diff options
Diffstat (limited to 'examples/pdf-create.cc')
| -rw-r--r-- | examples/pdf-create.cc | 59 |
1 files changed, 24 insertions, 35 deletions
diff --git a/examples/pdf-create.cc b/examples/pdf-create.cc index e0fa93b1..c793b5f8 100644 --- a/examples/pdf-create.cc +++ b/examples/pdf-create.cc @@ -1,7 +1,6 @@ // -// This is an example of creating a PDF file from scratch. It -// illustrates use of several QPDF operations for creating objects and -// streams. It also serves as an illustration of how to use +// This is an example of creating a PDF file from scratch. It illustrates use of several QPDF +// operations for creating objects and streams. It also serves as an illustration of how to use // StreamDataProvider with different types of filters. // @@ -20,8 +19,8 @@ static char const* whoami = nullptr; -// This is a simple StreamDataProvider that writes image data for an -// orange square of the given width and height. +// This is a simple StreamDataProvider that writes image data for an orange square of the given +// width and height. class ImageProvider: public QPDFObjectHandle::StreamDataProvider { public: @@ -130,8 +129,7 @@ usage() static QPDFObjectHandle createPageContents(QPDF& pdf, std::string const& text) { - // Create a stream that displays our image and the given text in - // our font. + // Create a stream that displays our image and the given text in our font. std::string contents = "BT /F1 24 Tf 72 320 Td (" + text + ") Tj ET\n" "q 244 0 0 144 184 100 cm /Im1 Do Q\n"; @@ -159,11 +157,9 @@ add_page( { QPDF& pdf(dh.getQPDF()); - // Create a stream to encode our image. QPDFWriter will fill in - // the length and will respect our filters based on stream data - // mode. Since we are not specifying, QPDFWriter will compress - // with /FlateDecode if we don't provide any other form of - // compression. + // Create a stream to encode our image. QPDFWriter will fill in the length and will respect our + // filters based on stream data mode. Since we are not specifying, QPDFWriter will compress with + // /FlateDecode if we don't provide any other form of compression. auto* p = new ImageProvider(color_space, filter); std::shared_ptr<QPDFObjectHandle::StreamDataProvider> provider(p); size_t width = p->getWidth(); @@ -219,20 +215,17 @@ check( std::vector<std::string> const& color_spaces, std::vector<std::string> const& filters) { - // Each stream is compressed the way it is supposed to be. We will - // add additional tests in qpdf.test to exercise QPDFWriter more - // fully. In this case, we want to make sure that we actually have - // RunLengthDecode and DCTDecode where we are supposed to and - // FlateDecode where we provided no filters. + // Each stream is compressed the way it is supposed to be. We will add additional tests in + // qpdf.test to exercise QPDFWriter more fully. In this case, we want to make sure that we + // actually have RunLengthDecode and DCTDecode where we are supposed to and FlateDecode where we + // provided no filters. - // Each image is correct. For non-lossy image compression, the - // uncompressed image data should exactly match what ImageProvider - // provided. For the DCTDecode data, allow for some fuzz to handle - // jpeg compression as well as its variance on different systems. + // Each image is correct. For non-lossy image compression, the uncompressed image data should + // exactly match what ImageProvider provided. For the DCTDecode data, allow for some fuzz to + // handle jpeg compression as well as its variance on different systems. - // These tests should use QPDFObjectHandle's stream data retrieval - // methods, but don't try to fully exercise them here. That is - // done elsewhere. + // These tests should use QPDFObjectHandle's stream data retrieval methods, but don't try to + // fully exercise them here. That is done elsewhere. size_t n_color_spaces = color_spaces.size(); size_t n_filters = filters.size(); @@ -254,8 +247,8 @@ check( // Check filter and color space. std::string desired_color_space = color_spaces[(pageno - 1) / n_color_spaces]; std::string desired_filter = filters[(pageno - 1) % n_filters]; - // In the default mode, QPDFWriter will compress with - // /FlateDecode if no filters are provided. + // In the default mode, QPDFWriter will compress with /FlateDecode if no filters are + // provided. if (desired_filter == "null") { desired_filter = "/FlateDecode"; } @@ -288,11 +281,9 @@ check( std::cout << "page " << pageno << ": image data length mismatch" << std::endl; this_errors = errors = true; } else { - // Compare bytes. For JPEG, allow a certain number of - // the bytes to be off desired by more than a given - // tolerance. Any of the samples may be a little off - // because of lossy compression, and around sharp - // edges, things can be quite off. For non-lossy + // Compare bytes. For JPEG, allow a certain number of the bytes to be off desired by + // more than a given tolerance. Any of the samples may be a little off because of + // lossy compression, and around sharp edges, things can be quite off. For non-lossy // compression, do not allow any tolerance. unsigned char const* actual_bytes = actual_data->getBuffer(); unsigned char const* desired_bytes = desired_data->getBuffer(); @@ -332,8 +323,7 @@ create_pdf(char const* filename) // Start with an empty PDF that has no pages or non-required objects. pdf.emptyPDF(); - // Add an indirect object to contain a font descriptor for the - // built-in Helvetica font. + // Add an indirect object to contain a font descriptor for the built-in Helvetica font. QPDFObjectHandle font = pdf.makeIndirectObject( // line-break "<<" @@ -362,8 +352,7 @@ create_pdf(char const* filename) QPDFWriter w(pdf, filename); w.write(); - // For test suite, verify that everything is the way it is - // supposed to be. + // For test suite, verify that everything is the way it is supposed to be. check(filename, color_spaces, filters); } |