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#include <string.h>
unsigned long GetPixel( int x , int y ) ;
void SetPixel( int x , int y , unsigned long Color ) ;
#define MAXTEXT 1024
extern  int Width ;
extern  int Height ;
void  WriteHiddenText( unsigned char *Ptr)  /* $BJ8;zNs$NKd9~$_(B */
{
   unsigned char    Bit2 ;
   unsigned long    Color ;
   int x , y , Cnt , Index = 0 ;
   Cnt = [        a        ] ;
   for( y = 0 ; y < Height ; y++ ) {
      for( x = 0 ; x < Width ; x++ ) {
         Color = GetPixel( x , y ) ;
         Color &= 0xfffffc ;
         Bit2 = *Ptr ; 
         Bit2 >>= ( 6 - Index * 2 ) ;
         Bit2 &= 0x3 ;
         Color |= Bit2 ;
         SetPixel( x , y , Color ) ;
         Index++ ;
         if ( Index > 3 ) {
            Ptr++ ; Index = 0 ;
         }
         Cnt-- ;
         if ( Cnt <= 0 ) break ;
      } 
      if ( Cnt<= 0 ) break ;
   }
}

int ReadHiddenText( unsigned char *Ptr )  /* $BJ8;zNs$NI|85(B */
{
   unsigned char    Bit2 ; 
   unsigned long    Color ;
   int x , y , Cnt = 1 , Index = 0 ;
   *Ptr = '\0' ;
   for( y = 0 ; y < Height ; y++ ) {
      for( x = 0 ; x < Width ; x++ ) {
         Color = GetPixel( x , y ) ;
         Bit2 = ( unsigned char )Color ;
         Bit2 &= 0x3 ;
         [          b          ] ;    
         [          c          ] ;    
         if (( Index == 3 ) && ( *Ptr == '\0' ))
            return Cnt ;
         Index++ ;
         if ( Index > 3 ) {
            Ptr++ ; [          d          ] ; Index = 0 ; Cnt++ ;
            if ( Cnt > MAXTEXT ) {
               *( Ptr - 1 ) = '\0' ;
               return MAXTEXT ;
            }
         }
      }
   }
   return Cnt ;
}

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  $B%"(B  strlen( Ptr )                 $B%$(B  strlen( Ptr ) + 1

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  $B%&(B  *( Ptr $B!>(B1 ) = '\0'          $B%((B  *( Ptr - 1 ) = 0xff

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  $B%1(B  *Ptr *= Bit2                 $B%3(B  *Ptr /= Bit2

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