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Less copying in the JPX coder, merged and rebased

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This commit is contained in:
fkaelberer 2014-04-16 10:40:04 +02:00
parent 3940dc5a41
commit 04602c8a5e
3 changed files with 148 additions and 174 deletions
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91
src/core/stream.js
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@ -942,78 +942,35 @@ var JpxStream = (function JpxStreamClosure() {
var width = jpxImage.width;
var height = jpxImage.height;
var componentsCount = jpxImage.componentsCount;
if (componentsCount != 1 && componentsCount != 3 && componentsCount != 4) {
error('JPX with ' + componentsCount + ' components is not supported');
}
var tileCount = jpxImage.tiles.length;
if (tileCount === 1) {
this.buffer = jpxImage.tiles[0].items;
} else {
var data = new Uint8Array(width * height * componentsCount);
var data = new Uint8Array(width * height * componentsCount);
for (var k = 0; k < tileCount; k++) {
var tileComponents = jpxImage.tiles[k];
var tileWidth = tileComponents.width;
var tileHeight = tileComponents.height;
var tileLeft = tileComponents.left;
var tileTop = tileComponents.top;
for (var k = 0, kk = jpxImage.tiles.length; k < kk; k++) {
var tileCompoments = jpxImage.tiles[k];
var tileWidth = tileCompoments[0].width;
var tileHeight = tileCompoments[0].height;
var tileLeft = tileCompoments[0].left;
var tileTop = tileCompoments[0].top;
var src = tileComponents.items;
var srcPosition = 0;
var dataPosition = (width * tileTop + tileLeft) * componentsCount;
var imgRowSize = width * componentsCount;
var tileRowSize = tileWidth * componentsCount;
var dataPosition, sourcePosition, data0, data1, data2, data3, rowFeed;
var i, j;
switch (componentsCount) {
case 1:
data0 = tileCompoments[0].items;
dataPosition = width * tileTop + tileLeft;
rowFeed = width - tileWidth;
sourcePosition = 0;
for (j = 0; j < tileHeight; j++) {
for (i = 0; i < tileWidth; i++) {
data[dataPosition++] = data0[sourcePosition++];
}
dataPosition += rowFeed;
}
break;
case 3:
data0 = tileCompoments[0].items;
data1 = tileCompoments[1].items;
data2 = tileCompoments[2].items;
dataPosition = (width * tileTop + tileLeft) * 3;
rowFeed = (width - tileWidth) * 3;
sourcePosition = 0;
for (j = 0; j < tileHeight; j++) {
for (i = 0; i < tileWidth; i++) {
data[dataPosition++] = data0[sourcePosition];
data[dataPosition++] = data1[sourcePosition];
data[dataPosition++] = data2[sourcePosition];
sourcePosition++;
}
dataPosition += rowFeed;
}
break;
case 4:
data0 = tileCompoments[0].items;
data1 = tileCompoments[1].items;
data2 = tileCompoments[2].items;
data3 = tileCompoments[3].items;
dataPosition = (width * tileTop + tileLeft) * 4;
rowFeed = (width - tileWidth) * 4;
sourcePosition = 0;
for (j = 0; j < tileHeight; j++) {
for (i = 0; i < tileWidth; i++) {
data[dataPosition++] = data0[sourcePosition];
data[dataPosition++] = data1[sourcePosition];
data[dataPosition++] = data2[sourcePosition];
data[dataPosition++] = data3[sourcePosition];
sourcePosition++;
}
dataPosition += rowFeed;
}
break;
for (var j = 0; j < tileHeight; j++) {
var rowBytes = src.subarray(srcPosition, srcPosition + tileRowSize);
data.set(rowBytes, dataPosition);
srcPosition += tileRowSize;
dataPosition += imgRowSize;
}
}
this.buffer = data;
}
this.buffer = data;
this.bufferLength = data.length;
this.bufferLength = this.buffer.length;
this.eof = true;
};