{
    $Id$
    This file is part of the Free Pascal run time library.
    Copyright (c) 1993,97 by the Free Pascal development team

    See the file COPYING.FPC, included in this distribution,
    for details about the copyright.

    This program is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.

 **********************************************************************}

procedure DrawPattern(x1,x2,y:integer);
begin
  asm
    movswl x1,%ebx
    movswl x2,%ecx
    movswl y,%edx
    subl   %ebx,%ecx
    incl   %ecx
    movl   _X_ARRAY(,%ebx,4),%eax
    movl   _Y_ARRAY(,%edx,4),%edi       // { Offset in %edi }
    addl   %eax,%edi
    andl   _WINLOMASK,%edi
    andl   $0x7,%edx                    // { y and $7                }
    shll   $0x5,%edx                    // { y * 8 * sizeof(longint) }
    leal   _PATTERNBUFFER,%esi          // 
    addl   %edx,%esi                    // { Offset in Patternbuffer }
    movl   $0x7,%edx
    addl   _WBUFFER,%edi
    pushw  %es
    movw   _SEG_WRITE,%ax
    movw   %ax,%es
    testw  $1,_AKTWRITEMODE
    jnz    pl_xord
 pl_movd:
    testw  $1,_BYTESPERPIXEL
    jz     pl_movdw

 .align 4,0x90
 pl_movdb:
    andl   %edx,%ebx
    movb   (%esi,%ebx,4),%al
    movb   %al,%es:(%edi)
    incl   %edi
    incl   %ebx
    decl   %ecx
    jnz    pl_movdb
    jz     pl_d_exit    

 .align 4,0x90
 pl_movdw:
    andl   %edx,%ebx
    movw   (%esi,%ebx,4),%ax
    movw   %ax,%es:(%edi)
    addl   $2,%edi
    incl   %ebx
    decl   %ecx
    jnz    pl_movdw
    jz     pl_d_exit    
 pl_xord:
    testw  $1,_BYTESPERPIXEL
    jz     pl_xordw
 .align 4,0x90
 pl_xordb:
    andl   %edx,%ebx
    movb   (%esi,%ebx,4),%al
    xorb   %al,%es:(%edi)
    incl   %edi
    incl   %ebx
    decl   %ecx
    jnz    pl_xordb
    jz     pl_d_exit 
 .align 4,0x90
 pl_xordw:
    andl   %edx,%ebx
    movw   (%esi,%ebx,4),%ax
    xorw   %ax,%es:(%edi)
    addl   $2,%edi
    incl   %ebx
    decl   %ecx
    jnz    pl_xordw
 pl_d_exit:
    popw   %es
 pl_exit:
 end;
end;

procedure PatternLine(x1,x2,y:integer);
var bank1,bank2    : longint;
    ofs1,ofs2      : longint;
    diff           : integer;
    viewport       : ViewPortType;
begin
  x1:= x1 + aktviewport.x1 ;
  y:=  y +  aktviewport.y1 ;
  x2:= x2 + aktviewport.x1 ;
  
  if aktviewport.clip then viewport:=aktviewport else viewport:=aktscreen;
  if (y < viewport.y1) or (y > viewport.y2) then exit;
  if x1 > x2 then begin diff:=x2; x2:=x1; x1:=diff; end;
  if (x1> viewport.x2) or (x2< viewport.x1) then exit;
  if x1 < viewport.x1 then x1:=viewport.x1;
  if x2 > viewport.x2 then x2:=viewport.x2;
  ofs1:= Y_ARRAY[y];
  ofs2:= ofs1 + X_ARRAY[x2];
  ofs1:= ofs1 + X_ARRAY[x1];
  bank1:=ofs1 shr winshift;
  bank2:=ofs2 shr winshift;
  if bank1 <> AW_BANK then
  begin
    Switchbank(bank1);
    AW_BANK:=bank1;
  end;
  if bank1 <> bank2 then begin
     diff:=(((bank2 shl winshift)-ofs1) div BytesPerPixel)+x1;  
     DrawPattern(x1,diff-1,y);
     Switchbank(bank2); AW_BANK:=bank2;
     DrawPattern(diff,x2,y);
  end else DrawPattern(x1,x2,y);
end;


procedure HorizontalLine(x1,x2,y:integer);
{ without bankswitching }
begin
  asm
    movw   %es,%dx
    movzwl y,%ebx
    movzwl x1,%eax
    movzwl x2,%ecx
    incl   %ecx
    movl   _X_ARRAY(,%eax,4),%eax
    movl   _X_ARRAY(,%ecx,4),%ecx
    movl   _Y_ARRAY(,%ebx,4),%edi       // { Offset in %edi }
    subl   %eax,%ecx                    // { Counter }
    addl   %eax,%edi
    andl   _WINLOMASK,%edi
    movl   _AKTCOLOR,%eax
    movzwl _AKTWRITEMODE,%esi
    addl   _WBUFFER,%edi    
    movw   _SEG_WRITE,%bx
    movw   %bx,%es 
    testl  %esi,%esi                    // { Writemode ?       }
    jnz    hl_xor
    shrl   %ecx
    jnc    _movw
    stosb
 _movw:
    shrl   %ecx
    jnc    _movd
    stosw
 _movd:
    rep
    stosl
    jmp    hl_exit

 hl_xor:   // -------------------------------------------------

    movl   $4,%esi
    shrl   %ecx
    jnc    hl_xorw
    xorb   %al,%es:(%edi)
    incl   %edi 
 hl_xorw:
    shrl   %ecx
    jnc    hl_xord
    xorw   %ax,%es:(%edi)
    addl   $2,%edi
 hl_xord:   
    jecxz  hl_exit
 .align 4,0x90
 hl_xorloop:
    xorl   %eax,%es:(%edi)
    addl   %esi,%edi
    decl   %ecx
    jnz    hl_xorloop
 hl_exit:
    movw   %dx,%es
 end;
end;

procedure Line(x1,y1,x2,y2: integer);
var dx,dy,d        : longint;
    i,j            : integer; 
    ofs,ofs2       : longint;
    i1,i2,ix       : longint; 
    x,y            : Integer; 
    flag,dontcheck : Boolean;
    viewport       : ViewPortType;
begin
  
  x1:= x1 + aktviewport.x1 ;
  y1:= y1 + aktviewport.y1 ;
  x2:= x2 + aktviewport.x1 ;
  y2:= y2 + aktviewport.y1 ;
  if aktviewport.clip then viewport:=aktviewport else viewport:=aktscreen;
  
  { ************ Horizontalline ************** }

  if y1=y2 then begin
    if x1>x2 then begin d:=x1; x1:=x2; x2:=d; end; 
    if aktlineinfo.thickness=3 then y1:=y1-1;
    i:=0;
    if x1 < viewport.x1 then x1:=viewport.x1;
    if x2 > viewport.x2 then x2:=viewport.x2;
    if (y1 > viewport.y2) or (x1 > x2 ) then exit;
    repeat  
      if (y1 >= viewport.y1) and (y1 <=viewport.y2) 
      then begin
        ofs:= Y_ARRAY[y1];
        ofs2:=ofs+X_ARRAY[x2];
        ofs:= ofs+X_ARRAY[x1];
        i1:=ofs shr winshift; i2:=ofs2 shr winshift;
        if i1 <> aw_bank then 
          begin 
            switchbank(i1); 
            aw_bank:=i1; 
          end;
        if i1=i2 then Horizontalline(x1,x2,y1)
          else                             
            begin 
            dx:=((i2 shl winshift)-ofs) div BytesPerPixel;
            horizontalline(x1,x1+dx-1,y1);
            Switchbank(i2); AW_BANK:=i2;
            horizontalline(dx+x1,x2,y1); 
          end;
      end;
      i:=i+1; y1:=y1+1;
    until i=aktlineinfo.thickness;  
    exit;
  end;  
  
  { *********** End Horizontalline *********** }

  if y1 > y2 then begin
    x:=x1; x1:=x2; x2:=x;
    y:=y1; y1:=y2; y2:=y;
  end;

  { ************** Verticalline ************** }

  if x1=x2 then
  begin
    if y1 < viewport.y1 then y1:=viewport.y1;
    if y2 > viewport.y2 then y2:=viewport.y2;
    if ( y1 > y2) or (x1 < viewport.x1) or (x1 > viewport.x2) then exit;
    ofs:= Y_Array[y2]+X_Array[x1];
    ofs2:=Y_Array[y1]+X_Array[x1];
    while ofs >= ofs2 do begin
       pixel(ofs);
       if aktlineinfo.thickness=3 then begin
         if x1>viewport.x1 then pixel(ofs-1);
         if x1<viewport.x2 then pixel(ofs+1);
       end;
       ofs:=ofs-BytesPerLine;
    end;
    exit;
  end;

  { ************ End Verticalline ************ }

  dy:=y2-y1;
  dx:=abs(x2-x1);
  if x1>x2 then ix:=-1 else ix:= 1;
  if dx<dy then begin d:=dx; dx:=dy; dy:=d; Flag:=true end else Flag:=false;
  i1:=dy shl 1;
   d:=i1 - dx;
  i2:=(dx shl 1)-i1;

dontcheck:=(y1>=viewport.y1) and (y2<=viewport.y2) and 
           (x1>=viewport.x1) and (x1<=viewport.x2) and
           (x2>=viewport.x1) and (x2<=viewport.x2);

if aktlineinfo.thickness=3 then 

    { *************************************** }
    { **** Thickness=3 with rangechecking *** }
    { *************************************** } 
    
begin
  repeat
    for i:=y1-1 to y1+1 do
      for j:=x1-1 to x1+1 do 
      if (i>=viewport.y1) and (j>=viewport.x1) and 
         (j<=viewport.x2) and (i<=viewport.y2) then pixel(X_ARRAY[j]+Y_ARRAY[i]);
    if d < 0
    then begin 
      if Flag then y1:=y1+1 else x1:=x1+ix;
      d:=d+i1;
    end  
    else begin
      d:=d-i2; x1:=x1+ix; y1:=y1+1;
    end; 
  dx:=dx-1;
  until ( dx=0 ) or ( y1 > viewport.y2 )
end else 
  if dontcheck then

    { *************************************** }
    { ** Thickness=1 without rangechecking ** }
    { *************************************** } 
    
    begin 
    asm
     pushw  %gs
     movw   _SEG_WRITE,%ax
     movw   %ax,%gs                   // { ScreenSelector }
  
  // selfmodify to speedup Code   
     xorl   %ebx,%ebx
     movl   ix,%eax
     testl  %eax,%eax
     jns    line1_inc
     movl   $0x08,%ebx
   line1_inc:
     addl   $0x43,%ebx                // Opcode incl %ebx
     movb   %bl,inc_dec1
     movb   %bl,inc_dec2
     movl   i1,%eax
     movl   %eax,i1long1
     movl   %eax,i1long2
     movl   i2,%eax
     movl   %eax,i2long
     movl   _WBUFFER,%eax
     movl   %eax,.Lwbuffer
     movl   _WINSHIFT,%eax
     movb   %al,.Lwinshift
     movl   _WINLOMASK,%eax
     movl   %eax,.Lwinlomask
     movb   $0x90,operandprefix       // Opcade nop  
     testw  $1,_AKTWRITEMODE
     jnz    line1XOR
     movb   $0x88,linemode            // Opcode movb
     jmp    linedepth
    line1XOR:
      movb   $0x30,linemode           // Opcode xorb
    linedepth:  
      testw  $1,_BYTESPERPIXEL
      jnz    is_byte
      movb   $0x66,operandprefix      // Prefix for operandsize
      incb   linemode                 // incr. for wordacces
    is_byte:      
      movl   dx,%ecx
      movl   _AKTCOLOR,%eax
      movzwl y1,%esi
      movzwl x1,%ebx
      movswl d,%edx
   //----------------//
   //  Linemainloop  //
   //----------------//   
.align 4,0x90
line1_loop:  
      pushl  %ecx
      pushl  %eax
      movl   _Y_ARRAY(,%esi,4),%edi
      addl   _X_ARRAY(,%ebx,4),%edi
      movl   %edi,%eax
      .byte 0x81,0xe7                 // andl ..,%edi
    .Lwinlomask:                        //
      .long 0x88888888                // _WINLOMASK
      .byte 0xc1,0xe8                 // shrl ..,%eax
    .Lwinshift:                         //
      .byte 0x88                      // _WINSHIFT
      
      pushl  %edi
      cmpl   _AW_BANK,%eax
      je     line1_dontswitch
      
      pushl  %ebx
      pushl  %edx
      pushl  %esi   
      movl   %eax,_AW_BANK             // newbank
      pushl  %eax
      movl   _BANKSWITCHPTR,%eax
      call   %eax
      popl   %esi
      popl   %edx
      popl   %ebx
.align 4,0x90
line1_dontswitch:
      popl   %edi
      popl   %eax
      popl   %ecx
     .byte   0x81,0xc7                 // addl ..,%edi
    .Lwbuffer:                           //
     .long   0x88888888                // _WBUFFER
    operandprefix:
     .byte   0x90                      // Operandprefix (nop for Byte,$66 for Word)
     .byte   0x65                      // Segmentprefix %gs:
    linemode:
     .byte   0x88,0x07                 // modified OpCode<movb,xorb...>,%edi
      decl   %ecx
      jz     line1_end      
      testl  %edx,%edx                 // { if d < 0 then }
      jns    is_positive
      testb  $1,flag                   // { if flag then }
      jz     no_flag
      incl   %esi                      // { y1:=y1+1  }   
     .byte   0x81,0xc2
    i1long1:   
     .long   0x88888888                // { d:=d+i1   }
      jmp    line1_loop
.align 4,0x90
no_flag:
    inc_dec1: 
     .byte   0x88                      // { x1:=x1+ix }   
     .byte   0x81,0xc2
    i1long2:   
     .long   0x88888888                // { d:=d+i1   }
      jmp    line1_loop
.align 4,0x90
is_positive:
    inc_dec2:  
     .byte   0x88                      // { x1:=x1+ix }
      incl   %esi                      // { y1:=y1+1  }      
     .byte   0x81,0xea 
    i2long:  
     .long   0x88888888                // { d:=d-i2   }
      jmp    line1_loop
line1_end:
      popw   %gs
    end;
  end else
    
    { *************************************** }
    { **** Thickness=1 with rangechecking *** }
    { *************************************** } 
    
    begin
    repeat
      if y1 > viewport.y2 then exit;
      if (y1>=viewport.y1) and (x1>=viewport.x1) and 
         (x1<=viewport.x2) then pixel(Y_ARRAY[y1]+X_ARRAY[x1]);    
      if d < 0
      then begin 
        if Flag then y1:=y1+1 else x1:=x1+ix;
        d:=d+i1;
      end  
      else begin
        d:=d-i2; x1:=x1+ix; y1:=y1+1;
      end; 
    dx:=dx-1;
    until  dx=0 ;
  end;
end;

procedure MoveTo(x,y : integer);
begin
  _graphresult:=grOk;
  if not isgraphmode then
     begin
       _graphresult:=grnoinitgraph;
       exit;
     end;
  curx:=x;
  cury:=y;
end;

procedure MoveRel(dx,dy : integer);
begin
  _graphresult:=grOk;
  if not isgraphmode then
     begin
       _graphresult:=grnoinitgraph;
       exit;
     end;
  curx:=curx+dx;
  cury:=cury+dy;
end;

procedure LineTo(x,y : integer);
begin
  _graphresult:=grOk;
  if not isgraphmode then
     begin
       _graphresult:=grnoinitgraph;
       exit;
     end;
  Line(curx,cury,x,y);
  MoveTo(x,y);
end;

procedure LineRel(dx,dy : integer);
begin
  _graphresult:=grOk;
  if not isgraphmode then
     begin
       _graphresult:=grnoinitgraph;
     exit;
   end;
  Line(curx,cury,curx+dx,cury+dy);
  curx:=curx+dx; 
  cury:=cury+dy;
end;

procedure SetLineStyle(LineStyle : word;pattern : word;thickness : word);
const
  linepatterns : array[0..3] of word =
  ($ffff,$aaaa,$fafa,$ffff);

begin
  if (linestyle<0) or (linestyle>4) or
     ((thickness<>1) and (thickness<>3)) then
     begin
       _graphresult:=grerror;
       exit;
     end;
     aktlineinfo.linestyle:=linestyle;
     if aktlineinfo.linestyle=UserBitLn then
        aktlineinfo.pattern:=pattern
        else
        aktlineinfo.pattern:=linepatterns[aktlineinfo.linestyle];
        aktlineinfo.thickness:=thickness;
end;

    procedure DrawPoly(points : word;var polypoints);

      type
         ppointtype = ^pointtype;

      var
         i : longint;

      begin
         _graphresult:=grOk;
         if not isgraphmode then
           begin
              _graphresult:=grnoinitgraph;
              exit;
           end;
         line(ppointtype(@polypoints)[points-1].x,
              ppointtype(@polypoints)[points-1].y,
              ppointtype(@polypoints)[0].x,
              ppointtype(@polypoints)[0].y);
         for i:=0 to points-2 do
           line(ppointtype(@polypoints)[i].x,
                ppointtype(@polypoints)[i].y,
                ppointtype(@polypoints)[i+1].x,
                ppointtype(@polypoints)[i+1].y);
      end;

{
  $Log$
  Revision 1.2  1998-09-02 08:16:00  pierre
    * local asm labels with global variable names removed !!

  Revision 1.1.1.1  1998/03/25 11:18:42  root
  * Restored version

  Revision 1.4  1998/03/03 22:48:43  florian
    + graph.drawpoly procedure
    + putimage with xorput uses mmx if available

  Revision 1.3  1998/01/26 11:58:18  michael
  + Added log at the end

  Working file: rtl/dos/ppi/line.ppi
  description:
  ----------------------------
  revision 1.2
  date: 1997/12/01 12:21:31;  author: michael;  state: Exp;  lines: +14 -0
  + added copyright reference in header.
  ----------------------------
  revision 1.1
  date: 1997/11/27 08:33:51;  author: michael;  state: Exp;
  Initial revision
  ----------------------------
  revision 1.1.1.1
  date: 1997/11/27 08:33:51;  author: michael;  state: Exp;  lines: +0 -0
  FPC RTL CVS start
  =============================================================================
}