#include "hyd2asc.h"
#include "varext.h"


/***************** decompression algorithm ******************************
*
*************************************************************************/


void decomp(hyd_header *hyd, short int ph_len)
{
   unsigned short int m, mask, mask2, bits, len;
   unsigned long int l1;
   unsigned short int remain;
   unsigned short int pixels[4*MAXLIN], mark, inbuf[4*MAXLIN];
   unsigned short int j, k, l;
	short int i;


   len = (0x07ff & ph_len) - size_pixh;

//   printf("\n\n len=%d\n",len);

   if (fread(&inbuf,len,1,hyd_fil)!=1) perror(" decomp01 ");

   bits = (0x7800 & ph_len)>>11;
   mark=2*hyd->lines_a+2*hyd->lines_b;
   mask=0;
   for (j=0;j<bits;j++) mask |= (1<<j);

   j=0;
   l1=0;
   mask2=0;
   remain=0;
   m=0;

   for(k=0;k<len;k++){
     for (l=0;l<remain;l++) mask2 |= (1<<l);
     l1 = (l1>>(m*bits));
     l1 &= mask2;
     m=(short int)((16+remain)/bits);
     l1 |= ((long)(inbuf[k])<<remain);
     for(l=0;l<m;l++){
       if(j<mark) pixels[j]=(short int)((l1>>bits*l)&mask);
       j++;
       }
     remain += 16-m*bits;
     }

   for (i=0;i<hyd->lines_a;i++) {
     pixA[0][i]=pixels[i]+hyd->min_a;
     }

	if ( ((2*hyd->lines_a+2*hyd->lines_b) >= (4*MAXLIN)) ||
        ((hyd->lines_a) >= MAXLIN) ||
        ((hyd->lines_b) >= MAXLIN) ){
	  fprintf(stderr,"decomp: MAXLIN exceeded");
//	  getch();
	  }

   mark=hyd->lines_a;
   for (i=0;i<hyd->lines_a;i++) pixA[1][i]=pixels[mark+i]+hyd->min_a;
   mark=2*hyd->lines_a;
   for (i=0;i<hyd->lines_b;i++) pixB[0][i]=pixels[mark+i]+hyd->min_b;
   mark=2*hyd->lines_a+hyd->lines_b;
   for (i=0;i<hyd->lines_b;i++) pixB[1][i]=pixels[mark+i]+hyd->min_b;
   mark=2*hyd->lines_a+2*hyd->lines_b;

   return;

   }