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refactored image drawing code

sbarman 14 years ago
parent
25c27cbda1
commit
1f4fcfbd69
1 changed files with 167 additions and 155 deletions
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  1. 322
      pdf.js

322
pdf.js
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@ -4234,23 +4234,11 @@ var CanvasGraphics = (function() {
paintImageXObject: function(ref, image, inline) { paintImageXObject: function(ref, image, inline) {
this.save(); this.save();
if (image.getParams) {
// JPX/JPEG2000 streams directly contain bits per component
// and color space mode information.
TODO("get params from actual stream");
// var bits = ...
// var colorspace = ...
}
// TODO cache rendered images?
var ctx = this.ctx;
var dict = image.dict; var dict = image.dict;
var w = dict.get2("Width", "W"); var w = dict.get2("Width", "W");
var h = dict.get2("Height", "H"); var h = dict.get2("Height", "H");
if (w < 1 || h < 1)
error("Invalid image width or height");
var ctx = this.ctx;
// scale the image to the unit square // scale the image to the unit square
ctx.scale(1/w, -1/h); ctx.scale(1/w, -1/h);
@ -4265,154 +4253,15 @@ var CanvasGraphics = (function() {
return; return;
} }
var interpolate = dict.get2("Interpolate", "I"); var imageObj = new PDFImage(this.xref, this.res, image, inline);
if (!IsBool(interpolate))
interpolate = false;
var imageMask = dict.get2("ImageMask", "IM");
if (!IsBool(imageMask))
imageMask = false;
var bitsPerComponent = image.bitsPerComponent;
if (!bitsPerComponent) {
bitsPerComponent = dict.get2("BitsPerComponent", "BPC");
if (!bitsPerComponent) {
if (imageMask)
bitsPerComponent = 1;
else
error("Bits per component missing in image");
}
}
if (bitsPerComponent !== 8) {
TODO("Support bpc="+ bitsPerComponent);
this.restore();
return;
}
var xref = this.xref;
var colorSpaces = this.colorSpaces;
if (imageMask) {
error("support image masks");
}
// actual image
var csStream = dict.get2("ColorSpace", "CS");
csStream = xref.fetchIfRef(csStream);
if (IsName(csStream) && inline)
csStream = colorSpaces.get(csStream);
var colorSpace = new ColorSpace(xref, csStream);
var decode = dict.get2("Decode", "D");
TODO("create color map");
var mask = image.dict.get("Mask");
mask = xref.fetchIfRef(mask);
var smask = image.dict.get("SMask");
smask = xref.fetchIfRef(smask);
if (IsStream(smask)) {
if (inline)
error("cannot combine smask and inlining");
var maskDict = smask.dict;
var maskW = maskDict.get2("Width", "W");
var maskH = maskDict.get2("Height", "H");
if (!IsNum(maskW) || !IsNum(maskH) || maskW < 1 || maskH < 1)
error("Invalid image width or height");
if (maskW !== w || maskH !== h)
error("Invalid image width or height");
var maskInterpolate = maskDict.get2("Interpolate", "I");
if (!IsBool(maskInterpolate))
maskInterpolate = false;
var maskBPC = maskDict.get2("BitsPerComponent", "BPC");
if (!maskBPC)
error("Invalid image mask bpc");
var maskCsStream = maskDict.get2("ColorSpace", "CS");
maskCsStream = xref.fetchIfRef(maskCsStream);
var maskColorSpace = new ColorSpace(xref, maskCsStream);
if (maskColorSpace.mode !== "DeviceGray")
error("Invalid color space for smask");
var maskDecode = maskDict.get2("Decode", "D");
if (maskDecode)
TODO("Handle mask decode");
// handle matte object
}
var tmpCanvas = new this.ScratchCanvas(w, h); var tmpCanvas = new this.ScratchCanvas(w, h);
var tmpCtx = tmpCanvas.getContext("2d"); var tmpCtx = tmpCanvas.getContext("2d");
var imgData = tmpCtx.getImageData(0, 0, w, h); var imgData = tmpCtx.getImageData(0, 0, w, h);
var pixels = imgData.data; var pixels = imgData.data;
if (bitsPerComponent != 8) imageObj.fillRgbaBuffer(pixels);
error("unhandled number of bits per component");
if (smask) {
if (maskColorSpace.numComps != 1)
error("Incorrect number of components in smask");
var numComps = colorSpace.numComps;
var imgArray = image.getBytes(numComps * w * h);
var imgIdx = 0;
var smArray = smask.getBytes(w * h);
var smIdx = 0;
var length = 4 * w * h;
switch (numComps) {
case 1:
for (var i = 0; i < length; i += 4) {
var p = imgArray[imgIdx++];
pixels[i] = p;
pixels[i+1] = p;
pixels[i+2] = p;
pixels[i+3] = smArray[smIdx++];
}
break;
case 3:
for (var i = 0; i < length; i += 4) {
pixels[i] = imgArray[imgIdx++];
pixels[i+1] = imgArray[imgIdx++];
pixels[i+2] = imgArray[imgIdx++];
pixels[i+3] = smArray[smIdx++];
}
break;
default:
TODO("Images with "+ numComps + " components per pixel");
}
} else {
var numComps = colorSpace.numComps;
var imgArray = image.getBytes(numComps * w * h);
var imgIdx = 0;
var length = 4 * w * h;
switch (numComps) {
case 1:
for (var i = 0; i < length; i += 4) {
var p = imgArray[imgIdx++];
pixels[i] = p;
pixels[i+1] = p;
pixels[i+2] = p;
pixels[i+3] = 255;
}
break;
case 3:
for (var i = 0; i < length; i += 4) {
pixels[i] = imgArray[imgIdx++];
pixels[i+1] = imgArray[imgIdx++];
pixels[i+2] = imgArray[imgIdx++];
pixels[i+3] = 255;
}
break;
default:
TODO("Images with "+ numComps + " components per pixel");
}
}
tmpCtx.putImageData(imgData, 0, 0); tmpCtx.putImageData(imgData, 0, 0);
ctx.drawImage(tmpCanvas, 0, -h); ctx.drawImage(tmpCanvas, 0, -h);
this.restore(); this.restore();
@ -4541,6 +4390,169 @@ var ColorSpace = (function() {
return constructor; return constructor;
})(); })();
var PDFImage = (function() {
function constructor(xref, res, image, inline) {
this.image = image;
if (image.getParams) {
// JPX/JPEG2000 streams directly contain bits per component
// and color space mode information.
TODO("get params from actual stream");
// var bits = ...
// var colorspace = ...
}
// TODO cache rendered images?
var dict = image.dict;
this.width = dict.get2("Width", "W");
this.height = dict.get2("Height", "H");
if (this.width < 1 || this.height < 1)
error("Invalid image width or height");
this.interpolate = dict.get2("Interpolate", "I") || false;
this.imageMask = dict.get2("ImageMask", "IM") || false;
var bitsPerComponent = image.bitsPerComponent;
if (!bitsPerComponent) {
bitsPerComponent = dict.get2("BitsPerComponent", "BPC");
if (!bitsPerComponent) {
if (this.imageMask)
bitsPerComponent = 1;
else
error("Bits per component missing in image");
}
}
this.bpc = bitsPerComponent;
var colorSpaces = res.get("ColorSpace");
var csStream = xref.fetchIfRef(dict.get2("ColorSpace", "CS"));
if (IsName(csStream) && inline)
csStream = colorSpaces.get(csStream);
this.colorSpace = new ColorSpace(xref, csStream);
this.numComps = this.colorSpace.numComps;
this.decode = dict.get2("Decode", "D");
var mask = xref.fetchIfRef(image.dict.get("Mask"));
var smask = xref.fetchIfRef(image.dict.get("SMask"));
if (mask) {
TODO("masked images");
} else if (smask) {
this.smask = new PDFImage(xref, res, smask);
}
};
constructor.prototype = {
getCompFunction: function getCompFunction(bpc, width, numComps, buffer) {
var bufferPos = 0;
if (bpc == 8) {
var getComp = function() {
return buffer[bufferPos++];
}
} else {
var rowBytes = (width * numComps * bpc + 7) >> 3;
var bits = 0;
var buf = 0;
var getComp = function() {
while (bits < bpc) {
buf = (buf << 8) | buffer[bufferPos++];
bits += 8;
}
var remainingBits = bits - bpc;
var ret = buf >> remainingBits;
if (bufferPos % rowBytes == 0) {
buf = 0;
bits = 0;
} else {
buf = buf & ((1 << remainingBits) - 1);
bits = remainingBits;
}
return Math.round(255 * ret / ((1 << bpc) - 1));
}
}
return getComp;
},
getOpacityFunction: function getOpacityFunction() {
var smask = this.smask;
if (smask) {
var w = smask.width;
var h = smask.height;
if (w != this.width || h != this.height)
error("smask dimensions do not match image dimensions");
var buf = new Uint8Array(w * h);
smask.fillGrayBuffer(buf);
var bufPos = 0;
var opacity = function() {
return buf[bufPos++];
}
} else {
var opacity = function() { return 255; }
}
return opacity;
},
fillRgbaBuffer: function fillRgbaBuffer(buffer) {
var numComps = this.numComps;
var width = this.width;
var height = this.height;
var bpc = this.bpc;
// rows start at byte boundary;
var rowBytes = (width * numComps * bpc + 7) >> 3;
var imgArray = this.image.getBytes(height * rowBytes);
var imgPos = 0;
var getComp = this.getCompFunction(bpc, width, numComps, imgArray)
var getOpacity = this.getOpacityFunction();
var length = width * height * 4;
switch (numComps) {
case 1:
for (var i = 0; i < length; i += 4) {
var p = getComp();
buffer[i] = p;
buffer[i+1] = p;
buffer[i+2] = p;
buffer[i+3] = getOpacity();
}
break;
case 3:
for (var i = 0; i < length; i += 4) {
buffer[i] = getComp();
buffer[i+1] = getComp();
buffer[i+2] = getComp();
buffer[i+3] = getOpacity();
}
break;
default:
TODO("Images with "+ numComps + " components per pixel");
}
},
fillGrayBuffer: function fillGrayScaleBuffer(buffer) {
var numComps = this.numComps;
if (numComps != 1)
error("Reading gray scale from a color image");
var width = this.width;
var height = this.height;
var bpc = this.bpc;
// rows start at byte boundary;
var rowBytes = (width * numComps * bpc + 7) >> 3;
var imgArray = this.image.getBytes(height * rowBytes);
var getComp = this.getCompFunction(bpc, width, numComps, imgArray)
var length = width * height;
for (var i = 0; i < length; ++i)
buffer[i] = getComp();
},
};
return constructor;
})();
var PDFFunction = (function() { var PDFFunction = (function() {
function constructor(xref, fn) { function constructor(xref, fn) {
var dict = fn.dict; var dict = fn.dict;

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