/* findcrosshair.cpp
 */

static char usage[] = "usage: %s in.png [out.png]\n";

#include <stdio.h>
#include <stdlib.h>
#include "imageLib.h"

// multiply by 100 and add random integer in [-49..49]
inline int randoff(int n) {
  return 100 * n + 49 - (rand() % 99);
}

int inbounds(int x, int y, int w, int h) {
    return
	x >= 0 && x < w && 
	y >= 0 && y < h;
}

void enhanceContrast(CByteImage im) {
    CShape sh = im.Shape();
    int width = sh.width, height = sh.height, x, y;
    int max = 0;
    for (y = 0; y < height; y++) {
	for (x = 0; x < width; x++) {
	    max = __max(max, im.Pixel(x, y, 0));
	}
    }
    // map max intensity to 220
    float scale = 220.0 / max;
    for (y = 0; y < height; y++) {
	for (x = 0; x < width; x++) {
	    im.Pixel(x, y, 0) = (int)(scale * im.Pixel(x, y, 0));
	}
    }
}

int main(int argc, char **argv)
{
  int verbose = 0;
  if (argc < 2) {
    fprintf(stderr, usage, argv[0]);
    exit(1);
  }
  int optind = 1;
  char *imname = argv[optind++];
  char *outname = argc > 2? argv[optind++] : NULL;

  try {
    CByteImage im;
    ReadImageVerb(im, imname, verbose);
    im = ConvertToGray(im);
    CShape sh = im.Shape();
    int width = sh.width, height = sh.height, x, y;
    sh.nBands = 2;
    CIntImage cnt(sh);
    cnt.ClearPixels();

    for (y = 0; y < height; y++) {
      for (x = 0; x < width; x++) {
	cnt.Pixel(x, 0, 0) += im.Pixel(x, y, 0);
	cnt.Pixel(0, y, 1) += im.Pixel(x, y, 0);
      }
    }
    for (x = 4; x < width-4; x++)
      cnt.Pixel(x, 1, 0) = 7*cnt.Pixel(x, 0, 0) 
	- cnt.Pixel(x-2, 0, 0) 
	- cnt.Pixel(x-3, 0, 0) 
	- cnt.Pixel(x-4, 0, 0) 
	- cnt.Pixel(x+2, 0, 0)
	- cnt.Pixel(x+3, 0, 0)
	- cnt.Pixel(x+4, 0, 0);
    for (y = 4; y < height-4; y++)
      cnt.Pixel(1, y, 1) = 7*cnt.Pixel(0, y, 1) 
	- cnt.Pixel(0, y-2, 1) 
	- cnt.Pixel(0, y-3, 1) 
	- cnt.Pixel(0, y-4, 1) 
	- cnt.Pixel(0, y+2, 1)
	- cnt.Pixel(0, y+3, 1)
	- cnt.Pixel(0, y+4, 1);

    int maxx = 0, maxy = 0;
    for (x = 5; x < width-5; x++)
      maxx = __max(maxx, cnt.Pixel(x, 1, 0));
    for (y = 5; y < height-5; y++)
      maxy = __max(maxy, cnt.Pixel(1, y, 1));

    //im.ClearPixels();
    float bestval = -1e20;
    int bestx = 0, besty = 0;
    for (y = 5; y < height-5; y++) {
      for (x = 5; x < width-5; x++) {
	float val = (float(cnt.Pixel(x, 1, 0) / (float)maxx) *
		     float(cnt.Pixel(1, y, 1) / (float)maxy));
	//im.Pixel(x, y, 0) = __max(0, __min(255, int(255 * val)));
	if (val > bestval) {
	  bestval = val;
	  bestx = x;
	  besty = y;
	}
      }
    }

    enhanceContrast(im);
    
    // mark max with "X"
    for (int k = -8; k <= 8; k++) {
	if (inbounds(bestx+k, besty+k, width, height))
	    im.Pixel(bestx+k, besty+k, 0) = 255;
	if (inbounds(bestx+k, besty-k, width, height))
	    im.Pixel(bestx+k, besty-k, 0) = 255;
    }


    if (outname != NULL)
	WriteImageVerb(im, outname, verbose);
    //printf("max at %d, %d\n", bestx, besty);
    //printf("bestval = %f\n", bestval);
    printf("%d %d\n", bestx, besty);
  }
  catch (CError &err) {
    fprintf(stderr, err.message);
    fprintf(stderr, "\n");
    exit(1);
  }

  return 0;
}