uses Printers;
type
PPalEntriesArray = ^TPalEntriesArray; {for palette re-construction}
TPalEntriesArray = array[0..0] of TPaletteEntry;
procedure BltTBitmapAsDib(DestDc : hdc; {Handle of where to blt}
x : word; {Bit at x}
y : word; {Blt at y}
Width : word; {Width to stretch}
Height : word; {Height to stretch}
bm : TBitmap); {the TBitmap to Blt}
var
OriginalWidth :LongInt; {width of BM}
dc : hdc; {screen dc}
IsPaletteDevice : bool; {if the device uses palettes}
IsDestPaletteDevice : bool; {if the device uses palettes}
BitmapInfoSize : integer; {sizeof the bitmapinfoheader}
lpBitmapInfo : PBitmapInfo; {the bitmap info header}
hBm : hBitmap; {handle to the bitmap}
hPal : hPalette; {handle to the palette}
OldPal : hPalette; {temp palette}
hBits : THandle; {handle to the DIB bits}
pBits : pointer; {pointer to the DIB bits}
lPPalEntriesArray : PPalEntriesArray; {palette entry array}
NumPalEntries : integer; {number of palette entries}
i : integer; {looping variable}
begin
{If range checking is on - lets 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 acc[i] without error}
{$IFOPT R+}
{$DEFINE CKRANGE}
{$R-}
{$ENDIF}
{Save the original width of the bitmap}
OriginalWidth := bm.Width;
{Get the screen's dc to use since memory dc's are not reliable}
dc := GetDc(0);
{Are we a palette device?}
IsPaletteDevice :=
GetDeviceCaps(dc, RASTERCAPS) and RC_PALETTE = RC_PALETTE;
{Give back the screen dc}
dc := ReleaseDc(0, dc);
{Allocate the BitmapInfo structure}
if IsPaletteDevice then
BitmapInfoSize := sizeof(TBitmapInfo) + (sizeof(TRGBQUAD) * 255)
else
BitmapInfoSize := sizeof(TBitmapInfo);
GetMem(lpBitmapInfo, BitmapInfoSize);
{Zero out the BitmapInfo structure}
FillChar(lpBitmapInfo^, BitmapInfoSize, #0);
{Fill in the BitmapInfo structure}
lpBitmapInfo^.bmiHeader.biSize := sizeof(TBitmapInfoHeader);
lpBitmapInfo^.bmiHeader.biWidth := OriginalWidth;
lpBitmapInfo^.bmiHeader.biHeight := bm.Height;
lpBitmapInfo^.bmiHeader.biPlanes := 1;
if IsPaletteDevice then
lpBitmapInfo^.bmiHeader.biBitCount := 8
else
lpBitmapInfo^.bmiHeader.biBitCount := 24;
lpBitmapInfo^.bmiHeader.biCompression := BI_RGB;
lpBitmapInfo^.bmiHeader.biSizeImage :=
((lpBitmapInfo^.bmiHeader.biWidth *
longint(lpBitmapInfo^.bmiHeader.biBitCount)) div 8) *
lpBitmapInfo^.bmiHeader.biHeight;
lpBitmapInfo^.bmiHeader.biXPelsPerMeter := 0;
lpBitmapInfo^.bmiHeader.biYPelsPerMeter := 0;
if IsPaletteDevice then begin
lpBitmapInfo^.bmiHeader.biClrUsed := 256;
lpBitmapInfo^.bmiHeader.biClrImportant := 256;
end else begin
lpBitmapInfo^.bmiHeader.biClrUsed := 0;
lpBitmapInfo^.bmiHeader.biClrImportant := 0;
end;
{Take ownership of the bitmap handle and palette}
hBm := bm.ReleaseHandle;
hPal := bm.ReleasePalette;
{Get the screen's dc to use since memory dc's are not reliable}
dc := GetDc(0);
if IsPaletteDevice then begin
{If we are using a palette, it must be}
{selected into the dc during the conversion}
OldPal := SelectPalette(dc, hPal, TRUE);
{Realize the palette}
RealizePalette(dc);
end;
{Tell GetDiBits to fill in the rest of the bitmap info structure}
GetDiBits(dc,
hBm,
0,
lpBitmapInfo^.bmiHeader.biHeight,
nil,
TBitmapInfo(lpBitmapInfo^),
DIB_RGB_COLORS);
{Allocate memory for the Bits}
hBits := GlobalAlloc(GMEM_MOVEABLE,
lpBitmapInfo^.bmiHeader.biSizeImage);
pBits := GlobalLock(hBits);
{Get the bits}
GetDiBits(dc,
hBm,
0,
lpBitmapInfo^.bmiHeader.biHeight,
pBits,
TBitmapInfo(lpBitmapInfo^),
DIB_RGB_COLORS);
if IsPaletteDevice then begin
{Lets fix up the color table for buggy video drivers}
GetMem(lPPalEntriesArray, sizeof(TPaletteEntry) * 256);
{$IFDEF VER100}
NumPalEntries := GetPaletteEntries(hPal,
0,
256,
lPPalEntriesArray^);
{$ELSE}
NumPalEntries := GetSystemPaletteEntries(dc,
0,
256,
lPPalEntriesArray^);
{$ENDIF}
for i := 0 to (NumPalEntries - 1) do begin
lpBitmapInfo^.bmiColors[i].rgbRed :=
lPPalEntriesArray^[i].peRed;
lpBitmapInfo^.bmiColors[i].rgbGreen :=
lPPalEntriesArray^[i].peGreen;
lpBitmapInfo^.bmiColors[i].rgbBlue :=
lPPalEntriesArray^[i].peBlue;
end;
FreeMem(lPPalEntriesArray, sizeof(TPaletteEntry) * 256);
end;
if IsPaletteDevice then begin
{Select the old palette back in}
SelectPalette(dc, OldPal, TRUE);
{Realize the old palette}
RealizePalette(dc);
end;
{Give back the screen dc}
dc := ReleaseDc(0, dc);
{Is the Dest dc a palette device?}
IsDestPaletteDevice :=
GetDeviceCaps(DestDc, RASTERCAPS) and RC_PALETTE = RC_PALETTE;
if IsPaletteDevice then begin
{If we are using a palette, it must be}
{selected into the dc during the conversion}
OldPal := SelectPalette(DestDc, hPal, TRUE);
{Realize the palette}
RealizePalette(DestDc);
end;
{Do the blt}
StretchDiBits(DestDc,
x,
y,
Width,
Height,
0,
0,
OriginalWidth,
lpBitmapInfo^.bmiHeader.biHeight,
pBits,
lpBitmapInfo^,
DIB_RGB_COLORS,
SrcCopy);
if IsDestPaletteDevice then begin
{Select the old palette back in}
SelectPalette(DestDc, OldPal, TRUE);
{Realize the old palette}
RealizePalette(DestDc);
end;
{De-Allocate the Dib Bits}
GlobalUnLock(hBits);
GlobalFree(hBits);
{De-Allocate the BitmapInfo}
FreeMem(lpBitmapInfo, BitmapInfoSize);
{Set the ownership of the bimap handles back to the bitmap}
bm.Handle := hBm;
bm.Palette := hPal;
{Turn range checking back on if it was on when we started}
{$IFDEF CKRANGE}
{$UNDEF CKRANGE}
{$R+}
{$ENDIF}
end;
procedure TForm1.Button1Click(Sender: TObject);
begin
if PrintDialog1.Execute then begin
Printer.BeginDoc;
BltTBitmapAsDib(Printer.Canvas.Handle,
0,
0,
Image1.Picture.Bitmap.Width,
Image1.Picture.Bitmap.Height,
Image1.Picture.Bitmap);
Printer.EndDoc;
end;
end; |