harmstyler/contrast-ratio-calculator

Calculate contrast ratios of colors.

Contrast Ratio Calculator

Accessibility library that calculates contrast ratios of colors as well as rates the contrast ratio against WCAG standards., _(*1)

Getting started

1. PHP 7.1.x is required
2. Install the Contrast Ratio Calculator using Composer (recommended) or manually

Composer Installation

1. Get Composer
2. Install with composer require harmstyler/contrast-ratio-calculator
3. Add the following to your application's main PHP file: require 'vendor/autoload.php';

Usage

<?php

use HarmsTyler\ContrastRatioCalculator\Color;
use HarmsTyler\ContrastRatioCalculator\ContrastRatio;
use HarmsTyler\ContrastRatioCalculator\WCAGContrastRating;

$primaryColor = new Color();
$primaryColor->setHex('#ffffff');
$secondaryColor = new Color();
$secondaryColor->setHex('#000000');

$contrastRatio = new ContrastRatio($primaryColor, $secondaryColor);

echo $contrastRatio->getRatio(); // floating decimal point of calculated ratio

$rating = new WCAGContrastRating();
echo $rating->rateContrastRatio($contrastRatio); // the WCAGContrast grade, either 'fail', 'aa-large', 'aa', or 'aaa'

Run the tests

./vendor/bin/phpunit tests/