Thai Text Support for RPG Maker MV & MZ

ThaiTextSupport.js

//=============================================================================
// ThaiTextSupport.js
// This code is licensed under the terms of the MIT license
//=============================================================================

/*:
 * @plugindesc
 * Fix font render that contain upper or/and lower glypts in message box.
 * @author Admannon
 *
 * @help This plugin does not provide plugin commands.
 */

(function () {
	// Intl.Segmenter polyfill
	const Segmenter =
		Intl.Segmenter ||
		(() => {
			if (!Intl.v8BreakIterator) {
				throw new Error("unsupported segmenter");
			}

			function _granularityToV8Type(granularity) {
				switch (granularity) {
					case "word":
					case "sentence":
					case "line":
						return granularity;
					default:
						return "character";
				}
			}

			return class Segmenter {
				constructor(locales, { granularity } = {}) {
					this._v8Instance = Intl.v8BreakIterator(locales ? [locales] : undefined, {
						type: _granularityToV8Type(granularity),
					});
				}

				segment(text) {
					this._v8Instance.adoptText(text);

					let instance = this._v8Instance;
					let start = instance.first();
					return {
						*[Symbol.iterator]() {
							while (start !== -1) {
								let next = instance.next();
								if (next === -1) break;

								yield {
									segment: text.slice(start, next),
									index: text.current,
									input: text,
								};
								start = next;
							}
						},
					};
				}
			};
		})();

	// Segmenter Object
	const iterator = new Segmenter("th");

	function makeGraphemeProxy(text) {
		const graphemes = [...iterator.segment(text)].map((graphemeObj) => graphemeObj.segment);
		const handler = {
			get({ value }, accessorName) {
				const graphemeAccessor = graphemes[accessorName];
				if (typeof graphemeAccessor == "function") {
					return (...arguments) => {
						const result = graphemeAccessor.call(graphemes, ...arguments);
						return Array.isArray(result) ? result.join("") : result;
					};
				}

				if (graphemeAccessor) {
					return graphemeAccessor;
				}

				const accessor = value[accessorName];
				return typeof accessor == "function" ? accessor.bind(value) : accessor;
			},
		};
		return new Proxy({ value: text }, handler);
	}

	const WindowBasePrototypeConvertEscapeCharacters = Window_Base.prototype.convertEscapeCharacters;
	Window_Base.prototype.convertEscapeCharacters = function (text) {
		text = WindowBasePrototypeConvertEscapeCharacters.call(this, text);
		text = makeGraphemeProxy(text);

		return text;
	};
})();