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.
Related
I'm creating a shape with certain width and height (this shape is a clipping rect) inside canvas. Then inside this shape I'm loading an object which can be moved and rotated.
I wrote a custom function for get center point inside this shape, and it works good if object are not rotated.
If I rotate this object over 90deg and click "center" button - the object is moved up outside the clipping rect.
I cannot use a native FabricJs "centerV" function, because I would like that object will be centered inside clipping rect - not the canvas container, so that is why I made a variable "objectVerticalCenter".
My code is presented here:
var canvas = new fabric.Canvas('canvas', {
'selection': false
});
var clippingRect = new fabric.Rect({
left: 170,
top: 90,
width: 185,
height: 400,
fill: 'transparent',
stroke: 1,
opacity: 1,
hasBorders: false,
hasControls: false,
hasRotatingPoint: false,
selectable: false,
preserveObjectStacking: true,
objectCaching: false
});
var retinaScalling = canvas.getRetinaScaling();
var pol = new fabric.Polygon([{
x: 200,
y: 0
}, {
x: 250,
y: 50
}, {
x: 250,
y: 100
}, {
x: 150,
y: 100
}, {
x: 150,
y: 50
}], {
left: 250,
top: 150,
angle: 0,
fill: 'green'
});
pol.scaleX = 0.5;
pol.scaleY = 0.5;
pol.set('id', 'shape');
pol.scaleToWidth(clippingRect.getWidth());
pol.setCoords();
pol.clipTo = function(ctx) {
ctx.save();
ctx.setTransform(retinaScalling, 0, 0, retinaScalling, 0, 0);
clippingRect.render(ctx);
ctx.restore();
};
canvas.centerObjectH(pol);
canvas.add(pol);
canvas.renderAll();
canvas.setActiveObject(pol);
canvas.add(pol);
canvas.renderAll();
document.getElementById('rotate').onclick = function() {
var activeObject = canvas.getActiveObject();
activeObject.setAngle(200);
activeObject.setCoords();
canvas.renderAll();
};
document.getElementById('center').onclick = function() {
var activeObject = canvas.getActiveObject();
var rectHeight = activeObject.getBoundingRectHeight();
var objectVerticalCenter = (clippingRect.getHeight() / 2) - (rectHeight / 2) + clippingRect.top;
activeObject.set('top', objectVerticalCenter);
activeObject.setCoords();
canvas.renderAll();
};
<script src="https://cdnjs.cloudflare.com/ajax/libs/fabric.js/1.7.21/fabric.min.js"></script>
<button id="rotate">Rotate</button>
<button id="center">Center</button>
<canvas id="canvas" width="530" height="600"></canvas>
JSFiddle
To reproduce my problem you have to, click "rotate", then "center" button and you will see that shape is moved up outside the clipping rect.
If object is not rotated centering works fine.
Is there any way to fix my centering function or way to use "centerV" function inside the clipping rect?
Regards
If you want to center an object inside another, the safest thing to do is:
get the center point of the container
set the center point of the object in that point
in code this could equal to:
var clipCenter = clippingRect.getCenterPoint();
activeObject.setPositionByOrigin(clipCenter,'center','center');
var canvas = new fabric.Canvas('canvas', {
'selection': false
});
var clippingRect = new fabric.Rect({
left: 170,
top: 90,
width: 185,
height: 400,
fill: 'transparent',
stroke: 1,
opacity: 1,
hasBorders: false,
hasControls: false,
hasRotatingPoint: false,
selectable: false,
preserveObjectStacking: true,
objectCaching: false
});
var retinaScalling = canvas.getRetinaScaling();
var pol = new fabric.Polygon([{
x: 200,
y: 0
}, {
x: 250,
y: 50
}, {
x: 250,
y: 100
}, {
x: 150,
y: 100
}, {
x: 150,
y: 50
}], {
left: 250,
top: 150,
angle: 0,
fill: 'green'
});
pol.scaleX = 0.5;
pol.scaleY = 0.5;
pol.set('id', 'shape');
pol.scaleToWidth(clippingRect.getWidth());
pol.setCoords();
pol.clipTo = function(ctx) {
ctx.save();
ctx.setTransform(retinaScalling, 0, 0, retinaScalling, 0, 0);
clippingRect.render(ctx);
ctx.restore();
};
canvas.centerObjectH(pol);
canvas.setActiveObject(pol);
canvas.add(pol);
canvas.renderAll();
document.getElementById('rotate').onclick = function() {
var activeObject = canvas.getActiveObject();
activeObject.setAngle(200);
activeObject.setCoords();
canvas.renderAll();
};
document.getElementById('center').onclick = function() {
var activeObject = canvas.getActiveObject();
var clipCenter = clippingRect.getCenterPoint();
activeObject.setPositionByOrigin(clipCenter,'center','center');
canvas.renderAll();
};
<script src="https://cdnjs.cloudflare.com/ajax/libs/fabric.js/1.7.21/fabric.min.js"></script>
<button id="rotate">Rotate</button>
<button id="center">Center</button>
<canvas id="canvas" width="530" height="600"></canvas>
I need to build a frame for my image in Fabric JS. This frame should be built dynamically to fit any size of the image.
To do this I use two images:
http://i.imgur.com/3VqKv1O.png - image for side
http://i.imgur.com/w41HYN3.png - image for corner
I've developed an algorithm, which does it and it works! That's great.
But I have a problem with the positioning of pieces of the frame.
As you can see in my example, there is strange space between pieces and they placed not on the same level by Y axis. I'm very surprised because these pieces have the same height and they have correct values for left and top.
Anybody knows what can be a reason of this problem?
Thanks in advance
JS Fiddle https://jsfiddle.net/Eugene_Ilyin/gzjxhLtm/9/
var sideObj = new fabric.Rect(),
frameSideTopImage = new fabric.Image(new Image(), {type: 'image'}),
frameCornerTLImage = new fabric.Image(new Image(), {type: 'image'}),
imageSize = 172,// Size of the image (width = height).
leftOffset = 100,
topOffset = 100;
// Load image for corner.
fabric.util.loadImage('http://i.imgur.com/w41HYN3.png', function (img) {
// Set image and options for top left corner.
frameCornerTLImage.setElement(img);
frameCornerTLImage.setOptions({
strokeWidth: 0,
left: leftOffset,
top: topOffset
});
// Load image for side.
fabric.util.loadImage('http://i.imgur.com/3VqKv1O.png', function (img) {
frameSideTopImage.setElement(img);
// Create canvas for pattern.
var canvasForFill = new fabric.StaticCanvas(fabric.util.createCanvasElement(), {enableRetinaScaling: false});
canvasForFill.add(frameSideTopImage);
// Configure top side for the frame.
sideObj.setOptions({
strokeWidth: 0,
objectCaching: false,
originX: 'left',
originY: 'top',
left: imageSize + 100,
top: 100,
width: 800,
height: imageSize,
fill: new fabric.Pattern({
source: function () {
canvasForFill.setDimensions({
width: imageSize,
height: imageSize
});
return canvasForFill.getElement();
},
repeat: 'repeat-x'
})
});
var canvas = new fabric.Canvas('c');
var frame = new fabric.Group([sideObj, frameCornerTLImage], {
strokeWidth: 0,
width: 800 * 3,
height: imageSize * 3,
scaleX: 1/3,
scaleY: 1/3,
}
);
canvas.add(frame);
canvas.renderAll();
});
});
<script src="https://cdnjs.cloudflare.com/ajax/libs/fabric.js/1.7.7/fabric.js"></script>
<body>
<canvas id="c" width="1000" height="1000"></canvas>
</body>
var sideObj = new fabric.Rect(),
frameSideTopImage = new fabric.Image(new Image(), {type: 'image'}),
frameCornerTLImage = new fabric.Image(new Image(), {type: 'image'}),
imageSize = 172,// Size of the image (width = height).
leftOffset = 100,
topOffset = 100;
// Load image for corner.
fabric.util.loadImage('http://i.imgur.com/w41HYN3.png', function (img) {
// Set image and options for top left corner.
frameCornerTLImage.setElement(img);
frameCornerTLImage.setOptions({
left: leftOffset,
top: topOffset
});
// Load image for side.
fabric.util.loadImage('http://i.imgur.com/3VqKv1O.png', function (img) {
frameSideTopImage.setElement(img);
// Create canvas for pattern.
var canvasForFill = new fabric.StaticCanvas(fabric.util.createCanvasElement(), {enableRetinaScaling: false});
canvasForFill.add(frameSideTopImage);
// Configure top side for the frame.
sideObj.setOptions({
objectCaching: false,
originX: 'left',
originY: 'top',
left: imageSize + 100,
top: 100,
width: 800,
strokeWidth:0,
height: imageSize,
fill: new fabric.Pattern({
source: function () {
canvasForFill.setDimensions({
width: imageSize,
height: imageSize
});
return canvasForFill.getElement();
},
repeat: 'repeat-x'
})
});
var canvas = new fabric.Canvas('c');
canvas.add(sideObj);
canvas.add(frameCornerTLImage);
canvas.renderAll();
});
});
<script src="https://cdnjs.cloudflare.com/ajax/libs/fabric.js/1.7.7/fabric.js"></script>
<body>
<canvas id="c" width="1000" height="1000"></canvas>
</body>
set strokeWidth:0 , strokeWidth is by default 1, so it creates a border of width 1 .
So I want to save the canvas based on scale 1 and I want to include all existing/visible objects.
So right now, my canvas is 600x400 and if I were to save it, it would only save what's inside that 600x400, and it respects zoom level (a higher zoom will see less things, a lower zoom will see more things but smaller).
I've gotten around this by running this code:
let zoom = this.canvas.getZoom();
this.canvas.setZoom(1);
let url = this.canvas.toDataURL({width: 1000, height: 700, multiplier: 1});
this.canvas.setZoom(zoom);
window.open(
url,
'_blank' // <- This is what makes it open in a new window.
);
What this does is save the image as 1000x700, so stuff that were past 600px but under 1000 still gets saved.
However, this is hard coded. So I was wondering if there was an existing function or a clean/simple way to detect where all the objects are in and returns the full size (width and height).
fiddle: http://jsfiddle.net/1pxceaLj/3/
Update 1:
var gr = new this.fabric.Group([], {
left: 0,
top: 0
});
this.canvas.forEachObject( (o) => {
gr.add(o);
});
this.canvas.add(gr);
this.canvas.renderAll();
console.log(gr.height, gr.width); // 0 0
Solution
Using group was the best idea. Best example: http://jsfiddle.net/softvar/mRA8Z/
function selectAllCanvasObjects(){
var objs = canvas.getObjects().map(function(o) {
return o.set('active', true);
});
var group = new fabric.Group(objs, {
originX: 'center',
originY: 'center'
});
canvas._activeObject = null;
canvas.setActiveGroup(group.setCoords()).renderAll();
console.log(canvas.getActiveGroup().height);
}
One possibility would be to create a kind of Container using a fabricjs group and adding all created objects to this container.
I updated your fiddle here: http://jsfiddle.net/1pxceaLj/4/
Thus, you could just use group.width and group.height, perhaps adding a little offset or minimum values, and there you are having dynamical value to pass into toDataUrl even when having a smaller canvas.
code:
var canvas = new fabric.Canvas('c');
var shadow = {
color: 'rgba(0,0,0,0.6)',
blur: 20,
offsetX: 10,
offsetY: 10,
opacity: 0.6,
fillShadow: true,
strokeShadow: true
}
var rect = new fabric.Rect({
left: 100,
top: 100,
fill: "#FF0000",
stroke: "#000",
width: 100,
height: 100,
strokeWidth: 10,
opacity: .8
});
var rect2 = new fabric.Rect({
left: 800,
top: 100,
fill: "#FF0000",
stroke: "#000",
width: 100,
height: 100,
strokeWidth: 10,
opacity: .8
});
rect.setShadow(shadow);
//canvas.add(rect);
//canvas.add(rect2);
var gr = new fabric.Group([ rect, rect2 ], {
left: 0,
top: 0
});
canvas.add(gr);
function save()
{
alert(gr.width);
alert(gr.height);
let zoom = canvas.getZoom();
var minheight = 700;
canvas.setZoom(1);
let url = this.canvas.toDataURL({width: gr.width, height: gr.height > minheight ? gr.height : minheight, multiplier: 1});
canvas.setZoom(zoom);
window.open(
url,
'_blank'
);
}
I am working at a project with fabric js. I tried to minimize my problem, so I'm hoping that the code isn't too messed up.
I am creating some Objects which are linked with each other:
A Line, which contains a Start and an Endpoint
A Circle, which is StartPoint of 1 line and Endpoint of another line
with this combination i can create different shapes(like a polygon) and modify my move-functions for them too.
When a Circle is dragged, the related Lines are scaling and moving too. (in my code you can move the lines too and the shape is resized after that, but i didnt put it into this example, bc this short extract should be enough to show what my problem is.)
I got a little example in jsfiddle: https://jsfiddle.net/bxgox7cr/
When you look at the ends of the lines, you can clearly see a cut, so the eye soon recognize, that this is not a connected shape but rather some lines which are close to each other. Is there a way to modify the look of the lines, that the shape looks "closed"?
Here is my code, i tried to put some comments, that it is easy to read:
var canvas = new fabric.Canvas('canvas');
fabric.Object.prototype.originX = fabric.Object.prototype.originY = 'center';
document.getElementById("canvas").tabIndex = 1000;
/** ------------creating a Line Object, which contains a start and an endpoint ------------**/
fabric.LineWithPoints = fabric.util.createClass(fabric.Line, {
initialize: function(points, options) {
options || (options = {});
this.callSuper('initialize', points, options);
options &&
this.set('type', options.type),
this.set('name', options.name),
this.set('start_point', options.start_point),
this.set('end_point', options.end_point),
this.set('current_x', options.current_x),
this.set('current_y', options.current_y)
},
setStartPointAndEndPoint: function(start_point, end_point) {
this.set({
start_point: start_point,
end_point: end_point
});
},
setValues: function(new_x1, new_y1, new_x2, new_y2) {
// console.log(this);
this.set({
x1: new_x1,
x2: new_x2,
y1: new_y1,
y2: new_y2
});
this.setCoords();
}
});
/**--- modifie the circle element, adding new functions for the movement of the object-------*/
fabric.LinePoint = fabric.util.createClass(fabric.Circle, {
initialize: function(options) {
options || (options = {});
this.callSuper('initialize', options);
options &&
this.set('subtype', 'line_point'),
this.set('x', this.left),
this.set('y', this.top)
},
setPointCoordinates: function(new_left, new_top) {
this.set({
x: new_left,
y: new_top,
left: new_left,
top: new_top
});
this.setCoords();
},
move: function(new_left, new_top) {
var wall_1 = this.line1;
var wall_2 = this.line2;
this.setPointCoordinates(new_left, new_top);
wall_1.setValues(wall_1.x1, wall_1.y1, this.getLeft(), this.getTop());
wall_2.setValues(this.getLeft(), this.getTop(), wall_2.x2, wall_2.y2);
canvas.renderAll();
},
});
/**------------------- Moving Function------------------------------------------------- */
canvas.on('object:moving', function(event) {
var object = event.target;
if (object.subtype == "line_point") {
object.move(object.getLeft(), object.getTop());
}
});
/**------------------------------ create functions for the objects -----------------------*/
function newCircleObject(left, top, wall_1, wall_2) {
var circle = new fabric.LinePoint({
left: left,
top: top,
strokeWidth: 2,
radius: 15,
fill: 'grey',
stroke: 'black',
opacity: 0.1,
perPixelTargetFind: true,
subtype: 'line_point',
includeDefaultValues: false
});
circle.hasControls = false;
circle.hasBorders = false;
circle.line1 = wall_1;
circle.line2 = wall_2;
return circle;
}
function newWallObject(coords) {
var wall = new fabric.LineWithPoints(coords, {
stroke: 'black',
strokeWidth: 6,
lockScalingX: true,
lockScalingY: true,
perPixelTargetFind: true,
subtype: 'line',
type: 'line',
padding: 10,
includeDefaultValues: false
});
wall.hasControls = false;
wall.hasBorders = false;
return wall;
}
/**------------------------------ adding the shapes--------------------------------*/
var wall_1 = newWallObject([100, 100, 100, 500]);
var wall_2 = newWallObject([100, 500, 500, 500]);
var wall_3 = newWallObject([500, 500, 500, 100]);
var wall_4 = newWallObject([500, 100, 100, 100]);
var end_point_1 = newCircleObject(wall_1.x1, wall_1.y1, wall_4, wall_1);
var end_point_2 = newCircleObject(wall_2.x1, wall_2.y1, wall_1, wall_2);
var end_point_3 = newCircleObject(wall_3.x1, wall_3.y1, wall_2, wall_3);
var end_point_4 = newCircleObject(wall_4.x1, wall_4.y1, wall_3, wall_4);
wall_1.setStartPointAndEndPoint(end_point_1.name, end_point_2.name);
wall_2.setStartPointAndEndPoint(end_point_2.name, end_point_3.name);
wall_3.setStartPointAndEndPoint(end_point_3.name, end_point_4.name);
wall_4.setStartPointAndEndPoint(end_point_4.name, end_point_1.name);
canvas.add(wall_1, wall_2, wall_3, wall_4, end_point_1, end_point_2, end_point_3, end_point_4);
Add strokeLineCap: 'round',:
function newWallObject(coords) {
var wall = new fabric.LineWithPoints(coords, {
stroke: 'black',
strokeWidth: 6,
lockScalingX: true,
lockScalingY: true,
perPixelTargetFind: true,
strokeLineCap: 'round',
subtype: 'line',
type: 'line',
padding: 10,
includeDefaultValues: false
});
wall.hasControls = false;
wall.hasBorders = false;
return wall;
}
I looked up: http://fabricjs.com/docs/fabric.Object.html#strokeLineCap
I have checked all the answers to clone existing canvas to another one. But I could not get it done.
Please check my current progress.
http://jsfiddle.net/37n8rtdf/5/
First canvas will be clipped to that square you see initially and content of that canvas will be added in another canvas. But I don't know it always throw TYPE_MISMATCH_ERR: DOM Exception 171 in chrome. I am using fabricjs to clipping content.
Bit of help is appreciated.
Thanks
Here is code of my script:
HTML
<textarea id="line_1"></textarea>
<input type="button" id="render" value="Apply" />
<input type="button" id="preview" value="preview" />
<canvas id="c" width="500" height="500" style="border:1px solid #ccc"></canvas>
<canvas id="c_new" width="500" height="500" style="border:1px solid red; margin: 30px;"></canvas>
`
Javascript
var canvas = this.__canvas = new fabric.Canvas('c');
var canvas_new = this.__canvas = new fabric.Canvas('c_new');
var product_image = 'http://www.jail.se/hardware/digital_camera/canon/ixus_800is-powershot_sd700/images/sample_photos/sample3.jpg';
//var ctx = canvas.getContext("2d");
var polygon;
$(document).ready(function(){
fabric.Object.prototype.transparentCorners = false;
//canvas.setDimensions({width:w,height:h});
var center = canvas.getCenter();
canvas.setBackgroundImage(product_image,
canvas.renderAll.bind(canvas), {
scaleX:1,
scaleY:1,
top: center.top,
left: center.left,
originX: 'center',
originY: 'center',
backgroundImageOpacity: 0,
backgroundImageStretch: false
});
canvas_new.setBackgroundImage(product_image,
canvas_new.renderAll.bind(canvas_new), {
scaleX:1,
scaleY:1,
top: center.top,
left: center.left,
originX: 'center',
originY: 'center'
});
polygon = new fabric.Polygon([
{x: 0, y: 0},
{x: 220, y: 0},
{x: 220, y: 180},
{x: 0, y: 180} ], {
left: 140,
top: 150,
angle: 0,
fill: 'transparent',
stroke: '#000', strokeWidth: 1,
lockMovementX: true,
lockMovementY: true,
lockScalingX: true,
lockScalingY: true,
lockRotation: true,
hasControls: false,
hasBorders: false,
hoverCursor: 'default',
overflow: 'hidden'
});
canvas.add(polygon);
$('#render').click(function(){ return render(); });
$('#preview').click(function(){ return rasterize(); });
});
function render()
{
var text_val = $('#line_1').val();
var comicSansText = new fabric.Text(text_val, {
fontWeight: 'normal'
});
canvas.add(comicSansText.set({ left: 200, top: 150, angle: 0 }));
}
function rasterize()
{
var shape = canvas.item(0);
polygon.strokeWidth=0;
canvas.renderAll();
//canvas.remove(shape);
canvas.clipTo = function(ctx) {
shape.render(ctx);
};
var ctx2 = canvas_new.getContext('2d');
ctx2.drawImage(canvas, 0, 0);
}
`
#WinterMute is right, you are trying to draw the Fabric object instead of the canvas element.
You fabric object seems to have two canvases embedded (lowerCanvasEl and upperCanvasEl).
So you can modify just a little bit your code to make it look like :
function rasterize() {
var shape = canvas.item(0);
polygon.strokeWidth = 0;
canvas.renderAll();
canvas.clipTo = function(ctx) {
shape.render(ctx);
};
var ctx2 = canvas_new.getContext('2d');
ctx2.drawImage(canvas.lowerCanvasEl, 0, 0);
ctx2.drawImage(canvas.upperCanvasEl, 0, 0);
}
Updated fiddle