On Thu, 25 Jan 2007 09:44:59 -0700, alexander Serechenko Alexander =
<sk...@gm...> wrote:
> Is there any way to copy some transparent image over another?
> Only way I found is to use AlphaCopyToDC to some virtual DC, but i
> can't find any way to get Win32::GUI::DC not associated with any
> device.
> Is any one can help me?
Win32::GUI::DC::CreateCompatibleDC()
Creates a memory device context (DC) compatible with the specified devic=
e.
That's all the documentation there is. According to the source (DC.xs), =
it =
returns a Win32::GUI::DC object, not just a handle. Of course, if it is =
=
just a handle, it's easy enough to do:
my $dc =3D bless {
-handle =3D> Win32::GUI::CreateCompatibleDC(),
}, 'Win32::GUI::DC';
And according to Microsoft, calling it with no handle should give you a =
DC =
compatible with the current screen. Here's an excerpt:
The CreateCompatibleDC function creates a memory device context (DC) =
compatible with the specified device.
HDC CreateCompatibleDC(
HDC hdc // handle to DC
);
Parameters
hdc
[in] Handle to an existing DC. If this handle is NULL, the function =
creates a memory DC compatible with the application's current screen.
Return Values
If the function succeeds, the return value is the handle to a memory DC.=
If the function fails, the return value is NULL.
Remarks
A memory DC exists only in memory. When the memory DC is created, its =
display surface is exactly one monochrome pixel wide and one monochrome =
=
pixel high. Before an application can use a memory DC for drawing =
operations, it must select a bitmap of the correct width and height into=
=
the DC. To select a bitmap into a DC, use the CreateCompatibleBitmap =
function, specifying the height, width, and color organization required.=
When a memory DC is created, all attributes are set to normal default =
values. The memory DC can be used as a normal DC. You can set the =
attributes; obtain the current settings of its attributes; and select =
pens, brushes, and regions.
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