* obsolete

rtl/linux/graph.pp

@@ -1,1825 +0,0 @@
-unit Graph;
-
-{ *********************************************************************
-
-  $Id$
-
-  Copyright 1997,1998 Matthias K"oppe <[email protected]>
-  This library is free software in the sense of the GNU Library GPL;
-  see `License Conditions' below.
-
-  Info:
-
-  This unit provides the functions of Borland's Graph unit for linux,
-  it uses the SVGAlib to do the actual work, so you must have svgalib
-
-  on your system
-
-  This version requires Free Pascal 0.99.5 or higher.
-
-  Large parts have not yet been implemented or tested.
-
-  History:
-
-  Date       Version  Who     Comments
-  ---------- -------- ------- -------------------------------------
-  25-Sep-97  0.1      mkoeppe Initial multi-target version.
-  05-Oct-97  0.1.1    mkoeppe Linux: Added mouse use. Improved clipping.
-                              Added bitmap functions.
-  ??-Oct-97  0.1.2    mkoeppe Fixed screenbuf functions.
-  07-Feb-98  0.1.3    mkoeppe Fixed a clipping bug in DOS target.
-  12-Apr-98  0.1.4    mkoeppe Linux: Using Michael's re-worked SVGALIB
-                              interface; prepared for FPC 0.99.5; removed
-                              dependencies.
-  15-Apr-98  0.1.5    michael Renamed to graph, inserted needed SVGlib
-                              declarations here so it can be used independently
-                              of the svgalib unit. Removed things that are NOT
-                              part of Borland's Graph from the unit interface.
-
-
-  License Conditions:
-
-  This library is free software; you can redistribute it and/or
-  modify it under the terms of the GNU Library General Public
-  License as published by the Free Software Foundation; either
-  version 2 of the License, or (at your option) any later version.
-
-  This library 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.  See the GNU
-  Library General Public License for more details.
-
-  You should have received a copy of the GNU Library General Public
-  License along with this library; if not, write to the Free
-  Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
-
-
-  *********************************************************************}
-
-{
-  Functions not currently implemented :
-  -------------------------------------
-  SetWriteMode
-  SetLineStyle
-  SetFillPattern
-  SetUserCharSize
-  SetTextStyle
-  FillPoly
-  FloodFill
-  SetAspectRatio
-
-  (please remove what you implement fom this list)
-}
-
-
-interface
-
-
-{ ---------------------------------------------------------------------
-   Constants
-  ---------------------------------------------------------------------}
-
-const
-  NormalPut       = 0;
-  CopyPut         = 0;
-  XORPut          = 1;
-  ORPut           = 2;
-  ANDPut          = 3;
-  NotPut          = 4;
-  BackPut         = 8;
-
-  Black           =  0;
-  Blue            =  1;
-  Green           =  2;
-  Cyan            =  3;
-  Red             =  4;
-  Magenta         =  5;
-  Brown           =  6;
-  LightGray       =  7;
-  DarkGray        =  8;
-  LightBlue       =  9;
-  LightGreen      = 10;
-  LightCyan       = 11;
-  LightRed        = 12;
-  LightMagenta    = 13;
-  Yellow          = 14;
-  White           = 15;
-  Border          = 16;
-
-  SolidLn         = 0;
-  DottedLn        = 1;
-  CenterLn        = 2;
-  DashedLn        = 3;
-  UserBitLn       = 4;
-
-  EmptyFill       = 0;
-  SolidFill       = 1;
-  LineFill        = 2;
-  LtSlashFill     = 3;
-  SlashFill       = 4;
-  BkSlashFill     = 5;
-  LtBkSlashFill   = 6;
-  HatchFill       = 7;
-  XHatchFill      = 8;
-  InterleaveFill  = 9;
-  WideDotFill     = 10;
-  CloseDotFill    = 11;
-  UserFill        = 12;
-
-  NormWidth       = 1;
-  ThickWidth      = 3;
-
-  LeftText      = 0;
-  CenterText    = 1;
-  RightText     = 2;
-  BottomText    = 0;
-  TopText       = 2;
-  BaseLine      = 3;
-  LeadLine      = 4;
-
-  { Error codes }
-  grOK             = 0;
-  grNoInitGraph    = -1;
-  grNotDetected    = -2;
-  grFileNotFound   = -3;
-  grInvalidDriver  = -4;
-  grNoLOadMem      = -5;
-  grNoScanMem      = -6;
-  grNoFloodMem     = -7;
-  grFontNotFound   = -8;
-  grNoFontMem      = -9;
-  grInvalidmode    = -10;
-  grError          = -11;
-  grIOerror        = -12;
-  grInvalidFont    = -13;
-  grInvalidFontNum = -14;
-
-  { graphic drivers }
-  CurrentDriver = -128;
-  Detect = 0;
-
-  { graph modes }
-   Default = 0;
-
-
-{ ---------------------------------------------------------------------
-   Types
-  ---------------------------------------------------------------------}
-
-Type
-  FillPatternType = array[1..8] of byte;
-
-  ArcCoordsType = record
-     x,y : integer;
-     xstart,ystart : integer;
-     xend,yend : integer;
-  end;
-
-  RGBColor = record
-    r,g,b,i : byte;
-  end;
-
-
-  PaletteType = record
-     Size   : integer;
-     Colors : array[0..767]of Byte;
-  end;
-
-
-  LineSettingsType = record
-     linestyle : word;
-     pattern : word;
-     thickness : word;
-  end;
-
-  TextSettingsType = record
-     font : word;
-     direction : word;
-     charsize : word;
-     horiz : word;
-     vert : word;
-  end;
-
-  FillSettingsType = record
-     pattern : word;
-     color : longint;
-  end;
-
-  PointType = record
-     x,y : integer;
-  end;
-
-  ViewPortType = record
-     x1,y1,x2,y2 : integer;
-     Clip : boolean;
-  end;
-
-
-
- const
-  fillpattern : array[0..12] of FillPatternType = (
-      ($00,$00,$00,$00,$00,$00,$00,$00),     { Hintergrundfarbe }
-      ($ff,$ff,$ff,$ff,$ff,$ff,$ff,$ff),     { Vordergrundfarbe }
-      ($ff,$ff,$00,$00,$ff,$ff,$00,$00),     { === }
-      ($01,$02,$04,$08,$10,$20,$40,$80),     { /// }
-      ($07,$0e,$1c,$38,$70,$e0,$c1,$83),     { /// als dicke Linien }
-      ($07,$83,$c1,$e0,$70,$38,$1c,$0e),     { \\\ als dicke Linien }
-      ($5a,$2d,$96,$4b,$a5,$d2,$69,$b4),     { \ \\ \ }
-      ($ff,$88,$88,$88,$ff,$88,$88,$88),     { K„stchen }
-      ($18,$24,$42,$81,$81,$42,$24,$18),     { Rauten }
-      ($cc,$33,$cc,$33,$cc,$33,$cc,$33),     { "Mauermuster" }
-      ($80,$00,$08,$00,$80,$00,$08,$00),     { weit auseinanderliegende Punkte }
-      ($88,$00,$22,$00,$88,$00,$22,$00),     { dichte Punkte}
-      (0,0,0,0,0,0,0,0)                      { benutzerdefiniert }
-     );
-
-
-
-{ ---------------------------------------------------------------------
-   Function Declarations
-
-  ---------------------------------------------------------------------}
-
-{ Retrieving coordinates }
-function  GetX: Integer;
-function  GetY: Integer;
-
-{ Pixel-oriented routines }
-procedure PutPixel(X, Y: Integer; Pixel: Word);
-function  GetPixel(X, Y: Integer): Word;
-
-{ Line-oriented primitives }
-procedure SetWriteMode(WriteMode: Integer);
-procedure LineTo(X, Y: Integer);
-procedure LineRel(Dx, Dy: Integer);
-procedure MoveTo(X, Y: Integer);
-procedure MoveRel(Dx, Dy: Integer);
-procedure Line(x1, y1, x2, y2: Integer);
-procedure SetLineStyle(LineStyle: Word; Pattern: Word; Thickness: Word);
-
-{ Linearly bounded primitives }
-procedure Rectangle(x1, y1, x2, y2: Integer);
-procedure Bar(x1, y1, x2, y2: Integer);
-procedure Bar3D(x1, y1, x2, y2: Integer; Depth: Word; Top: Boolean);
-procedure DrawPoly(NumPoints: Word; var PolyPoints);
-procedure FillPoly(NumPoints: Word; var PolyPoints);
-procedure SetFillStyle(Pattern: Word; Color: Word);
-procedure SetFillPattern(Pattern: FillPatternType; Color: Word);
-procedure FloodFill(X, Y: Integer; Border: Word);
-
-{ Nonlinearly bounded primitives }
-
-procedure Arc(X, Y: Integer; StAngle, EndAngle, Radius: Word);
-procedure GetArcCoords(var ArcCoords: ArcCoordsType);
-procedure Circle(X, Y: Integer; Radius: Word);
-procedure Ellipse(X, Y: Integer; StAngle, EndAngle: Word; XRadius, YRadius : Word);
-procedure FillEllipse(X, Y: Integer; XRadius, YRadius : Word);
-procedure SetAspectRatio(Xasp, Yasp: Word);
-procedure PieSlice(X, Y: Integer; StAngle, EndAngle, Radius: Word);
-procedure Sector(X, Y: Integer; StAngle, EndAngle, XRadius, YRadius: Word);
-
-{ Color routines }
-procedure SetBkColor(ColorNum: Word);
-procedure SetColor(Color: Word);
-Function  GetBkColor : Word;
-Function  GetColor : Word;
-function  GetMaxColor : Word;
-Procedure GetDefaultPalette (Var Palette : PaletteType);
-Procedure GetPalette (Var Palette : PaletteType);
-Function  GetPaletteSize : Word;
-Procedure SetAllPalette (Var Palette);
-Procedure SetPalette (ColorNr : Word; NewColor  : ShortInt);
-
-{ Filling/linestyle utilities }
-Procedure  GetFillSettings (Var FillSettings : FillSettingsType);
-Procedure  GetFillPattern (Var FillPattern : FillPatternType);
-Procedure  GetLineSettings (Var LineInfo : LineSettingsType);
-
-{ Bitmap utilities }
-procedure GetImage(x1, y1, x2, y2: Integer; var BitMap);
-procedure PutImage(X, Y: Integer; var BitMap; BitBlt: Word);
-function  ImageSize(x1, y1, x2, y2: Integer): LongInt;
-
-{ Text routines}
-procedure OutText(TextString: string);
-procedure OutTextXY(X, Y: Integer; TextString: string);
-procedure SetTextJustify(Horiz, Vert: Word);
-procedure SetTextStyle(Font, Direction: Word; CharSize: Word);
-procedure SetUserCharSize(MultX, DivX, MultY, DivY: Word);
-procedure GetTextSettings (Var TextInfo : TextSettingsType);
-
-{ Graph clipping method }
-Procedure SetViewPort(x1, y1, x2, y2: Integer; Clip: Boolean);
-Procedure ClearViewPort;
-Procedure GetViewSettings (Var ViewPort : ViewPortType);
-
-{ Init/Done }
-procedure InitVideo;
-procedure DoneVideo;
-
-{ Other }
-function  GetResX: Integer;
-function  GetResY: Integer;
-function  GetAspect: Real;
-Procedure GetAspectRatio (Var x,y : Word);
-function  GetMaxX : Integer;
-function  GetMAxY : Integer;
-
-{ For compatibility }
-Procedure DetectGraph (Var Driver,Mode : Integer);
-Procedure InitGraph (Var Driver,Mode : Integer;DriverPath : String);
-Procedure CloseGraph;
-Function  GraphResult : Integer;
-Procedure GraphDefaults ;
-Function  GraphErrorMsg (Errcode : Integer) : String;
-Procedure ClearDevice;
-Function  GetDriverName : String;
-Function  GetGraphMode : Integer;
-Function  GetMaxMode : Word;
-Function  GetModeName (Var Modus : INteger) : String;
-Procedure GetModeRange (Driver : Integer; Var loModus,HiModus : Integer);
-Function  InstallUserDriver (DriverPat :String; AutodetectPtr : Pointer) : Integer;
-Function  InstallUserFont (FontPath : String) : Integer;
-Function  RegisterBGIDriver (Driver : Pointer) : Integer;
-Function  RegisterBGIFont (Font : Pointer) : Integer;
-Procedure RestoreCRTmode;
-Procedure SetActivePage (Page : Word);
-Procedure SetGraphBufSize (BufSize : Word);
-Procedure SetGraphMode (Mode :Integer);
-Procedure SetVisualPage (Page : Word);
-
-const
-  NoGraphics: Boolean = false;
-
-  { VGA modes }
-  GTEXT             = 0;                { Compatible with VGAlib v1.2 }
-  G320x200x16       = 1;
-  G640x200x16       = 2;
-  G640x350x16       = 3;
-  G640x480x16       = 4;
-  G320x200x256      = 5;
-  G320x240x256      = 6;
-  G320x400x256      = 7;
-  G360x480x256      = 8;
-  G640x480x2        = 9;
-
-  G640x480x256      = 10;
-  G800x600x256      = 11;
-  G1024x768x256     = 12;
-
-  G1280x1024x256    = 13;   { Additional modes. }
-
-  G320x200x32K      = 14;
-  G320x200x64K      = 15;
-  G320x200x16M      = 16;
-  G640x480x32K      = 17;
-  G640x480x64K      = 18;
-  G640x480x16M      = 19;
-  G800x600x32K      = 20;
-  G800x600x64K      = 21;
-  G800x600x16M      = 22;
-  G1024x768x32K     = 23;
-  G1024x768x64K     = 24;
-  G1024x768x16M     = 25;
-  G1280x1024x32K    = 26;
-  G1280x1024x64K    = 27;
-  G1280x1024x16M    = 28;
-
-  G800x600x16       = 29;
-  G1024x768x16      = 30;
-  G1280x1024x16     = 31;
-
-  G720x348x2        = 32;               { Hercules emulation mode }
-
-  G320x200x16M32    = 33;       { 32-bit per pixel modes. }
-  G640x480x16M32    = 34;
-  G800x600x16M32    = 35;
-  G1024x768x16M32   = 36;
-  G1280x1024x16M32  = 37;
-
-  { additional resolutions }
-  G1152x864x16      = 38;
-  G1152x864x256     = 39;
-  G1152x864x32K     = 40;
-  G1152x864x64K     = 41;
-  G1152x864x16M     = 42;
-  G1152x864x16M32   = 43;
-
-  G1600x1200x16     = 44;
-  G1600x1200x256    = 45;
-  G1600x1200x32K    = 46;
-  G1600x1200x64K    = 47;
-  G1600x1200x16M    = 48;
-  G1600x1200x16M32  = 49;
-
-  GLASTMODE         = 49;
-
-
-
-implementation
-
-uses Objects, Linux;
-
-
-{ ---------------------------------------------------------------------
-   SVGA bindings.
-
-  ---------------------------------------------------------------------}
-
-{  Link with VGA, gl and c libraries }
-{$linklib vga}
-{$linklib vgagl}
-{$linklib c}
-
-Const
-  { Text }
-
-  WRITEMODE_OVERWRITE = 0;
-  WRITEMODE_MASKED    = 1;
-  FONT_EXPANDED       = 0;
-  FONT_COMPRESSED     = 2;
-
- { Types }
- type
-   pvga_modeinfo = ^vga_modeinfo;
-   vga_modeinfo = record
-     width,
-     height,
-     bytesperpixel,
-     colors,
-     linewidth,          { scanline width in bytes }
-     maxlogicalwidth,    { maximum logical scanline width }
-     startaddressrange,  { changeable bits set }
-     maxpixels,          { video memory / bytesperpixel }
-     haveblit,           { mask of blit functions available }
-     flags: Longint;     { other flags }
-    { Extended fields: }
-     chiptype,           { Chiptype detected }
-     memory,             { videomemory in KB }
-     linewidth_unit: Longint;    { Use only a multiple of this as parameter for                                   set_displaystart }
-     linear_aperture: PChar;     { points to mmap secondary mem aperture of card }
-     aperture_size: Longint;     { size of aperture in KB if size>=videomemory.}
-
-     set_aperture_page: procedure (page: Longint);
-            { if aperture_size<videomemory select a memory page }
-     extensions: Pointer;        { points to copy of eeprom for mach32 }
-            { depends from actual driver/chiptype.. etc. }
-     end;
-
-  PGraphicsContext = ^TGraphicsContext;
-  TGraphicsContext = record
-                       ModeType: Byte;
-                       ModeFlags: Byte;
-                       Dummy: Byte;
-                       FlipPage: Byte;
-                       Width: LongInt;
-                       Height: LongInt;
-                       BytesPerPixel: LongInt;
-                       Colors: LongInt;
-                       BitsPerPixel: LongInt;
-                       ByteWidth: LongInt;
-                       VBuf: pointer;
-                       Clip: LongInt;
-                       ClipX1: LongInt;
-                       ClipY1: LongInt;
-                       ClipX2: LongInt;
-                       ClipY2: LongInt;
-                       ff: pointer;
-                     end;
-
-
- { vga functions }
- Function vga_init: Longint; Cdecl; External;
- Function vga_getdefaultmode: Longint; Cdecl; External;
-
- Function vga_hasmode(mode: Longint): Boolean; Cdecl; External;
-
- Function vga_getmodeinfo(mode: Longint): pvga_modeinfo; Cdecl; External;
- Function vga_setmode(mode: Longint): Longint; Cdecl; External;
- Function vga_getxdim : Longint; cdecl;external;
- Function vga_getydim : longint; cdecl;external;
-
- { gl functions }
- procedure gl_setpixel(x, y, c: LongInt); Cdecl; External;
- function  gl_getpixel(x, y: LongInt): LongInt; cdecl; external;
- procedure gl_line(x1, y1, x2, y2, c: LongInt); Cdecl; External;
- procedure gl_fillbox(x, y, w, h, c: LongInt); Cdecl; External;
- procedure gl_circle(x, y, r, c: LongInt ); Cdecl; External;
- procedure gl_getbox(x, y, w, h: LongInt; dp: pointer); Cdecl; External;
- procedure gl_putbox(x, y, w, h: LongInt; dp: pointer); Cdecl; External;
- procedure gl_disableclipping; Cdecl; External;
- procedure gl_enableclipping; Cdecl; External;
- procedure gl_putboxpart(x, y, w, h, bw, bh: LongInt; b: pointer; xo, yo: LongInt); Cdecl; External;
- function  gl_rgbcolor(r, g, b: LongInt): LongInt; Cdecl; External;
- function  gl_setcontextvga(m: LongInt): LongInt; Cdecl; External;
- function  gl_allocatecontext: PGraphicsContext; Cdecl; External;
- procedure gl_getcontext(gc: PGraphicsContext); Cdecl; External;
- procedure gl_setrgbpalette; Cdecl; External;
- procedure gl_freecontext(gc: PGraphicsContext); Cdecl; External;
- procedure gl_setclippingwindow(x1, y1, x2, y2: LongInt); Cdecl; External;
- procedure gl_setwritemode(wm: LongInt); Cdecl; External;
- procedure gl_setfontcolors(bg, fg: LongInt); Cdecl; External;
- procedure gl_writen(x, y, n: LongInt; s: PChar); Cdecl; External;
- procedure gl_setfont(fw, fh: LongInt; fdp: pointer); Cdecl; External;
-
- procedure gl_copyboxfromcontext(var gc: TGraphicsContext; x1, y1, w, h, x2, y2: LongInt); Cdecl; External;
- procedure gl_setcontext(gc: PGraphicsContext); Cdecl; External;
-
- function  gl_setcontextvgavirtual(m: LongInt): LongInt; cdecl; external;
- procedure gl_font8x8; Cdecl; External;
-
-
-{ ---------------------------------------------------------------------
-   Types, constants and variables
-
-  ---------------------------------------------------------------------}
-
-var
-  DrawDelta: TPoint;
-  CurX, CurY: Integer;
-  TheColor, TheFillColor: LongInt;
-  IsVirtual: Boolean;
-  PhysicalScreen, BackScreen: PGraphicsContext;
-  ColorTable: array[0..15] of LongInt;
-  TheFillPattern : FillPatternType;
-  TheLineSettings : LineSettingsType;
-  ThePalette : PaletteType;
-  TheTextSettings : TextSettingsType;
-  TheFillSettings : FillSettingsType;
-
-const
-  BgiColors: array[0..15] of LongInt
-    = ($000000, $000080, $008000, $008080,
-       $800000, $800080, $808000, $C0C0C0,
-       $808080, $0000FF, $00FF00, $00FFFF,
-       $FF0000, $FF00FF, $FFFF00, $FFFFFF);
-
-const
-  DoUseMarker: Boolean = true;
-  TheMarker: Char      = '~';
-  TextColor: LongInt   = 15;
-  MarkColor: LongInt   = 15;
-  BackColor: LongInt   = 0;
-  FontWidth: Integer   = 8;
-  FontHeight: Integer  = 8;
-
-var
-  sHoriz, sVert: Word;
-
-{ initialisierte Variablen }
-const
-  SourcePage: Word = 0;
-  DestPage: Word = 0;
-
-{ Retrieves the capabilities for the current mode }
-const
-  vmcImage       = 1;
-  vmcCopy        = 2;
-  vmcSaveRestore = 4;
-  vmcBuffer      = 8;
-  vmcBackPut     = 16;
-
-{ ---------------------------------------------------------------------
-   Graphics Vision Layer
-  ---------------------------------------------------------------------}
-
-
-{ Types and constants }
-var
-  SizeX, SizeY: Word;
-
-{ Draw origin and clipping rectangle }
-var
-  DrawOrigin: TPoint;
-  ClipRect: TRect;
-  MetaClipRect: TRect;
-  MetaOrigin: TPoint;
-
-{ Font attributes }
-const
-  ftNormal          = 0;
-  ftBold            = 1;
-  ftThin            = 2;
-  ftItalic          = 4;
-
-var
-  sFont, sColor:Word;
-  sCharSpace: Integer;
-{ Not used
-  sMarker: Char;
-  sAttr: Word; }
-
-{ Windows-style text metric }
-type
-  PTextMetric = ^TTextMetric;
-  TTextMetric = record
-    tmHeight: Integer;
-    tmAscent: Integer;
-    tmDescent: Integer;
-    tmInternalLeading: Integer;
-    tmExternalLeading: Integer;
-    tmAveCharWidth: Integer;
-    tmMaxCharWidth: Integer;
-    tmWeight: Integer;
-    tmItalic: Byte;
-    tmUnderlined: Byte;
-    tmStruckOut: Byte;
-    tmFirstChar: Byte;
-    tmLastChar: Byte;
-    tmDefaultChar: Byte;
-    tmBreakChar: Byte;
-    tmPitchAndFamily: Byte;
-    tmCharSet: Byte;
-    tmOverhang: Integer;
-    tmDigitizedAspectX: Integer;
-    tmDigitizedAspectY: Integer;
-  end;
-
-
-{ Bitmap utilities }
-type
-  PBitmap = ^TBitmap;
-  TBitmap = record
-              Width, Height: Integer;
-              Data: record end;
-            end;
-
-
- { Storing screen regions }
-type
-  TVgaBuf = record
-    Bounds: TRect;
-    Mem: Word;
-    Size: Word;
-  end;
-
-const
-  pbNone  = 0;
-  pbCopy  = 1;
-  pbClear = 2;
-
-type
-  PScreenBuf = ^TScreenBuf;
-  TScreenBuf = record
-    Mode: Word;
-    Rect: TRect;
-    Size: LongInt;
-    Info: LongInt
-  end;
-
-
-
- { Procedures and functions }
-
-
-procedure SetColors;
-var
-  i: Integer;
-begin
-  for i:=0 to 15 do
-    ColorTable[i] := gl_rgbcolor(BgiColors[i] shr 16,
-                                 (BgiColors[i] shr 8) and 255,
-                                 BgiColors[i] and 255)
-end;
-
-
-
-procedure InitVideo;
-var
-  VgaMode: Integer;
-  ModeInfo: pvga_modeinfo;
-begin
-  if NoGraphics
-  then begin
-    SizeX := 640;
-    SizeY := 480
-  end
-  else begin
-    VgaMode := vga_getdefaultmode;
-    if (VgaMode = -1) then VgaMode := G320X200X256;
-    if (not vga_hasmode(VgaMode))
-      then begin
-        WriteLn('BGI: Mode not available.');
-        Halt(1)
-      end;
-    ModeInfo := vga_getmodeinfo(VgaMode);
-    {IsVirtual := (ModeInfo^.colors = 16) or (ModeInfo^.flags and IS_MODEX <> 0);}
-    IsVirtual := true;
-    { We always want a back screen (for buffering). }
-    if IsVirtual
-      then begin
-        { Create virtual screen }
-        gl_setcontextvgavirtual(VgaMode);
-        BackScreen := gl_allocatecontext;
-        gl_getcontext(BackScreen)
-      end;
-    vga_setmode(VgaMode);
-    gl_setcontextvga(VgaMode);  { Physical screen context. }
-    PhysicalScreen := gl_allocatecontext;
-    gl_getcontext(PhysicalScreen);
-    if (PhysicalScreen^.colors = 256) then gl_setrgbpalette;
-    SetColors;
-    SizeX := PhysicalScreen^.Width;
-    SizeY := PhysicalScreen^.Height
-  end
-end;
-
-procedure DoneVideo;
-begin
-  if not NoGraphics
-    then begin
-      if IsVirtual then gl_freecontext(BackScreen);
-      vga_setmode(GTEXT)
-    end
-end;
-
-procedure SetDelta;
-begin
-  if ClipRect.Empty
-  then begin
-    DrawDelta.X := 10000;
-    DrawDelta.Y := 10000;
-  end
-  else begin
-    DrawDelta.X := DrawOrigin.X;
-    DrawDelta.y := DrawOrigin.y
-  end
-end;
-
-procedure SetDrawOrigin(x, y: Integer);
-begin
-  DrawOrigin.x := x;
-  DrawOrigin.y := y;
-  SetDelta;
-end;
-
-procedure SetDrawOriginP(var P: TPoint);
-begin
-  SetDrawOrigin(P.x, P.y)
-end;
-
-procedure SetClipRect(x1, y1, x2, y2: Integer);
-begin
-  Cliprect.Assign(x1, y1, x2, y2);
-  if not NoGraphics
-    then begin
-      if ClipRect.Empty
-        then gl_setclippingwindow(0, 0, 0, 0)
-        else gl_setclippingwindow(x1, y1, x2 - 1, y2 - 1);
-      {gl_enableclipping(0);}
-    end;
-  SetDelta
-end;
-
-procedure SetClipRectR(var R: TRect);
-begin
-  SetClipRect(R.A.X, R.A.Y, R.B.X, R.B.Y);
-end;
-
-procedure SetMetaOrigin(x, y: Integer);
-begin
-  MetaOrigin.x := x;
-  MetaOrigin.y := y
-end;
-
-procedure SetMetaOriginP(P: TPoint);
-begin
-  SetMetaOrigin(P.x, P.y)
-end;
-
-procedure SetMetaClipRect(x1, y1, x2, y2: Integer);
-begin
-  MetaCliprect.Assign(x1, y1, x2, y2)
-end;
-
-procedure SetMetaClipRectR(var R: TRect);
-begin
-  MetaCliprect := R
-end;
-
-function GetBuffer(Size: Word): pointer;
-begin
-  { No metafiling available. }
-  GetBuffer := nil
-end;
-
-Procedure HoriLine(x1,y1,x2: Integer);
-begin
-  Line(x1, y1, x2, y1)
-end;
-
-Procedure VertLine(x1,y1,y2: Integer);
-begin
-  Line(x1, y1, x1, y2)
-end;
-
-procedure FillCircle(xm, ym, r: Integer);
-begin
-  FillEllipse(xm, ym, r, r)
-end;
-
-{ Text routines }
-
-function TextWidth(s: string): Integer;
-var
-  i: Integer;
-begin
-  if DoUseMarker
-  then begin
-    For i := Length(s) downto 1 do
-      If s[i] = TheMarker then Delete(s, i, 1);
-    If s = ''
-    then TextWidth := 0
-    else TextWidth := Length(s) * FontWidth
-  end
-  else TextWidth := Length(s) * FontWidth
-end;
-
-function TextHeight(s: string): Integer;
-begin
-  TextHeight := FontHeight
-end;
-
-
-procedure OutText(TextString: string);
-begin
-  OutTextXY(GetX, GetY, TextString)
-end;
-
-procedure OutTextXY(X, Y: Integer; TextString: string);
-var
-  P, Q: PChar;
-  i: Integer;
-  col: Boolean;
-begin
-  if NoGraphics or (TextString='') then Exit;
-  gl_setwritemode(FONT_COMPRESSED + WRITEMODE_MASKED);
-  case sHoriz of
-    CenterText : Dec(x, TextWidth(TextString) div 2);
-    RightText  : Dec(x, TextWidth(TextString));
-  end; { case }
-  case sVert of
-    CenterText : Dec(y, TextHeight(TextString) div 2);
-    BottomText, BaseLine : Dec(y, TextHeight(TextString));
-  end; { case }
-  MoveTo(X, Y);
-  P := @TextString[1]; Q := P;
-  col := false;
-  gl_setfontcolors(BackColor, TextColor);
-  For i := 1 to Length(TextString) do
-  begin
-    If (Q[0] = TheMarker) and DoUseMarker
-      then begin
-        If col then gl_setfontcolors(BackColor, MarkColor)
-        else gl_setfontcolors(BackColor, TextColor);
-        If Q <> P then begin
-          gl_writen(CurX, CurY, Q-P, P);
-          MoveRel(FontWidth * (Q-P), 0)
-        end;
-        col := not col;
-        P := Q + 1
-      end;
-    {Inc(Q)} Q := Q + 1
-  end;
-  If col then gl_setfontcolors(BackColor, MarkColor)
-  else gl_setfontcolors(BackColor, TextColor);
-  If Q <> P then begin
-    gl_writen(CurX, CurY, Q-P, P);
-    MoveRel(FontWidth * (Q-P), 0)
-  end
-end;
-
-procedure SetTextJustify(Horiz, Vert: Word);
-begin
-  sHoriz := Horiz; sVert := Vert;
-end;
-
-procedure SetTextStyle(Font, Direction: Word; CharSize: Word);
-begin
-end;
-
-procedure SetUserCharSize(MultX, DivX, MultY, DivY: Word);
-begin
-end;
-
-procedure SetKern(Enable: Boolean);
-begin
-end;
-
-procedure SetMarker(Marker: Char);
-begin
-  TheMarker := Marker
-end;
-
-
-procedure SetTextParams(Font: Word; CharSpace: Integer; Color: Word;
-  UseMarker: Boolean);
-type
-  pp = ^pointer;
-
-function FixCol(Col: Byte): Byte;
-{ SVGALIB cannot write black characters... }
-begin
-  if Col=0 then FixCol := 1 else FixCol := Col
-end; { FixCol }
-
-begin
-  sColor := Color; sCharSpace := CharSpace; sFont := Font;
-  if not NoGraphics then begin
-    TextColor := ColorTable[FixCol(Color and 15)];
-    MarkColor := ColorTable[FixCol((Color shr 8) and 15)];
-    DoUseMarker := UseMarker;
-    gl_setfont(8, 8, (pp(@gl_font8x8))^);
-  end
-end;
-
-
-function GetResX: Integer;
-begin
-  GetResX := 96;
-end; { GetResX }
-
-function GetResY: Integer;
-begin
-  GetResY := 96
-end; { GetResY }
-
-function GetAspect: Real;
-begin
-  GetAspect := 1.0
-end; { GetAspect }
-
-Procedure GetAspectRatio (Var x,y : Word);
-begin
-  X:=GetMaxX;
-  Y:=GetMaxY
-end; { GetAspect }
-
-Var LastViewPort : ViewPortType;
-
-procedure SetViewPort(x1, y1, x2, y2: Integer; Clip: Boolean);
-begin
-  LastViewPort.X1:=X1;
-  LastViewPort.Y1:=Y1;
-  LastViewPort.X2:=X2;
-  LastViewPort.Y2:=Y2;
-  LastViewPort.Clip:=Clip;
-  SetDrawOrigin(x1, y1);
-  if Clip then SetClipRect(x1, y1, x2+1, y2+1)
-  else SetClipRect(0, 0, SizeX, SizeY)
-end;
-
-
-Procedure ClearViewPort;
-
-begin
-  With LastViewPort do
-  gl_fillbox(X1,Y1,X2-X1,Y2-Y1,BackColor);
-end;
-
-Procedure GetViewSettings (Var ViewPort : ViewPortType);
-
-begin
-  ViewPort:=LastViewPort;
-end;
-
-{ VGAMEM }
-
-type
-  TImage = record
-  end;
-
-procedure CopyScreen(x1, y1, x2, y2, x3, y3: Integer);
-begin
-  if not NoGraphics and (x2 > x1) and (y2 > y1)
-    then gl_copyboxfromcontext(PhysicalScreen^, x1, y1, x2 - x1, y2 - y1, x3, y3);
-end;
-
-{ BGI-like Image routines
-}
-
-function CopyImage(Image: pointer): pointer;
-begin
-  CopyImage := nil
-end;
-
-function CutImage(x1, y1, x2, y2: Integer): pointer;
-var
-  Image: PBitmap;
-begin
-
-  GetMem(Image, ImageSize(x1, y1, x2, y2));
-  if Image <> nil
-    then GetImage(x1, y1, x2, y2, Image^);
-  CutImage := Image;
-end;
-
-procedure GetImageExtent(Image: pointer; var Extent: Objects.TPoint);
-begin
-  if Image = nil
-    then begin
-      Extent.X := 0;
-      Extent.Y := 0
-    end
-    else begin
-      Extent.X := PBitmap(Image)^.Width;
-      Extent.Y := PBitmap(Image)^.Height
-    end;
-end;
-
-
-procedure FreeImage(Image: pointer);
-var
-  P: TPoint;
-begin
-  if Image <> nil
-    then begin
-      GetImageExtent(Image, P);
-      FreeMem(Image, ImageSize(0, 0, P.x - 1, P.y - 1));
-    end;
-end;
-
-
-function LoadImage(var S: TStream): pointer;
-begin
-  LoadImage := nil
-end;
-
-function MaskedImage(Image: pointer): pointer;
-begin
-  MaskedImage := nil;
-end;
-
-procedure PasteImage(X, Y: Integer; Image: pointer; BitBlt: Word);
-begin
-  if Image <> nil then PutImage(X, Y, Image^, BitBlt)
-end;
-
-procedure StoreImage(var S: TStream; Image: pointer);
-begin
-end;
-
-{ Storing screen regions }
-function PrepBuf(var R: Objects.TRect; Action: Word; var Buf: TVgaBuf): Boolean;
-begin
-  if BackScreen <> nil
-    then begin
-      Buf.Bounds := R;
-      gl_setcontext(BackScreen);
-      gl_disableclipping;
-      case Action of
-        pbCopy  : gl_copyboxfromcontext(PhysicalScreen^,
-                                        R.A.X, R.A.Y, R.B.X - R.A.X, R.B.Y - R.A.Y,
-                                        R.A.X, R.A.Y);
-        pbClear : gl_fillbox(R.A.X, R.A.Y, R.B.X - R.A.X, R.B.Y - R.A.Y, 0);
-      end;
-      PrepBuf := true;
-      SetDrawOrigin(0, 0);
-      SetClipRectR(R);
-    end
-    else PrepBuf := false
-end; { PrepBuf }
-
-procedure EndBufDraw;
-begin
-  if not NoGraphics
-    then gl_setcontext(PhysicalScreen);
-end; { EndBufDraw }
-
-procedure ReleaseBuf(var Buf: TVgaBuf);
-begin
-end; { ReleaseBuf }
-
-procedure PasteRectAt(var R: Objects.TRect; P: Objects.TPoint; var Buf: TVgaBuf);
-begin
-  if not NoGraphics and (BackScreen <> nil)
-    then gl_copyboxfromcontext(BackScreen^,
-                               R.A.X, R.A.Y, R.B.X - R.A.X, R.B.Y - R.A.Y,
-                               P.X, P.Y);
-end;
-
-
-procedure PasteRect(var R: Objects.TRect; var Buf: TVgaBuf);
-begin
-  PasteRectAt(R, R.A, Buf);
-end; { PasteRect }
-
-
-function StoreScreen(x1, y1, x2, y2: Integer): PScreenBuf;
-var
-  s: LongInt;
-  p: pointer;
-  SaveOrigin: TPoint;
-
-function NewScreenBuf(AMode: Word; AnInfo: LongInt): PScreenBuf;
- var
-   p: PScreenBuf;
- Begin
-   New(p);
-   p^.Mode := AMode;
-   p^.Size := s;
-   p^.Rect.Assign(x1, y1, x2, y2);
-   p^.Info := AnInfo;
-   NewScreenBuf := p
- End;
-
-Begin
-  { General Images }
-  s := 0;
-  SaveOrigin := DrawOrigin;
-  SetDrawOrigin(0, 0);
-  p := CutImage(x1, y1, x2-1, y2-1);
-  SetDrawOriginP(SaveOrigin);
-  If p <> nil
-    then StoreScreen := NewScreenBuf(2, LongInt(p))
-  else StoreScreen := nil
-End;
-
-procedure FreeScreenBuf(Buf: PScreenBuf);
-Begin
-  If Buf <> nil then Begin
-    case Buf^.Mode of
-      2 : FreeImage(pointer(Buf^.Info));
-    end;
-    Dispose(Buf)
-  End
-End;
-
-procedure DrawScreenBufAt(Buf: PScreenBuf; x3, y3: Integer);
-var
-  SaveOrigin: TPoint;
-Begin
-  If Buf <> nil then
-    case Buf^.Mode of
-      2 :
-          begin
-            SaveOrigin := DrawOrigin;
-            SetDrawOrigin(0, 0);
-            PasteImage(x3, y3, pointer(Buf^.Info), NormalPut);
-            SetDrawOriginP(SaveOrigin);
-          end
-    end
-End;
-
-procedure DrawScreenBuf(Buf: PScreenBuf);
-Begin
-  If Buf <> nil then
-    DrawScreenBufAt(Buf, Buf^.Rect.A.x, Buf^.Rect.A.y)
-End;
-
-function GetVgaMemCaps: Word;
-begin
-  GetVgaMemCaps := vmcCopy
-end;
-
-procedure GetTextMetrics(var Metrics: TTextMetric);
-begin
-  with Metrics do
-  begin
-    tmHeight := 8;
-    tmAscent := 8;
-    tmDescent := 0;
-    tmInternalLeading := 0;
-    tmExternalLeading := 0;
-    tmAveCharWidth := 8;
-    tmMaxCharWidth := 8;
-    tmWeight := 700;
-    tmItalic := 0;
-    tmUnderlined := 0;
-    tmStruckOut := 0;
-    tmFirstChar := 0;
-    tmLastChar := 255;
-    tmDefaultChar := 32;
-    tmBreakChar := 32;
-    tmPitchAndFamily := 0;
-    tmCharSet := 0;
-    tmOverhang := 0;
-    tmDigitizedAspectX := 100;
-    tmDigitizedAspectY := 100
-  end;
-end;
-
-{ ---------------------------------------------------------------------
-   Real graph implementation
-  ---------------------------------------------------------------------}
-
-
-function GetX: Integer;
-begin
-  GetX := CurX - DrawDelta.X
-end;
-
-function GetY: Integer;
-begin
-  GetY := CurY - DrawDelta.Y
-end;
-
-{ Pixel-oriented routines }
-procedure PutPixel(X, Y: Integer; Pixel: Word);
-begin
-  if not NoGraphics
-    then gl_setpixel(X + DrawDelta.X, Y + DrawDelta.Y, Pixel)
-end;
-
-function GetPixel(X, Y: Integer): Word;
-begin
-  if NoGraphics
-    then GetPixel := 0
-    else GetPixel := gl_getpixel(X + DrawDelta.X, Y + DrawDelta.Y)
-end;
-
-{ Line-oriented primitives }
-procedure SetWriteMode(WriteMode: Integer);
-begin
-{  Graph.SetWriteMode(WriteMode) }
-end;
-
-procedure LineTo(X, Y: Integer);
-begin
-  if not NoGraphics
-    then gl_line(CurX, CurY, X + DrawDelta.X, Y + DrawDelta.Y, TheColor);
-  CurX := X + DrawDelta.X;
-  CurY := Y + DrawDelta.Y
-end;
-
-procedure LineRel(Dx, Dy: Integer);
-begin
-  if not NoGraphics
-    then gl_line(CurX, CurY, CurX + Dx, CurY + Dy, TheColor);
-  CurX := CurX + Dx;
-  CurY := CurY + Dy
-end;
-
-procedure MoveTo(X, Y: Integer);
-begin
-  CurX := X + DrawDelta.X;
-  CurY := Y + DrawDelta.Y
-end;
-
-procedure MoveRel(Dx, Dy: Integer);
-begin
-  CurX := CurX + Dx;
-  CurY := CurY + Dy
-end;
-
-procedure Line(x1, y1, x2, y2: Integer);
-begin
-  if not NoGraphics
-    then gl_line(x1 + DrawDelta.X, y1 + DrawDelta.Y,
-                 x2 + DrawDelta.X, y2 + DrawDelta.Y, TheColor)
-end;
-
-procedure SetLineStyle(LineStyle: Word; Pattern: Word; Thickness: Word);
-begin
-end;
-
-procedure SetFillPattern(Pattern: FillPatternType; Color: Word);
-
-begin
-end;
-
-
-{ Linearly bounded primitives }
-
-procedure Rectangle(x1, y1, x2, y2: Integer);
-begin
-  MoveTo(x1, y1);
-  LineTo(x2, y1);
-  LineTo(x2, y2);
-  LineTo(x1, y2);
-  LineTo(x1, y1)
-end;
-
-procedure Bar(x1, y1, x2, y2: Integer);
-var
-  R: TRect;
-begin
-  if not NoGraphics
-    then begin
-      R.Assign(x1 + DrawDelta.X, y1 + DrawDelta.Y,
-               x2 + DrawDelta.X + 1, y2 + DrawDelta.Y + 1);
-      R.Intersect(ClipRect);
-      if not R.Empty
-        then gl_fillbox(R.A.X, R.A.Y,
-                        R.B.X - R.A.X, R.B.Y - R.A.Y, TheFillColor)
-    end;
-end;
-
-procedure Bar3D(x1, y1, x2, y2: Integer; Depth: Word; Top: Boolean);
-begin
-  Bar(x1,y1,x2,y2);
-  Rectangle(x1,y1,x2,y2);
-  if top then begin
-     Moveto(x1,y1);
-     Lineto(x1+depth,y1-depth);
-     Lineto(x2+depth,y1-depth);
-     Lineto(x2,y1);
-  end;
-  Moveto(x2+depth,y1-depth);
-  Lineto(x2+depth,y2-depth);
-  Lineto(x2,y2);
-
-end;
-
-procedure DrawPoly(NumPoints: Word; var PolyPoints);
-
-type
-   ppointtype = ^pointtype;
-
-var
-   i : longint;
-
-begin
-   line(ppointtype(@polypoints)[NumPoints-1].x,
-        ppointtype(@polypoints)[NumPoints-1].y,
-        ppointtype(@polypoints)[0].x,
-        ppointtype(@polypoints)[0].y);
-   for i:=0 to NumPoints-2 do
-     line(ppointtype(@polypoints)[i].x,
-          ppointtype(@polypoints)[i].y,
-          ppointtype(@polypoints)[i+1].x,
-          ppointtype(@polypoints)[i+1].y);
-end;
-
-procedure FillPoly(NumPoints: Word; var PolyPoints);
-
-begin
- DrawPoly (NumPoints,PolyPoints);
-end;
-
-procedure SetFillStyle(Pattern: Word; Color: Word);
-begin
-  TheFillColor := ColorTable[Color]
-end;
-
-procedure FloodFill(X, Y: Integer; Border: Word);
-begin
-end;
-
-{ Nonlinearly bounded primitives
-}
-
-Var LastArcCoords : ArcCoordsType;
-
-
-procedure SetArcCoords (X,y,xradius,yradius,Stangle,endangle : integer);
-
-begin
-  LastArcCoords.X:=X;
-  LastArccOords.y:=y;
-  Lastarccoords.xstart:=x+round(xradius*cos(stangle*pi/180));
-  Lastarccoords.ystart:=y-round(yradius*sin(stangle*pi/180));
-  LastArccoords.xend:=x+round(xradius*cos(endangle*pi/180));
-  LastArccoords.yend:=y-round(yradius*sin(endangle*pi/180));
-end;
-
-
-procedure GetArcCoords(var ArcCoords: ArcCoordsType);
-
-begin
-  ArcCoords:=LastArcCoords;
-end;
-
-procedure Arc(X, Y: Integer; StAngle, EndAngle, Radius: Word);
-
-begin
- Ellipse (X,y,stangle,endangle,Radius,radius);
-end;
-
-procedure Circle(X, Y: Integer; Radius: Word);
-begin
-  if not NoGraphics
-    then gl_circle(X + DrawDelta.X, Y + DrawDelta.Y, Radius, TheColor)
-end;
-
-procedure Ellipse(X, Y: Integer;
-  StAngle, EndAngle: Word; XRadius, YRadius : Word);
-
-Var I : longint;
-    tmpang : real;
-
-begin
- SetArcCoords (X,Y,xradius,yradius,Stangle,EndAngle);
- For i:= StAngle To EndAngle Do
-  Begin
-   tmpAng:= i*Pi/180;
-   curX:= X + Round (xRadius*Cos (tmpAng));
-   curY:= Y - Round (YRadius*Sin (tmpAng));
-   PutPixel (curX, curY, TheColor);
-  End;
-end;
-
-procedure FillEllipse(X, Y: Integer; XRadius, YRadius : Word);
-
-Var I,tmpcolor : longint;
-    tmpang : real;
-    tmpx,tmpy : Integer;
-
-begin
- tmpcolor:=Thecolor;
- SetColor(TheFillColor);
- For i:= 0 to 180 Do
-  Begin
-   tmpAng:= i*Pi/180;
-   curX:= Round (xRadius*Cos (tmpAng));
-   curY:= Round (YRadius*Sin (tmpAng));
-   tmpX:= X - curx;
-   tmpy:= Y + cury;
-   curx:=x+curx;
-   cury:=y-cury;
-   Line (curX, curY,tmpx,tmpy);
-   PutPixel (curx,cury,tmpcolor);
-   PutPixel (tmpx,tmpy,tmpcolor);
-  End;
-  SetColor(tmpcolor);
-end;
-
-procedure SetAspectRatio(Xasp, Yasp: Word);
-begin
-  //!! Needs implementing.
-end;
-
-procedure PieSlice(X, Y: Integer; StAngle, EndAngle, Radius: Word);
-
-Begin
- sector (x,y,stangle,endangle,radius,radius);
-end;
-
-procedure Sector(X, Y: Integer;
-  StAngle, EndAngle, XRadius, YRadius: Word);
-
-Var I,tmpcolor : longint;
-    tmpang : real;
-    ac : arccoordstype;
-
-begin
- tmpcolor:=Thecolor;
- SetColor(TheFillColor);
- For i:= stangle to endangle Do
-   Begin
-   tmpAng:= i*Pi/180;
-   curX:= x+Round (xRadius*Cos (tmpAng));
-   curY:= y-Round (YRadius*Sin (tmpAng));
-   Line (x,y,curX, curY);
-   PutPixel (curx,cury,tmpcolor);
-   End;
- SetColor(tmpcolor);
- getarccoords(ac);
- Line (x,y,ac.xstart,ac.ystart);
- Line (x,y,ac.xend,ac.yend);
-end;
-
-{ Color routines
-}
-
-procedure SetBkColor(ColorNum: Word);
-begin
-  BackColor := ColorTable[ColorNum];
-end;
-
-Function GetBkColor : Word;
-
-begin
-  GetBkColor:=BackColor;
-end;
-
-procedure SetColor(Color: Word);
-begin
-  TheColor := ColorTable[Color];
-end;
-
-Function GetColor : Word;
-
-begin
-  GetColor:=TheColor;
-end;
-
-function GetMaxColor : Word;
-
-begin
-  getmaxcolor:=16;
-end;
-
-procedure GetImage(x1, y1, x2, y2: Integer; var BitMap);
-var
-  SaveClipRect: TRect;
-begin
-  with TBitmap(Bitmap) do
-  begin
-    Width := x2 - x1 + 1;
-    Height := y2 - y1 + 1;
-    if not NoGraphics
-      then begin
-        {gl_disableclipping(0);}
-        SaveClipRect := ClipRect;
-        SetClipRect(0, 0, SizeX, SizeY);
-        gl_getbox(x1 + DrawDelta.X, y1 + DrawDelta.Y,
-                  x2 - x1 + 1, y2 - y1 + 1, @Data);
-        SetClipRectR(SaveClipRect)
-      end;
-  end;
-end;
-
-procedure PutImage(X, Y: Integer; var BitMap; BitBlt: Word);
-var
-  R: TRect;
-  SaveClipRect: TRect;
-begin
-  if not NoGraphics then
-    with TBitmap(Bitmap) do
-    begin
-      {gl_putbox(x + DrawDelta.X, y + DrawDelta.Y, Width, Height, @Data)}
-      R.Assign(X + DrawDelta.X, Y + DrawDelta.Y,
-               X + DrawDelta.X + Width, Y + DrawDelta.Y + Height);
-      R.Intersect(ClipRect);
-      if not R.Empty
-        then begin
-          {gl_disableclipping(0);}
-          SaveClipRect := ClipRect;
-          SetClipRect(0, 0, SizeX, SizeY);
-          gl_putboxpart(R.A.X, R.A.Y,
-                        R.B.X - R.A.X, R.B.Y - R.A.Y,
-                        Width, Height,
-                        @Data,
-                        R.A.X - X, R.A.Y - Y);
-          SetClipRectR(SaveClipRect);
-        end;
-    end;
-end; { PutImage }
-
-function ImageSize(x1, y1, x2, y2: Integer): LongInt;
-begin
-  if NoGraphics
-    then ImageSize := SizeOf(TBitmap)
-    else ImageSize := SizeOf(TBitmap)
-      + LongInt(x2 - x1 + 1) * LongInt(y2 - y1 + 1) * PhysicalScreen^.BytesPerPixel;
-end;
-
-function GetMaxX : Integer;
-
-begin
-  GetMaxX:=vga_getxdim;
-end;
-
-function GetMAxY : Integer;
-begin
-  GetMaxY:=vga_getydim;
-end;
-
-Procedure DetectGraph (Var Driver,Mode : Integer);
-
-begin
-  Driver:=9;
-  Mode:=vga_getdefaultmode;
-  If Mode=-1 then mode:=0;
-end;
-
-Var VgaMode : Integer;
-
-Procedure InitGraph (Var Driver,Mode : Integer;DriverPath : String);
-
-var
-  ModeInfo: pvga_modeinfo;
-
-begin
-    If Mode=0 then
-      VgaMode := vga_getdefaultmode
-    else
-      VGAMode :=Mode;
-    if (VgaMode = -1) then VgaMode := G320X200X256;
-    if (not vga_hasmode(VgaMode))
-      then begin
-        WriteLn('BGI: Mode not available.');
-        Halt(1)
-      end;
-    ModeInfo := vga_getmodeinfo(VgaMode);
-    {IsVirtual := (ModeInfo^.colors = 16) or (ModeInfo^.flags and IS_MODEX <> 0);}
-    IsVirtual := true;
-    { We always want a back screen (for buffering). }
-    if IsVirtual
-      then begin
-        { Create virtual screen }
-        gl_setcontextvgavirtual(VgaMode);
-        BackScreen := gl_allocatecontext;
-        gl_getcontext(BackScreen)
-      end;
-    vga_setmode(VgaMode);
-    gl_setcontextvga(VgaMode);  { Physical screen context. }
-    PhysicalScreen := gl_allocatecontext;
-    gl_getcontext(PhysicalScreen);
-    if (PhysicalScreen^.colors = 256) then gl_setrgbpalette;
-    SetColors;
-    SizeX := PhysicalScreen^.Width;
-    SizeY := PhysicalScreen^.Height
-end;
-
-Procedure CloseGraph;
-
-begin
-  DoneVideo;
-end;
-
-Function GraphResult : Integer;
-
-begin
-  GraphResult:=0;
-end;
-
-Procedure GraphDefaults ;
-
-begin
-end;
-
-Function GraphErrorMsg (Errcode : Integer) : String;
-
-begin
-  GraphErrorMsg:='';
-end;
-
-Procedure ClearDevice;
-
-begin
- SetViewPort (0,0,GetMaxX,GetMaxY,False);
- ClearViewPort;
- MoveTo(0,0);
-end;
-
-Procedure GetDefaultPalette (Var Palette : Palettetype);
-
-begin
-  //!! Not yet implemented.
-end;
-
-Function GetDriverName : String;
-
-begin
-  GetDriverName:='libvga';
-end;
-
-Function  GetGraphMode : Integer;
-
-begin
-  GetGraphMode:=VgaMode;
-end;
-
-Procedure GetFillPattern (Var FillPattern : FillPatternType);
-
-begin
-  FillPattern:=TheFillPattern;
-end;
-
-Procedure GetFillSettings (Var FillSettings : FillSettingsType);
-
-begin
-  FillSettings:=TheFillSettings;
-end;
-
-Procedure GetLineSettings (Var LineInfo : LineSettingsType);
-
-begin
-  LineInfo:=TheLineSettings;
-end;
-
-Function GetMaxMode : Word;
-
-begin
-  GetMaxMode:=GLastMode;
-end;
-
-Function  GetModeName (Var Modus : INteger) : String;
-
-begin
-  GetModeName:='VGA'
-end;
-
-Procedure GetModeRange (Driver : Integer; Var loModus,HiModus : Integer);
-
-begin
-  LoModus:=1;
-  HiModus:=GLASTMODE;
-end;
-
-Procedure GetPalette (Var Palette : PaletteType);
-
-begin
-  Palette:=ThePalette;
-end;
-
-Procedure SetAllPalette (Var Palette);
-
-begin
-  ThePalette:=PaletteType(Palette);
-end;
-
-Procedure SetPalette (ColorNr : Word; NewColor  : ShortInt);
-
-begin
- //!! not implemented.
-end;
-
-Function GetPaletteSize : Word;
-
-begin
-  GetPaletteSize:=16;
-end;
-
-Procedure GetTextSettings (Var TextInfo : TextSettingsType);
-
-begin
-  TextInfo:=TheTextSettings;
-end;
-
-Function  InstallUserDriver (DriverPat :String; AutodetectPtr : Pointer) : Integer;
-
-begin
- InstallUserDriver:=grError;
-end;
-
-Function  InstallUserFont (FontPath : String) : Integer;
-
-begin
-  InstallUserFont:=0;
-end;
-
-Function  RegisterBGIDriver (Driver : Pointer) : Integer;
-
-begin
-  RegisterBGIDriver:=grError;
-end;
-
-Function  RegisterBGIFont (Font : Pointer) : Integer;
-begin
-  RegisterBGIFont:=grError;
-end;
-
-Procedure RestoreCRTmode;
-
-begin
-  vga_setmode(GTEXT);
-end;
-
-Procedure SetActivePage (Page : Word);
-
-begin
-  //!! Not implemented
-end;
-
-Procedure SetVisualPage (Page : Word);
-
-begin
-  //!! Not implemented
-end;
-
-Procedure SetGraphBufSize (BufSize : Word);
-
-begin
-end;
-
-Procedure SetGraphMode (Mode :Integer);
-
-begin
-    vga_setmode(Mode);
-    VgaMode:=Mode;
-end;
-
-begin
-  { Give up root permissions if we are root.  }
-  if geteuid = 0 then vga_init;
-end.
-
-{
-  $Log$
-  Revision 1.10  1999-01-25 20:31:30  peter
-    + detect,default constants
-
-  Revision 1.9  1998/09/13 19:22:06  michael
-  + Implemented dummies for all missing functions
-
-  Revision 1.8  1998/09/11 09:24:55  michael
-  Added missing functions so mandel compiles and runs
-
-  Revision 1.7  1998/08/24 08:23:47  michael
-  Better initgraph handling.
-
-  Revision 1.6  1998/08/14 09:20:36  michael
-  Typo fixed. linklib gl to linklib vgagl
-
-  Revision 1.5  1998/08/12 14:01:08  michael
-  small fix in sector, pieslice replaced by call to sector
-
-  Revision 1.4  1998/08/12 13:25:33  michael
-  + added arc,ellipse,fillelipse,sector,pieslice
-
-  Revision 1.3  1998/08/10 09:01:58  michael
-  + Added some functions to improve compatibility
-
-  Revision 1.2  1998/05/12 10:42:47  peter
-    * moved getopts to inc/, all supported OS's need argc,argv exported
-    + strpas, strlen are now exported in the systemunit
-    * removed logs
-    * removed $ifdef ver_above
-
-  Revision 1.1  1998/04/15 13:40:11  michael
-  + Initial implementation of graph unit
-
-}