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* Make bitblt and stretchblt alpha aware. In case of an alpha source or destination our alpha aware stretchmaskblt is used to blit a dc. (fixes #11694)

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git-svn-id: trunk@15893 -
This commit is contained in:
marc 2008-07-27 17:13:03 +00:00
parent 277a9e21e0
commit e1b010411a
2 changed files with 25 additions and 4 deletions
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17
lcl/interfaces/win32/win32proc.pp
View File

@ -120,6 +120,8 @@ procedure FillRawImageDescription(const ABitmapInfo: Windows.TBitmap; out ADesc:
function GetBitmapOrder(AWinBmp: Windows.TBitmap; ABitmap: HBITMAP):TRawImageLineOrder;
function GetBitmapBytes(AWinBmp: Windows.TBitmap; ABitmap: HBITMAP; const ARect: TRect; ALineEnd: TRawImageLineEnd; ALineOrder: TRawImageLineOrder; out AData: Pointer; out ADataSize: PtrUInt): Boolean;
function IsAlphaBitmap(ABitmap: HBITMAP): Boolean;
function IsAlphaDC(ADC: HDC): Boolean;
procedure BlendRect(ADC: HDC; const ARect: TRect; Color: ColorRef);
function GetLastErrorText(AErrorCode: Cardinal): String;
@ -1545,6 +1547,21 @@ begin
FreeMem(SrcData);
end;
function IsAlphaBitmap(ABitmap: HBITMAP): Boolean;
var
Info: Windows.BITMAP;
begin
FillChar(Info, SizeOf(Info), 0);
Result := (GetObject(ABitmap, SizeOf(Info), @Info) <> 0)
and (Info.bmBitsPixel = 32);
end;
function IsAlphaDC(ADC: HDC): Boolean;
begin
Result := (GetObjectType(ADC) = OBJ_MEMDC)
and IsAlphaBitmap(GetCurrentObject(ADC, OBJ_BITMAP));
end;
procedure BlendRect(ADC: HDC; const ARect: TRect; Color: ColorRef);
var
bmp, oldBmp: HBitmap;

12
lcl/interfaces/win32/win32winapi.inc
View File

@ -100,7 +100,10 @@ end;
------------------------------------------------------------------------------}
function TWin32WidgetSet.BitBlt(DestDC: HDC; X, Y, Width, Height: Integer; SrcDC: HDC; XSrc, YSrc: Integer; Rop: DWORD): Boolean;
begin
Result := Boolean(Windows.BitBlt(DestDC, X, Y, Width, Height, SrcDC, XSrc, YSrc, Rop));
// use stretchmaskblt for alpha images, since that one is customized for alpha
if IsAlphaDC(DestDC) or IsAlphaDC(SrcDC)
then Result := StretchMaskBlt(DestDC, X, Y, Width, Height, SrcDC, XSrc, YSrc, Width, Height, 0, 0, 0, Rop)
else Result := Windows.BitBlt(DestDC, X, Y, Width, Height, SrcDC, XSrc, YSrc, Rop);
end;
{------------------------------------------------------------------------------
@ -3053,9 +3056,10 @@ end;
------------------------------------------------------------------------------}
function TWin32WidgetSet.StretchBlt(DestDC: HDC; X, Y, Width, Height: Integer; SrcDC: HDC; XSrc, YSrc, SrcWidth, SrcHeight: Integer; Rop: Cardinal): Boolean;
begin
Assert(True, Format('Trace:> [TWin32WidgetSet.StretchBlt] DestDC:0x%x; X:%d, Y:%d, Width:%d, Height:%d; SrcDC:0x%x; XSrc:%d, YSrc:%d, SrcWidth:%d, SrcHeight:%d; Rop:0x%x', [DestDC, X, Y, Width, Height, SrcDC, XSrc, YSrc, SrcWidth, SrcHeight, Rop]));
Result := Boolean(Windows.StretchBlt(DestDc, X, Y, Width, Height, SrcDC, XSrc, YSrc, SrcWidth, SrcHeight, Rop));
Assert(True, Format('Trace:< [TWin32WidgetSet.StretchBlt] DestDC:0x%x --> %s', [DestDC, BOOL_TEXT[Result]]));
// use stretchmaskblt for alpha images, since that one is customized for alpha
if IsAlphaDC(DestDC) or IsAlphaDC(SrcDC)
then Result := StretchMaskBlt(DestDC, X, Y, Width, Height, SrcDC, XSrc, YSrc, SrcWidth, SrcHeight, 0, 0, 0, Rop)
else Result := Windows.StretchBlt(DestDc, X, Y, Width, Height, SrcDC, XSrc, YSrc, SrcWidth, SrcHeight, Rop);
end;
{------------------------------------------------------------------------------