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From: sundinKC@dna.lth.se (Anders Sundin)
Newsgroups: comp.sys.mac.programmer
Subject: How do I code for 8.24 GC QuickDraw?
Message-ID: <1991Apr13.192211.27446@lth.se>
Date: 13 Apr 91 19:22:11 GMT
Sender: newsuser@lth.se (LTH network news server)
Organization: Lund University Computing Center, Sweden
Lines: 111

How do I write for the 8.24 GC Display Card, or rather, where can I
find an example of code that really gets accelerated by this card?
I have read #TN 289 "Deaccelerated CopyBits & 8.24 GC QuickDraw".
I have also read #TN 277 about CopyBits, and Develop nr 1 and 3
about GWorlds and the 8.24 GC.
But I still don't have a clue why my CopyBits is *much* slower when
"accelerated" by a 8.24 GC Display Card.

program SlowWhenAccelerated;
uses  Types, QuickDraw, Events, Fonts, Menus, QDOffscreen,
       SegLoad, Traps, Windows, Dialogs;

var
   gDrawingPort : GWorldPtr;
   gWindow      : WindowPtr;
   gRect        : Rect;
   gRGBBlack    : RGBColor;
   gRGBWhite    : RGBColor;
   gVert        : Boolean;
   gFlags       : GWorldFlags;

procedure DrawSomeStuff;
begin
   RGBForeColor(gRGBBlack);
   RGBBackColor(gRGBWhite);
   ClipRect(gRect);
   PaintRect(gRect);
   RGBForeColor(gRGBWhite);
   if gVert then
   begin
      MoveTo(200, 50);
      LineTo(200, 350);
   end
   else
   begin
      MoveTo(50, 200);
      LineTo(350, 200);
   end;
   gVert := not gVert;
end;

procedure DrawInAltScreen;
var
   oldPort   : CGrafPtr;
   oldDevice : GDHandle;

begin
   gFlags := UpdateGWorld(gDrawingPort, 0, screenbits.bounds,
                          nil, GetMainDevice, []);
   GetGWorld(oldPort, oldDevice);
   SetGWorld(gDrawingPort, nil);
   if not LockPixels(gDrawingPort^.portPixMap) then
      ExitToShell;
   DrawSomeStuff;
   UnlockPixels(gDrawingPort^.portPixMap);
   SetGWorld(oldPort, oldDevice);
end;

procedure BlitIt;
begin
   RGBForeColor(gRGBBlack);
   RGBBackColor(gRGBWhite);
   if not LockPixels(gDrawingPort^.portPixMap) then
      ExitToShell;
   CopyBits( GrafPtr(gDrawingPort)^.portBits,
             gWindow^.portBits,
             gRect,
             gRect,
             srcCopy,
             nil);
   UnlockPixels(gDrawingPort^.portPixMap);
end;

begin
   InitGraf(@thePort);
   InitFonts;
   InitWindows;
   InitMenus;
   TEInit;
   InitDialogs(nil);
   InitCursor;
   gVert := true;
   gRGBBlack.red :=     $0000;
   gRGBBlack.green :=   $0000;
   gRGBBlack.blue :=    $0000;
   gRGBWhite.red :=     $FFFF;
   gRGBWhite.green :=   $FFFF;
   gRGBWhite.blue :=    $FFFF;
   SetRect(gRect, 50, 50, 450, 450);
   gWindow := NewCWindow(nil, gRect, '', true, noGrowDocProc,
                         WindowPtr(-1), false, 0);
   if gWindow = nil then
      ExitToShell;
   if NewGWorld(gDrawingPort, 0, screenBits.bounds,
                nil, GetMainDevice, []) <> noErr then
      ExitToShell;
   SetRect(gRect, 0, 0, 400, 400);
   repeat
      DrawInAltScreen;
      BlitIt;
   until Button;
   DisposeGWorld(gDrawingPort);
end.
-- 
   -------------------------------------------------------------
  |  Anders Sundin          |  e-mail: sundinKC@dna.lth.se      |
  |  University of Lund     |          ok2aps@gemini.ldc.lu.se  |
  |  Organic Chemistry 2,   |          ok2aps@seldc52.bitnet    |
  |  P.O. Box 124           |   phone:  +46 46 108214           |
  |  S-22100 Lund, Sweden   |   fax:    +46 46 108209           |
   -------------------------------------------------------------