dalexhd/SteamSpeak

import splitEntitiesFromText from './utils/splitEntitiesFromText';
import loadTwemojiImageByUrl from './utils/loadTwemojiImageByUrl';
import getFontSizeByCssFont from './utils/getFontSizeByCssFont';
import Canvas from 'canvas';

Canvas.CanvasRenderingContext2D.prototype.drawTextWithEmoji = async function (
    fillType: string,
    text: string,
    x: number,
    y: number,
    maxWidth?: number,
    emojiSideMarginPercent = 0.1,
    emojiTopMarginPercent = 0.1
): Promise<void> {
    const textEntities = splitEntitiesFromText(text);
    const fontSize = getFontSizeByCssFont(this.font);
    const baseLine = this.measureText('').alphabeticBaseline;
    const emojiSideMargin = fontSize * emojiSideMarginPercent;
    const emojiTopMargin = fontSize * emojiTopMarginPercent;
    let currentWidth = 0;

    for (let i = 0; i < textEntities.length; i++) {
        const entity = textEntities[i];
        if (typeof entity === 'string') {
            // Common text case
            if (fillType === 'fill') {
                this.fillText(entity, x + currentWidth, y, maxWidth);
            } else {
                this.strokeText(entity, x + currentWidth, y, maxWidth);
            }
            currentWidth += this.measureText(entity).width;
        } else {
            // Emoji case
            const emoji = await loadTwemojiImageByUrl(entity.url);
            this.drawImage(
                emoji,
                x + currentWidth + emojiSideMargin,
                y + emojiTopMargin - fontSize - baseLine,
                fontSize,
                fontSize
            );
            currentWidth += fontSize + emojiSideMargin * 2;
        }
    }
};