fonteditor-core/src/ttf/util/transformGlyfContours.js

fonts (ttf, woff, woff2, eot, svg, otf) parse, write, transform, glyph adjust.

/**
 * @file 转换复合字形的contours，以便于显示
 * @author mengke01(kekee000@gmail.com)
 */

import pathCeil from '../../graphics/pathCeil';
import pathTransform from '../../graphics/pathTransform';
import {clone} from '../../common/lang';


/**
 * 转换复合字形轮廓，结果保存在contoursList中，并返回当前glyf的轮廓
 *
 * @param  {Object} glyf glyf对象
 * @param  {Object} ttf ttfObject对象
 * @param  {Object=} contoursList 保存转换中间生成的contours
 * @param  {number} glyfIndex glyf对象当前的index
 * @return {Array} 转换后的轮廓
 */
export default function transformGlyfContours(glyf, ttf, contoursList = {}, glyfIndex) {

    if (!glyf.glyfs) {
        return glyf;
    }

    const compoundContours = [];
    glyf.glyfs.forEach(g => {
        const glyph = ttf.glyf[g.glyphIndex];

        if (!glyph || glyph === glyf) {
            return;
        }

        // 递归转换contours
        if (glyph.compound && !contoursList[g.glyphIndex]) {
            transformGlyfContours(glyph, ttf, contoursList, g.glyphIndex);
        }

        // 这里需要进行matrix变换，需要复制一份
        const contours = clone(glyph.compound ? (contoursList[g.glyphIndex] || []) : glyph.contours);
        const transform = g.transform;
        for (let i = 0, l = contours.length; i < l; i++) {
            pathTransform(
                contours[i],
                transform.a,
                transform.b,
                transform.c,
                transform.d,
                transform.e,
                transform.f
            );
            compoundContours.push(pathCeil(contours[i]));
        }
    });

    // eslint-disable-next-line eqeqeq
    if (null != glyfIndex) {
        contoursList[glyfIndex] = compoundContours;
    }

    return compoundContours;
}