/** Create a PDF page to display the given bitmap image.
* We need:
* - A page object, that points to the resources and contents of the page.
* - A resource object, that defines Im1 (image 1), the image to draw.
* - A content object, that says to draw Im1
* - An XObject, that gives the raw image data (zlib-compressed)
*/
public void AddImage(Bitmap bitmap)
{
PDFObject page = createPDFObject(PDFType.PDFTypePage);
PDFObject pagetree = getPDFObject(PDFType.PDFTypePageTree);
PDFObject pageResource = createPDFObject(PDFType.PDFTypePageResource);
PDFObject pageContent = createPDFObject(PDFType.PDFTypePageContent);
PDFObject pageContentLength = createPDFObject(PDFType.PDFTypeLength);
PDFObject pageXObject = createPDFObject(PDFType.PDFTypeXObject);
PDFObject pageXObjectLength = createPDFObject(PDFType.PDFTypeLength);
page.StringPairs = "<< /Type /Page /Parent " + pagetree.RefString +
" /Resources " + pageResource.RefString +
" /Contents " + pageContent.RefString +
" /MediaBox [0 0 840 1090] >>";
pageResource.StringPairs = "<< /ProcSet [ /PDF /ImageB /ImageC /ImageI ] /XObject << /Im1 " + pageXObject.RefString + " >> >>";
byte[] uncompressedValue = UTF8Encoding.UTF8.GetBytes("q Q q /Perceptual ri q " + bitmap.Width.ToString() + " 0 0 " + bitmap.Height.ToString() + " 0 0 cm /Im1 Do Q Q");
byte[] compressedValue = Compress(uncompressedValue);
pageContentLength.StringPairs = compressedValue.Length.ToString();
pageContent.StringPairs = "<< /Length " + pageContentLength.RefString + " /Filter /FlateDecode >>";
pageContent.StreamValue = compressedValue;
pageXObject.StringPairs = "<< /Length " + pageXObjectLength.RefString + " /Type /XObject /Subtype /Image /Width " + bitmap.Width.ToString() + " /Height " + bitmap.Height.ToString() + " /Interpolate false /ColorSpace /DeviceRGB /BitsPerComponent 8 /Filter /FlateDecode >>";
pageXObject.StreamValue = CompressImage(bitmap);
pageXObjectLength.StringPairs = pageXObject.StreamValue.Length.ToString();
}
/** Allocate a new PDF Object */
PDFObject createPDFObject(PDFType type)
{
PDFObject obj = new PDFObject(pdfobjects.Count + 1, type);
pdfobjects.Add(obj);
return(obj);
}
/** Write the PDF trailer */
void WriteTrailer()
{
TimeSpan epoch = (DateTime.UtcNow - new DateTime(1970, 1, 1));
int timestamp = (int)epoch.TotalSeconds;
PDFObject catalog = getPDFObject(PDFType.PDFTypeCatalog);
PDFObject info = getPDFObject(PDFType.PDFTypeInfo);
WriteString("trailer\n<< /Size " + (pdfobjects.Count + 1).ToString() + " /Root " + catalog.RefString + " /Info " + info.RefString + " /ID [ <" + timestamp.ToString() + "> <" + timestamp.ToString() + "> ] >>\n");
WriteString("startxref\n" + startxref.ToString() + "\n%%EOF\n");
}
/** Create the PDF catalog, info, and page tree objects */
void CreateHeaderObjects()
{
string datestring = DateTime.Now.ToString("yyyymmddhhmmss-00'00'");
PDFObject docinfo = createPDFObject(PDFType.PDFTypeInfo);
docinfo.StringPairs = "<< /Title (" + title + ") /Producer (MidiSheetMusic) /CreationDate (D:" + datestring + ") >>";
PDFObject catalog = createPDFObject(PDFType.PDFTypeCatalog);
PDFObject pagetree = createPDFObject(PDFType.PDFTypePageTree);
catalog.StringPairs = "<< /Type /Catalog /Pages " + pagetree.RefString + " /Version /1.4 >>";
}
/** Create the page tree object, which contains references to all the page objects */
void initPageTreeValue()
{
PDFObject pagetree = getPDFObject(PDFType.PDFTypePageTree);
string pageTreeValue = "<< /Type /Pages /MediaBox [0 0 840 1090] /Count " + numpages.ToString() + " /Kids [ ";
foreach (PDFObject obj in pdfobjects)
{
if (obj.PDFType == PDFType.PDFTypePage)
{
pageTreeValue += obj.RefString + " ";
}
}
pageTreeValue += "] >>";
pagetree.StringPairs = pageTreeValue;
}