365 lines
11 KiB
JavaScript
365 lines
11 KiB
JavaScript
(function (global, factory) {
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typeof exports === 'object' && typeof module !== 'undefined' ? factory(exports) :
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typeof define === 'function' && define.amd ? define(['exports'], factory) :
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(factory((global.blockies = {})));
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}(this, (function (exports) { 'use strict';
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/**
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* A handy class to calculate color values.
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*
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* @version 1.0
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* @author Robert Eisele <[email protected]>
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* @copyright Copyright (c) 2010, Robert Eisele
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* @link http://www.xarg.org/2010/03/generate-client-side-png-files-using-javascript/
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* @license http://www.opensource.org/licenses/bsd-license.php BSD License
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*
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*/
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// helper functions for that ctx
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function write(buffer, offs) {
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for (var i = 2; i < arguments.length; i++) {
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for (var j = 0; j < arguments[i].length; j++) {
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buffer[offs++] = arguments[i].charAt(j);
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}
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}
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}
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function byte2(w) {
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return String.fromCharCode((w >> 8) & 255, w & 255);
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}
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function byte4(w) {
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return String.fromCharCode((w >> 24) & 255, (w >> 16) & 255, (w >> 8) & 255, w & 255);
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}
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function byte2lsb(w) {
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return String.fromCharCode(w & 255, (w >> 8) & 255);
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}
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var PNG = function(width,height,depth) {
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this.width = width;
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this.height = height;
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this.depth = depth;
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// pixel data and row filter identifier size
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this.pix_size = height * (width + 1);
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// deflate header, pix_size, block headers, adler32 checksum
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this.data_size = 2 + this.pix_size + 5 * Math.floor((0xfffe + this.pix_size) / 0xffff) + 4;
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// offsets and sizes of Png chunks
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this.ihdr_offs = 0; // IHDR offset and size
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this.ihdr_size = 4 + 4 + 13 + 4;
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this.plte_offs = this.ihdr_offs + this.ihdr_size; // PLTE offset and size
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this.plte_size = 4 + 4 + 3 * depth + 4;
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this.trns_offs = this.plte_offs + this.plte_size; // tRNS offset and size
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this.trns_size = 4 + 4 + depth + 4;
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this.idat_offs = this.trns_offs + this.trns_size; // IDAT offset and size
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this.idat_size = 4 + 4 + this.data_size + 4;
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this.iend_offs = this.idat_offs + this.idat_size; // IEND offset and size
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this.iend_size = 4 + 4 + 4;
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this.buffer_size = this.iend_offs + this.iend_size; // total PNG size
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this.buffer = new Array();
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this.palette = new Object();
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this.pindex = 0;
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var _crc32 = new Array();
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// initialize buffer with zero bytes
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for (var i = 0; i < this.buffer_size; i++) {
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this.buffer[i] = "\x00";
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}
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// initialize non-zero elements
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write(this.buffer, this.ihdr_offs, byte4(this.ihdr_size - 12), 'IHDR', byte4(width), byte4(height), "\x08\x03");
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write(this.buffer, this.plte_offs, byte4(this.plte_size - 12), 'PLTE');
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write(this.buffer, this.trns_offs, byte4(this.trns_size - 12), 'tRNS');
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write(this.buffer, this.idat_offs, byte4(this.idat_size - 12), 'IDAT');
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write(this.buffer, this.iend_offs, byte4(this.iend_size - 12), 'IEND');
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// initialize deflate header
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var header = ((8 + (7 << 4)) << 8) | (3 << 6);
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header+= 31 - (header % 31);
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write(this.buffer, this.idat_offs + 8, byte2(header));
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// initialize deflate block headers
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for (var i = 0; (i << 16) - 1 < this.pix_size; i++) {
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var size, bits;
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if (i + 0xffff < this.pix_size) {
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size = 0xffff;
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bits = "\x00";
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} else {
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size = this.pix_size - (i << 16) - i;
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bits = "\x01";
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}
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write(this.buffer, this.idat_offs + 8 + 2 + (i << 16) + (i << 2), bits, byte2lsb(size), byte2lsb(~size));
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}
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/* Create crc32 lookup table */
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for (var i = 0; i < 256; i++) {
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var c = i;
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for (var j = 0; j < 8; j++) {
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if (c & 1) {
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c = -306674912 ^ ((c >> 1) & 0x7fffffff);
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} else {
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c = (c >> 1) & 0x7fffffff;
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}
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}
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_crc32[i] = c;
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}
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// compute the index into a png for a given pixel
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this.index = function(x,y) {
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var i = y * (this.width + 1) + x + 1;
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var j = this.idat_offs + 8 + 2 + 5 * Math.floor((i / 0xffff) + 1) + i;
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return j;
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};
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// convert a color and build up the palette
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this.color = function(red, green, blue, alpha) {
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alpha = alpha >= 0 ? alpha : 255;
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var color = (((((alpha << 8) | red) << 8) | green) << 8) | blue;
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if (typeof this.palette[color] == "undefined") {
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if (this.pindex == this.depth) return "\x00";
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var ndx = this.plte_offs + 8 + 3 * this.pindex;
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this.buffer[ndx + 0] = String.fromCharCode(red);
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this.buffer[ndx + 1] = String.fromCharCode(green);
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this.buffer[ndx + 2] = String.fromCharCode(blue);
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this.buffer[this.trns_offs+8+this.pindex] = String.fromCharCode(alpha);
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this.palette[color] = String.fromCharCode(this.pindex++);
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}
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return this.palette[color];
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};
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// output a PNG string, Base64 encoded
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this.getBase64 = function() {
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var s = this.getDump();
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var ch = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/=";
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var c1, c2, c3, e1, e2, e3, e4;
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var l = s.length;
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var i = 0;
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var r = "";
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do {
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c1 = s.charCodeAt(i);
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e1 = c1 >> 2;
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c2 = s.charCodeAt(i+1);
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e2 = ((c1 & 3) << 4) | (c2 >> 4);
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c3 = s.charCodeAt(i+2);
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if (l < i+2) { e3 = 64; } else { e3 = ((c2 & 0xf) << 2) | (c3 >> 6); }
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if (l < i+3) { e4 = 64; } else { e4 = c3 & 0x3f; }
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r+= ch.charAt(e1) + ch.charAt(e2) + ch.charAt(e3) + ch.charAt(e4);
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} while ((i+= 3) < l);
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return r;
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};
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// output a PNG string
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this.getDump = function() {
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// compute adler32 of output pixels + row filter bytes
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var BASE = 65521; /* largest prime smaller than 65536 */
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var NMAX = 5552; /* NMAX is the largest n such that 255n(n+1)/2 + (n+1)(BASE-1) <= 2^32-1 */
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var s1 = 1;
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var s2 = 0;
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var n = NMAX;
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for (var y = 0; y < this.height; y++) {
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for (var x = -1; x < this.width; x++) {
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s1+= this.buffer[this.index(x, y)].charCodeAt(0);
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s2+= s1;
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if ((n-= 1) == 0) {
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s1%= BASE;
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s2%= BASE;
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n = NMAX;
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}
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}
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}
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s1%= BASE;
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s2%= BASE;
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write(this.buffer, this.idat_offs + this.idat_size - 8, byte4((s2 << 16) | s1));
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// compute crc32 of the PNG chunks
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function crc32(png, offs, size) {
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var crc = -1;
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for (var i = 4; i < size-4; i += 1) {
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crc = _crc32[(crc ^ png[offs+i].charCodeAt(0)) & 0xff] ^ ((crc >> 8) & 0x00ffffff);
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}
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write(png, offs+size-4, byte4(crc ^ -1));
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}
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crc32(this.buffer, this.ihdr_offs, this.ihdr_size);
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crc32(this.buffer, this.plte_offs, this.plte_size);
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crc32(this.buffer, this.trns_offs, this.trns_size);
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crc32(this.buffer, this.idat_offs, this.idat_size);
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crc32(this.buffer, this.iend_offs, this.iend_size);
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// convert PNG to string
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return "\x89PNG\r\n\x1A\n"+this.buffer.join('');
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};
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this.fillRect = function (x, y, w, h, color) {
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for(var i = 0; i < w; i++) {
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for (var j = 0; j < h; j++) {
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this.buffer[this.index(x+i, y+j)] = color;
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}
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}
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};
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};
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// https://stackoverflow.com/questions/2353211/hsl-to-rgb-color-conversion
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/**
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* Converts an HSL color value to RGB. Conversion formula
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* adapted from http://en.wikipedia.org/wiki/HSL_color_space.
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* Assumes h, s, and l are contained in the set [0, 1] and
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* returns r, g, and b in the set [0, 255].
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*
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* @param {number} h The hue
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* @param {number} s The saturation
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* @param {number} l The lightness
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* @return {Array} The RGB representation
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*/
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function hue2rgb(p, q, t) {
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if(t < 0) t += 1;
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if(t > 1) t -= 1;
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if(t < 1/6) return p + (q - p) * 6 * t;
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if(t < 1/2) return q;
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if(t < 2/3) return p + (q - p) * (2/3 - t) * 6;
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return p;
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}
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function hsl2rgb(h, s, l){
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var r, g, b;
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if(s == 0){
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r = g = b = l; // achromatic
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}else{
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var q = l < 0.5 ? l * (1 + s) : l + s - l * s;
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var p = 2 * l - q;
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r = hue2rgb(p, q, h + 1/3);
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g = hue2rgb(p, q, h);
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b = hue2rgb(p, q, h - 1/3);
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}
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return [Math.round(r * 255), Math.round(g * 255), Math.round(b * 255), 255];
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}
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// The random number is a js implementation of the Xorshift PRNG
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var randseed = new Array(4); // Xorshift: [x, y, z, w] 32 bit values
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function seedrand(seed) {
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for (var i = 0; i < randseed.length; i++) {
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randseed[i] = 0;
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}
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for (var i = 0; i < seed.length; i++) {
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randseed[i % 4] = (randseed[i % 4] << 5) - randseed[i % 4] + seed.charCodeAt(i);
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}
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}
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function rand() {
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// based on Java's String.hashCode(), expanded to 4 32bit values
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var t = randseed[0] ^ (randseed[0] << 11);
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randseed[0] = randseed[1];
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randseed[1] = randseed[2];
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randseed[2] = randseed[3];
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randseed[3] = randseed[3] ^ (randseed[3] >> 19) ^ t ^ (t >> 8);
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return (randseed[3] >>> 0) / (1 << 31 >>> 0);
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}
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function createColor() {
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//saturation is the whole color spectrum
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var h = Math.floor(rand() * 360);
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//saturation goes from 40 to 100, it avoids greyish colors
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var s = rand() * 60 + 40;
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//lightness can be anything from 0 to 100, but probabilities are a bell curve around 50%
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var l = (rand() + rand() + rand() + rand()) * 25;
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return [h / 360,s / 100,l / 100];
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}
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function createImageData(size) {
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var width = size; // Only support square icons for now
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var height = size;
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var dataWidth = Math.ceil(width / 2);
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var mirrorWidth = width - dataWidth;
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var data = [];
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for (var y = 0; y < height; y++) {
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var row = [];
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for (var x = 0; x < dataWidth; x++) {
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// this makes foreground and background color to have a 43% (1/2.3) probability
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// spot color has 13% chance
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row[x] = Math.floor(rand() * 2.3);
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}
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var r = row.slice(0, mirrorWidth);
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r.reverse();
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row = row.concat(r);
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for (var i = 0; i < row.length; i++) {
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data.push(row[i]);
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}
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}
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return data;
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}
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function buildOpts(opts) {
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if (!opts.seed) {
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throw 'No seed provided'
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}
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seedrand(opts.seed);
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return Object.assign({
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size: 8,
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scale: 16,
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color: createColor(),
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bgcolor: createColor(),
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spotcolor: createColor(),
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}, opts)
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}
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function toDataUrl(address) {
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const opts = buildOpts({seed: address.toLowerCase()});
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const imageData = createImageData(opts.size);
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const width = Math.sqrt(imageData.length);
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const p = new PNG(opts.size*opts.scale, opts.size*opts.scale, 3);
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const bgcolor = p.color(...hsl2rgb(...opts.bgcolor));
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const color = p.color(...hsl2rgb(...opts.color));
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const spotcolor = p.color(...hsl2rgb(...opts.spotcolor));
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for (var i = 0; i < imageData.length; i++) {
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var row = Math.floor(i / width);
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var col = i % width;
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// if data is 0, leave the background
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if (imageData[i]) {
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// if data is 2, choose spot color, if 1 choose foreground
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const pngColor = imageData[i] == 1 ? color : spotcolor;
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p.fillRect(col * opts.scale, row * opts.scale, opts.scale, opts.scale, pngColor);
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}
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}
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return `data:image/png;base64,${p.getBase64()}`;
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}
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exports.toDataUrl = toDataUrl;
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Object.defineProperty(exports, '__esModule', { value: true });
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})));
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