangle.a.show();
triangle.b.show();
triangle.c.show();
layer.draw();
});
triangle.on('mouseout', function(){
//if( not near triangle ) // add some logic so that they don't disappear right away, maybe use distance formula?
triangle.a.hide();
triangle.b.hide();
triangle.c.hide();
layer.draw();
})