How to set a multiplier to scale a cloned image using FabricJS?-JS Tutorial-php.cn

Home

Web Front-end

JS Tutorial

How to set a multiplier to scale a cloned image using FabricJS?

王林

Aug 27, 2023 pm 07:21 PM

如何使用 FabricJS 设置倍数来缩放克隆图像？

In this tutorial, we will learn how to set a multiplier to scale a cloned image using FabricJS. We can create an Image object by creating an instance of fabric.Image. Since it is one of the basic elements of FabricJS, we can also easily customize it by applying properties such as angle, opacity, etc. To set the multiplier to scale the cloned image, we use the multiplier property.

grammar

cloneAsImage( callback: function, { multiplier: Number}: Object): fabric.Object

parameter

Callback (optional) - This parameter is a function that will use the cloned image instance as the first call argument.
Options (optional) - This parameter is an optional object that provides additional customization to our cloned image. Using this parameter we can set the multiplier, crop the cloned image, remove the current object transform or can change many properties where Multiplier is a property.

Option key

multiplier - This property accepts a Number value that represents the multiplier by which the final output image is scaled. The default value is 1.

Do not use multiplierAttribute

Example

Let's look at a code example to see how a cloned Image object displays when the multiplier property is not used. In this case, the default multiplier value of 1 is used.

<!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 id="Without-using-the-multiplier-property">Without using the multiplier property</h2> 
   <p>You can see that the clone image uses the default multiplier</p>
   <canvas id="canvas"></canvas>
   <img  src="/static/imghwm/default1.png"  data-src="https://www.tutorialspoint.com/images/logo.png"  class="lazy" id="img1"   style="max-width:90%" / alt="How to set a multiplier to scale a cloned image using FabricJS?" >
   <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 a shadow object
      var shadow = new fabric.Shadow({
         color: "#308080",
         blur: 3,
      });
      
      // Initiate an Image object
      var image = new fabric.Image(imageElement, {
         top: 50,
         left: 110,
         skewX: 20,
         shadow: shadow,
      });
      
      // Using cloneAsImage method
      image.cloneAsImage(function (Img) {
         canvas.add(Img);
      });
   </script>
</body>
</html>

Use MultiplierProperties

Example

In this example, we used the multiplier property and passed it a value of 2 to demonstrate that the final cloned image will be scaled twice in the x and y directions.

<!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 id="Using-the-multiplier-property">Using the multiplier property</h2>
   <p>You can see that the clone image has been scaled</p>
   <canvas id="canvas"></canvas>
   <img  src="/static/imghwm/default1.png"  data-src="https://www.tutorialspoint.com/images/logo.png"  class="lazy" id="img1"   style="max-width:90%" / alt="How to set a multiplier to scale a cloned image using FabricJS?" >
   <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 a shadow object
      var shadow = new fabric.Shadow({
         color: "#308080",
         blur: 3,
      });
      // Initiate an Image object
      var image = new fabric.Image(imageElement, {
         top: 50,
         left: 110,
         skewX: 20,
         shadow: shadow,
      });
      // Using cloneAsImage method
      image.cloneAsImage(
         function (Img) {
            Img.set("top", 90);
            canvas.add(Img);
         },
         {
            multiplier: 2,
         }
      );
   </script>
</body>
</html>

The above is the detailed content of How to set a multiplier to scale a cloned image using FabricJS?. For more information, please follow other related articles on the PHP Chinese website!

Statement

This article is reproduced at:tutorialspoint. If there is any infringement, please contact admin@php.cn delete

JavaScript in Action: Real-World Examples and ProjectsApr 19, 2025 am 12:13 AM

JavaScript's application in the real world includes front-end and back-end development. 1) Display front-end applications by building a TODO list application, involving DOM operations and event processing. 2) Build RESTfulAPI through Node.js and Express to demonstrate back-end applications.

JavaScript and the Web: Core Functionality and Use CasesApr 18, 2025 am 12:19 AM

The main uses of JavaScript in web development include client interaction, form verification and asynchronous communication. 1) Dynamic content update and user interaction through DOM operations; 2) Client verification is carried out before the user submits data to improve the user experience; 3) Refreshless communication with the server is achieved through AJAX technology.

Understanding the JavaScript Engine: Implementation DetailsApr 17, 2025 am 12:05 AM

Understanding how JavaScript engine works internally is important to developers because it helps write more efficient code and understand performance bottlenecks and optimization strategies. 1) The engine's workflow includes three stages: parsing, compiling and execution; 2) During the execution process, the engine will perform dynamic optimization, such as inline cache and hidden classes; 3) Best practices include avoiding global variables, optimizing loops, using const and lets, and avoiding excessive use of closures.

Python vs. JavaScript: The Learning Curve and Ease of UseApr 16, 2025 am 12:12 AM

Python is more suitable for beginners, with a smooth learning curve and concise syntax; JavaScript is suitable for front-end development, with a steep learning curve and flexible syntax. 1. Python syntax is intuitive and suitable for data science and back-end development. 2. JavaScript is flexible and widely used in front-end and server-side programming.

Python vs. JavaScript: Community, Libraries, and ResourcesApr 15, 2025 am 12:16 AM

Python and JavaScript have their own advantages and disadvantages in terms of community, libraries and resources. 1) The Python community is friendly and suitable for beginners, but the front-end development resources are not as rich as JavaScript. 2) Python is powerful in data science and machine learning libraries, while JavaScript is better in front-end development libraries and frameworks. 3) Both have rich learning resources, but Python is suitable for starting with official documents, while JavaScript is better with MDNWebDocs. The choice should be based on project needs and personal interests.

From C/C to JavaScript: How It All WorksApr 14, 2025 am 12:05 AM

The shift from C/C to JavaScript requires adapting to dynamic typing, garbage collection and asynchronous programming. 1) C/C is a statically typed language that requires manual memory management, while JavaScript is dynamically typed and garbage collection is automatically processed. 2) C/C needs to be compiled into machine code, while JavaScript is an interpreted language. 3) JavaScript introduces concepts such as closures, prototype chains and Promise, which enhances flexibility and asynchronous programming capabilities.

JavaScript Engines: Comparing ImplementationsApr 13, 2025 am 12:05 AM

Different JavaScript engines have different effects when parsing and executing JavaScript code, because the implementation principles and optimization strategies of each engine differ. 1. Lexical analysis: convert source code into lexical unit. 2. Grammar analysis: Generate an abstract syntax tree. 3. Optimization and compilation: Generate machine code through the JIT compiler. 4. Execute: Run the machine code. V8 engine optimizes through instant compilation and hidden class, SpiderMonkey uses a type inference system, resulting in different performance performance on the same code.

Beyond the Browser: JavaScript in the Real WorldApr 12, 2025 am 12:06 AM

JavaScript's applications in the real world include server-side programming, mobile application development and Internet of Things control: 1. Server-side programming is realized through Node.js, suitable for high concurrent request processing. 2. Mobile application development is carried out through ReactNative and supports cross-platform deployment. 3. Used for IoT device control through Johnny-Five library, suitable for hardware interaction.

See all articles