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How to limit this move function on zoomed image without exceed the image, I make limits at 0x,0y and I need the same at x,y max limits

How can I limit this move function on zoomed image without exceed the image, I make limits at 0x,0y and I need the same at x,y max limits
var scale = 1,
panning = false,
pointX = 0,
pointY = 0,
start = { x: 0, y: 0 },
zoom = document.getElementById("zoom");
function setTransform() {
zoom.style.transform = "translate(" + pointX + "px, " + pointY + "px) scale(" + scale + ")";
}
function centerMap() {
if(pointY>=0){
pointY = 0;
}
if(pointX>=0){
pointX = 0;
}
var offX= document.getElementById("img").offsetWidth
var offY = document.getElementById("img").offsetHeight
}
zoom.onmousedown = function (e) {
e.preventDefault();
start = { x: e.clientX - pointX, y: e.clientY - pointY };
panning = true;
}
zoom.onmouseup = function (e) {
panning = false;
}
zoom.onmousemove = function (e) {
console.log(e);
e.preventDefault();
if (!panning) {
return;
}
pointX = (e.clientX - start.x);
pointY = (e.clientY - start.y);
centerMap();
console.log(pointX,pointY, e.clientY,scale,);
setTransform();
}
zoom.onwheel = function (e) {
e.preventDefault();
var xs = (e.clientX - pointX) / scale,
ys = (e.clientY - pointY) / scale,
delta = (e.wheelDelta ? e.wheelDelta : -e.deltaY);
(delta > 0) ? (scale += 0.2) : (scale -= 0.2);
if(scale<1){
scale=1;
}
pointX = e.clientX - xs * scale;
pointY = e.clientY - ys * scale;
centerMap();
setTransform();
}
This is the JS code.
In function centerMap I move the image auto to not seeing the white background, but in right and bottom I didn't find the solve, I tried to make calculations with image coords, but I need a resolvation in any resolutions
Ex: https://shorturl.at/jlpw2

FabricJS: pan canvas while drawing

Here is the link to the codepen: https://codepen.io/Jsbbvk/pen/RwGBwOO
const edgePadding = 80;
const panSpeed = 5;
const expandCanvasEdge = (x, y) => {
let pan = {
x: 0,
y: 0,
};
const width = canvas.getWidth(),
height = canvas.getHeight();
if (x <= edgePadding) {
//left
const speedRatio = 1 - Math.max(0, x) / edgePadding;
pan.x = panSpeed * speedRatio;
} else if (x >= width - edgePadding) {
//right
const speedRatio =
1 - (width - Math.min(width, x)) / edgePadding;
pan.x = -panSpeed * speedRatio;
}
if (y <= edgePadding) {
//top
const speedRatio = 1 - Math.max(0, y) / edgePadding;
pan.y = panSpeed * speedRatio;
} else if (y >= height - edgePadding) {
//bottom
const speedRatio =
1 - (height - Math.min(height, y)) / edgePadding;
pan.y = -panSpeed * speedRatio;
}
if (pan.x || pan.y) {
canvas.relativePan(new fabric.Point(pan.x, pan.y));
}
}
canvas.on('mouse:move', function(opt) {
if (this.isMouseDown && this.isDrawingMode) {
let {x, y} = canvas.getPointer(opt.e, true);
expandCanvasEdge(x, y);
}
if (!this.isDrawingMode && this.isDragging) {
//panning
var e = opt.e;
var vpt = this.viewportTransform;
vpt[4] += e.clientX - this.lastPosX;
vpt[5] += e.clientY - this.lastPosY;
this.requestRenderAll();
this.lastPosX = e.clientX;
this.lastPosY = e.clientY;
}
});
In the demo, when you draw close to the edge of the canvas, the canvas should pan to allow more drawing space.
However, while the panning is happening, the drawing (path) is static on the canvas; it doesn't stretch as the canvas pans.
Is there a way to fix this issue?

I did some deep research for you and found a few examples.
You can overcome this situation by using the relativePan function.
One of the examples I have found:
function startPan(event) {
if (event.button != 2) {
return;
}
var x0 = event.screenX,
y0 = event.screenY;
function continuePan(event) {
var x = event.screenX,
y = event.screenY;
fc.relativePan({ x: x - x0, y: y - y0 });
x0 = x;
y0 = y;
}
function stopPan(event) {
$(window).off('mousemove', continuePan);
$(window).off('mouseup', stopPan);
};
$(window).mousemove(continuePan);
$(window).mouseup(stopPan);
$(window).contextmenu(cancelMenu);
};
function cancelMenu() {
$(window).off('contextmenu', cancelMenu);
return false;
}
$(canvasWrapper).mousedown(startPan);
You can determine a roadmap by examining the resources and demos here.
JSFiddle demo https://jsfiddle.net/tornado1979/up48rxLs/

How do you zoom into a specific point (no canvas)?

The goal is simple, using a mousewheel, zoom into a specific point (where the mouse is). This means after zooming the mouse will be in the same roughly the same spot of the picture.
(Purely illustrative, I don't care if you use dolphins, ducks or madonna for the image)
I do not wish to use canvas, and so far I've tried something like this:
HTML
<img src="whatever">
JS
function zoom(e){
var deltaScale = deltaScale || -e.deltaY / 1000;
var newScale = scale + deltaScale;
var newWidth = img.naturalWidth * newScale;
var newHeight = img.naturalHeight * newScale;
var x = e.pageX;
var y = e.pageY;
var newX = x * newWidth / img.width;
var newY = y * newHeight / img.height;
var deltaX = newX - x;
var deltaY = newY - y;
setScale(newScale);
setPosDelta(-deltaX,-deltaY);
}
function setPosDelta(dX, dY) {
var imgPos = getPosition();
setPosition(imgPos.x + dX, imgPos.y + dY);
}
function getPosition() {
var x = parseFloat(img.style.left);
var y = parseFloat(img.style.top);
return {
x: x,
y: y
}
}
function setScale(n) {
scale = n;
img.width = img.naturalWidth * n;
img.height = img.naturalHeight * n;
}
What this attempts to do is calculate the x,y coordinates of the dolphin's eye before and after the zoom, and after calculating the distance between those two points, substracts it from the left,top position in order to correct the zoom displacement, with no particular success.
The zoom occurs naturally extending the image to the right and to the bottom, so the correction tries to pull back to the left and to the top in order to keep the mouse on that damn dolphin eye! But it definitely doesn't.
Tell me, what's wrong with the code/math? I feel this question is not too broad, considering I couldn't find any solutions besides the canvas one.
Thanks!
[EDIT] IMPORTANT
CSS transform order matters, if you follow the selected answer, make sure you order the transition first, and then the scale. CSS transforms are executed backwards (right to left) so the scaling would be processed first, and then the translation.

Here is an implementation of zooming to a point. The code uses the CSS 2D transform and includes panning the image on a click and drag. This is easy because of no change in scale.
The trick when zooming is to normalize the offset amount using the current scale (in other words: divide it by the current scale) first, then apply the new scale to that normalized offset. This keeps the cursor exactly where it is independent of scale.
var scale = 1,
panning = false,
xoff = 0,
yoff = 0,
start = {x: 0, y: 0},
doc = document.getElementById("document");
function setTransform() {
doc.style.transform = "translate(" + xoff + "px, " + yoff + "px) scale(" + scale + ")";
}
doc.onmousedown = function(e) {
e.preventDefault();
start = {x: e.clientX - xoff, y: e.clientY - yoff};
panning = true;
}
doc.onmouseup = function(e) {
panning = false;
}
doc.onmousemove = function(e) {
e.preventDefault();
if (!panning) {
return;
}
xoff = (e.clientX - start.x);
yoff = (e.clientY - start.y);
setTransform();
}
doc.onwheel = function(e) {
e.preventDefault();
// take the scale into account with the offset
var xs = (e.clientX - xoff) / scale,
ys = (e.clientY - yoff) / scale,
delta = (e.wheelDelta ? e.wheelDelta : -e.deltaY);
// get scroll direction & set zoom level
(delta > 0) ? (scale *= 1.2) : (scale /= 1.2);
// reverse the offset amount with the new scale
xoff = e.clientX - xs * scale;
yoff = e.clientY - ys * scale;
setTransform();
}
html, body {
margin: 0;
padding: 0;
width: 100%;
height: 100%;
overflow: hidden;
}
#document {
width: 100%;
height: 100%;
transform-origin: 0px 0px;
transform: scale(1) translate(0px, 0px);
}
<div id="document">
<img style="width: 100%"
src="https://i.imgur.com/fHyEMsl.jpg"
crossOrigin="" />
</div>

This is an implementation that is closer to your original idea using top and left offsets and modifying the width attribute of the image instead of using the css transform in my other answer.
var scale = 1.0,
img = document.getElementById("image"),
deltaX = 0,
deltaY = 0;
// set the initial scale once the image is loaded
img.onload = function() {
scale = image.offsetWidth / image.naturalWidth;
}
img.onwheel = function(e) {
e.preventDefault();
// first, remove the scale so we have the native offset
var xoff = (e.clientX - deltaX) / scale,
yoff = (e.clientY - deltaY) / scale,
delta = (e.wheelDelta ? e.wheelDelta : -e.deltaY);
// get scroll direction & set zoom level
(delta > 0) ? (scale *= 1.05) : (scale /= 1.05);
// limit the smallest size so the image does not disappear
if (img.naturalWidth * scale < 16) {
scale = 16 / img.naturalWidth;
}
// apply the new scale to the native offset
deltaX = e.clientX - xoff * scale;
deltaY = e.clientY - yoff * scale;
// now modify the attributes of the image to reflect the changes
img.style.top = deltaY + "px";
img.style.left = deltaX + "px";
img.style.width = (img.naturalWidth * scale) + "px";
}
window.onresize = function(e) {
document.getElementById("wrapper").style.width = window.innerWidth + "px";
document.getElementById("wrapper").style.height = window.innerHeight + "px";
}
window.onload = function(e) {
document.getElementById("wrapper").style.width = window.innerWidth + "px";
document.getElementById("wrapper").style.height = window.innerHeight + "px";
}
html,
body {
height: 100%;
width: 100%;
margin: 0;
padding: 0;
overflow: hidden;
}
div {
overflow: hidden;
}
<div id="wrapper" style="position:relative;">
<img id="image" style="width:100%;position:absolute;top:0px;left:0px;"
src="https://i.imgur.com/fHyEMsl.jpg"
crossOrigin="" />
</div>

I liked the both posts from fmacdee. I factored the code he created out to be a reusable version that can be called on any image.
just call:
var imageScaler = new ImageScaler(document.getElementById("image"));
imageScaler.setup();
and include this code somewhere in your project:
var ImageScaler = function(img)
{
this.img = img;
this.scale = this.getImageScale();
this.panning = false;
this.start = {x: 0, y: 0};
this.delta = {x: 0, y: 0};
};
ImageScaler.prototype =
{
constructor: ImageScaler,
setup: function()
{
this.setupEvents();
},
setupEvents: function()
{
var img = this.img;
var callBack = this.onScale.bind(this);
var touchDown = this.touchDown.bind(this),
touhcMove = this.touchMove.bind(this),
touchUp = this.touchUp.bind(this);
img.onwheel = callBack;
img.onmousedown = touchDown;
img.onmousemove = touhcMove;
img.onmouseup = touchUp;
},
getImageScale: function()
{
var img = this.img;
return img.offsetWidth / img.naturalWidth;
},
getMouseDirection: function(e)
{
return (e.wheelDelta ? e.wheelDelta : -e.deltaY);
},
getOffset: function(e)
{
var scale = this.scale,
delta = this.delta;
// first, remove the scale so we have the native offset
return {
x: (e.clientX - delta.x) / scale,
y: (e.clientY - delta.y) / scale
};
},
scaleElement: function(x, y, scale)
{
var img = this.img;
img.style.top = y + "px";
img.style.left = x + "px";
img.style.width = (img.naturalWidth * scale) + "px";
},
minScale: 0.2,
updateScale: function(delta)
{
// get scroll direction & set zoom level
var scale = (delta > 0) ? (this.scale *= 1.05) : (this.scale /= 1.05);
// limit the smallest size so the image does not disappear
if (scale <= this.minScale)
{
this.scale = this.minScale;
}
return this.scale;
},
touchDown: function(e)
{
var delta = this.delta;
this.start = {x: e.clientX - delta.x, y: e.clientY - delta.y};
this.panning = true;
},
touchMove: function(e)
{
e.preventDefault();
if (this.panning === false)
{
return;
}
var delta = this.delta,
start = this.start;
delta.x = (e.clientX - start.x);
delta.y = (e.clientY - start.y);
console.log(delta, start)
this.scaleElement(delta.x, delta.y, this.scale);
},
touchUp: function(e)
{
this.panning = false;
},
onScale: function(e)
{
var offset = this.getOffset(e);
e.preventDefault();
// get scroll direction & set zoom level
var delta = this.getMouseDirection(e);
var scale = this.updateScale(delta);
// apply the new scale to the native offset
delta = this.delta;
delta.x = e.clientX - offset.x * scale;
delta.y = e.clientY - offset.y * scale;
this.scaleElement(delta.x, delta.y, scale);
}
};
I made a fiddle to view the results: http://jsfiddle.net/acqo5n8s/12/

Drag Bound with Konva.Layer

I am using KonvaJs in my project. I need to implement drag bound to Konva.Layer. My layer has so many other shapes and images. I need to restrict the movement of layer up to 50% of it's width and height. The way I have done in this plunkr. The problem arises when user zoom-in or zoom-out the layer using mouse wheel. After the zoom, I don't know why the drag bound is behaving differently. Seems like I am not able to do the Math correctly. I need to have the same behavior i.e. the way movement of layer is restricted when user does not perform zoom. This is what I am doing:
//... a helper object for zooming
var zoomHelper = {
stage: null,
scale: 1,
zoomFactor: 1.1,
origin: {
x: 0,
y: 0
},
zoom: function(event) {
event.preventDefault();
var delta;
if (navigator.userAgent.toLowerCase().indexOf('firefox') > -1) {
if (event.originalEvent.detail > 0) {
//scroll down
delta = 0.2;
} else {
//scroll up
delta = 0;
}
} else {
if (event.originalEvent.wheelDelta < 0) {
//scroll down
delta = 0.2;
} else {
//scroll up
delta = 0;
}
}
var evt = event.originalEvent,
mx = evt.clientX - zoomHelper.stage.getX(),
my = evt.clientY - zoomHelper.stage.getY(),
zoom = (zoomHelper.zoomFactor - delta),
newscale = zoomHelper.scale * zoom;
zoomHelper.origin.x = mx / zoomHelper.scale + zoomHelper.origin
.x - mx / newscale;
zoomHelper.origin.y = my / zoomHelper.scale + zoomHelper.origin
.y - my / newscale;
zoomHelper.stage.setOffset({
x: zoomHelper.origin.x,
y: zoomHelper.origin.y
});
zoomHelper.stage.setScale({
x: newscale,
y: newscale
});
zoomHelper.stage.draw();
zoomHelper.scale *= zoom;
preCalculation();
}
};
// Code goes here
var w = window.innerWidth;
var h = window.innerHeight;
var height, minX, minY, maxX, maxY;
var stage = new Konva.Stage({
container: 'container',
width: w,
height: h
});
zoomHelper.stage =stage;
var layer = new Konva.Layer({
draggable: true,
dragBoundFunc: function(pos) {
console.log('called');
var X = pos.x;
var Y = pos.y;
if (X < minX) {
X = minX;
}
if (X > maxX) {
X = maxX;
}
if (Y < minY) {
Y = minY;
}
if (Y > maxY) {
Y = maxY;
}
return ({
x: X,
y: Y
});
}
});
stage.add(layer);
function preCalculation(){
// pre-calc some bounds so dragBoundFunc has less calc's to do
height = layer.getHeight();
minX = stage.getX() - layer.getWidth() / 2;
maxX = stage.getX() + stage.getWidth() - layer.getWidth() / 2;
minY = stage.getY() - layer.getHeight() / 2;
maxY = stage.getY() + stage.getHeight() - layer.getHeight() / 2;
console.log(height, minX, minY, maxX, maxY);
}
preCalculation();
var img = new Image();
img.onload = function() {
var floorImage = new Konva.Image({
image: img,
width: w,
height: h
});
layer.add(floorImage);
layer.draw();
};
img.src = 'https://s.yimg.com/pw/images/coverphoto02_h.jpg.v3';
$(stage.container).on('mousewheel DOMMouseScroll', zoomHelper.zoom);

While using dragBoundFunc you have to return absolute position of layer. As you are changing attributes of top node (stage) it can be hard to maintain absolute position. So you can try to set bound function inside 'dragmove' event:
layer.on('dragmove', function() {
var x = Math.max(minX, Math.min(maxX, layer.x()));
var y = Math.max(minY, Math.min(maxY, layer.y()));
layer.x(x);
layer.y(y);
});
http://plnkr.co/edit/31MUmOjXBUVuaHVJsL3c?p=preview

Avoid cursor's default position on webpage being (0,0)

in the jsfiddle below im trying to get the yellow and red circles to initially appear in the center, as opposed to moving to the cursor's initial assumed position - which is (0,0) as the cursor is not yet in the actual screen of the page (if I'm guessing correctly).
http://jsfiddle.net/fhmkf/220/
Is there a way I can define the initial placement of the cursor - that is when calculating (window).mousemove(function(e){... - particularly the e.pageX and e.pageY?
The js looks like so:
var Circle = function(container, follower, r){
var center = {
x: $(container).width()/2 - r,
y: $(container).height()/2 - r
};
var distanceThreshold = $(container).width()/2 - r;
var mouseX = 0, mouseY = 0;
$(window).mousemove(function(e){
var d = {
x: e.pageX - center.x,
y: e.pageY - center.y
};
var distance = Math.sqrt(d.x*d.x + d.y*d.y);
if (distance < distanceThreshold) {
mouseX = e.pageX;
mouseY = e.pageY;
} else {
mouseX = d.x / distance * distanceThreshold + center.x;
mouseY = d.y / distance * distanceThreshold + center.y;
}
});
// cache the selector
var follower = $(follower);
var xp = 0, yp = 0;
var loop = setInterval(function(){
// change 12 to alter damping higher is slower
xp += (mouseX - xp) / 2;
yp += (mouseY - yp) / 2;
follower.css({left:xp, top:yp});
}, 30);
};
var c1 = new Circle(".container", "#follower", 15);
var c2 = new Circle(".container2", "#follower2", 25);