What is zrender?
zrender is a lightweight canvas library that provides a powerful and flexible way to create and manipulate 2D graphics. It is often used as a rendering engine for the ECharts library, but it can also be used independently for custom graphics and animations.
What are zrender's main functionalities?
Basic Shapes
This feature allows you to create basic shapes like circles, rectangles, and lines. The code sample demonstrates how to create a red circle and add it to the canvas.
const zrender = require('zrender');
const zr = zrender.init(document.getElementById('main'));
const circle = new zrender.Circle({
shape: {
cx: 150,
cy: 150,
r: 50
},
style: {
fill: 'red'
}
});
zr.add(circle);
Animations
This feature allows you to animate shapes. The code sample demonstrates how to animate a rectangle moving from one position to another over a duration of 1000 milliseconds.
const zrender = require('zrender');
const zr = zrender.init(document.getElementById('main'));
const rect = new zrender.Rect({
shape: {
x: 50,
y: 50,
width: 100,
height: 100
},
style: {
fill: 'blue'
}
});
zr.add(rect);
rect.animate('shape', true)
.when(1000, { x: 200 })
.start();
Event Handling
This feature allows you to handle events like click, mouseover, and mouseout on shapes. The code sample demonstrates how to add a click event listener to a circle that shows an alert when the circle is clicked.
const zrender = require('zrender');
const zr = zrender.init(document.getElementById('main'));
const circle = new zrender.Circle({
shape: {
cx: 150,
cy: 150,
r: 50
},
style: {
fill: 'green'
}
});
zr.add(circle);
circle.on('click', function () {
alert('Circle clicked!');
});
Other packages similar to zrender
fabric
Fabric.js is a powerful and simple JavaScript HTML5 canvas library. It provides an interactive object model on top of the canvas element, allowing for complex shapes, animations, and event handling. Compared to zrender, Fabric.js offers more built-in functionalities for object manipulation and interaction.
paper
Paper.js is an open-source vector graphics scripting framework that runs on top of the HTML5 Canvas. It is particularly well-suited for creating complex vector graphics and animations. Compared to zrender, Paper.js focuses more on vector graphics and provides a more extensive set of tools for path manipulation.
konva
Konva.js is a 2D canvas library that extends the 2D context by enabling high-performance animations, transitions, and event handling. It is designed to be fast and easy to use. Compared to zrender, Konva.js offers a more straightforward API for creating and animating shapes, but it may not be as flexible for custom rendering needs.
ZRender
A lightweight graphic library which provides 2d draw for Apache ECharts.
Documentation
https://ecomfe.github.io/zrender-doc/public/
License
BSD 3-Clause License
Copyright (c) 2017, Baidu Inc.
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