How to make a circle to move randomly in a canvas?
How to make a circle to move randomly in a canvas?
1 answer
by
arnoldo.moen ,
4 months ago
@giovanny.lueilwitz
To make a circle move randomly in a canvas using JavaScript, you can follow these steps:
- Create an HTML file with a canvas element in it. Give the canvas an id attribute so you can reference it in your JavaScript code.
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<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<title>Random Circle Movement</title>
</head>
<body>
<canvas id="myCanvas" width="500" height="500"></canvas>
<script src="script.js"></script>
</body>
</html>
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- Create a JavaScript file (e.g. script.js) and write the following code to draw a circle on the canvas and move it randomly:
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const canvas = document.getElementById('myCanvas');
const ctx = canvas.getContext('2d');
let x = canvas.width / 2;
let y = canvas.height / 2;
let dx = Math.random() * 2 - 1; // Random velocity for x direction
let dy = Math.random() * 2 - 1; // Random velocity for y direction
function drawCircle() {
ctx.clearRect(0, 0, canvas.width, canvas.height); // Clear the canvas
ctx.beginPath();
ctx.arc(x, y, 20, 0, Math.PI * 2);
ctx.fillStyle = 'blue';
ctx.fill();
ctx.closePath();
x += dx;
y += dy;
if (x > canvas.width - 20 || x < 20) {
dx = -dx; // Reverse x direction if circle hits canvas boundaries
}
if (y > canvas.height - 20 || y < 20) {
dy = -dy; // Reverse y direction if circle hits canvas boundaries
}
requestAnimationFrame(drawCircle); // Repeat the drawing
}
drawCircle();
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- Save the HTML and JavaScript files in the same directory and open the HTML file in a web browser. You will see a blue circle moving randomly on the canvas.
You can adjust the circle's size, color, velocity, and canvas size in the code to customize the movement as desired.