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Merge pull request #4122 from yurydelendik/bug878397

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Use a more compact typed array to pass the image mask from the worker
This commit is contained in:
Yury Delendik 2014-01-14 11:15:44 -08:00
commit 71cc234c6a
3 changed files with 68 additions and 34 deletions
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3
src/core/evaluator.js
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@ -262,8 +262,7 @@ var PartialEvaluator = (function PartialEvaluatorClosure() {
var inverseDecode = !!decode && decode[0] > 0;
operatorList.addOp(OPS.paintImageMaskXObject,
[PDFImage.createMask(imgArray, width, height,
inverseDecode)]
[PDFImage.createMask(imgArray, width, height, inverseDecode)]
);
return;
}

31
src/core/image.js
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@ -209,26 +209,21 @@ var PDFImage = (function PDFImageClosure() {
PDFImage.createMask = function PDFImage_createMask(imgArray, width, height,
inverseDecode) {
var buffer = new Uint8Array(width * height * 4);
var imgArrayPos = 0;
var i, j, mask, buf;
// removing making non-masked pixels transparent
var bufferPos = 3; // alpha component offset
for (i = 0; i < height; i++) {
mask = 0;
for (j = 0; j < width; j++) {
if (!mask) {
buf = imgArray[imgArrayPos++];
mask = 128;
}
if (!(buf & mask) !== inverseDecode) {
buffer[bufferPos] = 255;
}
bufferPos += 4;
mask >>= 1;
// Copy imgArray into a typed array (inverting if necessary) so it can be
// transferred to the main thread.
var length = ((width + 7) >> 3) * height;
var data = new Uint8Array(length);
if (inverseDecode) {
for (var i = 0; i < length; i++) {
data[i] = ~imgArray[i];
}
} else {
for (var i = 0; i < length; i++) {
data[i] = imgArray[i];
}
}
return {data: buffer, width: width, height: height};
return {data: data, width: width, height: height};
};
PDFImage.prototype = {

68
src/display/canvas.js
View File

@ -191,6 +191,18 @@ function compileType3Glyph(imgData) {
var points = new Uint8Array(width1 * (height + 1));
var POINT_TYPES =
new Uint8Array([0, 2, 4, 0, 1, 0, 5, 4, 8, 10, 0, 8, 0, 2, 1, 0]);
// decodes bit-packed mask data
var lineSize = (width + 7) & ~7, data0 = imgData.data;
var data = new Uint8Array(lineSize * height), pos = 0, ii;
for (i = 0, ii = data0.length; i < ii; i++) {
var mask = 128, elem = data0[i];
while (mask > 0) {
data[pos++] = (elem & mask) ? 0 : 255;
mask >>= 1;
}
}
// finding iteresting points: every point is located between mask pixels,
// so there will be points of the (width + 1)x(height + 1) grid. Every point
// will have flags assigned based on neighboring mask pixels:
@ -201,24 +213,25 @@ function compileType3Glyph(imgData) {
// - outside corners: 1, 2, 4, 8;
// - inside corners: 7, 11, 13, 14;
// - and, intersections: 5, 10.
var pos = 3, data = imgData.data, lineSize = width * 4, count = 0;
if (data[3] !== 0) {
var count = 0;
pos = 0;
if (data[pos] !== 0) {
points[0] = 1;
++count;
}
for (j = 1; j < width; j++) {
if (data[pos] !== data[pos + 4]) {
if (data[pos] !== data[pos + 1]) {
points[j] = data[pos] ? 2 : 1;
++count;
}
pos += 4;
pos++;
}
if (data[pos] !== 0) {
points[j] = 2;
++count;
}
pos += 4;
for (i = 1; i < height; i++) {
pos = i * lineSize;
j0 = i * width1;
if (data[pos - lineSize] !== data[pos]) {
points[j0] = data[pos] ? 1 : 8;
@ -228,37 +241,36 @@ function compileType3Glyph(imgData) {
// array (in order 8-1-2-4, so we can use '>>2' to shift the column).
var sum = (data[pos] ? 4 : 0) + (data[pos - lineSize] ? 8 : 0);
for (j = 1; j < width; j++) {
sum = (sum >> 2) + (data[pos + 4] ? 4 : 0) +
(data[pos - lineSize + 4] ? 8 : 0);
sum = (sum >> 2) + (data[pos + 1] ? 4 : 0) +
(data[pos - lineSize + 1] ? 8 : 0);
if (POINT_TYPES[sum]) {
points[j0 + j] = POINT_TYPES[sum];
++count;
}
pos += 4;
pos++;
}
if (data[pos - lineSize] !== data[pos]) {
points[j0 + j] = data[pos] ? 2 : 4;
++count;
}
pos += 4;
if (count > POINT_TO_PROCESS_LIMIT) {
return null;
}
}
pos -= lineSize;
pos = lineSize * (height - 1);
j0 = i * width1;
if (data[pos] !== 0) {
points[j0] = 8;
++count;
}
for (j = 1; j < width; j++) {
if (data[pos] !== data[pos + 4]) {
if (data[pos] !== data[pos + 1]) {
points[j0 + j] = data[pos] ? 4 : 8;
++count;
}
pos += 4;
pos++;
}
if (data[pos] !== 0) {
points[j0 + j] = 4;
@ -431,6 +443,34 @@ var CanvasGraphics = (function CanvasGraphicsClosure() {
ctx.putImageData(tmpImgData, 0, 0);
}
function putBinaryImageMask(ctx, imgData) {
var width = imgData.width, height = imgData.height;
var tmpImgData = ctx.createImageData(width, height);
var data = imgData.data;
var tmpImgDataPixels = tmpImgData.data;
var dataPos = 0;
// Expand the mask so it can be used by the canvas. Any required inversion
// has already been handled.
var tmpPos = 3; // alpha component offset
for (var i = 0; i < height; i++) {
var mask = 0;
for (var j = 0; j < width; j++) {
if (!mask) {
var elem = data[dataPos++];
mask = 128;
}
if (!(elem & mask)) {
tmpImgDataPixels[tmpPos] = 255;
}
tmpPos += 4;
mask >>= 1;
}
}
ctx.putImageData(tmpImgData, 0, 0);
}
function copyCtxState(sourceCtx, destCtx) {
var properties = ['strokeStyle', 'fillStyle', 'fillRule', 'globalAlpha',
'lineWidth', 'lineCap', 'lineJoin', 'miterLimit',
@ -1611,7 +1651,7 @@ var CanvasGraphics = (function CanvasGraphicsClosure() {
var maskCtx = maskCanvas.context;
maskCtx.save();
putBinaryImageData(maskCtx, img);
putBinaryImageMask(maskCtx, img);
maskCtx.globalCompositeOperation = 'source-in';
@ -1638,7 +1678,7 @@ var CanvasGraphics = (function CanvasGraphicsClosure() {
var maskCtx = maskCanvas.context;
maskCtx.save();
putBinaryImageData(maskCtx, image);
putBinaryImageMask(maskCtx, image);
maskCtx.globalCompositeOperation = 'source-in';