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Making src/core/jbig2.js adhere to the style guide

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This commit is contained in:
Tim van der Meij 2014-03-09 13:03:45 +01:00
parent 46487e3931
commit 2712a5a45a
1 changed files with 104 additions and 57 deletions
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161
src/core/jbig2.js
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@ -19,7 +19,6 @@
'use strict';
var Jbig2Image = (function Jbig2ImageClosure() {
// Annex E. Arithmetic Coding
var ArithmeticDecoder = (function ArithmeticDecoderClosure() {
var QeTable = [
@ -159,9 +158,9 @@ var Jbig2Image = (function Jbig2ImageClosure() {
}
// renormD;
do {
if (this.ct === 0)
if (this.ct === 0) {
this.byteIn();
}
this.a <<= 1;
this.chigh = ((this.chigh << 1) & 0xFFFF) | ((this.clow >> 15) & 1);
this.clow = (this.clow << 1) & 0xFFFF;
@ -181,8 +180,9 @@ var Jbig2Image = (function Jbig2ImageClosure() {
ContextCache.prototype = {
getContexts: function(id) {
if (id in this)
if (id in this) {
return this[id];
}
return (this[id] = new Int8Array(1<<16));
}
};
@ -214,52 +214,63 @@ var Jbig2Image = (function Jbig2ImageClosure() {
var toRead = 32, offset = 4436; // defaults for state 7
while (state) {
var bit = decoder.readBit(contexts, prev);
prev = prev < 256 ? (prev << 1) | bit :
(((prev << 1) | bit) & 511) | 256;
prev = (prev < 256 ? (prev << 1) | bit :
(((prev << 1) | bit) & 511) | 256);
switch (state) {
case 1:
s = !!bit;
break;
case 2:
if (bit) break;
if (bit) {
break;
}
state = 7;
toRead = 2;
offset = 0;
break;
case 3:
if (bit) break;
if (bit) {
break;
}
state = 7;
toRead = 4;
offset = 4;
break;
case 4:
if (bit) break;
if (bit) {
break;
}
state = 7;
toRead = 6;
offset = 20;
break;
case 5:
if (bit) break;
if (bit) {
break;
}
state = 7;
toRead = 8;
offset = 84;
break;
case 6:
if (bit) break;
if (bit) {
break;
}
state = 7;
toRead = 12;
offset = 340;
break;
default:
v = v * 2 + bit;
if (--toRead === 0)
if (--toRead === 0) {
state = 0;
}
continue;
}
state++;
}
v += offset;
return !s ? v : v > 0 ? -v : null;
return (!s ? v : (v > 0 ? -v : null));
}
// A.3 The IAID decoding procedure
@ -271,10 +282,10 @@ var Jbig2Image = (function Jbig2ImageClosure() {
var bit = decoder.readBit(contexts, prev);
prev = (prev * 2) + bit;
}
if (codeLength < 31)
if (codeLength < 31) {
return prev & ((1 << codeLength) - 1);
else
return prev - Math.pow(2, codeLength);
}
return prev - Math.pow(2, codeLength);
}
// 7.3 Segment types
@ -363,8 +374,9 @@ var Jbig2Image = (function Jbig2ImageClosure() {
// 6.2 Generic Region Decoding Procedure
function decodeBitmap(mmr, width, height, templateIndex, prediction, skip, at,
decodingContext) {
if (mmr)
if (mmr) {
error('JBIG2 error: MMR encoding is not supported');
}
var useskip = !!skip;
var template = CodingTemplates[templateIndex].concat(at);
@ -460,8 +472,9 @@ var Jbig2Image = (function Jbig2ImageClosure() {
offsetX, offsetY, prediction, at,
decodingContext) {
var codingTemplate = RefinementTemplates[templateIndex].coding;
if (templateIndex === 0)
if (templateIndex === 0) {
codingTemplate = codingTemplate.concat([at[0]]);
}
var codingTemplateLength = codingTemplate.length;
var codingTemplateX = new Int32Array(codingTemplateLength);
var codingTemplateY = new Int32Array(codingTemplateLength);
@ -469,9 +482,11 @@ var Jbig2Image = (function Jbig2ImageClosure() {
codingTemplateX[k] = codingTemplate[k].x;
codingTemplateY[k] = codingTemplate[k].y;
}
var referenceTemplate = RefinementTemplates[templateIndex].reference;
if (templateIndex === 0)
if (templateIndex === 0) {
referenceTemplate = referenceTemplate.concat([at[1]]);
}
var referenceTemplateLength = referenceTemplate.length;
var referenceTemplateX = new Int32Array(referenceTemplateLength);
var referenceTemplateY = new Int32Array(referenceTemplateLength);
@ -497,24 +512,28 @@ var Jbig2Image = (function Jbig2ImageClosure() {
var row = new Uint8Array(width);
bitmap.push(row);
for (var j = 0; j < width; j++) {
if (ltp)
if (ltp) {
error('JBIG2 error: prediction is not supported');
}
var contextLabel = 0;
for (var k = 0; k < codingTemplateLength; k++) {
var i0 = i + codingTemplateY[k], j0 = j + codingTemplateX[k];
if (i0 < 0 || j0 < 0 || j0 >= width)
if (i0 < 0 || j0 < 0 || j0 >= width) {
contextLabel <<= 1; // out of bound pixel
else
} else {
contextLabel = (contextLabel << 1) | bitmap[i0][j0];
}
}
for (var k = 0; k < referenceTemplateLength; k++) {
var i0 = i + referenceTemplateY[k] + offsetY;
var j0 = j + referenceTemplateX[k] + offsetX;
if (i0 < 0 || i0 >= referenceHeight || j0 < 0 || j0 >= referenceWidth)
if (i0 < 0 || i0 >= referenceHeight || j0 < 0 ||
j0 >= referenceWidth) {
contextLabel <<= 1; // out of bound pixel
else
} else {
contextLabel = (contextLabel << 1) | referenceBitmap[i0][j0];
}
}
var pixel = decoder.readBit(contexts, contextLabel);
row[j] = pixel;
@ -530,8 +549,9 @@ var Jbig2Image = (function Jbig2ImageClosure() {
huffmanTables, templateIndex, at,
refinementTemplateIndex, refinementAt,
decodingContext) {
if (huffman)
if (huffman) {
error('JBIG2 error: huffman is not supported');
}
var newSymbols = [];
var currentHeight = 0;
@ -547,21 +567,23 @@ var Jbig2Image = (function Jbig2ImageClosure() {
var totalWidth = 0;
while (true) {
var deltaWidth = decodeInteger(contextCache, 'IADW', decoder); // 6.5.7
if (deltaWidth === null)
if (deltaWidth === null) {
break; // OOB
}
currentWidth += deltaWidth;
totalWidth += currentWidth;
var bitmap;
if (refinement) {
// 6.5.8.2 Refinement/aggregate-coded symbol bitmap
var numberOfInstances = decodeInteger(contextCache, 'IAAI', decoder);
if (numberOfInstances > 1)
if (numberOfInstances > 1) {
error('JBIG2 error: number of instances > 1 is not supported');
}
var symbolId = decodeIAID(contextCache, decoder, symbolCodeLength);
var rdx = decodeInteger(contextCache, 'IARDX', decoder); // 6.4.11.3
var rdy = decodeInteger(contextCache, 'IARDY', decoder); // 6.4.11.4
var symbol = symbolId < symbols.length ? symbols[symbolId] :
newSymbols[symbolId - symbols.length];
var symbol = (symbolId < symbols.length ? symbols[symbolId] :
newSymbols[symbolId - symbols.length]);
bitmap = decodeRefinement(currentWidth, currentHeight,
refinementTemplateIndex, symbol, rdx, rdy, false, refinementAt,
decodingContext);
@ -579,14 +601,21 @@ var Jbig2Image = (function Jbig2ImageClosure() {
var totalSymbolsLength = symbols.length + numberOfNewSymbols;
while (flags.length < totalSymbolsLength) {
var runLength = decodeInteger(contextCache, 'IAEX', decoder);
while (runLength--)
while (runLength--) {
flags.push(currentFlag);
}
currentFlag = !currentFlag;
}
for (var i = 0, ii = symbols.length; i < ii; i++)
if (flags[i]) exportedSymbols.push(symbols[i]);
for (var j = 0; j < numberOfNewSymbols; i++, j++)
if (flags[i]) exportedSymbols.push(newSymbols[j]);
for (var i = 0, ii = symbols.length; i < ii; i++) {
if (flags[i]) {
exportedSymbols.push(symbols[i]);
}
}
for (var j = 0; j < numberOfNewSymbols; i++, j++) {
if (flags[i]) {
exportedSymbols.push(newSymbols[j]);
}
}
return exportedSymbols;
}
@ -597,16 +626,18 @@ var Jbig2Image = (function Jbig2ImageClosure() {
combinationOperator, huffmanTables,
refinementTemplateIndex, refinementAt,
decodingContext) {
if (huffman)
if (huffman) {
error('JBIG2 error: huffman is not supported');
}
// Prepare bitmap
var bitmap = [];
for (var i = 0; i < height; i++) {
var row = new Uint8Array(width);
if (defaultPixelValue) {
for (var j = 0; j < width; j++)
for (var j = 0; j < width; j++) {
row[j] = defaultPixelValue;
}
}
bitmap.push(row);
}
@ -702,8 +733,9 @@ var Jbig2Image = (function Jbig2ImageClosure() {
}
i++;
var deltaS = decodeInteger(contextCache, 'IADS', decoder); // 6.4.8
if (deltaS === null)
if (deltaS === null) {
break; // OOB
}
currentS += deltaS + dsOffset;
} while (true);
}
@ -715,11 +747,13 @@ var Jbig2Image = (function Jbig2ImageClosure() {
segmentHeader.number = readUint32(data, start);
var flags = data[start + 4];
var segmentType = flags & 0x3F;
if (!SegmentTypes[segmentType])
if (!SegmentTypes[segmentType]) {
error('JBIG2 error: invalid segment type: ' + segmentType);
}
segmentHeader.type = segmentType;
segmentHeader.typeName = SegmentTypes[segmentType];
segmentHeader.deferredNonRetain = !!(flags & 0x80);
var pageAssociationFieldSize = !!(flags & 0x40);
var referredFlags = data[start + 5];
var referredToCount = (referredFlags >> 5) & 7;
@ -733,28 +767,31 @@ var Jbig2Image = (function Jbig2ImageClosure() {
while (--bytes > 0) {
retainBits.push(data[position++]);
}
} else if (referredFlags == 5 || referredFlags == 6)
} else if (referredFlags == 5 || referredFlags == 6) {
error('JBIG2 error: invalid referred-to flags');
}
segmentHeader.retainBits = retainBits;
var referredToSegmentNumberSize = segmentHeader.number <= 256 ? 1 :
segmentHeader.number <= 65536 ? 2 : 4;
var referredToSegmentNumberSize = (segmentHeader.number <= 256 ? 1 :
(segmentHeader.number <= 65536 ? 2 : 4));
var referredTo = [];
for (var i = 0; i < referredToCount; i++) {
var number = referredToSegmentNumberSize == 1 ? data[position] :
referredToSegmentNumberSize == 2 ? readUint16(data, position) :
readUint32(data, position);
var number = (referredToSegmentNumberSize == 1 ? data[position] :
(referredToSegmentNumberSize == 2 ? readUint16(data, position) :
readUint32(data, position)));
referredTo.push(number);
position += referredToSegmentNumberSize;
}
segmentHeader.referredTo = referredTo;
if (!pageAssociationFieldSize)
if (!pageAssociationFieldSize) {
segmentHeader.pageAssociation = data[position++];
else {
} else {
segmentHeader.pageAssociation = readUint32(data, position);
position += 4;
}
segmentHeader.length = readUint32(data, position);
position += 4;
if (segmentHeader.length == 0xFFFFFFFF) {
// 7.2.7 Segment data length, unknown segment length
if (segmentType === 38) { // ImmediateGenericRegion
@ -810,8 +847,9 @@ var Jbig2Image = (function Jbig2ImageClosure() {
segment.end = position;
}
segments.push(segment);
if (segmentHeader.type == 51)
if (segmentHeader.type == 51) {
break; // end of file is found
}
}
if (header.randomAccess) {
for (var i = 0, ii = segments.length; i < ii; i++) {
@ -929,8 +967,9 @@ var Jbig2Image = (function Jbig2ImageClosure() {
textRegion.numberOfSymbolInstances = readUint32(data, position);
position += 4;
// TODO 7.4.3.1.7 Symbol ID Huffman table decoding
if (textRegion.huffman)
if (textRegion.huffman) {
error('JBIG2 error: huffman is not supported');
}
args = [textRegion, header.referredTo, data, position, end];
break;
case 38: // ImmediateGenericRegion
@ -963,8 +1002,9 @@ var Jbig2Image = (function Jbig2ImageClosure() {
resolutionX: readUint32(data, position + 8),
resolutionY: readUint32(data, position + 12)
};
if (pageInfo.height == 0xFFFFFFFF)
if (pageInfo.height == 0xFFFFFFFF) {
delete pageInfo.height;
}
var pageSegmentFlags = data[position + 16];
var pageStripingInformatiom = readUint16(data, position + 17);
pageInfo.lossless = !!(pageSegmentFlags & 1);
@ -989,13 +1029,15 @@ var Jbig2Image = (function Jbig2ImageClosure() {
header.type + ') is not implemented');
}
var callbackName = 'on' + header.typeName;
if (callbackName in visitor)
if (callbackName in visitor) {
visitor[callbackName].apply(visitor, args);
}
}
function processSegments(segments, visitor) {
for (var i = 0, ii = segments.length; i < ii; i++)
for (var i = 0, ii = segments.length; i < ii; i++) {
processSegment(segments[i], visitor);
}
}
function parseJbig2(data, start, end) {
@ -1003,8 +1045,9 @@ var Jbig2Image = (function Jbig2ImageClosure() {
if (data[position] != 0x97 || data[position + 1] != 0x4A ||
data[position + 2] != 0x42 || data[position + 3] != 0x32 ||
data[position + 4] != 0x0D || data[position + 5] != 0x0A ||
data[position + 6] != 0x1A || data[position + 7] != 0x0A)
data[position + 6] != 0x1A || data[position + 7] != 0x0A) {
error('JBIG2 error: invalid header');
}
var header = {};
position += 8;
var flags = data[position++];
@ -1101,17 +1144,20 @@ var Jbig2Image = (function Jbig2ImageClosure() {
referredSegments,
data, start, end) {
var huffmanTables;
if (dictionary.huffman)
if (dictionary.huffman) {
error('JBIG2 error: huffman is not supported');
}
// Combines exported symbols from all referred segments
var symbols = this.symbols;
if (!symbols)
if (!symbols) {
this.symbols = symbols = {};
}
var inputSymbols = [];
for (var i = 0, ii = referredSegments.length; i < ii; i++)
for (var i = 0, ii = referredSegments.length; i < ii; i++) {
inputSymbols = inputSymbols.concat(symbols[referredSegments[i]]);
}
var decodingContext = new DecodingContext(data, start, end);
symbols[currentSegment] = decodeSymbolDictionary(dictionary.huffman,
@ -1131,8 +1177,9 @@ var Jbig2Image = (function Jbig2ImageClosure() {
// Combines exported symbols from all referred segments
var symbols = this.symbols;
var inputSymbols = [];
for (var i = 0, ii = referredSegments.length; i < ii; i++)
for (var i = 0, ii = referredSegments.length; i < ii; i++) {
inputSymbols = inputSymbols.concat(symbols[referredSegments[i]]);
}
var symbolCodeLength = log2(inputSymbols.length);
var decodingContext = new DecodingContext(data, start, end);
@ -1146,7 +1193,7 @@ var Jbig2Image = (function Jbig2ImageClosure() {
},
onImmediateLosslessTextRegion:
function SimpleSegmentVisitor_onImmediateLosslessTextRegion() {
this.onImmediateTextRegion.apply(this, arguments);
this.onImmediateTextRegion.apply(this, arguments);
}
};