{$IFNDEF WIN32}

type

{Used for pointer math under Win16}

 PPtrRec = ^TPtrRec;

 TPtrRec = record

  Lo : Word;

  Hi : Word;

 end;

{$ENDIF}

{Used for huge pointer math}

function GetBigPointer(lp : pointer;

  Offset : Longint) : Pointer;

begin

{$IFDEF WIN32}

 GetBigPointer := @PByteArray(lp)^[Offset];

{$ELSE}

 Offset := Offset + TPtrRec(lp).Lo;

 GetBigPointer := Ptr(TPtrRec(lp).Hi + TPtrRec(Offset).Hi *

  SelectorInc,

  TPtrRec(Offset).Lo);

{$ENDIF}

end;

procedure TForm1.Button1Click(Sender: TObject);

var

 hPixelBuffer : THandle; {Handle to the pixel buffer}

 lpPixelBuffer : pointer; {pointer to the pixel buffer}

 lpPalBuffer : PLogPalette; {The palette buffer}

 lpBitmapInfo : PBitmapInfo; {The bitmap info header}

 BitmapInfoSize : longint; {Size of the bitmap info header}

 BitmapSize : longint; {Size of the pixel array}

 PaletteSize : integer; {Size of the palette buffer}

 i : longint; {loop variable}

 j : longint; {loop variable}

 OldPal : hPalette; {temp palette}

 hPal : hPalette; {handle to our palette}

 hBm : hBitmap; {handle to our bitmap}

 Bm : TBitmap; {temporary TBitmap}

 Dc : hdc; {used to convert the DOB to a DDB}

 IsPaletteDevice : bool;

begin

Application.ProcessMessages;

{If range checking is on - turn it off for now}

{we will remember if range checking was on by defining}

{a define called CKRANGE if range checking is on.}

{We do this to access array members past the arrays}

{defined index range without causing a range check}

{error at runtime. To satisfy the compiler, we must}

{also access the indexes with a variable. ie: if we}

{have an array defined as a: array[0..0] of byte,}

{and an integer i, we can now access a[3] by setting}

{i := 3; and then accessing a[i] without error}

{$IFOPT R+}

 {$DEFINE CKRANGE}

 {$R-}

{$ENDIF}

{Lets check to see if this is a palette device - if so, then}

{we must do palette handling for a successful operation.}

{Get the screen's dc to use since memory dc's are not reliable}

 dc := GetDc(0);

 IsPaletteDevice :=

  GetDeviceCaps(dc, RASTERCAPS) and RC_PALETTE = RC_PALETTE;

{Give back the screen dc}

 dc := ReleaseDc(0, dc);

{Размер информации о рисунке должен равняться размеру BitmapInfo}

{плюс размер таблицы цветов, минус одна таблица}

{так как она уже объявлена в TBitmapInfo}

 BitmapInfoSize := sizeof(TBitmapInfo) + (sizeof(TRGBQUAD) * 255);

{The bitmap size must be the width of the bitmap rounded}

{up to the nearest 32 bit boundary}

 BitmapSize := (sizeof(byte) * 256) * 256;

{Размер палитры должен равняться размеру TLogPalette}

{плюс количество ячеек цветовой палитры - 1, так как}

{одна палитра уже объявлена в TLogPalette}

 if IsPaletteDevice then

  PaletteSize := sizeof(TLogPalette) + (sizeof(TPaletteEntry) * 255);

{Выделяем память под BitmapInfo, PixelBuffer, и Palette}

 GetMem(lpBitmapInfo, BitmapInfoSize);

 hPixelBuffer := GlobalAlloc(GHND, BitmapSize);

 lpPixelBuffer := GlobalLock(hPixelBuffer);

 if IsPaletteDevice then

  GetMem(lpPalBuffer, PaletteSize);

{Заполняем нулями BitmapInfo, PixelBuffer, и Palette}

 FillChar(lpBitmapInfo^, BitmapInfoSize, #0);

 FillChar(lpPixelBuffer^, BitmapSize, #0);

 if IsPaletteDevice then

  FillChar(lpPalBuffer^,PaletteSize, #0);

{Заполняем структуру BitmapInfo}

 lpBitmapInfo^.bmiHeader.biSize := sizeof(TBitmapInfoHeader);

 lpBitmapInfo^.bmiHeader.biWidth := 256;

 lpBitmapInfo^.bmiHeader.biHeight := 256;

 lpBitmapInfo^.bmiHeader.biPlanes := 1;

 lpBitmapInfo^.bmiHeader.biBitCount := 8;

 lpBitmapInfo^.bmiHeader.biCompression := BI_RGB;

 lpBitmapInfo^.bmiHeader.biSizeImage := BitmapSize;

 lpBitmapInfo^.bmiHeader.biXPelsPerMeter := 0;

 lpBitmapInfo^.bmiHeader.biYPelsPerMeter := 0;

 lpBitmapInfo^.bmiHeader.biClrUsed := 256;

 lpBitmapInfo^.bmiHeader.biClrImportant := 256;

{Заполняем таблицу цветов BitmapInfo оттенками серого: от чёрного до белого}

 for i := 0 to 255 do begin

  lpBitmapInfo^.bmiColors[i].rgbRed := i;

  lpBitmapInfo^.bmiColors[i].rgbGreen := i;

  lpBitmapInfo^.bmiColors[i].rgbBlue := i;

 end;