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#include <fstream>
#include <iostream>
#include <string>

#include "public/fpdf_annot.h"
#include "public/fpdfview.h"
#include "public/fpdf_save.h"

using namespace std;

class FileWriter : public FPDF_FILEWRITE_ {
  std::ofstream outStream;
 public:
  FileWriter(const char* path)
      : outStream(path, std::ios::out | std::ios::binary) {
    version = 1;
    FPDF_FILEWRITE_::WriteBlock = WriteBlock;
  }

  ~FileWriter() { outStream.close(); }

  bool canWrite() const { return outStream.is_open(); }

  static int WriteBlock(struct FPDF_FILEWRITE_* pThis,
                        const void* pData,
                        unsigned long size) {
    auto thisPtr = static_cast<FileWriter*>(pThis);
    thisPtr->outStream.write((const char*)pData, (std::streamsize)size);
    return 1;
  }
};

int main() {
  FPDF_InitLibrary();

  auto document = FPDF_LoadDocument("sample.pdf", "");
  auto page = FPDF_LoadPage(document, 0);

  auto square = FPDFPage_CreateAnnot(page, FPDF_ANNOT_SQUARE);
  FPDFAnnot_SetColor(square, FPDFANNOT_COLORTYPE_Color, 255, 0, 0, 255);
  FS_RECTF rect{0, 0, 128, 128};
  FPDFAnnot_SetRect(square, &rect);

  FileWriter noIncrement("noIncrement.pdf");
  FPDF_SaveAsCopy(document, &noIncrement, FPDF_NO_INCREMENTAL);

  FileWriter increment("increment.pdf");
  FPDF_SaveAsCopy(document, &increment, FPDF_INCREMENTAL);

  FPDF_DestroyLibrary();
  return 0;
}