unit 286 Smooth
.386

assume ds:@code,cs:@code
NoJumps 

Extrn PaletteR:Byte, RGB2C:DWord 

cRGB =   5
sRGB =   1
xRGB =   (1 shl sRGB) shr 1
 
Procedure Far SmoothArea x, y, w, h, S, T
   imul di,y,320 
   add  di,x 
   mov  fs,S
   mov  es,T
   mov  gs,word ptr RGB2C+2
   cld 

   $Do 
      mov  si,w
   
      Even 
    
      $Do 
         mov  bx,offset PaletteR
         mov  cx,3
         xor  ax,ax
      
         $Do 
            mov  al,fs:[di-320-1]
            xlat
            mov  dx,ax
         
            mov  al,fs:[di-320]
            xlat
            add  dx,ax
            add  dx,ax
         
            mov  al,fs:[di-320+1]
            xlat
            add  dx,ax
         
            mov  al,fs:[di-1]
            xlat
            add  dx,ax
            add  dx,ax
         
            mov  al,fs:[di+1]
            xlat
            add  dx,ax
            add  dx,ax
         
            mov  al,fs:[di+320-1]
            xlat
            add  dx,ax
         
            mov  al,fs:[di+320]
            xlat
            add  dx,ax
            add  dx,ax
         
            mov  al,fs:[di+320+1]
            xlat
            add  dx,ax
         
            mov  al,fs:[di]
            xlat
            lea  ax,[eax*4+edx] 
         
            shr  ax,4
         
;           add  ax,xRGB -- xRGB=1 
            inc  ax 
            shr  ax,sRGB
         
            push ax
         
            inc  bh
         $EndDo Loop
      
         pop  ax
         mov  bx,ax
      
         pop  ax
         shl  ax,cRGB
         add  bx,ax
      
         pop  ax
         shl  ax,2*cRGB 
         add  bx,ax
      
         mov  al,gs:[bx]
         stosb
      
         dec  si
      $EndDo =0
   
      sub  di,w
      add  di,320
   
      dec  h
   $EndDo =0 
EndProc