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Paul, OpenGL has it as a fourth parameter besides three for RGB but would be nice to have an option for variable 0 to 1 drawing transparency for Salflibc graphics library to plot the graphs like this. Possible?
Thanks. I already have this on the wish list.
Dan,
Some years ago there was a post on transparency - I looked, but can't find it now. The original poster (my apologies to them for reposting their code) produced a routine:
logical function SetWindowOpacity(hWnd, alpha)
C ----------------------------------------------
! Set opacity level for a window (call after window creation) -
! automatically sets appropriate extended style and sets opacity
! from 0 (transparent) to 255 (no transparency).
use mswin
integer, parameter:: WS_EX_LAYERED = Z'00080000'
integer, parameter:: LWA_COLORKEY = Z'00000001'
integer, parameter:: LWA_ALPHA = Z'00000002'
STDCALL SetLayeredWindowAttributes 'SetLayeredWindowAttributes'
& (VAL, VAL, VAL, VAL) : LOGICAL*4
integer, intent(in):: hWnd
integer, intent(in):: alpha
integer:: attrib, i
! Get current window attributes to ensure WS_EX_LAYERED extended style is set
attrib = GetWindowLong(hWnd, GWL_EXSTYLE)
if (IAND(attrib,WS_EX_LAYERED) /= WS_EX_LAYERED) then
i = SetWindowLong(hWnd, GWL_EXSTYLE, IOR(attrib,WS_EX_LAYERED))
end if
! Set layered window alpha value
SetWindowOpacity = SetLayeredWindowAttributes
& (hWnd, 0, CORE1(LOC(alpha)), LWA_ALPHA)
end function SetWindowOpacity
I have been using this to make a borderless, no-caption initial splash screen gradually fade away (by changing the alpha value progressively in a %dl callback). It may be worth having a go to see if you can feed it to a %gr area, but whether it works only on a whole window or a single control, you would have to experiment.
Eddie
Thanks, Eddie, Well, making DRAW_LINE@ transparency based on this idea is beyond of my capabilities... As to the window transparency - that's definitely cool thing. In order for this trick has not been forgotten and more, have been used by the people spreading further greatness and Wow factor of CWP would be nice if we always end up with working flashy example placing everything into User Examples collection. If i had some time i'd do that
Quoted from PaulLaidler Thanks. I already have this on the wish list.
This one is quite easy to do. You just need a device context for the %gr graphics surface, to be able to create a GDI+ Graphics object.
Below is a example for the FTN95 callable ARGB color line drawing routine. For performance reasons calls to GdiplusStartup() and GdiplusShutdown() should probably be moved outside of the line drawing function.
##NOCONSOLE
##MAKEDLL
##USES 'gdiplus.lib'
type GdiplusStartupInput
int GdiplusVersion
int DebugEventCallback
int SuppressBackgroundThread
int SuppressExternalCodecs
endtype
@API GdiplusStartup(pointer pToken, pointer GdiplusStartupInput, int GdiplusStartupOutput),int
@API GdiplusShutdown(uint token)
@API GdipCreateFromHDC(uint hDC, pointer pGraphics),int
@API GdipDeleteGraphics(uint Graphics),int
@API GdipCreatePen1(uint argb,float w,int GpUnit, pointer pPen),int
@API GdipDeletePen(uint Pen),int
@API GdipDrawLineI(pointer pGraphics, pointer pPen, int x1, int y1, int x2, int y2),int
export ARGB
func ARGB(char a, char r, char g, char b),uint
union col
uint ARGB
char bytes[4]
endunion
col c
c.bytes[3] = a
c.bytes[2] = r
c.bytes[1] = g
c.bytes[0] = b
return c.ARGB
endf
export draw_line
func draw_line(uint hDC, int x1, int y1, int x2, int y2, float w, uint c)
int result
pointer pToken
pointer pGraphics
pointer pPen
GdiplusStartupInput gsi(1,NULL,FALSE,FALSE)
GdiplusStartup(&pToken,gsi,NULL)
result = GdipCreateFromHDC(hDC,&pGraphics)
result = GdipCreatePen1(c,w,2,&pPen)
result = GdipDrawLineI(pGraphics,pPen,x1,y1,x2,y2)
GdipDeletePen(pPen)
GdipDeleteGraphics(pGraphics)
GdiplusShutdown(pToken)
endf
Blue line drawn with different alpha values in a CW+ program
Jalih - as always - has the answer.
My suggestion was (a) that you draw your whole image in a window with a big %gr, find the handle of the window, and then apply transparency to the whole window. I know this works.
The second thing (which couldn't try because the hard drive on my laptop went bad while I was away from home) is to see if you can make a %gr area transparent with the routine - you get the handle of the %gr using %lc (maybe, as the handle you supply to %gr is a clearwin handle, not a windows one!)
Eddie
Thanks Jalih. That's very helpful.
Great, thanks all, Eddie, Jalih, Paul, hopefully we will see soon the new addition to the library!
Eddie,
The 'fade away' was a nice trick, thanks. I use it for numerous warnings now.
What the purpose was for declaring the transparency function as logical function? That is hell of uncommon, and even scary even just to try it, so I changed that to integer and here is the whole demo code
winapp
use clrwin
integer SetWindowOpacity
external SetWindowOpacity
ii=123456
i=winio@('%ww%sv%ca[Fade Away Example]&')
!..%sv is to close window by hovering mouse over window - earlier then the window will fade away by itself
i=winio@('%si# Some Parameter%rd&',ii)
i=winio@('%hw%lw',ihw, ilw)
do ialpha=255,0,-10
call temporary_yield@
iii = SetWindowOpacity(ihw, ialpha)
call sleep1@(0.2)
enddo
!.. This closes window at the end
ilw = 0
call window_update@(ilw)
end
!====================================================
integer function SetWindowOpacity(hWnd, alpha)
! ----------------------------------------------
! Set opacity level for a window (call after window creation) -
! automatically sets appropriate extended style and sets opacity
! from 0 (transparent) to 255 (no transparency).
use mswin
integer, parameter:: WS_EX_LAYERED = Z'00080000'
integer, parameter:: LWA_COLORKEY = Z'00000001'
integer, parameter:: LWA_ALPHA = Z'00000002'
STDCALL SetLayeredWindowAttributes 'SetLayeredWindowAttributes' &
& (VAL, VAL, VAL, VAL) : LOGICAL*4
integer, intent(in):: hWnd
integer, intent(in):: alpha
integer:: attrib, i
logical aaaaaa
! Get current window attributes to ensure WS_EX_LAYERED extended style is set
attrib = GetWindowLong(hWnd, GWL_EXSTYLE)
if (IAND(attrib,WS_EX_LAYERED) /= WS_EX_LAYERED) then
i = SetWindowLong(hWnd, GWL_EXSTYLE, IOR(attrib,WS_EX_LAYERED))
end if
! Set layered window alpha value
aaaaaa = SetLayeredWindowAttributes &
& (hWnd, 0, CORE1(LOC(alpha)), LWA_ALPHA)
SetWindowOpacity = 1
end function SetWindowOpacity
Dan,
I posted the code as I took it from the forum, so Logical is not my doing.
I also use [volatile] for some windows, then if you click anywhere else they go away.
Eddie