Sakurai/pdf.js
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Add feature detection for using Uint8Array as imageData

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This commit is contained in:
Julian Viereck 2011-11-04 07:55:27 +01:00
parent 5bae370a90
commit 01d2929401
1 changed files with 33 additions and 9 deletions
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42
src/canvas.js
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@ -3,6 +3,29 @@
'use strict';
// Some browsers can use UInt8Array directly as imageData.
PDFJS.FEATURE_CANVAS_UINT_IMAGE_DATA = false;
if (typeof window !== 'undefined') {
window.addEventListener('load', function featureCanvasUIntImgaData() {
var canvas = document.createElement('canvas');
canvas.width = 1;
canvas.height = 1;
var ctx = canvas.getContext('2d');
try {
ctx.putImageData({
width: 1,
height: 1,
data: new Uint8Array(4)
}, 0, 0);
} catch (e) {
return;
}
PDFJS.FEATURE_CANVAS_UINT_IMAGE_DATA = true;
});
}
// <canvas> contexts store most of the state we need natively.
// However, PDF needs a bit more state, which we store here.
@ -789,17 +812,18 @@ var CanvasGraphics = (function canvasGraphics() {
var tmpCtx = tmpCanvas.getContext('2d');
var tmpImgData;
// Some browsers can set an UInt8Array directly as imageData, some
// can't. As long as we don't have proper feature detection, just
// copy over each pixel and set the imageData that way.
tmpImgData = tmpCtx.getImageData(0, 0, w, h);
if (PDFJS.FEATURE_CANVAS_UINT_IMAGE_DATA) {
tmpImgData = imgData;
} else {
tmpImgData = tmpCtx.getImageData(0, 0, w, h);
// Copy over the imageData.
var tmpImgDataPixels = tmpImgData.data;
var len = tmpImgDataPixels.length;
// Copy over the imageData pixel by pixel.
var tmpImgDataPixels = tmpImgData.data;
var len = tmpImgDataPixels.length;
while (len--) {
tmpImgDataPixels[len] = imgData.data[len];
while (len--) {
tmpImgDataPixels[len] = imgData.data[len];
}
}
tmpCtx.putImageData(tmpImgData, 0, 0);