Source: \core\renderers\canvas\utils\canUseNewCanvasBlendModes.js
/**
* Creates a little colored canvas
*
* @ignore
* @param {string} color - The color to make the canvas
* @return {canvas} a small canvas element
*/
function createColoredCanvas(color)
{
const canvas = document.createElement('canvas');
canvas.width = 6;
canvas.height = 1;
const context = canvas.getContext('2d');
context.fillStyle = color;
context.fillRect(0, 0, 6, 1);
return canvas;
}
/**
* Checks whether the Canvas BlendModes are supported by the current browser
*
* @return {boolean} whether they are supported
*/
export default function canUseNewCanvasBlendModes()
{
if (typeof document === 'undefined')
{
return false;
}
const magenta = createColoredCanvas('#ff00ff');
const yellow = createColoredCanvas('#ffff00');
const canvas = document.createElement('canvas');
canvas.width = 6;
canvas.height = 1;
const context = canvas.getContext('2d');
context.globalCompositeOperation = 'multiply';
context.drawImage(magenta, 0, 0);
context.drawImage(yellow, 2, 0);
const imageData = context.getImageData(2, 0, 1, 1);
if (!imageData)
{
return false;
}
const data = imageData.data;
return (data[0] === 255 && data[1] === 0 && data[2] === 0);
}