Javascript 缩放后Fabricjs画布重置
我有一个画布,我需要能够放大和缩小,也改变了图像/对象内几次 为此,我在第一次加载页面时设置画布,如下所示:Javascript 缩放后Fabricjs画布重置,javascript,fabricjs,Javascript,Fabricjs,我有一个画布,我需要能够放大和缩小,也改变了图像/对象内几次 为此,我在第一次加载页面时设置画布,如下所示: fabric.Object.prototype.hasBorders = false; fabric.Object.prototype.hasControls = false; canvas = new fabric.Canvas('my_canvas', {renderOnAddRemove: false, stateful: false}); canvas.defaultCurs
fabric.Object.prototype.hasBorders = false;
fabric.Object.prototype.hasControls = false;
canvas = new fabric.Canvas('my_canvas', {renderOnAddRemove: false, stateful: false});
canvas.defaultCursor = "pointer";
canvas.backgroundImageStretch = false;
canvas.selection = false;
canvas.clear();
var image = document.getElementById('my_image');
if (image != null) {
imageSrc = image.src;
if(imageSrc.length > 0){
fabric.Image.fromURL(imageSrc, function(img) {
img = scaleImage(canvas, img); //shrinks the image to fit the canvas
img.selectable = false;
canvas.centerObject(img);
canvas.setActiveObject(img);
canvas.add(img);
});
}
}
canvas.deactivateAll().renderAll();
canvas.clear();
canvas.remove(canvas.getActiveObject());
var image = document.getElementById('my_image');
if (image != null) {
imageSrc = image.src;
if(imageSrc.length > 0){
fabric.Image.fromURL(imageSrc, function(img) {
img = scaleImage(canvas, img); //shrinks the image to fit the canvas
img.selectable = false;
canvas.centerObject(img);
canvas.setActiveObject(img);
canvas.add(img);
});
}
}
然后,当我需要更改画布中的图像/对象或页面重新加载时,我会尝试如下方式重置画布:
fabric.Object.prototype.hasBorders = false;
fabric.Object.prototype.hasControls = false;
canvas = new fabric.Canvas('my_canvas', {renderOnAddRemove: false, stateful: false});
canvas.defaultCursor = "pointer";
canvas.backgroundImageStretch = false;
canvas.selection = false;
canvas.clear();
var image = document.getElementById('my_image');
if (image != null) {
imageSrc = image.src;
if(imageSrc.length > 0){
fabric.Image.fromURL(imageSrc, function(img) {
img = scaleImage(canvas, img); //shrinks the image to fit the canvas
img.selectable = false;
canvas.centerObject(img);
canvas.setActiveObject(img);
canvas.add(img);
});
}
}
canvas.deactivateAll().renderAll();
canvas.clear();
canvas.remove(canvas.getActiveObject());
var image = document.getElementById('my_image');
if (image != null) {
imageSrc = image.src;
if(imageSrc.length > 0){
fabric.Image.fromURL(imageSrc, function(img) {
img = scaleImage(canvas, img); //shrinks the image to fit the canvas
img.selectable = false;
canvas.centerObject(img);
canvas.setActiveObject(img);
canvas.add(img);
});
}
}
不确定这是否重要,但我更改图像的方式是更改“my_image”中的源并使用上述方法重置画布
在我使用canvas.zoomToPoint之前,这一切都很好。根据线程,在此之后,当我重置缩放或在画布缩放时用鼠标单击画布时,图像/对象开始改变位置,似乎在左上角方向的每次更改时都会跳跃,最终从视图中消失
重置缩放:
canvas.setZoom(1);
resetCanvas(); //(above method)
如何恢复图像/对象位置
我试着做了初始设置,而不是重置和缝合,以直观地工作,但实际上是增加了一个新的上层画布层在每个新的设置,所以这是没有好处的
有没有办法将画布重置为原始状态而不导致此行为,并且仍然能够正确放大/缩小 请参见下面的代码片段-我在这里也做了同样的操作-将对象放大,但如果有人点击它,请将对象分组 可以解决获取原始对象属性的问题,将组解组并创建它们的副本,然后重新附加-有点烦人,但这是我找到的唯一解决方案
<script id="main">
// canvas and office background
var mainGroup;
var canvas = this.__canvas = new fabric.Canvas('c');
fabric.Object.prototype.transparentCorners = false;
fabric.Object.prototype.originX = fabric.Object.prototype.originY = 'center';
createOnjects(canvas);
// events - zoom
$(canvas.wrapperEl).on('mousewheel', function(e) {
var target = canvas.findTarget(e);
var delta = e.originalEvent.wheelDelta / 5000;
if (target) {
target.scaleX += delta;
target.scaleY += delta;
// constrain
if (target.scaleX < 0.1) {
target.scaleX = 0.1;
target.scaleY = 0.1;
}
// constrain
if (target.scaleX > 10) {
target.scaleX = 10;
target.scaleY = 10;
}
target.setCoords();
canvas.renderAll();
return false;
}
});
// mouse down
canvas.on('mouse:up', function(options) {
if (options.target) {
var thisTarget = options.target;
var mousePos = canvas.getPointer(options.e);
if (thisTarget.isType('group')) {
// unGroup
console.log(mousePos);
var clone = thisTarget._objects.slice(0);
thisTarget._restoreObjectsState();
for (var i = 0; i < thisTarget._objects.length; i++) {
var o = thisTarget._objects[i];
if (o._element.alt == "officeFloor")
continue;
else {
if (mousePos.x >= o.originalLeft - o.currentWidth / 2 && mousePos.x <= o.originalLeft + o.currentWidth / 2
&& mousePos.y >= o.originalTop - o.currentHeight / 2 && mousePos.y <= o.originalTop + o.currentHeight / 2)
console.log(o._element.alt);
}
}
// remove all objects and re-render
canvas.remove(thisTarget);
canvas.clear().renderAll();
var group = new fabric.Group();
for (var i = 0; i < clone.length; i++) {
group.addWithUpdate(clone[i]);
}
canvas.add(group);
canvas.renderAll();
}
}
});
// functions
function createOnjects(canvas) {
// ToDo: jQuery.parseJSON() for config file (or web service)
fabric.Image.fromURL('pics/OfficeFloor.jpg', function(img) {
var back = img.set({ left: 100, top: 100 });
back._element.alt = "officeFloor";
back.hasControls = false;
fabric.Image.fromURL('pics/me.png', function(img) {
var me = img.set({ left: -420, top: 275 });
me._element.alt = "me";
console.log(me);
var group = new fabric.Group([ back, me], { left: 700, top: 400, hasControls: false });
canvas.clear().renderAll();
canvas.add(group);
// remove all objects and re-render
});
});
}
</script>
//画布和办公室背景
var mainGroup;
var canvas=this.\uu canvas=newfabric.canvas('c');
fabric.Object.prototype.transparentCorners=false;
fabric.Object.prototype.originX=fabric.Object.prototype.originY='center';
创建对象(画布);
//事件-缩放
$(canvas.wrapperEl).on('mousewheel',函数(e){
var target=canvas.findTarget(e);
var delta=e.originalEvent.wheelDelta/5000;
如果(目标){
target.scaleX+=delta;
target.scaleY+=delta;
//约束
如果(target.scaleX<0.1){
target.scaleX=0.1;
target.scaleY=0.1;
}
//约束
如果(target.scaleX>10){
target.scaleX=10;
target.scaleY=10;
}
target.setCoords();
canvas.renderAll();
返回false;
}
});
//鼠标落下
canvas.on('mouse:up',函数(选项){
if(options.target){
var thisTarget=options.target;
var mousePos=canvas.getPointer(options.e);
if(thisTarget.isType('group')){
//解组
控制台日志(鼠标点);
var clone=thisTarget.\u objects.slice(0);
此目标。_restoreObjectsState();
对于(变量i=0;i 如果(mousePos.x>=o.originalLeft-o.currentWidth/2&&mousePos.x=o.originalTop-o.currentHeight/2&&mousePos.y我最终解决了我遇到的问题
为了重置缩放,我没有仅使用canvas.setZoom(1)
将缩放设置为1,而是将canvas.zoomToPoint
方法重新应用到相同的点,但使用了缩放1,以强制初始缩放,但与用于放大的相同点有关
至于在画布中恢复图像位置的问题(例如,在平移之后),只需移除图像,将其居中于画布中,然后像第一次添加图像时那样将其重新添加到画布中即可:
var img = canvas.getActiveObject();
canvas.remove(img);
canvas.centerObject(img);
canvas.setActiveObject(img);
canvas.add(img);
canvas.renderAll();
虽然这个问题很老,但下面是我使用fabric.js 2.2.4的当前版本所做的:
canvas.setViewportTransform([1,0,0,1,0,0]);
仅供参考:缩放到一个点是重新计算视口变换。上面的矩阵是这是初始视口变换矩阵。画布中只有一个对象,没有组