sundinKC@dna.lth.se (Anders Sundin) (04/14/91)
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 |
-------------------------------------------------------------keith@Apple.COM (Keith Rollin) (04/16/91)
In article <1991Apr13.192211.27446@lth.se> sundinKC@dna.lth.se (Anders Sundin) writes: >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. Anders, I sent your questions to The QuickDraw Dude in Mac DTS, Guillermo Ortiz. He had some comments for you. I've included them in the body of your program below. Note to the reader: Guillermo's comments are the _only_ comments in the program, so you should be able to pick them out pretty easily. > >program SlowWhenAccelerated; > { This program shows that although CopyBits is faster with acceleration on, the overall performance of the program suffers due to the numerous problems in the code giving the perception that QD is slower under acceleration. Note all the comments to see the points where changes to the code make things significantly faster} >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 { As in the case of NewGWorld when passing a depth of zero (see below) it doesn't make sense to pass a GDevice or the rect corresponding to the screen; you want to pass a nil for GDHandle and the windows port rect. It is also important to note that calling UpdateGWorld here is what really kills the performance of the resulting code since the pixmap is (most probably) uncached from the card to main then massaged and finally copied back to the card; since there is no change to make to the GWorld it does not make sense to have this call at all; it can and should be removed. } > 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; { The following line should be changed: IF NewGWorld(gDrawingPort, 0, screenbits.bounds, NIL, GetMainDevice, []) <> noErr THEN First it doesn't make sense to call GetMainDevice since passing zero as the depth makes the system ignore the GDevice being passes but also because second when you pass a depth of zero you want to pass the rect of a window you want to ensure the best performance for. So we have: } > if NewGWorld(gDrawingPort, 0, gWindow^.portRect, > nil, nil, []) <> noErr then > ExitToShell; > SetRect(gRect, 0, 0, 400, 400); { If there was a real reason to call UpdateGWorld I would put it here so it is called just once as in: } gFlags := UpdateGworld(gDrawingPort, 0, gWindow^.portRect, NIL, NIL, []); { No need for GDHandle } > 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 | > ------------------------------------------------------------- Hope this helps, -- ------------------------------------------------------------------------------ Keith Rollin --- Apple Computer, Inc. INTERNET: keith@apple.com UUCP: {decwrl, hoptoad, nsc, sun, amdahl}!apple!keith "But where the senses fail us, reason must step in." - Galileo