imej.cpp

#include <iostream>
#include <iomanip>
#include <cstdint>
#include <vector>
#include <string>
#include <sys/ioctl.h>
#include <unistd.h>
#include <Imlib2.h>

using std::cerr;
using std::cout;
using std::vector;
using std::string;
using std::endl;

int get_terminal_width(){
  winsize w;
  ioctl(STDOUT_FILENO, TIOCGWINSZ, &w);
  return w.ws_col;
}

void put_chars(Imlib_Color pixels[2]){

  Imlib_Color *bg = pixels, *fg = pixels + 1;

  int bg_x = 40
    + (bg->red > 0x7f)
    + ((bg->green > 0x7f) << 1)
    + ((bg->blue > 0x7f) << 2);

  int fg_x = 30
    + (fg->red > 0x7f)
    + ((fg->green > 0x7f) << 1) 
    + ((fg->blue > 0x7f) << 2);

  int bold = 
    (fg->red > 0xa0)
    ||(fg->green > 0xa0)
    ||(fg->blue > 0xa0);

  cout << "\033["
    << bold << ';'
    << fg_x << ';'
    << bg_x << 'm'
    << 'a';

}

void put_endl(){
  cout << "\033[0m" << endl;
}

int main(int argc, char* argv[]){
  if(argc < 2){
    cerr << "Usage: " << argv[0] << " <image file...>\n";
    return 1;
  }

  vector<string> args (argv + 1, argv + argc);

  for(auto const& path : args){

    Imlib_Image image = imlib_load_image(path.c_str());

    if(!image){
      cerr << "Couldn't open " << path << ": invalid image?\n";
      continue;
    }

    imlib_context_set_image(image);

    int w = imlib_image_get_width(), h = imlib_image_get_height();
    int scaled_w = get_terminal_width() - 1;
    int scaled_h = (int)((double)h / (double)w * (double)scaled_w) * 2;

    Imlib_Image scaled = imlib_create_cropped_scaled_image(
      0, 0, w, h, scaled_w, scaled_h
    );

    imlib_free_image();
    imlib_context_set_image(scaled);

    for(int y = 0; y < scaled_h - 1; y += 2){
      for(int x = 0; x < scaled_w; ++x){
        Imlib_Color color[2];
        imlib_image_query_pixel(x, y, color);
        imlib_image_query_pixel(x, y + 1, color + 1);
        put_chars(color);
      }
      put_endl();
    }
    imlib_free_image();
  }
}