LibHARU + PDF

main.cpp

/*
  
  PDF
  ----
  Very basic application which generates a poster from a 
  set of images. This application was created because I wanted
  to have a poster from my instagram images. It uses a couple of
  php files that login to my instagram account and generates a 
  shell script which downloads them to a directory. 

  Once downloaded all files are saved using a filename like: image-%d.jpg
  By setting the "num_images" below I load in all the files and add them to 
  the PDF.
  

 */
#include <iostream>
#include <math.h>
#include <stdio.h>
#include <stdlib.h>
#include <hpdf.h>

#define MM_TO_POINTS(mm) (mm * (72.0/25.4))

void error_handler(HPDF_STATUS errno, HPDF_STATUS detail, void* user) {
  printf("Error.\n");
}

int main() {
  printf("test.\n");
  HPDF_Doc pdf;
  HPDF_Page page;
  
  pdf = HPDF_New(error_handler, NULL);
  if(!pdf) {
    printf("Error: cannot create pdfdoc object.\n");
    return EXIT_FAILURE;
  }

  int num_images = 348;
  int img_padding = MM_TO_POINTS(8); 
  int poster_width = MM_TO_POINTS(841);
  int poster_height = MM_TO_POINTS(1189);
  int poster_padding = MM_TO_POINTS(70);
  int page_width = poster_width - poster_padding;
  int page_height = poster_height - poster_padding;

  int num_cols = 16;
  int img_width = (page_width-(img_padding*num_cols)) / num_cols;
  int img_height = img_width;
  int num_rows = page_height / img_height;
  int max_images = num_cols * num_rows;
   
  while(max_images > num_images) {
    num_rows--;
    max_images = num_cols * num_rows;
  }
  
  // reset/clamp page size
  page_width = num_cols * (img_width + img_padding);
  page_height = num_rows * (img_height + img_padding);
  int offset_x = 0.5 * (poster_width - page_width);
  int offset_y = 0.5 * (poster_height - page_height);

  printf("Cols per page: %d\n", num_cols);
  printf("Rows per page: %d\n", num_rows);
  printf("Offset x: %d, offset y: %d\n", offset_x, offset_y);

  // create page
  page = HPDF_AddPage(pdf);
  HPDF_Page_SetHeight(page, poster_height);
  HPDF_Page_SetWidth(page, poster_width);

  // create background fill
  HPDF_Page_SetRGBFill(page, 0, 0, 0);
  HPDF_Page_Rectangle(page, 0, 0, poster_width, poster_height);
  HPDF_Page_Fill(page);
  
  // add images
  char fname[512];
  int dx = 0;
  for(int j = 0; j < num_rows; ++j) {
    for(int i = 0; i < num_cols; ++i) {
      if(dx > num_images) {
        continue;
      }
      int x = offset_x + (i * img_width) + i * img_padding;
      int y = offset_y + (j * img_height) + j * img_padding;
      sprintf(fname, "./downloaded/image-%d.jpg", dx);
      printf("Image: %s, %d x %d\n", fname, x, y);

      HPDF_Image image;
      image = HPDF_LoadJpegImageFromFile(pdf, fname);
      HPDF_Page_DrawImage(page, image, x, y, img_width, img_height);
      ++dx;
    }
  }

  printf("Used: %d images.\n", dx);

  HPDF_SaveToFile(pdf, "test.pdf");
  HPDF_Free(pdf);
  return EXIT_SUCCESS;
}