How to find the true center coordinates of a Line object using FabricJS?-JS Tutorial-php.cn

Home

Web Front-end

JS Tutorial

How to find the true center coordinates of a Line object using FabricJS?

王林

Sep 16, 2023 pm 12:09 PM

如何使用 FabricJS 找到 Line 对象的真实中心坐标？

In this tutorial, we will learn how to find the center coordinates of a line using FabricJS. Line element is one of the basic elements provided in FabricJS. It is used to create straight lines. Since line elements are geometrically one-dimensional and contain no interiors, they are never filled. We can create a line object by creating an instance of fabric.Line, specifying the x and y coordinates of the line and adding it to the canvas. To find the true center coordinates of the Line object, we use the getCenterPoint method.

Syntax

 getCenterPoint(): fabric.Point

Using getCenterPoint Methods

Example

Let’s look at a code example to see getCenterPoint Used for the output recorded when the method is run. getCenterPoint The method returns the true center coordinates of the object. In this example, the recorded outputs are x= 110.5 and y= 150.5, which are the center points.

<!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-getCenterPoint-method">Using getCenterPoint method</h2>
   <p>
      You can open console from dev tools and see that the logged output contains the center points
   </p>
   <canvas id="canvas"></canvas>
   <script>
      
      // Initiate a canvas instance
      var canvas = new fabric.Canvas("canvas");
      canvas.setWidth(document.body.scrollWidth);
      canvas.setHeight(250);
      
      // Initiate a Line object
      var line = new fabric.Line([70, 100, 150, 200], {
         stroke: "blue",
      });
      
      // Add it to the canvas
      canvas.add(line);
      
      // Using the getCenterPoint method
      console.log(
         "The center point of Line object is: ",
         line.getCenterPoint()
      );
   </script>
</body>
</html>

Using the getCenterPoint method with different start and end coordinates of the line

Example

In this example we used the getCenterPoint The i> method obtains the center coordinates when the starting and ending coordinates of the Line instance are (100, 250) and (250, 40). The center points are 175.5 and 145.5.

<!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 getCenterPoint method with different starting and ending coordinates of line
   </h2>
   <p>
      You can open console from dev tools and see that the logged output contains the center points
   </p>
   <canvas id="canvas"></canvas>
   <script>
      
      // Initiate a canvas instance
      var canvas = new fabric.Canvas("canvas");
      canvas.setWidth(document.body.scrollWidth);
      canvas.setHeight(250);
      
      // Initiate a Line object
      var line = new fabric.Line([100, 250, 250, 40], {
         stroke: "blue",
      });
      
      // Add it to the canvas
      canvas.add(line);
      
      // Using the getCenterPoint method
      console.log(
         "The center point of Line object is: ",
         line.getCenterPoint()
      );
   </script>
</body>
</html>

The above is the detailed content of How to find the true center coordinates of a Line object 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 Data Types : Is there any difference between Browser and NodeJs?May 14, 2025 am 12:15 AM

JavaScript core data types are consistent in browsers and Node.js, but are handled differently from the extra types. 1) The global object is window in the browser and global in Node.js. 2) Node.js' unique Buffer object, used to process binary data. 3) There are also differences in performance and time processing, and the code needs to be adjusted according to the environment.

JavaScript Comments: A Guide to Using // and /* */May 13, 2025 pm 03:49 PM

JavaScriptusestwotypesofcomments:single-line(//)andmulti-line(//).1)Use//forquicknotesorsingle-lineexplanations.2)Use//forlongerexplanationsorcommentingoutblocksofcode.Commentsshouldexplainthe'why',notthe'what',andbeplacedabovetherelevantcodeforclari

Python vs. JavaScript: A Comparative Analysis for DevelopersMay 09, 2025 am 12:22 AM

The main difference between Python and JavaScript is the type system and application scenarios. 1. Python uses dynamic types, suitable for scientific computing and data analysis. 2. JavaScript adopts weak types and is widely used in front-end and full-stack development. The two have their own advantages in asynchronous programming and performance optimization, and should be decided according to project requirements when choosing.

Python vs. JavaScript: Choosing the Right Tool for the JobMay 08, 2025 am 12:10 AM

Whether to choose Python or JavaScript depends on the project type: 1) Choose Python for data science and automation tasks; 2) Choose JavaScript for front-end and full-stack development. Python is favored for its powerful library in data processing and automation, while JavaScript is indispensable for its advantages in web interaction and full-stack development.

Python and JavaScript: Understanding the Strengths of EachMay 06, 2025 am 12:15 AM

Python and JavaScript each have their own advantages, and the choice depends on project needs and personal preferences. 1. Python is easy to learn, with concise syntax, suitable for data science and back-end development, but has a slow execution speed. 2. JavaScript is everywhere in front-end development and has strong asynchronous programming capabilities. Node.js makes it suitable for full-stack development, but the syntax may be complex and error-prone.

JavaScript's Core: Is It Built on C or C ?May 05, 2025 am 12:07 AM

JavaScriptisnotbuiltonCorC ;it'saninterpretedlanguagethatrunsonenginesoftenwritteninC .1)JavaScriptwasdesignedasalightweight,interpretedlanguageforwebbrowsers.2)EnginesevolvedfromsimpleinterpreterstoJITcompilers,typicallyinC ,improvingperformance.

JavaScript Applications: From Front-End to Back-EndMay 04, 2025 am 12:12 AM

JavaScript can be used for front-end and back-end development. The front-end enhances the user experience through DOM operations, and the back-end handles server tasks through Node.js. 1. Front-end example: Change the content of the web page text. 2. Backend example: Create a Node.js server.

Python vs. JavaScript: Which Language Should You Learn?May 03, 2025 am 12:10 AM

Choosing Python or JavaScript should be based on career development, learning curve and ecosystem: 1) Career development: Python is suitable for data science and back-end development, while JavaScript is suitable for front-end and full-stack development. 2) Learning curve: Python syntax is concise and suitable for beginners; JavaScript syntax is flexible. 3) Ecosystem: Python has rich scientific computing libraries, and JavaScript has a powerful front-end framework.

See all articles