From a27649aadbdee1afd165e37b5a01a2ada3fbef50 Mon Sep 17 00:00:00 2001 From: sbosse Date: Mon, 21 Jul 2025 23:04:11 +0200 Subject: [PATCH] Mon 21 Jul 22:43:21 CEST 2025 --- js/x11/examples/png/node-png.js | 880 ++++++++++++++++++++++++++++++++ 1 file changed, 880 insertions(+) create mode 100644 js/x11/examples/png/node-png.js diff --git a/js/x11/examples/png/node-png.js b/js/x11/examples/png/node-png.js new file mode 100644 index 0000000..7047cf5 --- /dev/null +++ b/js/x11/examples/png/node-png.js @@ -0,0 +1,880 @@ +/* Extracted from https://github.com/devongovett/png.js/ */ +/* + # MIT LICENSE + # Copyright (c) 2011 Devon Govett + # + # Permission is hereby granted, free of charge, to any person obtaining a copy of this + # software and associated documentation files (the "Software"), to deal in the Software + # without restriction, including without limitation the rights to use, copy, modify, merge, + # publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons + # to whom the Software is furnished to do so, subject to the following conditions: + # + # The above copyright notice and this permission notice shall be included in all copies or + # substantial portions of the Software. + # + # THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING + # BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND + # NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, + # DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, + # OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. + */ + + +/* + * Extracted from pdf.js + * https://github.com/andreasgal/pdf.js + * + * Copyright (c) 2011 Mozilla Foundation + * + * Contributors: Andreas Gal + * Chris G Jones + * Shaon Barman + * Vivien Nicolas <21@vingtetun.org> + * Justin D'Arcangelo + * Yury Delendik + * + * Permission is hereby granted, free of charge, to any person obtaining a + * copy of this software and associated documentation files (the "Software"), + * to deal in the Software without restriction, including without limitation + * the rights to use, copy, modify, merge, publish, distribute, sublicense, + * and/or sell copies of the Software, and to permit persons to whom the + * Software is furnished to do so, subject to the following conditions: + * + * The above copyright notice and this permission notice shall be included in + * all copies or substantial portions of the Software. + * + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR + * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, + * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL + * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER + * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING + * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER + * DEALINGS IN THE SOFTWARE. + */ + +var DecodeStream = (function() { + function constructor() { + this.pos = 0; + this.bufferLength = 0; + this.eof = false; + this.buffer = null; + } + + constructor.prototype = { + ensureBuffer: function decodestream_ensureBuffer(requested) { + var buffer = this.buffer; + var current = buffer ? buffer.byteLength : 0; + if (requested < current) + return buffer; + var size = 512; + while (size < requested) + size <<= 1; + var buffer2 = new Uint8Array(size); + for (var i = 0; i < current; ++i) + buffer2[i] = buffer[i]; + return this.buffer = buffer2; + }, + getByte: function decodestream_getByte() { + var pos = this.pos; + while (this.bufferLength <= pos) { + if (this.eof) + return null; + this.readBlock(); + } + return this.buffer[this.pos++]; + }, + getBytes: function decodestream_getBytes(length) { + var pos = this.pos; + + if (length) { + this.ensureBuffer(pos + length); + var end = pos + length; + + while (!this.eof && this.bufferLength < end) + this.readBlock(); + + var bufEnd = this.bufferLength; + if (end > bufEnd) + end = bufEnd; + } else { + while (!this.eof) + this.readBlock(); + + var end = this.bufferLength; + } + + this.pos = end; + return this.buffer.subarray(pos, end); + }, + lookChar: function decodestream_lookChar() { + var pos = this.pos; + while (this.bufferLength <= pos) { + if (this.eof) + return null; + this.readBlock(); + } + return String.fromCharCode(this.buffer[this.pos]); + }, + getChar: function decodestream_getChar() { + var pos = this.pos; + while (this.bufferLength <= pos) { + if (this.eof) + return null; + this.readBlock(); + } + return String.fromCharCode(this.buffer[this.pos++]); + }, + makeSubStream: function decodestream_makeSubstream(start, length, dict) { + var end = start + length; + while (this.bufferLength <= end && !this.eof) + this.readBlock(); + return new Stream(this.buffer, start, length, dict); + }, + skip: function decodestream_skip(n) { + if (!n) + n = 1; + this.pos += n; + }, + reset: function decodestream_reset() { + this.pos = 0; + } + }; + + return constructor; +})(); + +var FlateStream = (function() { + var codeLenCodeMap = new Uint32Array([ + 16, 17, 18, 0, 8, 7, 9, 6, 10, 5, 11, 4, 12, 3, 13, 2, 14, 1, 15 + ]); + + var lengthDecode = new Uint32Array([ + 0x00003, 0x00004, 0x00005, 0x00006, 0x00007, 0x00008, 0x00009, 0x0000a, + 0x1000b, 0x1000d, 0x1000f, 0x10011, 0x20013, 0x20017, 0x2001b, 0x2001f, + 0x30023, 0x3002b, 0x30033, 0x3003b, 0x40043, 0x40053, 0x40063, 0x40073, + 0x50083, 0x500a3, 0x500c3, 0x500e3, 0x00102, 0x00102, 0x00102 + ]); + + var distDecode = new Uint32Array([ + 0x00001, 0x00002, 0x00003, 0x00004, 0x10005, 0x10007, 0x20009, 0x2000d, + 0x30011, 0x30019, 0x40021, 0x40031, 0x50041, 0x50061, 0x60081, 0x600c1, + 0x70101, 0x70181, 0x80201, 0x80301, 0x90401, 0x90601, 0xa0801, 0xa0c01, + 0xb1001, 0xb1801, 0xc2001, 0xc3001, 0xd4001, 0xd6001 + ]); + + var fixedLitCodeTab = [new Uint32Array([ + 0x70100, 0x80050, 0x80010, 0x80118, 0x70110, 0x80070, 0x80030, 0x900c0, + 0x70108, 0x80060, 0x80020, 0x900a0, 0x80000, 0x80080, 0x80040, 0x900e0, + 0x70104, 0x80058, 0x80018, 0x90090, 0x70114, 0x80078, 0x80038, 0x900d0, + 0x7010c, 0x80068, 0x80028, 0x900b0, 0x80008, 0x80088, 0x80048, 0x900f0, + 0x70102, 0x80054, 0x80014, 0x8011c, 0x70112, 0x80074, 0x80034, 0x900c8, + 0x7010a, 0x80064, 0x80024, 0x900a8, 0x80004, 0x80084, 0x80044, 0x900e8, + 0x70106, 0x8005c, 0x8001c, 0x90098, 0x70116, 0x8007c, 0x8003c, 0x900d8, + 0x7010e, 0x8006c, 0x8002c, 0x900b8, 0x8000c, 0x8008c, 0x8004c, 0x900f8, + 0x70101, 0x80052, 0x80012, 0x8011a, 0x70111, 0x80072, 0x80032, 0x900c4, + 0x70109, 0x80062, 0x80022, 0x900a4, 0x80002, 0x80082, 0x80042, 0x900e4, + 0x70105, 0x8005a, 0x8001a, 0x90094, 0x70115, 0x8007a, 0x8003a, 0x900d4, + 0x7010d, 0x8006a, 0x8002a, 0x900b4, 0x8000a, 0x8008a, 0x8004a, 0x900f4, + 0x70103, 0x80056, 0x80016, 0x8011e, 0x70113, 0x80076, 0x80036, 0x900cc, + 0x7010b, 0x80066, 0x80026, 0x900ac, 0x80006, 0x80086, 0x80046, 0x900ec, + 0x70107, 0x8005e, 0x8001e, 0x9009c, 0x70117, 0x8007e, 0x8003e, 0x900dc, + 0x7010f, 0x8006e, 0x8002e, 0x900bc, 0x8000e, 0x8008e, 0x8004e, 0x900fc, + 0x70100, 0x80051, 0x80011, 0x80119, 0x70110, 0x80071, 0x80031, 0x900c2, + 0x70108, 0x80061, 0x80021, 0x900a2, 0x80001, 0x80081, 0x80041, 0x900e2, + 0x70104, 0x80059, 0x80019, 0x90092, 0x70114, 0x80079, 0x80039, 0x900d2, + 0x7010c, 0x80069, 0x80029, 0x900b2, 0x80009, 0x80089, 0x80049, 0x900f2, + 0x70102, 0x80055, 0x80015, 0x8011d, 0x70112, 0x80075, 0x80035, 0x900ca, + 0x7010a, 0x80065, 0x80025, 0x900aa, 0x80005, 0x80085, 0x80045, 0x900ea, + 0x70106, 0x8005d, 0x8001d, 0x9009a, 0x70116, 0x8007d, 0x8003d, 0x900da, + 0x7010e, 0x8006d, 0x8002d, 0x900ba, 0x8000d, 0x8008d, 0x8004d, 0x900fa, + 0x70101, 0x80053, 0x80013, 0x8011b, 0x70111, 0x80073, 0x80033, 0x900c6, + 0x70109, 0x80063, 0x80023, 0x900a6, 0x80003, 0x80083, 0x80043, 0x900e6, + 0x70105, 0x8005b, 0x8001b, 0x90096, 0x70115, 0x8007b, 0x8003b, 0x900d6, + 0x7010d, 0x8006b, 0x8002b, 0x900b6, 0x8000b, 0x8008b, 0x8004b, 0x900f6, + 0x70103, 0x80057, 0x80017, 0x8011f, 0x70113, 0x80077, 0x80037, 0x900ce, + 0x7010b, 0x80067, 0x80027, 0x900ae, 0x80007, 0x80087, 0x80047, 0x900ee, + 0x70107, 0x8005f, 0x8001f, 0x9009e, 0x70117, 0x8007f, 0x8003f, 0x900de, + 0x7010f, 0x8006f, 0x8002f, 0x900be, 0x8000f, 0x8008f, 0x8004f, 0x900fe, + 0x70100, 0x80050, 0x80010, 0x80118, 0x70110, 0x80070, 0x80030, 0x900c1, + 0x70108, 0x80060, 0x80020, 0x900a1, 0x80000, 0x80080, 0x80040, 0x900e1, + 0x70104, 0x80058, 0x80018, 0x90091, 0x70114, 0x80078, 0x80038, 0x900d1, + 0x7010c, 0x80068, 0x80028, 0x900b1, 0x80008, 0x80088, 0x80048, 0x900f1, + 0x70102, 0x80054, 0x80014, 0x8011c, 0x70112, 0x80074, 0x80034, 0x900c9, + 0x7010a, 0x80064, 0x80024, 0x900a9, 0x80004, 0x80084, 0x80044, 0x900e9, + 0x70106, 0x8005c, 0x8001c, 0x90099, 0x70116, 0x8007c, 0x8003c, 0x900d9, + 0x7010e, 0x8006c, 0x8002c, 0x900b9, 0x8000c, 0x8008c, 0x8004c, 0x900f9, + 0x70101, 0x80052, 0x80012, 0x8011a, 0x70111, 0x80072, 0x80032, 0x900c5, + 0x70109, 0x80062, 0x80022, 0x900a5, 0x80002, 0x80082, 0x80042, 0x900e5, + 0x70105, 0x8005a, 0x8001a, 0x90095, 0x70115, 0x8007a, 0x8003a, 0x900d5, + 0x7010d, 0x8006a, 0x8002a, 0x900b5, 0x8000a, 0x8008a, 0x8004a, 0x900f5, + 0x70103, 0x80056, 0x80016, 0x8011e, 0x70113, 0x80076, 0x80036, 0x900cd, + 0x7010b, 0x80066, 0x80026, 0x900ad, 0x80006, 0x80086, 0x80046, 0x900ed, + 0x70107, 0x8005e, 0x8001e, 0x9009d, 0x70117, 0x8007e, 0x8003e, 0x900dd, + 0x7010f, 0x8006e, 0x8002e, 0x900bd, 0x8000e, 0x8008e, 0x8004e, 0x900fd, + 0x70100, 0x80051, 0x80011, 0x80119, 0x70110, 0x80071, 0x80031, 0x900c3, + 0x70108, 0x80061, 0x80021, 0x900a3, 0x80001, 0x80081, 0x80041, 0x900e3, + 0x70104, 0x80059, 0x80019, 0x90093, 0x70114, 0x80079, 0x80039, 0x900d3, + 0x7010c, 0x80069, 0x80029, 0x900b3, 0x80009, 0x80089, 0x80049, 0x900f3, + 0x70102, 0x80055, 0x80015, 0x8011d, 0x70112, 0x80075, 0x80035, 0x900cb, + 0x7010a, 0x80065, 0x80025, 0x900ab, 0x80005, 0x80085, 0x80045, 0x900eb, + 0x70106, 0x8005d, 0x8001d, 0x9009b, 0x70116, 0x8007d, 0x8003d, 0x900db, + 0x7010e, 0x8006d, 0x8002d, 0x900bb, 0x8000d, 0x8008d, 0x8004d, 0x900fb, + 0x70101, 0x80053, 0x80013, 0x8011b, 0x70111, 0x80073, 0x80033, 0x900c7, + 0x70109, 0x80063, 0x80023, 0x900a7, 0x80003, 0x80083, 0x80043, 0x900e7, + 0x70105, 0x8005b, 0x8001b, 0x90097, 0x70115, 0x8007b, 0x8003b, 0x900d7, + 0x7010d, 0x8006b, 0x8002b, 0x900b7, 0x8000b, 0x8008b, 0x8004b, 0x900f7, + 0x70103, 0x80057, 0x80017, 0x8011f, 0x70113, 0x80077, 0x80037, 0x900cf, + 0x7010b, 0x80067, 0x80027, 0x900af, 0x80007, 0x80087, 0x80047, 0x900ef, + 0x70107, 0x8005f, 0x8001f, 0x9009f, 0x70117, 0x8007f, 0x8003f, 0x900df, + 0x7010f, 0x8006f, 0x8002f, 0x900bf, 0x8000f, 0x8008f, 0x8004f, 0x900ff + ]), 9]; + + var fixedDistCodeTab = [new Uint32Array([ + 0x50000, 0x50010, 0x50008, 0x50018, 0x50004, 0x50014, 0x5000c, 0x5001c, + 0x50002, 0x50012, 0x5000a, 0x5001a, 0x50006, 0x50016, 0x5000e, 0x00000, + 0x50001, 0x50011, 0x50009, 0x50019, 0x50005, 0x50015, 0x5000d, 0x5001d, + 0x50003, 0x50013, 0x5000b, 0x5001b, 0x50007, 0x50017, 0x5000f, 0x00000 + ]), 5]; + + function error(e) { + throw new Error(e) + } + + function constructor(bytes) { + //var bytes = stream.getBytes(); + var bytesPos = 0; + + var cmf = bytes[bytesPos++]; + var flg = bytes[bytesPos++]; + if (cmf == -1 || flg == -1) + error('Invalid header in flate stream'); + if ((cmf & 0x0f) != 0x08) + error('Unknown compression method in flate stream'); + if ((((cmf << 8) + flg) % 31) != 0) + error('Bad FCHECK in flate stream'); + if (flg & 0x20) + error('FDICT bit set in flate stream'); + + this.bytes = bytes; + this.bytesPos = bytesPos; + + this.codeSize = 0; + this.codeBuf = 0; + + DecodeStream.call(this); + } + + constructor.prototype = Object.create(DecodeStream.prototype); + + constructor.prototype.getBits = function(bits) { + var codeSize = this.codeSize; + var codeBuf = this.codeBuf; + var bytes = this.bytes; + var bytesPos = this.bytesPos; + + var b; + while (codeSize < bits) { + if (typeof (b = bytes[bytesPos++]) == 'undefined') + error('Bad encoding in flate stream'); + codeBuf |= b << codeSize; + codeSize += 8; + } + b = codeBuf & ((1 << bits) - 1); + this.codeBuf = codeBuf >> bits; + this.codeSize = codeSize -= bits; + this.bytesPos = bytesPos; + return b; + }; + + constructor.prototype.getCode = function(table) { + var codes = table[0]; + var maxLen = table[1]; + var codeSize = this.codeSize; + var codeBuf = this.codeBuf; + var bytes = this.bytes; + var bytesPos = this.bytesPos; + + while (codeSize < maxLen) { + var b; + if (typeof (b = bytes[bytesPos++]) == 'undefined') + error('Bad encoding in flate stream'); + codeBuf |= (b << codeSize); + codeSize += 8; + } + var code = codes[codeBuf & ((1 << maxLen) - 1)]; + var codeLen = code >> 16; + var codeVal = code & 0xffff; + if (codeSize == 0 || codeSize < codeLen || codeLen == 0) + error('Bad encoding in flate stream'); + this.codeBuf = (codeBuf >> codeLen); + this.codeSize = (codeSize - codeLen); + this.bytesPos = bytesPos; + return codeVal; + }; + + constructor.prototype.generateHuffmanTable = function(lengths) { + var n = lengths.length; + + // find max code length + var maxLen = 0; + for (var i = 0; i < n; ++i) { + if (lengths[i] > maxLen) + maxLen = lengths[i]; + } + + // build the table + var size = 1 << maxLen; + var codes = new Uint32Array(size); + for (var len = 1, code = 0, skip = 2; + len <= maxLen; + ++len, code <<= 1, skip <<= 1) { + for (var val = 0; val < n; ++val) { + if (lengths[val] == len) { + // bit-reverse the code + var code2 = 0; + var t = code; + for (var i = 0; i < len; ++i) { + code2 = (code2 << 1) | (t & 1); + t >>= 1; + } + + // fill the table entries + for (var i = code2; i < size; i += skip) + codes[i] = (len << 16) | val; + + ++code; + } + } + } + + return [codes, maxLen]; + }; + + constructor.prototype.readBlock = function() { + function repeat(stream, array, len, offset, what) { + var repeat = stream.getBits(len) + offset; + while (repeat-- > 0) + array[i++] = what; + } + + // read block header + var hdr = this.getBits(3); + if (hdr & 1) + this.eof = true; + hdr >>= 1; + + if (hdr == 0) { // uncompressed block + var bytes = this.bytes; + var bytesPos = this.bytesPos; + var b; + + if (typeof (b = bytes[bytesPos++]) == 'undefined') + error('Bad block header in flate stream'); + var blockLen = b; + if (typeof (b = bytes[bytesPos++]) == 'undefined') + error('Bad block header in flate stream'); + blockLen |= (b << 8); + if (typeof (b = bytes[bytesPos++]) == 'undefined') + error('Bad block header in flate stream'); + var check = b; + if (typeof (b = bytes[bytesPos++]) == 'undefined') + error('Bad block header in flate stream'); + check |= (b << 8); + if (check != (~blockLen & 0xffff)) + error('Bad uncompressed block length in flate stream'); + + this.codeBuf = 0; + this.codeSize = 0; + + var bufferLength = this.bufferLength; + var buffer = this.ensureBuffer(bufferLength + blockLen); + var end = bufferLength + blockLen; + this.bufferLength = end; + for (var n = bufferLength; n < end; ++n) { + if (typeof (b = bytes[bytesPos++]) == 'undefined') { + this.eof = true; + break; + } + buffer[n] = b; + } + this.bytesPos = bytesPos; + return; + } + + var litCodeTable; + var distCodeTable; + if (hdr == 1) { // compressed block, fixed codes + litCodeTable = fixedLitCodeTab; + distCodeTable = fixedDistCodeTab; + } else if (hdr == 2) { // compressed block, dynamic codes + var numLitCodes = this.getBits(5) + 257; + var numDistCodes = this.getBits(5) + 1; + var numCodeLenCodes = this.getBits(4) + 4; + + // build the code lengths code table + var codeLenCodeLengths = Array(codeLenCodeMap.length); + var i = 0; + while (i < numCodeLenCodes) + codeLenCodeLengths[codeLenCodeMap[i++]] = this.getBits(3); + var codeLenCodeTab = this.generateHuffmanTable(codeLenCodeLengths); + + // build the literal and distance code tables + var len = 0; + var i = 0; + var codes = numLitCodes + numDistCodes; + var codeLengths = new Array(codes); + while (i < codes) { + var code = this.getCode(codeLenCodeTab); + if (code == 16) { + repeat(this, codeLengths, 2, 3, len); + } else if (code == 17) { + repeat(this, codeLengths, 3, 3, len = 0); + } else if (code == 18) { + repeat(this, codeLengths, 7, 11, len = 0); + } else { + codeLengths[i++] = len = code; + } + } + + litCodeTable = + this.generateHuffmanTable(codeLengths.slice(0, numLitCodes)); + distCodeTable = + this.generateHuffmanTable(codeLengths.slice(numLitCodes, codes)); + } else { + error('Unknown block type in flate stream'); + } + + var buffer = this.buffer; + var limit = buffer ? buffer.length : 0; + var pos = this.bufferLength; + while (true) { + var code1 = this.getCode(litCodeTable); + if (code1 < 256) { + if (pos + 1 >= limit) { + buffer = this.ensureBuffer(pos + 1); + limit = buffer.length; + } + buffer[pos++] = code1; + continue; + } + if (code1 == 256) { + this.bufferLength = pos; + return; + } + code1 -= 257; + code1 = lengthDecode[code1]; + var code2 = code1 >> 16; + if (code2 > 0) + code2 = this.getBits(code2); + var len = (code1 & 0xffff) + code2; + code1 = this.getCode(distCodeTable); + code1 = distDecode[code1]; + code2 = code1 >> 16; + if (code2 > 0) + code2 = this.getBits(code2); + var dist = (code1 & 0xffff) + code2; + if (pos + len >= limit) { + buffer = this.ensureBuffer(pos + len); + limit = buffer.length; + } + for (var k = 0; k < len; ++k, ++pos) + buffer[pos] = buffer[pos - dist]; + } + }; + + return constructor; +})(); + + + /* + # MIT LICENSE + # Copyright (c) 2011 Devon Govett + # + # Permission is hereby granted, free of charge, to any person obtaining a copy of this + # software and associated documentation files (the "Software"), to deal in the Software + # without restriction, including without limitation the rights to use, copy, modify, merge, + # publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons + # to whom the Software is furnished to do so, subject to the following conditions: + # + # The above copyright notice and this permission notice shall be included in all copies or + # substantial portions of the Software. + # + # THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING + # BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND + # NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, + # DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, + # OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. + */ + + var __bind = function(fn, me){ return function(){ return fn.apply(me, arguments); }; }; + var APNG_BLEND_OP_OVER, APNG_BLEND_OP_SOURCE, APNG_DISPOSE_OP_BACKGROUND, APNG_DISPOSE_OP_NONE, APNG_DISPOSE_OP_PREVIOUS, makeImage, scratchCanvas, scratchCtx; + APNG_DISPOSE_OP_NONE = 0; + APNG_DISPOSE_OP_BACKGROUND = 1; + APNG_DISPOSE_OP_PREVIOUS = 2; + APNG_BLEND_OP_SOURCE = 0; + APNG_BLEND_OP_OVER = 1; + function PNG(data) { + var chunkSize, colors, delayDen, delayNum, frame, i, section, short, _ref; + this.data = data; + this.pos = 8; + this.palette = []; + this.imgData = []; + this.transparency = {}; + this.animation = null; + frame = null; + while (true) { + chunkSize = this.readUInt32(); + section = ((function() { + var _results; + _results = []; + for (i = 0; i < 4; i++) { + _results.push(String.fromCharCode(this.data[this.pos++])); + } + return _results; + }).call(this)).join(''); + switch (section) { + case 'IHDR': + this.width = this.readUInt32(); + this.height = this.readUInt32(); + this.bits = this.data[this.pos++]; + this.colorType = this.data[this.pos++]; + this.compressionMethod = this.data[this.pos++]; + this.filterMethod = this.data[this.pos++]; + this.interlaceMethod = this.data[this.pos++]; + break; + case 'acTL': + this.animation = { + numFrames: this.readUInt32(), + numPlays: this.readUInt32() || Infinity, + frames: [] + }; + break; + case 'PLTE': + this.palette = this.read(chunkSize); + break; + case 'fcTL': + if (frame) { + this.animation.frames.push(frame); + } + this.pos += 4; + frame = { + width: this.readUInt32(), + height: this.readUInt32(), + xOffset: this.readUInt32(), + yOffset: this.readUInt32() + }; + delayNum = this.readUInt16(); + delayDen = this.readUInt16() || 100; + frame.delay = 1000 * delayNum / delayDen; + frame.disposeOp = this.data[this.pos++]; + frame.blendOp = this.data[this.pos++]; + frame.data = []; + break; + case 'IDAT': + case 'fdAT': + if (section === 'fdAT') { + this.pos += 4; + chunkSize -= 4; + } + data = (frame != null ? frame.data : void 0) || this.imgData; + for (i = 0; 0 <= chunkSize ? i < chunkSize : i > chunkSize; 0 <= chunkSize ? i++ : i--) { + data.push(this.data[this.pos++]); + } + break; + case 'tRNS': + this.transparency = {}; + switch (this.colorType) { + case 3: + this.transparency.indexed = this.read(chunkSize); + short = 255 - this.transparency.indexed.length; + if (short > 0) { + for (i = 0; 0 <= short ? i < short : i > short; 0 <= short ? i++ : i--) { + this.transparency.indexed.push(255); + } + } + break; + case 0: + this.transparency.grayscale = this.read(chunkSize)[0]; + break; + case 2: + this.transparency.rgb = this.read(chunkSize); + } + break; + case 'IEND': + if (frame) { + this.animation.frames.push(frame); + } + this.colors = (function() { + switch (this.colorType) { + case 0: + case 3: + case 4: + return 1; + case 2: + case 6: + return 3; + } + }).call(this); + this.hasAlphaChannel = (_ref = this.colorType) === 4 || _ref === 6; + colors = this.colors + (this.hasAlphaChannel ? 1 : 0); + this.pixelBitlength = this.bits * colors; + this.colorSpace = (function() { + switch (this.colors) { + case 1: + return 'DeviceGray'; + case 3: + return 'DeviceRGB'; + } + }).call(this); + this.imgData = new Uint8Array(this.imgData); + return; + default: + this.pos += chunkSize; + } + this.pos += 4; + } + return; + } + PNG.prototype.read = function(bytes) { + var i, _results; + _results = []; + for (i = 0; 0 <= bytes ? i < bytes : i > bytes; 0 <= bytes ? i++ : i--) { + _results.push(this.data[this.pos++]); + } + return _results; + }; + PNG.prototype.readUInt32 = function() { + var b1, b2, b3, b4; + b1 = this.data[this.pos++] << 24; + b2 = this.data[this.pos++] << 16; + b3 = this.data[this.pos++] << 8; + b4 = this.data[this.pos++]; + return b1 | b2 | b3 | b4; + }; + PNG.prototype.readUInt16 = function() { + var b1, b2; + b1 = this.data[this.pos++] << 8; + b2 = this.data[this.pos++]; + return b1 | b2; + }; + PNG.prototype.decodePixels = function(data) { + var byte, col, filter, i, left, length, p, pa, paeth, pb, pc, pixelBytes, pixels, pos, row, rowData, s, scanlineLength, upper, upperLeft, _ref, _step; + if (data == null) { + data = this.imgData; + } + if (data.length === 0) { + return []; + } + data = new FlateStream(data); + data = data.getBytes(); + pixelBytes = this.pixelBitlength / 8; + scanlineLength = pixelBytes * this.width; + row = 0; + pixels = []; + length = data.length; + pos = 0; + while (pos < length) { + filter = data[pos++]; + i = 0; + rowData = []; + switch (filter) { + case 0: + while (i < scanlineLength) { + rowData[i++] = data[pos++]; + } + break; + case 1: + while (i < scanlineLength) { + byte = data[pos++]; + left = i < pixelBytes ? 0 : rowData[i - pixelBytes]; + rowData[i++] = (byte + left) % 256; + } + break; + case 2: + while (i < scanlineLength) { + byte = data[pos++]; + col = (i - (i % pixelBytes)) / pixelBytes; + upper = row === 0 ? 0 : pixels[row - 1][col][i % pixelBytes]; + rowData[i++] = (upper + byte) % 256; + } + break; + case 3: + while (i < scanlineLength) { + byte = data[pos++]; + col = (i - (i % pixelBytes)) / pixelBytes; + left = i < pixelBytes ? 0 : rowData[i - pixelBytes]; + upper = row === 0 ? 0 : pixels[row - 1][col][i % pixelBytes]; + rowData[i++] = (byte + Math.floor((left + upper) / 2)) % 256; + } + break; + case 4: + while (i < scanlineLength) { + byte = data[pos++]; + col = (i - (i % pixelBytes)) / pixelBytes; + left = i < pixelBytes ? 0 : rowData[i - pixelBytes]; + if (row === 0) { + upper = upperLeft = 0; + } else { + upper = pixels[row - 1][col][i % pixelBytes]; + upperLeft = col === 0 ? 0 : pixels[row - 1][col - 1][i % pixelBytes]; + } + p = left + upper - upperLeft; + pa = Math.abs(p - left); + pb = Math.abs(p - upper); + pc = Math.abs(p - upperLeft); + if (pa <= pb && pa <= pc) { + paeth = left; + } else if (pb <= pc) { + paeth = upper; + } else { + paeth = upperLeft; + } + rowData[i++] = (byte + paeth) % 256; + } + break; + default: + throw new Error("Invalid filter algorithm: " + filter); + } + s = []; + for (i = 0, _ref = rowData.length, _step = pixelBytes; 0 <= _ref ? i < _ref : i > _ref; i += _step) { + s.push(rowData.slice(i, i + pixelBytes)); + } + pixels.push(s); + row += 1; + } + return pixels; + }; + PNG.prototype.decodePalette = function() { + var alpha, decodingMap, i, index, palette, pixel, transparency, _ref, _ref2, _ref3, _step; + palette = this.palette; + transparency = (_ref = this.transparency.indexed) != null ? _ref : []; + decodingMap = []; + index = 0; + for (i = 0, _ref2 = palette.length, _step = 3; 0 <= _ref2 ? i < _ref2 : i > _ref2; i += _step) { + alpha = (_ref3 = transparency[index++]) != null ? _ref3 : 255; + pixel = palette.slice(i, i + 3).concat(alpha); + decodingMap.push(pixel); + } + return decodingMap; + }; + PNG.prototype.copyToImageData = function(imageData, pixels) { + //console.log(this); + var alpha, byte, colors, data, i, palette, pixel, row, v, _i, _j, _k, _len, _len2, _len3, _ref; + colors = this.colors; + palette = null; + alpha = this.hasAlphaChannel; + if (this.palette.length) { + palette = (_ref = this._decodedPalette) != null ? _ref : this._decodedPalette = this.decodePalette(); + colors = 4; + alpha = true; + } + data = imageData.data; + i = 0; + for (_i = 0, _len = pixels.length; _i < _len; _i++) { + row = pixels[_i]; + for (_j = 0, _len2 = row.length; _j < _len2; _j++) { + pixel = row[_j]; + if (palette) { + pixel = palette[pixel]; + } + if (colors === 1) { + v = pixel[0]; + data[i++] = v; + data[i++] = v; + data[i++] = v; + data[i++] = pixel[1] || 255; + } else { + //console.log(pixel.length); + //if (pixel.length == 4 && pixel[3] != 0) + //console.log(pixel); + //for (_k = 0, _len3 = pixel.length; _k < _len3; _k++) { + //for (_k = 0; _k < 4; _k++) { + // byte = pixel[_k]; + // data[i++] = byte; + //} + var a = (256 - pixel[3])/256.; + var aa = (1.-a)*255.; + + data[i++] = parseInt(pixel[2]*a + aa); + data[i++] = parseInt(pixel[1]*a + aa); + data[i++] = parseInt(pixel[0]*a + aa); + data[i++] = pixel[3]; + if (!alpha) { + data[i++] = 255; + } + } + } + } + }; + PNG.prototype.decodeFrames = function(ctx) { + var frame, i, imageData, pixels, _len, _ref, _results; + if (!this.animation) { + return; + } + _ref = this.animation.frames; + _results = []; + for (i = 0, _len = _ref.length; i < _len; i++) { + frame = _ref[i]; + imageData = ctx.createImageData(frame.width, frame.height); + pixels = this.decodePixels(new Uint8Array(frame.data)); + this.copyToImageData(imageData, pixels); + frame.imageData = imageData; + _results.push(frame.image = makeImage(imageData)); + } + return _results; + }; + PNG.prototype.renderFrame = function(ctx, number) { + var frame, frames, prev; + frames = this.animation.frames; + frame = frames[number]; + prev = frames[number - 1]; + if (number === 0) { + ctx.clearRect(0, 0, this.width, this.height); + } + if ((prev != null ? prev.disposeOp : void 0) === APNG_DISPOSE_OP_BACKGROUND) { + ctx.clearRect(prev.xOffset, prev.yOffset, prev.width, prev.height); + } else if ((prev != null ? prev.disposeOp : void 0) === APNG_DISPOSE_OP_PREVIOUS) { + ctx.putImageData(prev.imageData, prev.xOffset, prev.yOffset); + } + if (frame.blendOp === APNG_BLEND_OP_SOURCE) { + ctx.clearRect(frame.xOffset, frame.yOffset, frame.width, frame.height); + } + return ctx.drawImage(frame.image, frame.xOffset, frame.yOffset); + }; + PNG.prototype.animate = function(ctx) { + var doFrame, frameNumber, frames, numFrames, numPlays, _ref; + frameNumber = 0; + _ref = this.animation, numFrames = _ref.numFrames, frames = _ref.frames, numPlays = _ref.numPlays; + return (doFrame = __bind(function() { + var f, frame; + f = frameNumber++ % numFrames; + frame = frames[f]; + this.renderFrame(ctx, f); + if (numFrames > 1 && frameNumber / numFrames < numPlays) { + return this.animation._timeout = setTimeout(doFrame, frame.delay); + } + }, this))(); + }; + PNG.prototype.stopAnimation = function() { + var _ref; + return clearTimeout((_ref = this.animation) != null ? _ref._timeout : void 0); + }; + PNG.prototype.render = function(data) { + this.copyToImageData(data, this.decodePixels()); + }; + + +var Buffer = require('buffer').Buffer; +var fs = require('fs'); + +module.exports.readPng = function(path) +{ + var pngData = fs.readFileSync(path); + var j = new PNG(pngData); + var imageData = {}; + imageData.width = j.width; + imageData.height = j.height; + imageData.data = new Buffer(j.width*j.height*4); + j.render(imageData); + return imageData; +}