Fabric.js 2.3.6
我正在尝试将对象剪切到使用自由绘制衬套绘制的路径。代码无法显示路径内的图像，我不确定自己在做什么错。
可能会剪切多个对象，因此我无法将路径应用于画布本身。
let image = new Image();
let object;
let canvas;
// canvas
canvas = new fabric.Canvas("canvas", {
backgroundColor: "lightgray",
width: 1280,
height: 720,
preserveObjectStacking: true,
selection: false
});
canvas.isDrawingMode = true;
canvas.freeDrawingBrush.color = "black";
canvas.freeDrawingBrush.width = 2;
canvas.on("path:created", function(options) {
clip(options.path);
});
// clip
function clip(path) {
object.set({
clipTo: function(ctx) {
path.render(ctx);
}
});
canvas.requestRenderAll();
}
// image
image.onload = function() {
object = new fabric.Image(image, {
width: 500,
height: 500,
top: 50,
left: 50
});
canvas.add(object);
};
image.src = "http://i.imgur.com/8rmMZI3.jpg";
答案 0 :(得分：2)
为了在绘制路径时在同一位置上进行剪辑，您需要将{
...
"aggregations" : {
"genres" : {
"doc_count_error_upper_bound": 0,
"sum_other_doc_count": 0,
"buckets" : {"color": [
{
"key" : "red",
"doc_count" : 6
},
{
"key" : "blue",
"doc_count" : 3
},
],
{"size": [
{
"key" : "M",
"doc_count" : 6
},
],
{"wifi": [
{
"key" : "ac/g/n",
"doc_count" : 1
},
]
}
}
}
重置为SVG路径，并将pathOffset重置为setTransform。剪辑功能如下所示：
ctx function clip(path) {
path.set({pathOffset: {x: 0, y: 0}});
object.set({
clipTo: function(ctx) {
ctx.save();
ctx.setTransform(1,0,0,1,0,0);
ctx.beginPath();
path._renderPathCommands(ctx);
ctx.restore();
}
});
canvas.requestRenderAll();
}
-呈现路径。
更新了fiddle
要剪辑多个对象，您需要具有某种对象数组，然后将其组合成单个_renderPathCommands：
path这是一个具有多个剪切路径的示例：
function combinePaths (paths) {
if (!paths.length) {
return null;
}
let singlePath = paths[0].path;
for (let i = 1; i < paths.length; i++){
singlePath = [...singlePath, ...paths[i].path];
}
return new fabric.Path(singlePath, {
top: 0,
left: 0,
pathOffset: {
x: 0,
y: 0
}
});
}
// canvas
let canvas = new fabric.Canvas("canvas", {
backgroundColor: "lightgray",
width: 1280,
height: 720,
preserveObjectStacking: true,
selection: false
});
let paths = [];
canvas.isDrawingMode = true;
canvas.freeDrawingBrush.color = "black";
canvas.freeDrawingBrush.width = 2;
canvas.on("path:created", function (options) {
paths.push(options.path);
clip(combinePaths(paths));
});
function combinePaths(paths) {
if (!paths.length) {
return null;
}
let singlePath = paths[0].path;
for (let i = 1; i < paths.length; i++) {
singlePath = [...singlePath, ...paths[i].path];
}
return new fabric.Path(singlePath, {
top: 0,
left: 0,
pathOffset: {
x: 0,
y: 0
}
});
}
function clip(path) {
if (!path) {
return;
}
object.set({
clipTo: function (ctx) {
var retina = this.canvas.getRetinaScaling();
ctx.save();
ctx.setTransform(retina, 0, 0, retina, 0, 0);
ctx.beginPath();
path._renderPathCommands(ctx);
ctx.restore();
}
});
canvas.requestRenderAll();
}
// image
let image = new Image();
let object;
image.onload = function () {
object = new fabric.Image(image, {
width: 500,
height: 500,
top: 50,
left: 50
});
object.globalCompositeOperation = 'source-atop';
canvas.add(object);
};
image.src = "http://i.imgur.com/8rmMZI3.jpg";