{
    $Id$
    This file is part of the Free Pascal run time library.
    Copyright (c) 1999-2000 by Florian Klaempfl
    member of the Free Pascal development team

    Video unit for linux

    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.

 **********************************************************************}
unit Video;

interface

{$i videoh.inc}

var
  VideoSeg : word;


implementation

uses
  mouse,
  go32;

{$i video.inc}

{$ASMMODE ATT}

var
  OldVideoBuf : PVideoBuf;

  { used to know if LastCursorType is valid }
const
  InitVideoCalled : boolean = false;
  LastCursorType : word = crUnderline;

{ allways set blink state again }

procedure SetHighBitBlink;
var
  regs : trealregs;
begin
  regs.ax:=$1003;
  regs.bx:=$0001;
  realintr($10,regs);
end;

function BIOSGetScreenMode(var Cols,Rows: word; var Color: boolean): boolean;
var r: trealregs;
    L: longint;
    LSel,LSeg: word;
    B: array[0..63] of byte;
type TWord = word; PWord = ^TWord;
var Size: word;
    OK: boolean;
begin
  L:=global_dos_alloc(64);
  LSeg:=(L shr 16);
  LSel:=(L and $ffff);

  r.ah:=$1b; r.bx:=0;
  r.es:=LSeg; r.di:=0;
  realintr($10,r);
  OK:=(r.al=$1b);
  if OK then
  begin
    dpmi_dosmemget(LSeg,0,B,64);
    Cols:=PWord(@B[5])^; Rows:=B[$22];
    Color:=PWord(@B[$27])^<>0;
  end;
  global_dos_free(LSel);
  BIOSGetScreenMode:=OK;
end;

procedure InitVideo;
var
  regs : trealregs;
begin
  VideoSeg:=$b800;
  if (ScreenWidth=$ffff) or (ScreenHeight=$ffff) or
    (ScreenWidth=0) or (ScreenHeight=0) then
    begin
       ScreenColor:=true;
       regs.ah:=$0f;
       realintr($10,regs);
       if (regs.al and 1)=0 then
         ScreenColor:=false;
       if regs.al=7 then
         begin
            ScreenColor:=false;
            VideoSeg:=$b000;
         end
       else
         VideoSeg:=$b800;
       ScreenWidth:=regs.ah;
       regs.ax:=$1130;
       regs.bx:=0;
       realintr($10,regs);
       ScreenHeight:=regs.dl+1;
       BIOSGetScreenMode(ScreenWidth,ScreenHeight,ScreenColor);
    end;
  regs.ah:=$03;
  regs.bh:=0;
  realintr($10,regs);
  CursorLines:=regs.cl;
  CursorX:=regs.dl;
  CursorY:=regs.dh;
  If InitVideoCalled then
    Begin
      FreeMem(VideoBuf,VideoBufSize);
      FreeMem(OldVideoBuf,VideoBufSize);
    End;
{ allocate pmode memory buffer }
  VideoBufSize:=ScreenWidth*ScreenHeight*2;
  GetMem(VideoBuf,VideoBufSize);
  GetMem(OldVideoBuf,VideoBufSize);
  InitVideoCalled:=true;
  SetHighBitBlink;
  SetCursorType(LastCursorType);
  { ClearScreen; removed here
    to be able to catch the content of the monitor }
end;


procedure DoneVideo;
begin
  If InitVideoCalled then
    Begin
      LastCursorType:=GetCursorType;
      ClearScreen;
      SetCursorType(crUnderLine);
      SetCursorPos(0,0);
      FreeMem(VideoBuf,VideoBufSize);
      VideoBuf:=nil;
      FreeMem(OldVideoBuf,VideoBufSize);
      OldVideoBuf:=nil;
      InitVideoCalled:=false;
      VideoBufSize:=0;
    End;
end;


function GetCapabilities: Word;
begin
  GetCapabilities := $3F;
end;


procedure SetCursorPos(NewCursorX, NewCursorY: Word);
var
  regs : trealregs;
begin
  regs.ah:=$02;
  regs.bh:=0;
  regs.dh:=NewCursorY;
  regs.dl:=NewCursorX;
  realintr($10,regs);
  CursorY:=regs.dh;
  CursorX:=regs.dl;
end;

{ I don't know the maximum value for the scan line
  probably 7 or 15 depending on resolution !!
  }
function GetCursorType: Word;
var
  regs : trealregs;
begin
  regs.ah:=$03;
  regs.bh:=0;
  realintr($10,regs);
  GetCursorType:=crHidden;
  if (regs.ch and $60)=0 then
   begin
     GetCursorType:=crBlock;
     if (regs.ch and $1f)<>0 then
      begin
        GetCursorType:=crHalfBlock;
        if regs.cl+1=(regs.ch and $1F) then
         GetCursorType:=crUnderline;
      end;
   end;
end;


procedure SetCursorType(NewType: Word);
var
  regs : trealregs;
const
  MaxCursorLines = 7;
begin
  regs.ah:=$01;
  regs.bx:=NewType;
  case NewType of
   crHidden    : regs.cx:=$2000;
   crHalfBlock : begin
                   regs.ch:=MaxCursorLines shr 1;
                   regs.cl:=MaxCursorLines;
                 end;
   crBlock     : begin
                   regs.ch:=0;
                   regs.cl:=MaxCursorLines;
                 end;
   else          begin
                   regs.ch:=MaxCursorLines-1;
                   regs.cl:=MaxCursorLines;
                 end;
  end;
  realintr($10,regs);
end;


function DefaultVideoModeSelector(const VideoMode: TVideoMode; Params: Longint): Boolean;
type
  wordrec=packed record
    lo,hi : word;
  end;
var
  regs : trealregs;
begin
  regs.ax:=wordrec(Params).lo;
  regs.bx:=wordrec(Params).hi;
  realintr($10,regs);
  defaultvideomodeselector:=true;
  DoCustomMouse(false);
end;

function VideoModeSelector8x8(const VideoMode: TVideoMode; Params: Longint): Boolean;
type
  wordrec=packed record
    lo,hi : word;
  end;
var
  regs : trealregs;
begin
  regs.ax:=3;
  regs.bx:=0;
  realintr($10,regs);
  regs.ax:=$1112;
  regs.bx:=$0;
  realintr($10,regs);
  videomodeselector8x8:=true;
  ScreenColor:=true;
  ScreenWidth:=80;
  ScreenHeight:=50;
  DoCustomMouse(false);
end;

procedure ClearScreen;
begin
  FillWord(VideoBuf^,VideoBufSize shr 1,$0720);
  UpdateScreen(true);
end;


procedure UpdateScreen(Force: Boolean);
begin
  if LockUpdateScreen<>0 then
   exit;
  if not force then
   begin
     asm
        movl    VideoBuf,%esi
        movl    OldVideoBuf,%edi
        movl    VideoBufSize,%ecx
        shrl    $2,%ecx
        repe
        cmpsl
        setne   force
     end;
   end;
  if Force then
   begin
     dosmemput(videoseg,0,videobuf^,VideoBufSize);
     move(videobuf^,oldvideobuf^,VideoBufSize);
   end;
end;


procedure RegisterVideoModes;
begin
  RegisterVideoMode(40, 25, False,@DefaultVideoModeSelector, $00000000);
  RegisterVideoMode(40, 25, True, @DefaultVideoModeSelector, $00000001);
  RegisterVideoMode(80, 25, False,@DefaultVideoModeSelector, $00000002);
  RegisterVideoMode(80, 25, True, @DefaultVideoModeSelector, $00000003);
  RegisterVideoMode(80, 50, True, @VideoModeSelector8x8, 0);
end;


initialization
  RegisterVideoModes;

finalization
  UnRegisterVideoModes;
end.
{
  $Log$
  Revision 1.2  2001-05-09 19:53:28  peter
    * removed asm for copy, use dosmemput (merged)

  Revision 1.1  2001/01/13 11:03:58  peter
    * API 2 RTL commit

}