X-Git-Url: https://git.yukkurigames.com/?p=string-lerp.git;a=blobdiff_plain;f=string-lerp.js;h=54731995783f405d7d0102d39556747cb2c0ea73;hp=6c240e44b61f9df46911224e1d51b6fd0aadca12;hb=HEAD;hpb=5bc5aa65b769e551177545fda77b31ea6c66467e diff --git a/string-lerp.js b/string-lerp.js index 6c240e4..5473199 100644 --- a/string-lerp.js +++ b/string-lerp.js @@ -1,13 +1,26 @@ /* string-lerp - progressively turn one string into another Copyright 2014 Joe Wreschnig - - This program is free software; you can redistribute it and/or modify - it under the terms of the GNU General Public License as published by - the Free Software Foundation; either version 2 of the License, or - (at your option) any later version. + Licensed under the terms of the GNU GPL v2 or later + @license http://www.gnu.org/licenses/gpl-2.0.html + @source: http://yukkurigames.com/string-lerp/ +*//* + This program is free software; you can redistribute it and/or + modify it under the terms of the GNU General Public License as + published by the Free Software Foundation; either version 2 of the + License, or (at your option) any later version. + + This program is distributed in the hope that it will be useful, but + WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + General Public License for more details. + + As additional permission, you may distribute the program or works + based on it without the copy of the GNU GPL normally required, + provided you include this license notice and a URL through which + recipients can access the corresponding source code. */ -/* @license Copyright 2014 Joe Wreschnig - GNU GPL v2 or later */ +/*globals exports, Uint32Array */ (function (exports) { "use strict"; @@ -116,42 +129,54 @@ return patcher(diff, source); } - var MULTI = /[\uD800-\uDBFF][\uDC00-\uDFFF]|[\u0300-\u036F\u1DC0-\u1DFF\u20D0-\u20FF\uFE20-\uFE2F]/; + // Matches if a string contains combining characters or astral + // codepoints (technically, the first half surrogate of an astral + // codepoint). + var MULTI = /[\u0300-\u036F\u1DC0-\u1DFF\u20D0-\u20FF\uD800-\uDBFF\uFE20-\uFE2F]/; - var GLYPH = /([\0-\u02FF\u0370-\u1DBF\u1E00-\u20CF\u2100-\uD7FF\uDC00-\uFE1F\uFE30-\uFFFF]|[\uD800-\uDBFF][\uDC00-\uDFFF]|[\uD800-\uDBFF])([\u0300-\u036F\u1DC0-\u1DFF\u20D0-\u20FF\uFE20-\uFE2F]*)/g; + // Match an entire (potentially astral) codepoint and any + // combining characters following it. + var GLYPH = /[\0-\u02FF\u0370-\u1DBF\u1E00-\u20CF\u2100-\uD7FF\uD800-\uFE1F\uFE30-\uFFFF][\u0300-\u036F\u1DC0-\u1DFF\u20D0-\u20FF\uDC00-\uDFFF\uFE20-\uFE2F]*/g; - function diffLerp(source, target, amount ) { - /** Interpolate between two strings using edit operations - - This interpolation algorithm applys a partial edit of one - string into the other. This produces nice looking results, - but can take a significant amount of time and memory to - compute the edits. It is not recommended for strings - longer than a few hundred characters. - */ - - // If given strings with astral codepoints or combining - // characters, split them into arrays of "glyphs" first, - // do the edit on the list of "glyphs", and rejoin them. - // + function diffLerpAstral(source, target, amount) { // This split is not perfect for all languages, but at least // it won't create invalid surrogate pairs or orphaned // combining characters. - // - // TODO: The way this is called is a hack. - if (source.match && (source.match(MULTI) || target.match(MULTI))) { - var sourceGlyphs = source.match(GLYPH) || []; - var targetGlyphs = target.match(GLYPH) || []; - return diffLerp(sourceGlyphs, targetGlyphs, amount).join(""); - } - + var sourceGlyphs = source.match(GLYPH) || []; + var targetGlyphs = target.match(GLYPH) || []; + var edits = diff(targetGlyphs, sourceGlyphs, 2, 2, 3); // The edit path works from the string end, forwards, because // that's how Levenshtein edits work. To match LTR reading // direction (and the behavior of fastLerp), swap the strings // and invert the parameter when editing. + var partial = edits.slice(0, Math.round((1 - amount) * edits.length)); + return patchArray(partial, targetGlyphs).join(""); + } + + function diffLerpBasic(source, target, amount) { var edits = diff(target, source, 2, 2, 3); + // The edit path works from the string end, forwards, because + // that's how Levenshtein edits work. To match LTR reading + // direction (and the behavior of fastLerp), swap the strings + // and invert the parameter when editing. var partial = edits.slice(0, Math.round((1 - amount) * edits.length)); - return patch(partial, target); + return patchString(partial, target); + } + + function diffLerp(source, target, amount) { + /** Interpolate between two strings using edit operations + + This interpolation algorithm applys a partial edit of one + string into the other. This produces nice looking results, + but can take a significant amount of time and memory to + compute the edits. It is not recommended for strings + longer than a few hundred characters. + */ + + if (source.match(MULTI) || target.match(MULTI)) + return diffLerpAstral(source, target, amount); + else + return diffLerpBasic(source, target, amount); } var NUMBERS = /(-?\d{1,20}(?:\.\d{1,20})?)/g; @@ -171,10 +196,10 @@ Numbers may have a leading "-" and a single "." to mark the decimal point, but something must be after the ".". No other floating point syntax (e.g. 1e6) is supported. - If both of the numbers in a pair are integers, the result - is clamped to an integer. + They are treated as fixed-point values, with the point's + position itself interpolating. - For example, numericLerp("0.0", "100", 0.123) === "12.3" + For example, numericLerp("0.0", "100".0, 0.123) === "12.3" because the "." in "0.0" is interpreted as a decimal point. But numericLerp("0.", "100.", 0.123) === "12." because the strings are interpreted as integers followed @@ -184,11 +209,11 @@ numerals gives undefined results. */ - var sourceParts = source.split(NUMBERS); var targetParts = target.split(NUMBERS); - var destParts = targetParts; - for (var i = 1; i < sourceParts.length; i += 2) { - var sourcePart = sourceParts[i]; + var match; + var i = 1; + while ((match = NUMBERS.exec(source))) { + var sourcePart = match[0]; var targetPart = targetParts[i]; var part = nlerp(+sourcePart, +targetPart, amount); var sourcePoint = sourcePart.indexOf("."); @@ -198,6 +223,7 @@ targetPoint >= 0 ? (targetPart.length - 1) - targetPoint : 0, amount)); targetParts[i] = part.toFixed(point); + i += 2; } return targetParts.join(""); }