53113644a0
The utility functions colorutils.js assume that background colors are in CSS hex format, so require userColor to do the same, rather than allowing inputs like "red" and "rgba(...)", to insure that inversion checks will succeed.
145 lines
3.9 KiB
JavaScript
145 lines
3.9 KiB
JavaScript
/**
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* This code is mostly from the old Etherpad. Please help us to comment this code.
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* This helps other people to understand this code better and helps them to improve it.
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* TL;DR COMMENTS ON THIS FILE ARE HIGHLY APPRECIATED
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*/
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// DO NOT EDIT THIS FILE, edit infrastructure/ace/www/colorutils.js
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// THIS FILE IS ALSO SERVED AS CLIENT-SIDE JS
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/**
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* Copyright 2009 Google Inc.
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*
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* Licensed under the Apache License, Version 2.0 (the "License");
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* you may not use this file except in compliance with the License.
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* You may obtain a copy of the License at
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*
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* http://www.apache.org/licenses/LICENSE-2.0
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*
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* Unless required by applicable law or agreed to in writing, software
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* distributed under the License is distributed on an "AS-IS" BASIS,
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* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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* See the License for the specific language governing permissions and
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* limitations under the License.
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*/
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var colorutils = {};
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// Check that a given value is a css hex color value, e.g.
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// "#ffffff" or "#fff"
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colorutils.isCssHex = function(cssColor)
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{
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return /^#([0-9a-f]{3}|[0-9a-f]{6})$/i.test(cssColor);
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}
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// "#ffffff" or "#fff" or "ffffff" or "fff" to [1.0, 1.0, 1.0]
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colorutils.css2triple = function(cssColor)
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{
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var sixHex = colorutils.css2sixhex(cssColor);
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function hexToFloat(hh)
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{
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return Number("0x" + hh) / 255;
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}
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return [hexToFloat(sixHex.substr(0, 2)), hexToFloat(sixHex.substr(2, 2)), hexToFloat(sixHex.substr(4, 2))];
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}
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// "#ffffff" or "#fff" or "ffffff" or "fff" to "ffffff"
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colorutils.css2sixhex = function(cssColor)
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{
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var h = /[0-9a-fA-F]+/.exec(cssColor)[0];
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if (h.length != 6)
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{
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var a = h.charAt(0);
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var b = h.charAt(1);
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var c = h.charAt(2);
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h = a + a + b + b + c + c;
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}
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return h;
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}
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// [1.0, 1.0, 1.0] -> "#ffffff"
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colorutils.triple2css = function(triple)
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{
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function floatToHex(n)
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{
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var n2 = colorutils.clamp(Math.round(n * 255), 0, 255);
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return ("0" + n2.toString(16)).slice(-2);
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}
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return "#" + floatToHex(triple[0]) + floatToHex(triple[1]) + floatToHex(triple[2]);
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}
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colorutils.clamp = function(v, bot, top)
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{
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return v < bot ? bot : (v > top ? top : v);
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};
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colorutils.min3 = function(a, b, c)
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{
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return (a < b) ? (a < c ? a : c) : (b < c ? b : c);
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};
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colorutils.max3 = function(a, b, c)
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{
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return (a > b) ? (a > c ? a : c) : (b > c ? b : c);
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};
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colorutils.colorMin = function(c)
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{
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return colorutils.min3(c[0], c[1], c[2]);
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};
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colorutils.colorMax = function(c)
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{
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return colorutils.max3(c[0], c[1], c[2]);
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};
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colorutils.scale = function(v, bot, top)
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{
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return colorutils.clamp(bot + v * (top - bot), 0, 1);
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};
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colorutils.unscale = function(v, bot, top)
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{
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return colorutils.clamp((v - bot) / (top - bot), 0, 1);
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};
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colorutils.scaleColor = function(c, bot, top)
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{
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return [colorutils.scale(c[0], bot, top), colorutils.scale(c[1], bot, top), colorutils.scale(c[2], bot, top)];
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}
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colorutils.unscaleColor = function(c, bot, top)
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{
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return [colorutils.unscale(c[0], bot, top), colorutils.unscale(c[1], bot, top), colorutils.unscale(c[2], bot, top)];
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}
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colorutils.luminosity = function(c)
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{
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// rule of thumb for RGB brightness; 1.0 is white
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return c[0] * 0.30 + c[1] * 0.59 + c[2] * 0.11;
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}
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colorutils.saturate = function(c)
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{
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var min = colorutils.colorMin(c);
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var max = colorutils.colorMax(c);
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if (max - min <= 0) return [1.0, 1.0, 1.0];
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return colorutils.unscaleColor(c, min, max);
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}
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colorutils.blend = function(c1, c2, t)
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{
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return [colorutils.scale(t, c1[0], c2[0]), colorutils.scale(t, c1[1], c2[1]), colorutils.scale(t, c1[2], c2[2])];
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}
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colorutils.invert = function(c)
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{
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return [1 - c[0], 1 - c[1], 1- c[2]];
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}
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colorutils.complementary = function(c)
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{
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var inv = colorutils.invert(c);
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return [
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(inv[0] >= c[0]) ? Math.min(inv[0] * 1.30, 1) : (c[0] * 0.30),
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(inv[1] >= c[1]) ? Math.min(inv[1] * 1.59, 1) : (c[1] * 0.59),
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(inv[2] >= c[2]) ? Math.min(inv[2] * 1.11, 1) : (c[2] * 0.11)
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];
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}
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exports.colorutils = colorutils;
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