Brunobkr/llama.cpp_AlgMor24_github

1/**2 * This file does conversion between units.  In particular, it provides3 * calculateSize to convert other units into ems.4 */5 6import ParseError from "./ParseError";7import Options from "./Options";8 9// This table gives the number of TeX pts in one of each *absolute* TeX unit.10// Thus, multiplying a length by this number converts the length from units11// into pts.  Dividing the result by ptPerEm gives the number of ems12// *assuming* a font size of ptPerEm (normal size, normal style).13const ptPerUnit: Record<string, number> = {14    // https://en.wikibooks.org/wiki/LaTeX/Lengths and15    // https://tex.stackexchange.com/a/826316    "pt": 1,            // TeX point17    "mm": 7227 / 2540,  // millimeter18    "cm": 7227 / 254,   // centimeter19    "in": 72.27,        // inch20    "bp": 803 / 800,    // big (PostScript) points21    "pc": 12,           // pica22    "dd": 1238 / 1157,  // didot23    "cc": 14856 / 1157, // cicero (12 didot)24    "nd": 685 / 642,    // new didot25    "nc": 1370 / 107,   // new cicero (12 new didot)26    "sp": 1 / 65536,    // scaled point (TeX's internal smallest unit)27    // https://tex.stackexchange.com/a/4137128    "px": 803 / 800,    // \pdfpxdimen defaults to 1 bp in pdfTeX and LuaTeX29};30 31// Dictionary of relative units, for fast validity testing.32const relativeUnit = {33    "ex": true,34    "em": true,35    "mu": true,36};37 38export type Measurement = { number: number, unit: string };39 40/**41 * Determine whether the specified unit (either a string defining the unit42 * or a "size" parse node containing a unit field) is valid.43 */44export const validUnit = function(unit: string | Measurement): boolean {45    if (typeof unit !== "string") {46        unit = unit.unit;47    }48    return (unit in ptPerUnit || unit in relativeUnit || unit === "ex");49};50 51/*52 * Convert a "size" parse node (with numeric "number" and string "unit" fields,53 * as parsed by functions.js argType "size") into a CSS em value for the54 * current style/scale.  `options` gives the current options.55 */56export const calculateSize = function(57        sizeValue: Measurement, options: Options): number {58    let scale;59    if (sizeValue.unit in ptPerUnit) {60        // Absolute units61        scale = ptPerUnit[sizeValue.unit]   // Convert unit to pt62           / options.fontMetrics().ptPerEm  // Convert pt to CSS em63           / options.sizeMultiplier;        // Unscale to make absolute units64    } else if (sizeValue.unit === "mu") {65        // `mu` units scale with scriptstyle/scriptscriptstyle.66        scale = options.fontMetrics().cssEmPerMu;67    } else {68        // Other relative units always refer to the *textstyle* font69        // in the current size.70        let unitOptions;71        if (options.style.isTight()) {72            // isTight() means current style is script/scriptscript.73            unitOptions = options.havingStyle(options.style.text());74        } else {75            unitOptions = options;76        }77        // TODO: In TeX these units are relative to the quad of the current78        // *text* font, e.g. cmr10. KaTeX instead uses values from the79        // comparably-sized *Computer Modern symbol* font. At 10pt, these80        // match. At 7pt and 5pt, they differ: cmr7=1.138894, cmsy7=1.170641;81        // cmr5=1.361133, cmsy5=1.472241. Consider $\scriptsize a\kern1emb$.82        // TeX \showlists shows a kern of 1.13889 * fontsize;83        // KaTeX shows a kern of 1.171 * fontsize.84        if (sizeValue.unit === "ex") {85            scale = unitOptions.fontMetrics().xHeight;86        } else if (sizeValue.unit === "em") {87            scale = unitOptions.fontMetrics().quad;88        } else {89            throw new ParseError("Invalid unit: '" + sizeValue.unit + "'");90        }91        if (unitOptions !== options) {92            scale *= unitOptions.sizeMultiplier / options.sizeMultiplier;93        }94    }95    return Math.min(sizeValue.number * scale, options.maxSize);96};97 98/**99 * Round `n` to 4 decimal places, or to the nearest 1/10,000th em. See100 * https://github.com/KaTeX/KaTeX/pull/2460.101 */102export const makeEm = function(n: number): string {103    return +n.toFixed(4) + "em";104};105