canvas-multiline-emoji

Typesafe multiline text on canvas with emoji support

Draws text in a rectangle on a canvas, on multiple lines.

Instalattion

To install use:

npm i canvas-multiline-emoji

Usage

Exports a single function that draws text on a canvas, breaking it into multiple lines if needed.

Also shrinks the font size to make in fit in the defined rectangle.

Returns the font size used

const fontSize = await drawText(canvas2Dcontext, text, options);

Example

import fs from 'node:fs';
import { Canvas } from 'canvas';
import { drawText } from 'canvas-multiline-emoji';

const canvas = new Canvas(500, 500);
const ctx = canvas.getContext('2d');
const text = 'The old rusted farm equipment 🤪 surrounded the house predicting its demise. He uses onomatopoeia as a weapon of mental destruction. 👍';
const options = {
    font: 'OpenSans',
    verbose: true,
    rect: {
        x: 50,
        y: 50,
        width: canvas.width - (50 * 2),
        height: canvas.height - (50 * 2),
    },
    minFontSize: 10,
    maxFontSize: 40,
    lineHeight: 1.2
};

const test = async () => {
    /* --- background --- */
    ctx.fillStyle = '#4a4aad';
    ctx.fillRect(0, 0, ctx.canvas.width, ctx.canvas.height);
    /* --- font color --- */
    ctx.fillStyle = '#ceceec';
    
    const fontSizeUsed = await drawText(ctx, text, options);
    console.log('Font size used: ', fontSizeUsed);

    const buffer = canvas.toBuffer();
    fs.writeFileSync('test.png', buffer);
};

test();

Options

The options type is defined as MultilineOptions and (almost) all its keys are optional.

Parameter	Description	Default
font	Font name / family to use	sans-serif
rect	Rectangle object with x, y, width, height. Text will be drawn inside this.	Canvas Size
minFontSize	Minimum font size to use.	8
maxFontSize	Maximum font size to use.	100
lineHeight	Multiplicator for line height	1
stroke	Defines whether strokeText will be used instead of fillText	false
verbose	Defines whether if should print debug info	false
logFunction	Custome function for logging.	console.log

Dependencies

This module requires some kind of Canvas object.

Inspired on: https://gitlab.com/davideblasutto/canvas-multiline-text