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* fixed getting data from non memory devicecontexts

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git-svn-id: trunk@11994 -
This commit is contained in:
marc 2007-09-10 22:30:15 +00:00
parent 685d6ecf01
commit 577cc95c71
1 changed files with 75 additions and 5 deletions
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80
lcl/interfaces/win32/win32lclintf.inc
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@ -586,13 +586,83 @@ end;
------------------------------------------------------------------------------}
function TWin32WidgetSet.RawImage_FromDevice(out ARawImage: TRawImage; ADC: HDC; const ARect: TRect): Boolean;
const
FILL_PIXEL: array[0..3] of Byte = ($00, $00, $00, $FF);
var
bmp: HBITMAP;
Info: record
Header: Windows.TBitmapInfoHeader;
Colors: array[0..1] of Cardinal; // reserve extra color for mono bitmaps
end;
BitsPtr: Pointer;
copyDC, fillDC: HDC;
bmp, copyOld, fillOld, copyBmp, fillBmp: HBITMAP;
w, h: Integer;
begin
bmp := Windows.GetCurrentObject(ADC, OBJ_BITMAP);
if bmp = 0
then Result := False
else Result := RawImage_FromBitmap(ARawImage, bmp, 0, ARect);
if Windows.GetObjectType(ADC) = OBJ_MEMDC
then begin
// we can use bitmap directly
bmp := Windows.GetCurrentObject(ADC, OBJ_BITMAP);
copyBmp := 0;
end
else begin
// we need to copy the image
// use a dibsection, so we can easily retrieve the bytes
copyDC := Windows.CreateCompatibleDC(ADC);
w := Windows.GetDeviceCaps(ADC, DESKTOPHORZRES);
if w = 0
then w := Windows.GetDeviceCaps(ADC, HORZRES);
h := Windows.GetDeviceCaps(ADC, DESKTOPVERTRES);
if h = 0
then h := Windows.GetDeviceCaps(ADC, VERTRES);
FillChar(Info, SizeOf(Info), 0);
Info.Header.biSize := SizeOf(Info.Header);
Info.Header.biWidth := w;
Info.Header.biHeight := -h;
Info.Header.biPlanes := 1;
Info.Header.biBitCount := Windows.GetDeviceCaps(ADC, BITSPIXEL);
Info.Header.biCompression := BI_RGB;
copyBmp := Windows.CreateDIBSection(copyDC, Windows.PBitmapInfo(@Info)^, DIB_RGB_COLORS, BitsPtr, 0, 0);
copyOld := Windows.SelectObject(copyDC, copyBmp);
// prefill bitmap, to create an alpha channel in case of 32bpp bitmap
if Info.Header.biBitCount > 24
then begin
// using a stretchblt is faster than filling the memory ourselves,
// which is in its turn faster than using a 24bpp bitmap
fillBmp := Windows.CreateBitmap(1, 1, 1, 32, @FILL_PIXEL);
fillDC := Windows.CreateCompatibleDC(ADC);
fillOld := Windows.SelectObject(fillDC, fillBmp);
Windows.StretchBlt(copyDC, 0, 0, w, h, fillDC, 0, 0, 1, 1, SRCCOPY);
Windows.SelectObject(fillDC, fillOld);
Windows.DeleteDC(fillDC);
Windows.DeleteObject(fillBmp);
Windows.BitBlt(copyDC, 0, 0, w, h, ADC, 0, 0, SRCPAINT);
end
else begin
// copy image
Windows.BitBlt(copyDC, 0, 0, w, h, ADC, 0, 0, SRCCOPY);
end;
Windows.SelectObject(copyDC, copyOld);
Windows.DeleteDC(copyDC);
bmp := copyBmp;
end;
if bmp = 0 then Exit(False);
Result := RawImage_FromBitmap(ARawImage, bmp, 0, ARect);
if copyBmp <> 0
then Windows.DeleteObject(copyBmp);
end;
procedure TWin32WidgetSet.RemoveEventHandler(var AHandler: PEventHandler);