File size: 3,001 Bytes
f56a29b | 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 | import temml from 'temml';
import { mml2omml } from 'mathml2omml';
import { createLogger } from '@/lib/logger';
const log = createLogger('LatexToOmml');
/**
* Strip MathML elements unsupported by mathml2omml (e.g. `<mpadded>`),
* replacing them with their inner content.
*/
function stripUnsupportedMathML(mathml: string): string {
const unsupported = ['mpadded'];
let result = mathml;
for (const tag of unsupported) {
result = result.replace(new RegExp(`<${tag}[^>]*>`, 'g'), '');
result = result.replace(new RegExp(`</${tag}>`, 'g'), '');
}
return result;
}
/**
* Build <a:rPr> for math runs. PowerPoint requires Cambria Math font.
* @param szHundredths - font size in hundredths of a point (e.g. 1200 = 12pt). Omit for no sz.
*/
function buildMathRPr(szHundredths?: number): string {
const szAttr = szHundredths ? ` sz="${szHundredths}"` : '';
return (
`<a:rPr lang="en-US" i="1"${szAttr}>` +
'<a:latin typeface="Cambria Math" panose="02040503050406030204" charset="0"/>' +
'<a:cs typeface="Cambria Math" panose="02040503050406030204" charset="0"/>' +
'</a:rPr>'
);
}
/**
* Post-process OMML for PPTX compatibility:
* 1. Strip xmlns:w (wordprocessingml is DOCX-only, not valid in PPTX)
* 2. Strip redundant xmlns:m (already declared at <p:sld> level)
* 3. Inject <a:rPr> with Cambria Math font (and optional sz) into <m:r> and <m:ctrlPr>
*/
function postProcessOmml(omml: string, szHundredths?: number): string {
let result = omml;
const rpr = buildMathRPr(szHundredths);
// Strip DOCX-only xmlns:w and redundant xmlns:m from <m:oMath>
result = result.replace(/ xmlns:w="[^"]*"/g, '');
result = result.replace(/ xmlns:m="[^"]*"/g, '');
// Insert <a:rPr> before <m:t> inside <m:r> (only if not already present)
result = result.replace(/<m:r>(\s*)<m:t/g, `<m:r>$1${rpr}$1<m:t`);
// Fill empty <m:ctrlPr/> with <a:rPr>
result = result.replace(/<m:ctrlPr\/>/g, `<m:ctrlPr>${rpr}</m:ctrlPr>`);
// Fill empty <m:ctrlPr></m:ctrlPr> with <a:rPr>
result = result.replace(/<m:ctrlPr><\/m:ctrlPr>/g, `<m:ctrlPr>${rpr}</m:ctrlPr>`);
return result;
}
/**
* Convert a LaTeX string to OMML (Office Math Markup Language) XML.
*
* Pipeline: LaTeX → MathML (temml) → strip unsupported → OMML (mathml2omml) → inject font props
*
* @param latex - LaTeX math expression (without delimiters)
* @param fontSize - Optional font size in points (e.g. 12). Applied as sz on every <a:rPr> in the OMML.
* @returns OMML XML string (an `<m:oMath>` element), or `null` if conversion fails
*/
export function latexToOmml(latex: string, fontSize?: number): string | null {
try {
const mathml = temml.renderToString(latex);
const cleaned = stripUnsupportedMathML(mathml);
const omml = String(mml2omml(cleaned));
const szHundredths = fontSize ? Math.round(fontSize * 100) : undefined;
return postProcessOmml(omml, szHundredths);
} catch {
log.warn(`Failed to convert: "${latex}"`);
return null;
}
}
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