protected override void TransformOperator(PDFContentStreamOperator input, List <PDFContentStreamOperator> output)
{
// Scan the operators in the page content and keep track of used resources (fonts, images, colorspaces, patterns)
switch (input.Type)
{
case PDFContentStreamOperatorType.SetStrokeColorSpace:
PDFSetStrokeColorSpaceOperator sscs = input as PDFSetStrokeColorSpaceOperator;
colorspaces.Add(sscs.ColorSpaceID.Value);
break;
case PDFContentStreamOperatorType.SetStrokeColorN:
PDFSetStrokeColorNOperator sscn = input as PDFSetStrokeColorNOperator;
if (sscn.PatternID != null)
{
patterns.Add(sscn.PatternID.Value);
}
break;
case PDFContentStreamOperatorType.SetFillColorSpace:
PDFSetFillColorSpaceOperator sfcs = input as PDFSetFillColorSpaceOperator;
colorspaces.Add(sfcs.ColorSpaceID.Value);
break;
case PDFContentStreamOperatorType.SetFillColorN:
PDFSetFillColorNOperator sfcn = input as PDFSetFillColorNOperator;
if (sfcn.PatternID != null)
{
patterns.Add(sfcn.PatternID.Value);
}
break;
case PDFContentStreamOperatorType.DisplayXObject:
PDFDisplayImageXObjectOperator ixoo = input as PDFDisplayImageXObjectOperator;
if (ixoo != null)
{
xObjects.Add(ixoo.ImageID.Value);
}
else
{
PDFDisplayFormXObjectOperator fxoo = input as PDFDisplayFormXObjectOperator;
if (fxoo != null)
{
xObjects.Add(fxoo.FormXObjectID.Value);
}
}
break;
case PDFContentStreamOperatorType.SetTextFontAndSize:
PDFSetTextFontAndSizeOperator stfs = input as PDFSetTextFontAndSizeOperator;
fonts.Add(stfs.FontID.Value);
break;
}
output.Add(input);
}
protected override void TransformOperator(PDFContentStreamOperator input, List <PDFContentStreamOperator> output)
{
PDFContentStreamOperator op = input;
switch (input.Type)
{
case PDFContentStreamOperatorType.SaveGraphicsState:
strokeSeparationStack.Push(isStrokeSeparationActive);
fillSeparationStack.Push(isFillSeparationActive);
break;
case PDFContentStreamOperatorType.RestoreGraphicsState:
isStrokeSeparationActive = strokeSeparationStack.Pop();
isFillSeparationActive = fillSeparationStack.Pop();
break;
case PDFContentStreamOperatorType.MoveTo:
case PDFContentStreamOperatorType.LineTo:
case PDFContentStreamOperatorType.CCurveTo:
case PDFContentStreamOperatorType.VCurveTo:
case PDFContentStreamOperatorType.YCurveTo:
case PDFContentStreamOperatorType.Rectangle:
case PDFContentStreamOperatorType.CloseSubpath:
operators.Add(input);
op = null;
break;
case PDFContentStreamOperatorType.SetRgbFill:
case PDFContentStreamOperatorType.SetCmykFill:
case PDFContentStreamOperatorType.SetGrayFill:
isFillSeparationActive = false;
break;
case PDFContentStreamOperatorType.SetRgbStroke:
case PDFContentStreamOperatorType.SetCmykStroke:
case PDFContentStreamOperatorType.SetGrayStroke:
isStrokeSeparationActive = false;
break;
case PDFContentStreamOperatorType.SetFillColorSpace:
PDFSetFillColorSpaceOperator fillColorSpaceOperator = input as PDFSetFillColorSpaceOperator;
PDFSeparationColorSpace fillSepCs = fillColorSpaceOperator.ColorSpace as PDFSeparationColorSpace;
isFillSeparationActive = (fillSepCs != null) && (fillSepCs.Colorant == separationName);
break;
case PDFContentStreamOperatorType.SetStrokeColorSpace:
PDFSetStrokeColorSpaceOperator strokeColorSpaceOperator = input as PDFSetStrokeColorSpaceOperator;
PDFSeparationColorSpace strokeSepCs = strokeColorSpaceOperator.ColorSpace as PDFSeparationColorSpace;
isStrokeSeparationActive = (strokeSepCs != null) && (strokeSepCs.Colorant == separationName);
break;
case PDFContentStreamOperatorType.SetClipNonZero:
case PDFContentStreamOperatorType.SetClipEvenOdd:
output.AddRange(operators);
operators.Clear();
break;
case PDFContentStreamOperatorType.EndPath:
if (operators.Count > 0)
{
op = null;
operators.Clear();
}
else
{
// we had a sequence "path W/W* n", points already cleared by W/W*, n needs to be kept
}
break;
case PDFContentStreamOperatorType.Stroke:
case PDFContentStreamOperatorType.CloseStroke:
// The path painting operator is discarded and the path points are cleared
if ((isStrokeSeparationActive && !keepSeparation) ||
(!isStrokeSeparationActive && keepSeparation))
{
if (operators.Count > 0)
{
op = null;
}
else // we had a sequence "path W/W* S/s", points already cleared by W, S/s needs to be replaced by n
{
op = new PDFContentStreamOperator(PDFContentStreamOperatorType.EndPath);
}
}
else
{
output.AddRange(operators);
}
operators.Clear();
break;
case PDFContentStreamOperatorType.FillNonZero:
case PDFContentStreamOperatorType.FillNonZero2:
case PDFContentStreamOperatorType.FillOddEven:
// The path painting operator is discarded and the path points are cleared
if ((isFillSeparationActive && !keepSeparation) ||
(!isFillSeparationActive && keepSeparation))
{
if (operators.Count > 0)
{
op = null;
}
else // we had a sequence "path W/W* f/f*", points already cleared by W, f/f* needs to be replaced by n
{
op = new PDFContentStreamOperator(PDFContentStreamOperatorType.EndPath);
}
}
else
{
output.AddRange(operators);
}
operators.Clear();
break;
case PDFContentStreamOperatorType.CloseFillNonZeroStroke:
case PDFContentStreamOperatorType.CloseFillEvenOddStroke:
case PDFContentStreamOperatorType.FillNonZeroStroke:
case PDFContentStreamOperatorType.FillEvenOddStroke:
int discardContent = 0;
// The path painting operator is transformed into no-op when the path needs to be discarded
if ((isStrokeSeparationActive && !keepSeparation) ||
(!isStrokeSeparationActive && keepSeparation))
{
discardContent += 1;
}
if ((isFillSeparationActive && !keepSeparation) ||
(!isFillSeparationActive && keepSeparation))
{
discardContent += 2;
}
switch (discardContent)
{
case 3: // Discard all
if (operators.Count > 0)
{
op = null;
}
else // we had a sequence "path W/W* B/B*/b/b*", points already cleared by W, B/B*/b/b* needs to be replaced by n
{
op = new PDFContentStreamOperator(PDFContentStreamOperatorType.EndPath);
}
break;
case 2: // Discard fill
if ((input.Type == PDFContentStreamOperatorType.CloseFillNonZeroStroke) ||
(input.Type == PDFContentStreamOperatorType.CloseFillEvenOddStroke))
{
op = new PDFContentStreamOperator(PDFContentStreamOperatorType.CloseStroke);
}
else
{
op = new PDFContentStreamOperator(PDFContentStreamOperatorType.Stroke);
}
break;
case 1: // Discard stroke
if ((input.Type == PDFContentStreamOperatorType.CloseFillNonZeroStroke) ||
(input.Type == PDFContentStreamOperatorType.FillNonZeroStroke))
{
op = new PDFContentStreamOperator(PDFContentStreamOperatorType.FillNonZero);
}
else
{
op = new PDFContentStreamOperator(PDFContentStreamOperatorType.FillOddEven);
}
break;
case 0:
output.AddRange(operators);
break;
}
operators.Clear();
break;
case PDFContentStreamOperatorType.DisplayXObject:
PDFDisplayImageXObjectOperator diop = input as PDFDisplayImageXObjectOperator;
if (diop != null)
{
PDFSeparationColorSpace imageSepCs = diop.Image.ColorSpace as PDFSeparationColorSpace;
bool isImageSeparationActive = (imageSepCs != null) && (imageSepCs.Colorant == separationName);
if ((isImageSeparationActive && !keepSeparation) ||
(!isImageSeparationActive && keepSeparation))
{
op = null;
}
}
break;
case PDFContentStreamOperatorType.ShowText:
case PDFContentStreamOperatorType.ShowText2:
case PDFContentStreamOperatorType.ShowText3:
case PDFContentStreamOperatorType.ShowText4:
// The text showing operator is simply discarded
if ((isFillSeparationActive && !keepSeparation) ||
(!isFillSeparationActive && keepSeparation))
{
op = null;
}
break;
case PDFContentStreamOperatorType.SetShading:
PDFSetShadingOperator sso = input as PDFSetShadingOperator;
PDFSeparationColorSpace shadingSepCs = sso.Shading.ColorSpace as PDFSeparationColorSpace;
bool isShadingSeparationActive = (shadingSepCs != null) && (shadingSepCs.Colorant == separationName);
if ((isShadingSeparationActive && !keepSeparation) ||
(!isShadingSeparationActive && keepSeparation))
{
op = null;
}
break;
}
if (op != null)
{
output.Add(op);
}
}