JavaScript Graphics Quiz: Coordinates of Canvas Center, Rectangles, and Circles

Study Notes

JavaScript Graphics: Creating Visuals with Rectangles, Circles, 2D Graphics, and Canvas API

JavaScript graphics encompass a wide range of techniques for creating visual representations on websites and applications. Some of the key aspects include drawing rectangles, circles, working with 2D graphics, and utilizing the Canvas API.

Rectangle Drawing

In JavaScript, rectangles can be drawn using the fillRect() method on the canvas context. This method takes four parameters: the x and y coordinates of the top left corner of the rectangle, as well as the width and height of the rectangle. Here's an example of drawing a rectangle:

const canvas = document.getElementById('canvas');
const ctx = canvas.getContext('2d');
ctx.fillStyle = 'blue';
ctx.fillRect(50, 50, 100, 100);

Circle Drawing

Drawing circles in JavaScript is similar to drawing rectangles. The fillCircle() method on the canvas context is used, and it takes three parameters: the center x and y coordinates, and the radius of the circle. Here's an example of drawing a circle:

const canvas = document.getElementById('canvas');
const ctx = canvas.getContext('2d');
ctx.fillStyle = 'red';
ctx.fillCircle(50, 50, 50);

2D Graphics and Coordinate System

2D graphics in JavaScript are typically drawn on the canvas element using the Canvas API. This API allows for various drawing operations, including drawing shapes like rectangles and circles, as well as manipulating colors, stroke styles, and more.

The coordinate system in JavaScript graphics is based on the top-left corner of the canvas being (0, 0). The x-axis increases to the right, and the y-axis increases downwards. Positive coordinates are located to the right and below the origin, while negative coordinates are located to the left and above the origin.

Canvas API

The Canvas API is a key component of JavaScript graphics. It allows for dynamic and interactive visualizations on web pages. The API provides a set of functions for drawing shapes, manipulating colors, and handling user interactions. The Canvas API is compatible with most modern browsers, making it a versatile tool for creating web-based graphics.

In summary, JavaScript graphics offer a wide range of capabilities for creating visually engaging content on the web. From drawing basic shapes like rectangles and circles to utilizing the Canvas API for more complex visualizations, JavaScript provides a flexible and powerful platform for graphics creation.

Description

Test your knowledge about drawing rectangles, circles, working with 2D graphics, and utilizing the Canvas API in JavaScript. Learn about methods like fillRect() for rectangles and fillCircle() for circles, the coordinate system in 2D graphics, and the capabilities of the Canvas API for dynamic visualizations.