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Merge pull request #97 from sbarman/bwimage

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Refactor of draw image code r=gal
This commit is contained in:
Andreas Gal 2011-06-27 11:44:50 -07:00
commit fdb4d770c4
1 changed files with 201 additions and 155 deletions
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pdf.js
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@ -4234,23 +4234,11 @@ var CanvasGraphics = (function() {
paintImageXObject: function(ref, image, inline) {
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 w = dict.get2("Width", "W");
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
ctx.scale(1/w, -1/h);
@ -4265,154 +4253,15 @@ var CanvasGraphics = (function() {
return;
}
var interpolate = dict.get2("Interpolate", "I");
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 imageObj = new PDFImage(this.xref, this.res, image, inline);
var tmpCanvas = new this.ScratchCanvas(w, h);
var tmpCtx = tmpCanvas.getContext("2d");
var imgData = tmpCtx.getImageData(0, 0, w, h);
var pixels = imgData.data;
if (bitsPerComponent != 8)
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");
}
}
imageObj.fillRgbaBuffer(pixels);
tmpCtx.putImageData(imgData, 0, 0);
ctx.drawImage(tmpCanvas, 0, -h);
this.restore();
@ -4541,6 +4390,203 @@ var ColorSpace = (function() {
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 = {
getComponents: function getComponents(buffer) {
var bpc = this.bpc;
if (bpc == 8)
return buffer;
var width = this.width;
var height = this.height;
var numComps = this.numComps;
var length = width * height;
var bufferPos = 0;
var output = new Uint8Array(length);
if (bpc == 1) {
var rowComps = width * numComps;
var mask = 0;
var buf = 0;
for (var i = 0, ii = length; i < ii; ++i) {
if (i % rowComps == 0) {
mask = 0;
buf = 0;
} else {
mask >>= 1;
}
if (mask <= 0) {
buf = buffer[bufferPos++];
mask = 128;
}
var t = buf & mask;
if (t == 0)
output[i] = 0;
else
output[i] = 255;
}
} else {
var rowComps = width * numComps;
var bits = 0;
var buf = 0;
for (var i = 0, ii = length; i < ii; ++i) {
while (bits < bpc) {
buf = (buf << 8) | buffer[bufferPos++];
bits += 8;
}
var remainingBits = bits - bpc;
var ret = buf >> remainingBits;
if (i % rowComps == 0) {
buf = 0;
bits = 0;
} else {
buf = buf & ((1 << remainingBits) - 1);
bits = remainingBits;
}
output[i] = Math.round(255 * ret / ((1 << bpc) - 1));
}
}
return output;
},
getOpacity: function getOpacity() {
var smask = this.smask;
var width = this.width;
var height = this.height;
var buf = new Uint8Array(width * height);
if (smask) {
var sw = smask.width;
var sh = smask.height;
if (sw != this.width || sh != this.height)
error("smask dimensions do not match image dimensions");
smask.fillGrayBuffer(buf);
return buf;
} else {
for (var i = 0, ii = width * height; i < ii; ++i)
buf[i] = 255;
}
return buf;
},
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 comps = this.getComponents(imgArray);
var compsPos = 0;
var opacity = this.getOpacity();
var opacityPos = 0;
var length = width * height * 4;
switch (numComps) {
case 1:
for (var i = 0; i < length; i += 4) {
var p = comps[compsPos++];
buffer[i] = p;
buffer[i+1] = p;
buffer[i+2] = p;
buffer[i+3] = opacity[opacityPos++];
}
break;
case 3:
for (var i = 0; i < length; i += 4) {
buffer[i] = comps[compsPos++];
buffer[i+1] = comps[compsPos++];
buffer[i+2] = comps[compsPos++];
buffer[i+3] = opacity[opacityPos++];
}
break;
default:
TODO("Images with "+ numComps + " components per pixel");
}
},
fillGrayBuffer: function fillGrayBuffer(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 comps = this.getComponents(imgArray);
var length = width * height;
for (var i = 0; i < length; ++i)
buffer[i] = comps[i];
},
};
return constructor;
})();
var PDFFunction = (function() {
function constructor(xref, fn) {
var dict = fn.dict;