#include "gwic.h"/* Construct 2D significance heap */heap2d *gen_2d_heap(U32 *buf, int width, int height, int levels){  int c1,c2,c3,c4,c,size,h,i,j,k,l,m,w,lev,b,t;  heap2d *heap;  BYTE *p;  int n=0;  MALLOC(heap,sizeof(heap2d));  for(size=0, i=1; i<=levels; i++) size += (width>>i)*(height>>i);  size += (width>>levels)*(height>>levels);    /* Allocate and initialize heap structure */  MALLOC(heap->heap,size+1);  MALLOC(heap->lines,(height*sizeof(U32 *)));  heap->width = width;   heap->height = height;  heap->levels = levels;  h = height>>levels;   w = width>>levels;  i = h<<1;  p = heap->heap;  for(j=0; j<height; j++)  {    *(heap->lines+j) = p;    if (j>=i) {h = h << 1;  w = w << 1;  i += h;}    p += w;  }  /* Prepare the bottom level */   w = width>>1; h=height>>1; k=h*width;   for(j=0; j<h; j++) for(i=0; i<w; i++) {     l = i+j*width;     c1 = *(buf+w+l) & MASK;     c2 = *(buf+k+l) & MASK;     c3 = *(buf+w+k+l) & MASK;     c = c1>c2 ? (c1>c3?c1:c3) : (c2>c3?c2:c3);     for(l=0;c>0;l++,c=c>>1);      *(*(heap->lines+h+j) + i) = l;   }     /* Prepare the middle levels */   for (lev=1; lev < levels; lev++) {     w = width>>(lev+1); h=height>>(lev+1); k=h*width;     for(j=0; j<h; j++) for(i=0; i<w; i++) {       l = i+j*width;       c1 = *(buf+w+l) & MASK;       c2 = *(buf+k+l) & MASK;       c3 = *(buf+w+k+l) & MASK;       c = c1>c2 ? (c1>c3?c1:c3) : (c2>c3?c2:c3);       for(l=0;c>0;l++,c=c>>1); c=l;       l = *(*(heap->lines +(h<<1)+ (j<<1)) + (i<<1)); if(l>c)c=l;       l = *(*(heap->lines +(h<<1)+ (j<<1)) + (i<<1)+1); if(l>c)c=l;       l = *(*(heap->lines +(h<<1)+ (j<<1)+1) + (i<<1)); if(l>c)c=l;       l = *(*(heap->lines +(h<<1)+ (j<<1)+1) + (i<<1)+1); if(l>c)c=l;       *(*(heap->lines+h+j) + i) = c;     }   }   /* Prepare the top level */   w = width>>levels; h=height>>levels; k=h*width;   for(j=0; j<h; j++) for(i=0; i<w; i++) {     c = *(buf+i+j*width) & MASK;       for(l=0;c>0;l++,c=c>>1); c=l;       l = *(*(heap->lines+h+j)+i);       *(*(heap->lines+j) + i) = l>c ? l : c;   }    /* Calculate max n */  h = height>>levels; w = width>>levels;  for (j=0; j<h; j++) for (i=0; i<w; i++)     n = n > *(*(heap->lines+j)+i) ? n : *(*(heap->lines+j)+i);  heap->max = n;  return(heap);}