/************************************************************************/
// compile as:
// fltk-config --use-images --compile twin_image.cxx
//
// invoke as:
// twin_image somefile.jpg (should work with many image types, jpg, png, etc...)

#include <stdlib.h>
#include <stdio.h>
#include <string.h>

#include <FL/Fl.H>
#include <FL/Fl_Box.H>
#include <FL/Fl_Double_Window.H>
#include <FL/Fl_Image.H>
#include <FL/Fl_Shared_Image.H>
#include <FL/Fl_Button.H>
#include <FL/fl_draw.H>

Fl_Double_Window *main_win = NULL;
Fl_Shared_Image *img = NULL;
Fl_RGB_Image *img_3 = NULL;

int depth = 0;
int count = 0;
int width = 0;
int height = 0;
const char *datap = NULL;
int xoff = 0;
int yoff = 0;

const double frame_delay = (1.0 / 10.0);

/************************************************************************/
Fl_Box *box_1;
Fl_Box *box_3;

/************************************************************************/
void load_file(const char *n)
{
    if (img) img->release();

    img = Fl_Shared_Image::get(n);
    if (!img) {
        puts("Image file format not recognized!");
        fflush(stdout);
        return;
    }
    if (img->w() > box_1->w() || img->h() > box_1->h()) {
        Fl_Image *temp;
        if (img->w() > img->h()) temp = img->copy(box_1->w(), box_1->h() * img->h() / img->w());
        else temp = img->copy(box_1->w() * img->w() / img->h(), box_1->h());

        img->release();
        img = (Fl_Shared_Image *)temp;
    }

    box_1->image(img);
    box_1->redraw();
} // load_file

/************************************************************************/
void quit_cb(Fl_Button *, void *)
{
    main_win->hide();
} // quit_cb

/************************************************************************/
void process_cb(void *)
{
  unsigned total = width * height * depth;
  static char *processed_data = NULL;

  if (processed_data == NULL) { // setup processed data
      processed_data = new char [total];
      for (unsigned idx = 0; idx < total; idx ++)
      {
        processed_data[idx] = datap[idx];
      }
  }
  else { // process data
      for (unsigned idx = 0; idx < total; idx ++)
      {
        processed_data[idx] = (processed_data[idx] + 3) & 0xFF;
      }
  }

  if (img_3 != NULL) {
      delete img_3;
  }

  img_3 = new Fl_RGB_Image((const uchar *)processed_data, width, height, depth);
  box_3->image(img_3);
  box_3->redraw();

  Fl::repeat_timeout(frame_delay, process_cb);
} // process_cb

/************************************************************************/
int main(int argc, char **argv)
{
    fl_register_images();
    Fl::get_system_colors();

    main_win = new Fl_Double_Window(615, 300);
    main_win->begin();

    box_1 = new Fl_Box(0, 0, 200, 200);

    box_3 = new Fl_Box(410, 0, 200, 200);

    Fl_Button *quit = new Fl_Button(540, 260, 60, 30);
    quit->label("Quit");
    quit->callback((Fl_Callback *)quit_cb);

    main_win->end();

    if (argv[1]) {
        load_file(argv[1]);
    }
    else {
        printf("Need a file ot process\n");
        return -1;
    }

    depth = img->d();
    count = img->count();
    datap = img->data()[0];
    width = img->w();
    height = img->h();

    if (height < box_1->h()) {
        yoff = (box_1->h() - height) / 2;
    }

    if (width < box_1->w()) {
        xoff = (box_1->w() - width) / 2;
    }

    printf("Depth: %d   Count: %d  W: %d H: %d\n", depth, count, width, height);
    printf("X offs %d Y offs %d\n", xoff, yoff);
    fflush(stdout);

    main_win->show();

   // animate the refresh
   Fl::add_timeout(frame_delay, process_cb);

    return Fl::run();
} // main

/* End of File */