Sorry, the last sentences are wrong, so I will correct them.
What I found when I read uniscribe-factor is that a bitmap is created with the
device context
given by with-memory-dc. However, if you simply use that dc, the bitmap has a
black background.
My guess is that you won't be able to create an image of a string with a
transparent background
unless you transfer the original window bitmap to the device context created by
with-memory-dc.
--
KUSUMOTO Norio
> 2019/05/28 14:36、KUSUMOTO Norio <kusum...@na.rim.or.jp> のメール：
>
> Hello all,
>
> I've been researching for a while about Windows Factor's inability to
> correctly render texts on
> transparent backgrounds. I haven't solved the problem yet, but I've just come
> to an idea.
> I'd be happy to hear your opinions on that.
>
> For example, labels for button widgets are tentatively drawn with gray
> background text because
> they cannot draw labels with a transparent background. I disabled this
> behavior and tried to make
> transparent drawing work correctly, but only on a black background. I kept
> trying to figure
> out what was behind the black background, but I couldn't find the widget.
>
> That's why I came up with the idea that Uniscribe works to make the
> background transparent,
> but where the characters are written is black. At first it seemed like a
> silly idea, but I wrote
> the code to confirm it.
>
>
> USING: accessors alien.c-types alien.data colors images.viewer
> io io.encodings.string io.encodings.utf16n io.styles kernel
> literals math sequences ui ui.commands ui.gadgets
> ui.gadgets.borders ui.gadgets.panes ui.gadgets.tracks
> ui.gestures windows.gdi32 windows.offscreen windows.ole32
> windows.types windows.usp10 locals fonts windows.fonts
> windows.errors ;
> IN: hello-uniscribe
>
>
> ! NOTE: The following declaration is required in gdi32.factor
> !
> ! FUNCTION: int SetBkMode ( HDC hdc, int iBkMode )
>
> TUPLE: hello-gadget < track ;
>
> : <hello-gadget> ( -- gadget )
> horizontal hello-gadget new-track
> [
> { { font-size 24 } } [
> "Hello" print
> "Grüß dich" print
> "здравствуйте" print
> "こんにちは" print
> "안녕하세요" print
> "שָׁלוֹם " print
> ] with-style
> ] make-pane { 10 10 } <border>
> f track-add ;
>
> :: com-screen-shot ( gadget -- )
> [ :> dc
> gadget dim>> dc [ ] make-bitmap-image image-window
> ] with-memory-dc ;
>
> CONSTANT: ssa-dwFlags flags{ SSA_GLYPHS SSA_FALLBACK SSA_TAB }
>
> :: (com-screen-shot-with-text) ( dim bkMode uOptions -- )
> [ :> dc
> dim dc [
> dc sans-serif-font cache-font SelectObject win32-error=0/f
> dc T{ rgba f 0.0 0.0 1.0 0.0 } color>RGB SetBkColor drop
> dc T{ rgba f 1.0 1.0 1.0 1.0 } color>RGB SetTextColor drop
> dc bkMode SetBkMode drop
>
> dc
> "Hello!"
> [ utf16n encode ] ! pString
> [ length ] bi ! cString
> dup 1.5 * 16 + >integer ! cGlyphs -- MSDN says this is "recommended
> size"
> -1 ! iCharset -- Unicode
> ssa-dwFlags
> 0 ! iReqWidth
> f ! psControl
> f ! psState
> f ! piDx
> f ! pTabdef
> f ! pbInClass
> f void* <ref> ! pssa
> [ ScriptStringAnalyse ] keep
> [ check-ole32-error ] [ |ScriptStringFree void* deref ] bi*
>
> 0 ! iX
> 0 ! iY
> uOptions
> { 0 0 } dim <RECT>
> 0 ! iMinSel
> 0 ! iMaxSel
> FALSE ! fDisabled
> ScriptStringOut check-ole32-error
> ] make-bitmap-image image-window
> ] with-memory-dc ;
>
> : com-screen-shot-with-text-opaque ( gadget -- )
> dim>> OPAQUE ETO_OPAQUE (com-screen-shot-with-text) ;
>
> : com-screen-shot-with-text-transparent-1 ( gadget -- )
> dim>> OPAQUE 0 (com-screen-shot-with-text) ;
>
> : com-screen-shot-with-text-transparent-2 ( gadget -- )
> dim>> TRANSPARENT ETO_OPAQUE (com-screen-shot-with-text) ;
>
> : com-screen-shot-with-text-transparent-3 ( gadget -- )
> dim>> TRANSPARENT 0 (com-screen-shot-with-text) ;
>
> hello-gadget "gestures" f {
> { T{ key-down { sym "1" } } com-screen-shot }
> { T{ key-down { sym "2" } } com-screen-shot-with-text-opaque }
> { T{ key-down { sym "3" } } com-screen-shot-with-text-transparent-1 }
> { T{ key-down { sym "4" } } com-screen-shot-with-text-transparent-2 }
> { T{ key-down { sym "5" } } com-screen-shot-with-text-transparent-3 }
> } define-command-map
>
> MAIN-WINDOW: hello-uniscribe { { title "გამარჯობა, uniscribe" } }
> <hello-gadget> >>gadgets ;
>
>
> My understanding from reading Uniscribe.factor is that it renders characters
> in the device context
> given by with-memory-dc. However, if you create a bitmap from that dc, its
> background is black,
> regardless of the drawing on the current window.
>
> My guess is that you won't be able to create an image of a string with a
> transparent background
> unless you transfer the original window bitmap to the device context created
> by with-memory-dc.
>
> --
> KUSUMOTO Norio
>
>
>
>
>
>
>
> _______________________________________________
> Factor-talk mailing list
> Factor-talk@lists.sourceforge.net
> https://lists.sourceforge.net/lists/listinfo/factor-talk
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