/* 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";
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;
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
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(".");
var targetPoint = targetPart.indexOf(".");
- var point = Math.max(
+ var point = Math.round(nlerp(
sourcePoint >= 0 ? (sourcePart.length - 1) - sourcePoint : 0,
- targetPoint >= 0 ? (targetPart.length - 1) - targetPoint : 0);
+ targetPoint >= 0 ? (targetPart.length - 1) - targetPoint : 0,
+ amount));
targetParts[i] = part.toFixed(point);
+ i += 2;
}
return targetParts.join("");
}
projects / string-lerp.git / blobdiff