/*
  dither 8 bit depth yuv images
  Copyright (C) 2000  Martin Vogt

  This program is free software; you can redistribute it and/or modify
  it under the terms of the GNU Library General Public License as published by
  the Free Software Foundation.

  For more information look at the file COPYRIGHT in this package

 */


#include "dither8Bit.h"


Dither8Bit::Dither8Bit(unsigned char pixel[256]) {

  int i;
  for(i=0;i<256;i++) {
    this->pixel[i]=pixel[i];
  }
  colorTable8Bit=new ColorTable8Bit();

  lum_values = colorTable8Bit->getLumValues();
  cr_values = colorTable8Bit->getCrValues();
  cb_values = colorTable8Bit->getCbValues();



  initOrderedDither();

}


Dither8Bit::~Dither8Bit() {
  int i;
  for (i=0; i<DITH_SIZE; i++) {
    delete cb_darrays[i];
    delete l_darrays[i];
    delete cr_darrays[i];
  }
}





/*
 *--------------------------------------------------------------
 *
 *  InitOrderedDither--
 *
 *	Structures initialized for ordered dithering. 
 *
 * Results:
 *	None.
 *
 * Side effects:
 *      None.
 *
 *--------------------------------------------------------------
 */
void Dither8Bit::initOrderedDither() {
  int i, j, k, err_range, threshval;
  unsigned char *lmark, *cmark;

  for (i=0; i<DITH_SIZE; i++) {
    lmark = l_darrays[i] = new unsigned char[256];
    for (j=0; j<lum_values[0]; j++) {
      *lmark++ = 0;
    }
    for (j=0; j<(LUM_RANGE-1); j++) {
      err_range = lum_values[j+1] - lum_values[j];
      threshval = ((i * err_range) / DITH_SIZE)+lum_values[j];

      for (k=lum_values[j]; k<lum_values[j+1]; k++) {
        if (k > threshval) {
          *lmark++ = ((j+1) * (CR_RANGE * CB_RANGE));
        }
        else {
          *lmark++ = (j * (CR_RANGE * CB_RANGE));
        }
      }
    }
    for (j=lum_values[LUM_RANGE-1]; j<256; j++) {
      *lmark++ = (LUM_RANGE-1)*(CR_RANGE * CB_RANGE);
    }
  }
  for (i=0; i<DITH_SIZE; i++) {
    cmark = cr_darrays[i] = new unsigned char[256];

    for (j=0; j<cr_values[0]; j++) {
      *cmark++ = 0;
    }

    for (j=0; j<(CR_RANGE-1); j++) {
      err_range = cr_values[j+1] - cr_values[j];
      threshval = ((i * err_range) / DITH_SIZE)+cr_values[j];

      for (k=cr_values[j]; k<cr_values[j+1]; k++) {
        if (k > threshval) {
          *cmark++ = ((j+1) * CB_RANGE);
        }
        else {
          *cmark++ = (j * CB_RANGE);
        }
      }
    }

    for (j=cr_values[CR_RANGE-1]; j<256; j++) {
      *cmark++ = (CR_RANGE-1)*(CB_RANGE);
    }
  }

  for (i=0; i<DITH_SIZE; i++) {
    cmark = cb_darrays[i] = new unsigned char[256];

    for (j=0; j<cb_values[0]; j++) {
      *cmark++ = 0;
    }

    for (j=0; j<(CB_RANGE-1); j++) {
      err_range = cb_values[j+1] - cb_values[j];
      threshval = ((i * err_range) / DITH_SIZE)+cb_values[j];

      for (k=cb_values[j]; k<cb_values[j+1]; k++) {
        if (k > threshval) {
          *cmark++ = j+1;
        }
        else {
          *cmark++ = j;
        }
      }
    }

    for (j=cb_values[CB_RANGE-1]; j<256; j++) {
      *cmark++ = CB_RANGE-1;
    }
  }
}



/*
 *--------------------------------------------------------------
 *
 * OrderedDitherImage --
 *
 *	Dithers an image using an ordered dither.
 *	Assumptions made:
 *	  1) The color space is allocated y:cr:cb = 8:4:4
 *	  2) The spatial resolution of y:cr:cb is 4:1:1
 *      The channels are dithered based on the standard
 *      ordered dither pattern for a 4x4 area. 
 *
 * Results:
 *	None.
 *
 * Side effects:
 *	None.
 *
 *--------------------------------------------------------------
 */

void  Dither8Bit::ditherImageOrdered (unsigned char* lum,
				      unsigned char* cr,
				      unsigned char* cb,
				      unsigned char* out,
				      int h,
				      int w) {
  unsigned char *l, *r, *b, *o1, *o2;
  unsigned char *l2;
  unsigned char L, R, B;
  int i, j;

  l = lum;
  l2 = lum+w;
  r = cr;
  b = cb;
  o1 = out;
  o2 = out+w;


  for (i=0; i<h; i+=4) {

    for (j=0; j<w; j+=8) {

      R = r[0]; B = b[0];

      L = l[0];
      o1[0] = pixel[(l_darrays[0][L] + cr_darrays[0][R] + cb_darrays[0][B])];
      L = l[1];
      o1[1] = pixel[(l_darrays[8][L] + cr_darrays[8][R] + cb_darrays[8][B])];
      L = l2[0];
      o2[0] = pixel[(l_darrays[12][L] + cr_darrays[12][R] + cb_darrays[12][B])];
      L = l2[1];
      o2[1] = pixel[(l_darrays[4][L] + cr_darrays[4][R] + cb_darrays[4][B])];

      R = r[1]; B = b[1];

      L = l[2];
      o1[2] = pixel[(l_darrays[2][L] + cr_darrays[2][R] + cb_darrays[2][B])];
      L = l[3];
      o1[3] = pixel[(l_darrays[10][L] + cr_darrays[10][R] + cb_darrays[10][B])];
      L = l2[2];
      o2[2] = pixel[(l_darrays[14][L] + cr_darrays[14][R] + cb_darrays[14][B])];
      L = l2[3];
      o2[3] = pixel[(l_darrays[6][L] + cr_darrays[6][R] + cb_darrays[6][B])];

      R = r[2]; B = b[2];

      L = l[4];
      o1[4] = pixel[(l_darrays[0][L] + cr_darrays[0][R] + cb_darrays[0][B])];
      L = l[5];
      o1[5] = pixel[(l_darrays[8][L] + cr_darrays[8][R] + cb_darrays[8][B])];
      L = l2[4];
      o2[4] = pixel[(l_darrays[12][L] + cr_darrays[12][R] + cb_darrays[12][B])];
      L = l2[5];
      o2[5] = pixel[(l_darrays[4][L] + cr_darrays[4][R] + cb_darrays[4][B])];

      R = r[3]; B = b[3];

      L = l[6];
      o1[6] = pixel[(l_darrays[2][L] + cr_darrays[2][R] + cb_darrays[2][B])];
      L = l[7];
      o1[7] = pixel[(l_darrays[10][L] + cr_darrays[10][R] + cb_darrays[10][B])];
      L = l2[6];
      o2[6] = pixel[(l_darrays[14][L] + cr_darrays[14][R] + cb_darrays[14][B])];
      L = l2[7];
      o2[7] = pixel[(l_darrays[6][L] + cr_darrays[6][R] + cb_darrays[6][B])];

      l += 8;
      l2 += 8;
      r += 4;
      b += 4;
      o1 += 8;
      o2 += 8;
    }

    l += w; 
	l2 += w;
    o1 += w; 
	o2 += w;

    for (j=0; j<w; j+=8) {

      R = r[0]; B = b[0];

      L = l[0];
      o1[0] = pixel[(l_darrays[3][L] + cr_darrays[3][R] + cb_darrays[3][B])];
      L = l[1];
      o1[1] = pixel[(l_darrays[11][L] + cr_darrays[11][R] + cb_darrays[11][B])];
      L = l2[0];
      o2[0] = pixel[(l_darrays[15][L] + cr_darrays[15][R] + cb_darrays[15][B])];
      L = l2[1];
      o2[1] = pixel[(l_darrays[7][L] + cr_darrays[7][R] + cb_darrays[7][B])];

      R = r[1]; B = b[1];

      L = l[2];
      o1[2] = pixel[(l_darrays[1][L] + cr_darrays[1][R] + cb_darrays[1][B])];
      L = l[3];
      o1[3] = pixel[(l_darrays[9][L] + cr_darrays[9][R] + cb_darrays[9][B])];
      L = l2[2];
      o2[2] = pixel[(l_darrays[13][L] + cr_darrays[13][R] + cb_darrays[13][B])];
      L = l2[3];
      o2[3] = pixel[(l_darrays[5][L] + cr_darrays[5][R] + cb_darrays[5][B])];

      R = r[2]; B = b[2];

      L = l[4];
      o1[4] = pixel[(l_darrays[3][L] + cr_darrays[3][R] + cb_darrays[3][B])];
      L = l[5];
      o1[5] = pixel[(l_darrays[11][L] + cr_darrays[11][R] + cb_darrays[11][B])];
      L = l2[4];
      o2[4] = pixel[(l_darrays[15][L] + cr_darrays[15][R] + cb_darrays[15][B])];
      L = l2[5];
      o2[5] = pixel[(l_darrays[7][L] + cr_darrays[7][R] + cb_darrays[7][B])];

      R = r[3]; B = b[3];

      L = l[6];
      o1[6] = pixel[(l_darrays[1][L] + cr_darrays[1][R] + cb_darrays[1][B])];
      L = l[7];
      o1[7] = pixel[(l_darrays[9][L] + cr_darrays[9][R] + cb_darrays[9][B])];
      L = l2[6];
      o2[6] = pixel[(l_darrays[13][L] + cr_darrays[13][R] + cb_darrays[13][B])];
      L = l2[7];
      o2[7] = pixel[(l_darrays[5][L] + cr_darrays[5][R] + cb_darrays[5][B])];

      l += 8;
      l2 += 8;
      r += 4;
      b += 4;
      o1 += 8;
      o2 += 8;
    }

    l += w; 
	l2 += w;
    o1 += w; 
	o2 += w;
  }
}