{

}

unit crt;

interface

{$i crth.inc}

implementation

uses
  watcom;


{$ASMMODE ATT}

var
  DelayCnt,
  ScreenWidth,
  ScreenHeight : longint;
  VidSeg : Word;

{
  definition of textrec is in textrec.inc
}
{$i textrec.inc}


{****************************************************************************
                           Low level Routines
****************************************************************************}

procedure setscreenmode(mode : byte);
var
  regs : trealregs;
begin
  regs.realeax:=mode;
  realintr($10,regs);
end;


function GetScreenHeight : longint;
begin
  getscreenheight:=mem[$40:$84]+1;
  If mem[$40:$84]=0 then
    getscreenheight := 25;
end;


function GetScreenWidth : longint;
begin
  getscreenwidth:=memw[$40:$4a];
end;


procedure SetScreenCursor(x,y : longint);
var
  regs : trealregs;
begin
  regs.realeax:=$0200;
  regs.realebx:=0;
  regs.realedx:=(y-1) shl 8+(x-1);
  realintr($10,regs);
end;


procedure GetScreenCursor(var x,y : longint);
begin
  x:=mem[$40:$50]+1;
  y:=mem[$40:$51]+1;
end;


{****************************************************************************
                              Helper Routines
****************************************************************************}

Function WinMinX: Byte;
{
  Current Minimum X coordinate
}
Begin
  WinMinX:=(WindMin and $ff)+1;
End;



Function WinMinY: Byte;
{
  Current Minimum Y Coordinate
}
Begin
  WinMinY:=(WindMin shr 8)+1;
End;



Function WinMaxX: Byte;
{
  Current Maximum X coordinate
}
Begin
  WinMaxX:=(WindMax and $ff)+1;
End;



Function WinMaxY: Byte;
{
  Current Maximum Y coordinate;
}
Begin
  WinMaxY:=(WindMax shr 8) + 1;
End;



Function FullWin:boolean;
{
  Full Screen 80x25? Window(1,1,80,25) is used, allows faster routines
}
begin
  FullWin:=(WinMinX=1) and (WinMinY=1) and
           (WinMaxX=ScreenWidth) and (WinMaxY=ScreenHeight);
end;


{****************************************************************************
                             Public Crt Functions
****************************************************************************}


procedure TextMode (Mode: word);

var
   regs : trealregs;

begin
  lastmode:=mode;
  mode:=mode and $ff;
  setscreenmode(mode);

  { set 8x8 font }
  if (lastmode and $100)<>0 then
    begin
       regs.realeax:=$1112;
       regs.realebx:=$0;
       realintr($10,regs);
    end;

  screenwidth:=getscreenwidth;
  screenheight:=getscreenheight;
  windmin:=0;
  windmax:=(screenwidth-1) or ((screenheight-1) shl 8);
end;


Procedure TextColor(Color: Byte);
{
  Switch foregroundcolor
}
Begin
  TextAttr:=(Color and $f) or (TextAttr and $70);
  If (Color>15) Then TextAttr:=TextAttr Or Blink;
End;



Procedure TextBackground(Color: Byte);
{
  Switch backgroundcolor
}
Begin
  TextAttr:=((Color shl 4) and ($f0 and not Blink)) or (TextAttr and ($0f OR Blink) );
End;



Procedure HighVideo;
{
  Set highlighted output.
}
Begin
  TextColor(TextAttr Or $08);
End;



Procedure LowVideo;
{
  Set normal output
}
Begin
  TextColor(TextAttr And $77);
End;



Procedure NormVideo;
{
  Set normal back and foregroundcolors.
}
Begin
  TextColor(7);
  TextBackGround(0);
End;


Procedure GotoXy(X: Byte; Y: Byte);
{
  Go to coordinates X,Y in the current window.
}
Begin
  If (X>0) and (X<=WinMaxX- WinMinX+1) and
     (Y>0) and (Y<=WinMaxY-WinMinY+1) Then
   Begin
     Inc(X,WinMinX-1);
     Inc(Y,WinMinY-1);
     SetScreenCursor(x,y);
   End;
End;


Procedure Window(X1, Y1, X2, Y2: Byte);
{
  Set screen window to the specified coordinates.
}
Begin
  if (X1>X2) or (X2>ScreenWidth) or
     (Y1>Y2) or (Y2>ScreenHeight) then
   exit;
  WindMin:=((Y1-1) Shl 8)+(X1-1);
  WindMax:=((Y2-1) Shl 8)+(X2-1);
  GoToXY(1,1);
End;


Procedure ClrScr;
{
  Clear the current window, and set the cursor on 1,1
}
var
  fil : word;
  y   : longint;
begin
  fil:=32 or (textattr shl 8);
  if FullWin then
   DosmemFillWord(VidSeg,0,ScreenHeight*ScreenWidth,fil)
  else
   begin
     for y:=WinMinY to WinMaxY do
      DosmemFillWord(VidSeg,((y-1)*ScreenWidth+(WinMinX-1))*2,WinMaxX-WinMinX+1,fil);
   end;
  Gotoxy(1,1);
end;


Procedure ClrEol;
{
  Clear from current position to end of line.
}
var
  x,y : longint;
  fil : word;
Begin
  GetScreenCursor(x,y);
  fil:=32 or (textattr shl 8);
  if x<=WinMaxX then
   DosmemFillword(VidSeg,((y-1)*ScreenWidth+(x-1))*2,WinMaxX-x+1,fil);
End;



Function WhereX: Byte;
{
  Return current X-position of cursor.
}
var
  x,y : longint;
Begin
  GetScreenCursor(x,y);
  WhereX:=x-WinMinX+1;
End;



Function WhereY: Byte;
{
  Return current Y-position of cursor.
}
var
  x,y : longint;
Begin
  GetScreenCursor(x,y);
  WhereY:=y-WinMinY+1;
End;


{*************************************************************************
                            KeyBoard
*************************************************************************}

var
   is_last : boolean;
   last    : char;

function readkey : char;
var
  char2 : char;
  char1 : char;
  regs : trealregs;
begin
  if is_last then
   begin
     is_last:=false;
     readkey:=last;
   end
  else
   begin
     regs.ah:=$10;
     realintr($16,regs);
     if (regs.al=$e0) and (regs.ah<>0) then
      regs.al:=0;
     char1:=chr(regs.al);
     char2:=chr(regs.ah);
     if char1=#0 then
      begin
        is_last:=true;
        last:=char2;
      end;
     readkey:=char1;
   end;
end;


function keypressed : boolean;
var
  regs : trealregs;
begin
  if is_last then
   begin
     keypressed:=true;
     exit;
   end
  else
   begin
     regs.ah:=$11;
     realintr($16,regs);
     keypressed:=((regs.realflags and zeroflag) = 0);
   end;
end;


{*************************************************************************
                                   Delay
*************************************************************************}

procedure Delayloop;assembler;
asm
.LDelayLoop1:
        subl    $1,%eax
        jc      .LDelayLoop2
        cmpl    %fs:(%edi),%ebx
        je      .LDelayLoop1
.LDelayLoop2:
end;


procedure initdelay;assembler;
asm
        pushl %ebx
        pushl %edi
        { for some reason, using int $31/ax=$901 doesn't work here }
        { and interrupts are always disabled at this point when    }
        { running a program inside gdb(pas). Web bug 1345 (JM)     }
        sti
        movl    $0x46c,%edi
        movl    $-28,%edx
        movl    %fs:(%edi),%ebx
.LInitDel1:
        cmpl    %fs:(%edi),%ebx
        je      .LInitDel1
        movl    %fs:(%edi),%ebx
        movl    %edx,%eax
        call    DelayLoop

        notl    %eax
        xorl    %edx,%edx
        movl    $55,%ecx
        divl    %ecx
        movl    %eax,DelayCnt
        popl    %edi
        popl    %ebx
end;


procedure Delay(MS: Word);assembler;
asm
        pushl %ebx
        pushl %edi
        movzwl  MS,%ecx
        jecxz   .LDelay2
        movl    $0x400,%edi
        movl    DelayCnt,%edx
        movl    %fs:(%edi),%ebx
.LDelay1:
        movl    %edx,%eax
        call    DelayLoop
        loop    .LDelay1
.LDelay2:
        popl    %edi
        popl    %ebx
end;


procedure sound(hz : word);
begin
  if hz=0 then
   begin
     nosound;
     exit;
   end;
  asm
        movzwl  hz,%ecx
        movl    $1193046,%eax
        cltd
        divl    %ecx
        movl    %eax,%ecx
        inb     $0x61,%al
        testb   $0x3,%al
        jnz     .Lsound_next
        orb     $0x3,%al
        outb    %al,$0x61
        movb    $0xb6,%al
        outb    %al,$0x43
     .Lsound_next:
        movb    %cl,%al
        outb    %al,$0x42
        movb    %ch,%al
        outb    %al,$0x42
  end ['EAX','ECX','EDX'];
end;


procedure nosound;
begin
  asm
        inb     $0x61,%al
        andb    $0xfc,%al
        outb    %al,$0x61
  end ['EAX'];
end;



{****************************************************************************
                          HighLevel Crt Functions
****************************************************************************}

procedure removeline(y : longint);
var
  fil : word;
begin
  fil:=32 or (textattr shl 8);
  y:=WinMinY+y-1;
  While (y<WinMaxY) do
   begin
     dosmemmove(VidSeg,(y*ScreenWidth+(WinMinX-1))*2,
                VidSeg,((y-1)*ScreenWidth+(WinMinX-1))*2,(WinMaxX-WinMinX+1)*2);
     inc(y);
   end;
  dosmemfillword(VidSeg,((WinMaxY-1)*ScreenWidth+(WinMinX-1))*2,(WinMaxX-WinMinX+1),fil);
end;


procedure delline;
begin
  removeline(wherey);
end;


procedure insline;
var
  my,y : longint;
  fil : word;
begin
  fil:=32 or (textattr shl 8);
  y:=WhereY;
  my:=WinMaxY-WinMinY;
  while (my>=y) do
   begin
     dosmemmove(VidSeg,(((WinMinY+my-1)-1)*ScreenWidth+(WinMinX-1))*2,
                VidSeg,(((WinMinY+my)-1)*ScreenWidth+(WinMinX-1))*2,(WinMaxX-WinMinX+1)*2);
     dec(my);
   end;
  dosmemfillword(VidSeg,(((WinMinY+y-1)-1)*ScreenWidth+(WinMinX-1))*2,(WinMaxX-WinMinX+1),fil);
end;




{****************************************************************************
                             Extra Crt Functions
****************************************************************************}

procedure cursoron;
var
  regs : trealregs;
begin
  regs.realeax:=$0100;
  regs.realecx:=$90A;
  If VidSeg=$b800 then
    regs.realecx:=$90A
  else
    regs.realecx:=$b0d;
  realintr($10,regs);
end;


procedure cursoroff;
var
  regs : trealregs;
begin
  regs.realeax:=$0100;
  regs.realecx:=$ffff;
  realintr($10,regs);
end;


procedure cursorbig;
var
  regs : trealregs;
begin
  regs.realeax:=$0100;
  regs.realecx:=$10A;
  realintr($10,regs);
end;


{*****************************************************************************
                          Read and Write routines
*****************************************************************************}

var
  CurrX,CurrY : longint;

Procedure WriteChar(c:char);
var
  regs : trealregs;
begin
  case c of
   #10 : inc(CurrY);
   #13 : CurrX:=WinMinX;
    #8 : begin
           if CurrX>WinMinX then
            dec(CurrX);
         end;
    #7 : begin { beep }
           regs.dl:=7;
           regs.ah:=2;
           realintr($21,regs);
         end;
  else
   begin
     memw[VidSeg:((CurrY-1)*ScreenWidth+(CurrX-1))*2]:=(textattr shl 8) or byte(c);
     inc(CurrX);
   end;
  end;
  if CurrX>WinMaxX then
   begin
     CurrX:=WinMinX;
     inc(CurrY);
   end;
  while CurrY>WinMaxY do
   begin
     removeline(1);
     dec(CurrY);
   end;
end;


Function CrtWrite(var f : textrec):integer;
var
  i : longint;
begin
  GetScreenCursor(CurrX,CurrY);
  for i:=0 to f.bufpos-1 do
   WriteChar(f.buffer[i]);
  SetScreenCursor(CurrX,CurrY);
  f.bufpos:=0;
  CrtWrite:=0;
end;


Function CrtRead(Var F: TextRec): Integer;

  procedure BackSpace;
  begin
    if (f.bufpos>0) and (f.bufpos=f.bufend) then
     begin
       WriteChar(#8);
       WriteChar(' ');
       WriteChar(#8);
       dec(f.bufpos);
       dec(f.bufend);
     end;
  end;

var
  ch : Char;
Begin
  GetScreenCursor(CurrX,CurrY);
  f.bufpos:=0;
  f.bufend:=0;
  repeat
    if f.bufpos>f.bufend then
     f.bufend:=f.bufpos;
    SetScreenCursor(CurrX,CurrY);
    ch:=readkey;
    case ch of
    #0 : case readkey of
          #71 : while f.bufpos>0 do
                 begin
                   dec(f.bufpos);
                   WriteChar(#8);
                 end;
          #75 : if f.bufpos>0 then
                 begin
                   dec(f.bufpos);
                   WriteChar(#8);
                 end;
          #77 : if f.bufpos<f.bufend then
                 begin
                   WriteChar(f.bufptr^[f.bufpos]);
                   inc(f.bufpos);
                 end;
          #79 : while f.bufpos<f.bufend do
                 begin
                   WriteChar(f.bufptr^[f.bufpos]);
                   inc(f.bufpos);
                 end;
         end;
    ^S,
    #8 : BackSpace;
    ^Y,
   #27 : begin
           f.bufpos:=f.bufend;
           while f.bufend>0 do
            BackSpace;
         end;
   #13 : begin
           WriteChar(#13);
           WriteChar(#10);
           f.bufptr^[f.bufend]:=#13;
           f.bufptr^[f.bufend+1]:=#10;
           inc(f.bufend,2);
           break;
         end;
   #26 : if CheckEOF then
          begin
            f.bufptr^[f.bufend]:=#26;
            inc(f.bufend);
            break;
          end;
    else
     begin
       if f.bufpos<f.bufsize-2 then
        begin
          f.buffer[f.bufpos]:=ch;
          inc(f.bufpos);
          WriteChar(ch);
        end;
     end;
    end;
  until false;
  f.bufpos:=0;
  SetScreenCursor(CurrX,CurrY);
  CrtRead:=0;
End;


Function CrtReturn(Var F: TextRec): Integer;
Begin
  CrtReturn:=0;
end;


Function CrtClose(Var F: TextRec): Integer;
Begin
  F.Mode:=fmClosed;
  CrtClose:=0;
End;


Function CrtOpen(Var F: TextRec): Integer;
Begin
  If F.Mode=fmOutput Then
   begin
     TextRec(F).InOutFunc:=@CrtWrite;
     TextRec(F).FlushFunc:=@CrtWrite;
   end
  Else
   begin
     F.Mode:=fmInput;
     TextRec(F).InOutFunc:=@CrtRead;
     TextRec(F).FlushFunc:=@CrtReturn;
   end;
  TextRec(F).CloseFunc:=@CrtClose;
  CrtOpen:=0;
End;


procedure AssignCrt(var F: Text);
begin
  Assign(F,'');
  TextRec(F).OpenFunc:=@CrtOpen;
end;

{ use the C version to avoid using dpmiexcp unit
  which makes sysutils and exceptions working incorrectly  PM }

//function __djgpp_set_ctrl_c(enable : longint) : boolean;cdecl;external;

var
  x,y : longint;
begin
{ Load startup values }
  ScreenWidth:=GetScreenWidth;
  ScreenHeight:=GetScreenHeight;
  WindMax:=(ScreenWidth-1) or ((ScreenHeight-1) shl 8);
{ Load TextAttr }
  GetScreenCursor(x,y);
  lastmode := mem[$40:$49];
  if screenheight>25 then
    lastmode:=lastmode or $100;
  If not(lastmode=Mono) then
    VidSeg := $b800
  else
    VidSeg := $b000;
  TextAttr:=mem[VidSeg:((y-1)*ScreenWidth+(x-1))*2+1];
{ Redirect the standard output }
  assigncrt(Output);
  Rewrite(Output);
  TextRec(Output).Handle:=StdOutputHandle;
  assigncrt(Input);
  Reset(Input);
  TextRec(Input).Handle:=StdInputHandle;
{ Calculates delay calibration }
  initdelay;
{ Enable ctrl-c input (JM) }
//  __djgpp_set_ctrl_c(0);
end.
