How to fill the whole canvas with specific color?
JavascriptHtmlCanvasJavascript Problem Overview
How to fill the whole HTML5 <canvas> with one color.
I saw some solutions such as this to change the background color using CSS but this is not a good solution since the canvas remains transparent, the only thing that changes is the color of the space it occupies.
Another one is by creating something with the color inside the canvas, for example, a rectangle(see here) but it still does not fill the whole canvas with the color (in case the canvas is bigger than the shape we created).
Is there a solution to fill the whole canvas with a specific color?
Javascript Solutions
Solution 1 - Javascript
Yes, fill in a Rectangle with a solid color across the canvas, use the height and width of the canvas itself:
var canvas = document.getElementById("canvas");
var ctx = canvas.getContext("2d");
ctx.fillStyle = "blue";
ctx.fillRect(0, 0, canvas.width, canvas.height);
canvas{ border: 1px solid black; }
<canvas width=300 height=150 id="canvas">
Solution 2 - Javascript
If you want to do the background explicitly, you must be certain that you draw behind the current elements on the canvas.
var canvas = document.getElementById("canvas");
var ctx = canvas.getContext("2d");
// Add behind elements.
ctx.globalCompositeOperation = 'destination-over'
// Now draw!
ctx.fillStyle = "blue";
ctx.fillRect(0, 0, canvas.width, canvas.height);
Solution 3 - Javascript
You can change the background of the canvas by doing this:
<head>
<style>
canvas {
background-color: blue;
}
</style>
</head>
Solution 4 - Javascript
let canvas = document.getElementById('canvas');
canvas.setAttribute('width', window.innerWidth);
canvas.setAttribute('height', window.innerHeight);
let ctx = canvas.getContext('2d');
//Draw Canvas Fill mode
ctx.fillStyle = 'blue';
ctx.fillRect(0,0,canvas.width, canvas.height);
* { margin: 0; padding: 0; box-sizing: border-box; }
body { overflow: hidden; }
<canvas id='canvas'></canvas>
Solution 5 - Javascript
We don't need to access the canvas context.
Implementing hednek in pure JS you would get canvas.setAttribute('style', 'background-color:#00F8'). But my preferred method requires converting the kabab-case to camelCase.
> canvas.style.backgroundColor = '#00F8'
Solution 6 - Javascript
You know what, there is an entire library for canvas graphics. It is called p5.js You can add it with just a single line in your head element and an additional sketch.js file.
Do this to your html and body tags first:
<html style="margin:0 ; padding:0">
<body style="margin:0 ; padding:0">
Add this to your head:
<script type="text/javascript" src="https://cdnjs.cloudflare.com/ajax/libs/p5.js/0.6.1/p5.js"></script>
<script type="text/javascript" src="sketch.js"></script>
The sketch.js file
function setup() {
createCanvas(windowWidth, windowHeight);
background(r, g, b);
}