mirror of https://github.com/jkjoy/sunpeiwen.git
368 lines
7.0 KiB
JavaScript
368 lines
7.0 KiB
JavaScript
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/*!
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* Stylus - RGBA
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* Copyright (c) Automattic <developer.wordpress.com>
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* MIT Licensed
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*/
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/**
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* Module dependencies.
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*/
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var Node = require('./node')
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, HSLA = require('./hsla')
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, functions = require('../functions')
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, adjust = functions.adjust
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, nodes = require('./');
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/**
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* Initialize a new `RGBA` with the given r,g,b,a component values.
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*
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* @param {Number} r
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* @param {Number} g
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* @param {Number} b
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* @param {Number} a
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* @api public
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*/
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var RGBA = exports = module.exports = function RGBA(r,g,b,a){
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Node.call(this);
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this.r = clamp(r);
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this.g = clamp(g);
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this.b = clamp(b);
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this.a = clampAlpha(a);
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this.name = '';
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this.rgba = this;
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};
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/**
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* Inherit from `Node.prototype`.
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*/
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RGBA.prototype.__proto__ = Node.prototype;
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/**
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* Return an `RGBA` without clamping values.
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*
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* @param {Number} r
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* @param {Number} g
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* @param {Number} b
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* @param {Number} a
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* @return {RGBA}
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* @api public
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*/
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RGBA.withoutClamping = function(r,g,b,a){
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var rgba = new RGBA(0,0,0,0);
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rgba.r = r;
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rgba.g = g;
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rgba.b = b;
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rgba.a = a;
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return rgba;
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};
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/**
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* Return a clone of this node.
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*
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* @return {Node}
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* @api public
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*/
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RGBA.prototype.clone = function(){
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var clone = new RGBA(
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this.r
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, this.g
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, this.b
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, this.a);
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clone.raw = this.raw;
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clone.name = this.name;
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clone.lineno = this.lineno;
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clone.column = this.column;
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clone.filename = this.filename;
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return clone;
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};
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/**
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* Return a JSON representation of this node.
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*
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* @return {Object}
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* @api public
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*/
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RGBA.prototype.toJSON = function(){
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return {
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__type: 'RGBA',
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r: this.r,
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g: this.g,
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b: this.b,
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a: this.a,
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raw: this.raw,
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name: this.name,
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lineno: this.lineno,
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column: this.column,
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filename: this.filename
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};
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};
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/**
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* Return true.
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*
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* @return {Boolean}
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* @api public
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*/
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RGBA.prototype.toBoolean = function(){
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return nodes.true;
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};
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/**
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* Return `HSLA` representation.
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*
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* @return {HSLA}
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* @api public
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*/
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RGBA.prototype.__defineGetter__('hsla', function(){
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return HSLA.fromRGBA(this);
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});
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/**
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* Return hash.
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*
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* @return {String}
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* @api public
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*/
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RGBA.prototype.__defineGetter__('hash', function(){
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return this.toString();
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});
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/**
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* Add r,g,b,a to the current component values.
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*
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* @param {Number} r
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* @param {Number} g
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* @param {Number} b
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* @param {Number} a
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* @return {RGBA} new node
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* @api public
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*/
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RGBA.prototype.add = function(r,g,b,a){
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return new RGBA(
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this.r + r
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, this.g + g
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, this.b + b
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, this.a + a);
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};
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/**
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* Subtract r,g,b,a from the current component values.
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*
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* @param {Number} r
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* @param {Number} g
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* @param {Number} b
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* @param {Number} a
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* @return {RGBA} new node
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* @api public
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*/
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RGBA.prototype.sub = function(r,g,b,a){
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return new RGBA(
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this.r - r
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, this.g - g
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, this.b - b
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, a == 1 ? this.a : this.a - a);
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};
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/**
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* Multiply rgb components by `n`.
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*
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* @param {String} n
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* @return {RGBA} new node
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* @api public
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*/
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RGBA.prototype.multiply = function(n){
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return new RGBA(
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this.r * n
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, this.g * n
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, this.b * n
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, this.a);
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};
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/**
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* Divide rgb components by `n`.
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*
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* @param {String} n
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* @return {RGBA} new node
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* @api public
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*/
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RGBA.prototype.divide = function(n){
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return new RGBA(
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this.r / n
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, this.g / n
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, this.b / n
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, this.a);
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};
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/**
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* Operate on `right` with the given `op`.
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*
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* @param {String} op
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* @param {Node} right
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* @return {Node}
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* @api public
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*/
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RGBA.prototype.operate = function(op, right){
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if ('in' != op) right = right.first
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switch (op) {
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case 'is a':
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if ('string' == right.nodeName && 'color' == right.string) {
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return nodes.true;
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}
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break;
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case '+':
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switch (right.nodeName) {
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case 'unit':
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var n = right.val;
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switch (right.type) {
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case '%': return adjust(this, new nodes.String('lightness'), right);
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case 'deg': return this.hsla.adjustHue(n).rgba;
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default: return this.add(n,n,n,0);
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}
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case 'rgba':
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return this.add(right.r, right.g, right.b, right.a);
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case 'hsla':
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return this.hsla.add(right.h, right.s, right.l);
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}
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break;
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case '-':
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switch (right.nodeName) {
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case 'unit':
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var n = right.val;
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switch (right.type) {
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case '%': return adjust(this, new nodes.String('lightness'), new nodes.Unit(-n, '%'));
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case 'deg': return this.hsla.adjustHue(-n).rgba;
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default: return this.sub(n,n,n,0);
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}
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case 'rgba':
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return this.sub(right.r, right.g, right.b, right.a);
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case 'hsla':
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return this.hsla.sub(right.h, right.s, right.l);
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}
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break;
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case '*':
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switch (right.nodeName) {
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case 'unit':
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return this.multiply(right.val);
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}
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break;
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case '/':
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switch (right.nodeName) {
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case 'unit':
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return this.divide(right.val);
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}
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break;
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}
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return Node.prototype.operate.call(this, op, right);
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};
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/**
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* Return #nnnnnn, #nnn, or rgba(n,n,n,n) string representation of the color.
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*
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* @return {String}
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* @api public
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*/
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RGBA.prototype.toString = function(){
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function pad(n) {
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return n < 16
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? '0' + n.toString(16)
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: n.toString(16);
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}
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// special case for transparent named color
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if ('transparent' == this.name)
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return this.name;
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if (1 == this.a) {
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var r = pad(this.r)
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, g = pad(this.g)
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, b = pad(this.b);
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// Compress
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if (r[0] == r[1] && g[0] == g[1] && b[0] == b[1]) {
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return '#' + r[0] + g[0] + b[0];
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} else {
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return '#' + r + g + b;
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}
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} else {
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return 'rgba('
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+ this.r + ','
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+ this.g + ','
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+ this.b + ','
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+ (+this.a.toFixed(3)) + ')';
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}
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};
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/**
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* Return a `RGBA` from the given `hsla`.
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*
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* @param {HSLA} hsla
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* @return {RGBA}
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* @api public
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*/
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exports.fromHSLA = function(hsla){
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var h = hsla.h / 360
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, s = hsla.s / 100
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, l = hsla.l / 100
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, a = hsla.a;
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var m2 = l <= .5 ? l * (s + 1) : l + s - l * s
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, m1 = l * 2 - m2;
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var r = hue(h + 1/3) * 0xff
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, g = hue(h) * 0xff
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, b = hue(h - 1/3) * 0xff;
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function hue(h) {
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if (h < 0) ++h;
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if (h > 1) --h;
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if (h * 6 < 1) return m1 + (m2 - m1) * h * 6;
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if (h * 2 < 1) return m2;
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if (h * 3 < 2) return m1 + (m2 - m1) * (2/3 - h) * 6;
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return m1;
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}
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return new RGBA(r,g,b,a);
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};
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/**
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* Clamp `n` >= 0 and <= 255.
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*
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* @param {Number} n
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* @return {Number}
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* @api private
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*/
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function clamp(n) {
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return Math.max(0, Math.min(n.toFixed(0), 255));
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}
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/**
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* Clamp alpha `n` >= 0 and <= 1.
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*
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* @param {Number} n
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* @return {Number}
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* @api private
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*/
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function clampAlpha(n) {
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return Math.max(0, Math.min(n, 1));
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}
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