index.js

// https://knowledge.autodesk.com/ja/support/autocad/learn-explore/caas/CloudHelp/cloudhelp/2019/JPN/AutoCAD-Core/files/GUID-968CBC1D-BA99-4519-ABDD-88419EB2BF92-htm.html
// https://knowledge.autodesk.com/ja/support/autocad/learn-explore/caas/CloudHelp/cloudhelp/2019/JPN/AutoCAD-Core/files/GUID-518E1A9D-398C-4A8A-AC32-2D85590CDBE1-htm.html
const dxfTextControlCodeSymbolMap = {
    d: '°',
    c: '⌀',
    p: '±',
};
export const decodeDxfTextCharacterCodes = (text, mbcsEncoding) => {
    text = decodeDxfTextUnicodeCodePoints(text);
    return mbcsEncoding ? decodeDxfTextMbcsCharacterCodes(text, mbcsEncoding) : text;
};
export const decodeDxfTextUnicodeCodePoints = (text) => text.replace(/\\[uU]\+([0-9a-fA-F]{4})/g, (_, codePoint) => String.fromCodePoint(parseInt(codePoint, 16)));
export const decodeDxfTextMbcsCharacterCodes = (text, encoding) => {
    let decoder = encoding instanceof TextDecoder ? encoding : undefined;
    return text.replace(/\\[mM]\+1([0-9a-fA-F]{2})([0-9a-fA-F]{2})/g, (_, a, b) => (decoder = decoder || new TextDecoder(encoding)).decode(new Uint8Array([parseInt(a, 16), parseInt(b, 16)])));
};
export const parseDxfTextContent = (text, options) => {
    text = decodeDxfTextCharacterCodes(text, options?.encoding);
    let previousIndex = 0;
    let currentContent = { text: '' };
    const contents = [currentContent];
    for (const match of text.matchAll(/%%(\d\d\d|.)/g)) {
        currentContent.text += text.slice(previousIndex, match.index);
        const c = match[1];
        const code = c.toLowerCase();
        const symbol = dxfTextControlCodeSymbolMap[code];
        if (symbol) {
            currentContent.text += symbol;
        }
        else if (code.length === 3) {
            currentContent.text += String.fromCodePoint(+code);
        }
        else if (code === 'k' || code === 'o' || code === 'u') {
            currentContent = { ...currentContent, text: '' };
            if (currentContent[code]) {
                delete currentContent[code];
            }
            else {
                currentContent[code] = 1;
            }
            contents.push(currentContent);
        }
        else {
            currentContent.text += code;
        }
        previousIndex = match.index + match[0].length;
    }
    currentContent.text += text.slice(previousIndex);
    return contents.filter(content => content.text);
};