Web Front-end
JS Tutorial
FabricJS - Determine whether fill or stroke should be drawn first for a polygon object?
FabricJS - Determine whether fill or stroke should be drawn first for a polygon object?
We can create a Polygon object by creating an instance of fabric.Polygon. A polygon object can be characterized as any closed shape consisting of a set of connected straight line segments. 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 determine whether the fill or stroke should be drawn first, we use the paintFirst property.
grammar
new fabric.Polygon( points: Array, { paintFirst: String }: Object )
parameter
points - This parameter accepts an Array, which represents the array of points that make up the polygon object, where each point is represented by x and y object.
Options (optional) - This parameter is an object that provides additional customization to our object. Using this parameter, you can change the origin, stroke width, and many other properties associated with the Polygon object, where paintFirst is a property of that object.
Option key
paintFirst - This property accepts a String value that defines whether the fill or stroke is drawn first. The default value is "fill".
Example 1: Default appearance of polygon objects
Let's look at a code example to see how a polygon object appears when the paintFirst property is not applied. In this example, use the default value "fill". This means that when an object is drawn, the fill color is drawn first, followed by the stroke color.
<!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>Default appearance of polygon object</h2>
<p>You can see the default appearance of polygon object</p>
<canvas id="canvas"></canvas>
<script>
// Initiate a canvas instance
var canvas = new fabric.Canvas("canvas");
canvas.setWidth(document.body.scrollWidth);
canvas.setHeight(250);
// Initiating a polygon object
var polygon = new fabric.Polygon(
[
{ x: 200, y: 10 },
{ x: 250, y: 50 },
{ x: 250, y: 180 },
{ x: 150, y: 180 },
{ x: 150, y: 50 },
{ x: 200, y: 10 },
],
{
fill: "green",
stroke: "blue",
strokeWidth: 20,
}
);
// Adding it to the canvas
canvas.add(polygon);
</script>
</body>
</html>
Example 2: Using the paintFirst attribute
Let's look at a code example of how to use the paintFirst property to change the default behavior of a polygon object. Here we pass the value "lines" to the paintFirst property. This ensures that the stroke is drawn first and not the fill.
<!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 paintFirst property</h2>
<p>You can see that the stroke is painted first now</p>
<canvas id="canvas"></canvas>
<script>
// Initiate a canvas instance
var canvas = new fabric.Canvas("canvas");
canvas.setWidth(document.body.scrollWidth);
canvas.setHeight(250);
// Initiating a polygon object
var polygon = new fabric.Polygon(
[
{ x: 200, y: 10 },
{ x: 250, y: 50 },
{ x: 250, y: 180 },
{ x: 150, y: 180 },
{ x: 150, y: 50 },
{ x: 200, y: 10 },
],
{
fill: "green",
stroke: "blue",
strokeWidth: 20,
paintFirst: "stroke",
}
);
// Adding it to the canvas
canvas.add(polygon);
</script>
</body>
</html>
in conclusion
In this tutorial, we use two simple examples to demonstrate how to use FabricJS to determine whether a fill or stroke should be drawn first for a polygon.
The above is the detailed content of FabricJS - Determine whether fill or stroke should be drawn first for a polygon object?. For more information, please follow other related articles on the PHP Chinese website!
Hot AI Tools
Undresser.AI Undress
AI-powered app for creating realistic nude photos
AI Clothes Remover
Online AI tool for removing clothes from photos.
Undress AI Tool
Undress images for free
Clothoff.io
AI clothes remover
Video Face Swap
Swap faces in any video effortlessly with our completely free AI face swap tool!
Hot Article
Hot Tools
Notepad++7.3.1
Easy-to-use and free code editor
SublimeText3 Chinese version
Chinese version, very easy to use
Zend Studio 13.0.1
Powerful PHP integrated development environment
Dreamweaver CS6
Visual web development tools
SublimeText3 Mac version
God-level code editing software (SublimeText3)
Hot Topics
1673
14
1428
52
1333
25
1278
29
1257
24
Python vs. JavaScript: The Learning Curve and Ease of Use
Apr 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.
JavaScript and the Web: Core Functionality and Use Cases
Apr 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.
JavaScript in Action: Real-World Examples and Projects
Apr 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.
Understanding the JavaScript Engine: Implementation Details
Apr 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: Community, Libraries, and Resources
Apr 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.
Python vs. JavaScript: Development Environments and Tools
Apr 26, 2025 am 12:09 AM
Both Python and JavaScript's choices in development environments are important. 1) Python's development environment includes PyCharm, JupyterNotebook and Anaconda, which are suitable for data science and rapid prototyping. 2) The development environment of JavaScript includes Node.js, VSCode and Webpack, which are suitable for front-end and back-end development. Choosing the right tools according to project needs can improve development efficiency and project success rate.
The Role of C/C in JavaScript Interpreters and Compilers
Apr 20, 2025 am 12:01 AM
C and C play a vital role in the JavaScript engine, mainly used to implement interpreters and JIT compilers. 1) C is used to parse JavaScript source code and generate an abstract syntax tree. 2) C is responsible for generating and executing bytecode. 3) C implements the JIT compiler, optimizes and compiles hot-spot code at runtime, and significantly improves the execution efficiency of JavaScript.
Python vs. JavaScript: Use Cases and Applications Compared
Apr 21, 2025 am 12:01 AM
Python is more suitable for data science and automation, while JavaScript is more suitable for front-end and full-stack development. 1. Python performs well in data science and machine learning, using libraries such as NumPy and Pandas for data processing and modeling. 2. Python is concise and efficient in automation and scripting. 3. JavaScript is indispensable in front-end development and is used to build dynamic web pages and single-page applications. 4. JavaScript plays a role in back-end development through Node.js and supports full-stack development.
