如何使用 FabricJS 查找 Image 实例的复杂度?

在本教程中,我们将学习如何查找 Image 实例的复杂度 使用 FabricJS。我们可以通过创建fabric.Image的实例来创建一个Image对象。 由于它是FabricJS的基本元素之一,我们也可以轻松地自定义它 应用角度、不透明度等属性。为了找到图像的复杂度 例如,我们使用复杂性方法。如果当前对象是此方法将返回 1 直接从基类继承,而不是从子类继承。
语法
complexity(): Number
使用复杂性方法
示例
让我们看一个代码示例,看看使用complexity方法时记录的输出 获取 Image 实例的复杂度。除非进行子分类,否则复杂度为1。
<!DOCTYPE html>
<html>
<head>
<!-- Adding the Fabric JS Library-->
<script src="https://cdnjs.cloudflare.com/ajax/libs/fabric.js/510/fabric.min.js"></script>
</head>
<body>
<h2>Using the complexity method</h2>
<p>You can open console from dev tools and see the logged output</p>
<canvas id="canvas"></canvas>
<img src="https://www.tutorialspoint.com/images/logo.png" id="img1" style="display: none" />
<script>
// Initiate a canvas instance
var canvas = new fabric.Canvas("canvas");
canvas.setWidth(document.body.scrollWidth);
canvas.setHeight(250);
// Initiating the image element
var imageElement = document.getElementById("img1");
// Initiate an Image object
var image = new fabric.Image(imageElement, {
top: 50,
left: 110,
});
// Add it to the canvas
canvas.add(image);
// Using the complexity method
console.log("The complexity of Image instance is: ", image.complexity());
</script>
</body>
</html>
使用复杂度方法来比较不同的对象
示例
在此示例中,我们使用了复杂度方法来比较 图像实例和多边形实例。您可以从开发工具打开控制台 看到复杂性是不同的。
<!DOCTYPE html>
<html>
<head>
<!-- Adding the Fabric JS Library-->
<script src="https://cdnjs.cloudflare.com/ajax/libs/fabric.js/510/fabric.min.js"></script>
</head>
<body>
<h2>Using the complexity method to compare different objects</h2>
<p>You can open console from dev tools and see the logged output</p>
<canvas id="canvas"></canvas>
<img src="https://www.tutorialspoint.com/images/logo.png" id="img1" style="display: none" />
<script>
// Initiate a canvas instance
var canvas = new fabric.Canvas("canvas");
canvas.setWidth(document.body.scrollWidth);
canvas.setHeight(250);
// Initiating the image element
var imageElement = document.getElementById("img1");
// Initiate an Image object
var image = new fabric.Image(imageElement, {
top: 50,
left: 50,
});
// Initiate a Polygon object
var polygon = new fabric.Polyline(
[
{ x: 50, y: 30 },
{ x: 105, y: 10 },
{ x: 160, y: 30 },
{ x: 100, y: 150 },
],
{
fill: "red",
left: 450,
top: 70,
}
);
// Add them both to the canvas
canvas.add(image);
canvas.add(polygon);
// Using the complexity method
console.log("The complexity of Image instance is: ", image.complexity());
console.log(
"The complexity of Polygon instance is: ",
polygon.complexity()
);
</script>
</body>
</html>
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