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DirectDraw Pixel Manipulation

Started by chlupp2000 Jul 29, 2001 at 4:36 AM 4 replies 500+ views

Original Post

chlupp2000

Jul 29, 2001 at 4:36 AM

Hello! I have nearly all tried to get this thing working, but now I don''t know what to do. I am not able to manipulate a single pixel from a DirectDraw Surface. Here''s my code:

ddsd: TDDSurfaceDesc2;
Primary: IDirectDrawSurface7;
X,Y: Integer;

Primary.GetSurfaceDesc(ddsd);
if Primary.Lock(nil,ddsd, DDLOCK_SURFACEMEMORYPTR or DDLOCK_WAIT,0) = DD_OK then
  begin
    try
      begin
        for x:=0 to 1023 do
        begin
          for y:=0 to 767 do
          begin
            PByte(Integer(ddsd.lpSurface)+Y*ddsd.lpitch+X)^:= RGB(50,50,50);
          end;
        end;
      end;
    finally
      Primary.Unlock(nil);
    end;
  end;

Maybe someone can help me (and post his code)? thanks chlupp Starbyte Developments

turbo

Jul 31, 2001 at 12:06 AM

Try using...


pdword(integer(LockedSurfaceDesc.lpsurface) + // surface pointer
  y * LockedSurfaceDesc.lpitch + x * 3)^ :=
  (r shl 16) or (g shl 8) or b; // Could use RGB(r,g,b)
end;

Since RGB values are DWORDS not bytes. You also may have some locking issues. I use...


LockedRect := Rect(0, 0, LockedSurfaceDesc.dwWidth, LockedSurfaceDesc.dwHeight);
if LockedSurface.Lock(@LockedRect, LockedSurfaceDesc, DDLOCK_SURFACEMEMORYPTR + DDLOCK_WAIT,0) <> DD_OK then // etc...

but there are many ways to skin a cat

chlupp2000

Jul 31, 2001 at 10:43 AM

Thanks for replying, I''ll try it.

cu
chlupp20000

chlupp2000

Aug 2, 2001 at 2:16 AM

Yeah, it''s working!

Thank you!

chlupp2000

LoreKeeper

Aug 3, 2001 at 5:24 AM

Try looking at the Pixel code in TurboPixel or PixelCore... although they are mostly DelphiX related, the code still applies to the general case. And those pixel routines are still faster then the code above.

L-Tryosine

Aug 3, 2001 at 9:33 PM

Hey, this just solved a problem that I was having too!!!

Thanks guys!

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