is there a way to draw on the desktop with no window,and transparency

Community Forums/General Help/is there a way to draw on the desktop with no window,and transparency

Mainsworthy

(Posted 2017) [#1]

is there a way to draw on the desktop with no window,and transparency? Ive been looking for some way, and I'm stumped, so I throw it to you guys who know more than most about programing.

grable

(Posted 2017) [#2]

You would have to go the GDI route for that. Using GetDC(GetDesktopWindow()) to get a drawing context and go from there.
Whatever you draw will get overwritten the moment the window is updated though, so either use a thread (bad) or hook the window procedure and do the drawing when requested (better).
Using GDI to draw isnt exactly fun, and transparency isnt supported by most calls, but there is AlphaBlend which should work.

EDIT: Forgot to add, the above is for Windows. Dunno about linux.

Matty

(Posted 2017) [#3]

Yes in blitzplus I believe there is. You can capture the desktopbuffer and draw to that but it will be a static screenshot of the current desktop.

Mainsworthy

(Posted 2017) [#4]

thanks guys, I'm on the right track atleast.

Mainsworthy

(Posted 2017) [#5]

https://numbergamer8.itch.io/template-app-for-boardgames-on-a-pc

grable, I put you in the credits, because I used some code from the code archive of yours, I did lots to it, but you gave me the start I needed thanks

. its a boardgame tool, it allows you to measure on a tv or monitor , things you need to know in boardgames an miniatures. it pastes a template on the screen that you can rotate of any shape, so imagine Warhammer where you need to know who was in the blast area, you would use a circle, what makes this worth doing is it works with vassal.

grable

(Posted 2017) [#6]

Im glad you figured it out, layered windows is much easier to work with so i can understand why you chose it instead of drawing directly on the desktop.

I actually tried myself with overriding the windowproc but i keep forgetting blitz is 32bit while windows components are 64bit, bad match hehe. No matter, i probably need to DLL inject some code anyway which makes this more than just toying around...

grable, I put you in the credits, because I used some code from the code archive of yours, I did lots to it, but you gave me the start I needed thanks

Never been in any ones credits before, thanks :D

Mainsworthy

(Posted 2017) [#7]

I found info that you had to do a DLL for windows , and when windows updates etc.. its nogood anymore, I guess windows don't want us messing, also people that had done it were saying you have junk added, so I relied on your code a a base line, and I'm very happy, credit where credit is due thankyou

grable

(Posted 2017) [#8]

May i ask what junk they were talking about? If you mean [MaxGUI/Win32]: Transparent Window Gadgets, it looks pretty clean to me, for what it was designed for anyway (MaxGUI).

Mainsworthy

(Posted 2017) [#9]

no not this stuff, they said when they draw to the windows desktop they got junk added, They never used MaxGUI I don't think etc.. it was a generals comments about borderless windowless transparent drawing direct to desktop. I'm not as wise as you , and Ive ony been at this a short time, so I know you know better than me

grable

(Posted 2017) [#10]

Ah my mistake, no worries :)

Yeah, drawing to the desktop does cause "junk" so to say. Without also having control over the painting process, two entities end up fighting over when to draw what, causing artifacts.

Dan	(Posted 2017) [#11]

Autoit Script can draw transparent windows:

Dragable transparent gif image, in autoIt

Maybe someone can write something similar, for Blitz +,3d,max ?

p.s. the example from the link is trying to download a gif file, from a server, but its allready deleted.

here is the AutoIt code which loads local gif file, called Transparent_gif.gif


;  AutoIT 3 SCRIPT

;;----------------- Constants and Options

Global Const $GUI_EVENT_CLOSE = -3
Global Const $GUI_EVENT_PRIMARYUP = -8
Global Const $GUI_EVENT_MOUSEMOVE = -11

Global Const $WS_POPUP = 0x80000000
Global Const $WS_EX_LAYERED = 0x00080000
Global Const $WS_EX_MDICHILD = 0x00000040
Global Const $WS_EX_TOPMOST = 0x00000008

Opt("GUICloseOnESC", 1)
Opt("TrayIconHide", 1)

;;----------------- What is...
Dim $guiWinTitle = "TranaparentGUI"
Dim $Version = "v0700611a"

;;----------------- from:  Misc.au3 - _Singleton for $guiWinTitle
DllCall("kernel32.dll", "int", "CreateMutex", "int", 0, "long", 1, "str", $guiWinTitle)
Dim $lastError = DllCall("kernel32.dll", "int", "GetLastError")
If $lastError[0] == 183 Then
    MsgBox(266288, $guiWinTitle & " - Error", "...already running. Aborting.  ", 8)
    _Exit()
EndIf

;;----------------- Exit hotkey
HotKeySet("^+x", "_Exit")

;;----------------- Tramsparent gif/GUI core code
;InetGet("http://www.GypsyTrader.com/avatars/avatar_t80x80.gif", @ScriptDir & "\t80x80.gif")

Local $width = 80, $height = 80
Local $mainGUI = GUICreate($guiWinTitle, $width, $height, _
        (@DesktopWidth - $width) / 2, (@DesktopHeight - $height) / 2, _
        $WS_POPUP, $WS_EX_LAYERED + $WS_EX_MDICHILD + $WS_EX_TOPMOST, _
        WinGetHandle(WinGetTitle("Program Manager")))

Local $image = GUICtrlCreatePic("Transparent_gif.gif", 0, 0, $width, $height)
;Local $image = GUICtrlCreatePic("t80x80.gif", 0, 0, $width, $height)
;FileDelete( @ScriptDir & "\t80x80.gif" )
GUISetState(@SW_SHOW)

;;----------------- Variables for loop and dragging
Local $msg, $mouseOffsetPos, $dragging = $image

While 1
    $msg = GUIGetMsg()
    Select
        Case $msg = $GUI_EVENT_CLOSE
            _Exit()

        Case $msg = $GUI_EVENT_PRIMARYUP
            If $dragging Then $dragging = $image

        Case $msg = $image
            If $dragging <> $GUI_EVENT_MOUSEMOVE Then
                $dragging =  $GUI_EVENT_MOUSEMOVE
                Opt("MouseCoordMode", 0)
                $mouseOffsetPos = MouseGetPos()
                Opt("MouseCoordMode", 1)
            EndIf

        Case $msg = $dragging
            _BoundedDrag($mainGUI)

   EndSelect
WEnd

_Exit();; unreachable

;;----------------- Support functions

Func _BoundedDrag($win, $top=0, $left=0, $bottom=@DesktopHeight, $right=@DesktopWidth)
    Local $mousePos = MouseGetPos()
    Local $windowPos = WinGetPos($win)
    Local $x, $y
    If $mousePos[0] - $mouseOffsetPos[0] < $left Then
        $x = $left
    ElseIf $windowPos[2] - $mouseOffsetPos[0] + $mousePos[0] > $right Then
        $x = $right - $windowPos[2]
    Else
        $x = $mousePos[0] - $mouseOffsetPos[0]
    EndIf
    If $mousePos[1] - $mouseOffsetPos[1] < $top Then
        $y = $top
    ElseIf $windowPos[3] - $mouseOffsetPos[1] + $mousePos[1] > $bottom Then
        $y = $bottom - $windowPos[3]
    Else
        $y = $mousePos[1] - $mouseOffsetPos[1]
    EndIf
    WinMove($win, "", $x, $y)
EndFunc  ;==>_BoundedDrag

Func _Exit()
    Exit
EndFunc  ;==>_Exit

Mainsworthy

(Posted 2017) [#12]

very interesting Dan, thanks for this info,

Mainsworthy

(Posted 2017) [#13]

Dan, I grabed autoit, its free :) and did a compile, the big script you have isn't nessasary

here is the one that seems to do same thing, but I think animated. just add a gify.gif size 100x100 in your scripts folder.

they don't rotate, but its definatly worth looking at, and there are plenty of scripts even rotating to trawl thrugh, also it draws on the desktop, good find

#include <GUIConstants.au3>

$src = "gify.gif"
$dest = @ScriptDir & "\gify.gif"
InetGet($src,$dest)

$width = 100
$height = 100
$gui = GUICreate("GUI Transparency", $width, $height, -1, -1, $WS_POPUP, $WS_EX_LAYERED)
$pic = GUICtrlCreatePic($dest, 0, 0, $width, $height,-1,$GUI_WS_EX_PARENTDRAG)
GUISetState(@SW_SHOW)
WinSetOnTop($gui, "",1)
While 1
$msg = GUIGetMsg()
If $msg = $GUI_EVENT_CLOSE Then ExitLoop
Wend

grable

(Posted 2017) [#14]

I dont know what that AutoIt script looks like, but im guessing it does something similar to the below?

This one was not fun to figure out :( Im usually quite fond of MSDN but this time it lied to me, making me waste a lot of time :(
It seems the optional arguments to UpdateLayeredWindow are NOT optional after all hrmph.

Note that this ONLY displays the image supplied, though all the controls are still there and clickable.
And if you need rotation, you could pre-rotate the image to a bunch of them and switch between them when neeeded.

Also, this technique is only worthwhile if you need per-pixel alpha, otherwise the standard layered windows are much easier.

(press ESC or click the center to exit cleanly)


SuperStrict

Import MaxGUI.Drivers

Local pix:TPixmap = LoadPixmap("coca.png").Convert(PF_BGRA8888)
If Not pix Then Throw "no image!"

Local window:TGadget = CreateWindow( "LayeredWindow", 0,0, 256,256, Null, WINDOW_HIDDEN)
Local panel:TGadget = CreatePanel( 0,0, window.Width,window.Height, window, PANEL_ACTIVE) ' for moving the window
Local button:TGadget = CreateButton( "X", 120,120, 16,16, panel) ' controls dont show up, but they are there!

Local hwnd:Int = window.Query(QUERY_HWND)
Local screendc:Int = GetDC(0)

Local bmp:Int = BitmapFromPixmap32(pix)
Local bmpdc:Int = CreateCompatibleDC(screendc)
SelectObject( bmpdc, bmp)

Local zero:Int[2]
Local pos:Int[2]
Local size:Int[] = [ pix.Width, pix.Height]

Local blend:TBlendFunction = New TBlendFunction
blend.BlendOp = AC_SRC_OVER
blend.SourceConstantAlpha = 255
blend.AlphaFormat = AC_SRC_ALPHA

SetWindowLayered hwnd, True
UpdateLayeredWindow hwnd, screendc, pos, size, bmpdc, pos, 0, blend, ULW_ALPHA
ShowWindow( hwnd, True)

Local ismoving:Int
Local movex:Int, movey:Int
Local angle:Int

CreateTimer(60)
While WaitEvent()
	Select CurrentEvent.ID
		Case EVENT_MOUSEDOWN
			Local p:Int[2]
			GetCursorPos(p)
			movex = p[0] - pos[0]
			movey = p[1] - pos[1]
			ismoving = True

		Case EVENT_MOUSEUP
			ismoving = False
			
		Case EVENT_KEYDOWN
			If CurrentEvent.Data = KEY_ESCAPE Then Exit
			
		Case EVENT_TIMERTICK
			If ismoving Then
				Local p:Int[2]
				GetCursorPos(p)
				
				pos[0] = p[0] - movex
				pos[1] = p[1] - movey
			EndIf
			
			angle :+ 1
			If angle >= 360 Then angle = 0
			Local s:Float = (3.0 + Sin(angle)) / 4.0
			Local alpha:Int = s * 255
			
			SetPixmapAlpha pix, alpha
			UpdateBitmapFromPixmap bmpdc, bmp, pix
			
			UpdateLayeredWindow hwnd, screendc, pos, size, bmpdc, zero, 0, blend, ULW_ALPHA
						
		Case EVENT_GADGETACTION
			If CurrentEvent.Source = button Then Exit
			
		Case EVENT_WINDOWCLOSE
			Exit			
	EndSelect
Wend
ReleaseDC( 0, screendc)
DeleteObject(bmp)
DeleteDC( bmpdc)
End

Function SetPixmapAlpha( pix:TPixmap, alpha:Byte, lowbound:Byte = 0)
	For Local y:Int = 0 Until pix.Height
		For Local x:Int = 0 Until pix.Width
			Local p:Byte Ptr = pix.PixelPtr(x,y)
			If p[3] > lowbound Then
				p[3] = alpha
			EndIf
		Next
	Next
EndFunction



Type TBlendFunction
	Field BlendOp:Byte
	Field BlendFlags:Byte
	Field SourceConstantAlpha:Byte
	Field AlphaFormat:Byte
EndType

Extern "Win32"
	Const GWL_EXSTYLE:Int = -20
	Const GWL_STYLE:Int = -16
	
	Const WS_EX_TRANSPARENT:Int = $20
	Const WS_EX_LAYERED:Int = $80000
	
	Const LWA_COLORKEY:Int = $1
	Const LWA_ALPHA:Int = $2
	
	Const ULW_ALPHA:Int = $2
	Const ULW_COLORKEY:Int = $1
	Const ULW_OPAQUE:Int = $4
	Const ULW_EX_NORESIZE:Int = $8
	
	Const AC_SRC_ALPHA:Int = $1
	Const AC_SRC_OVER:Int = $0
	
	Function GetWindowLong:Int( hwnd:Int, index:Int) = "GetWindowLongA@8"
	Function SetWindowLong:Int( hwnd:Int, index:Int, value:Int) = "SetWindowLongA@12"

	Function UpdateLayeredWindow:Int( hwnd:Int, destdc:Int, destpoint:Byte Ptr, size:Byte Ptr, srcdc:Int, srcpoint:Byte Ptr, ckey:Int, blendfunc:Byte Ptr, flags:Int)

	Function UpdateLayeredWindowIndirect:Int( hwnd:Int, info:Byte Ptr)
	Function ReleaseDC:Int( hwnd:Int, dc:Int)
	
	Function CreateBitmap:Int( width:Int, height:Int, planes:Int, bitsperpel:Int, pixels:Byte Ptr)
	Function GetCursorPos:Int( p:Byte Ptr)
EndExtern


Function SetWindowLayered( hwnd:Int, layered:Int, transparent:Int = False)
	Local style:Int = GetWindowLong( hwnd, GWL_EXSTYLE)
	If layered Then 
		style :| WS_EX_LAYERED
	Else
		style :& ~WS_EX_LAYERED
	EndIf
	If transparent  Then 
		style:| WS_EX_TRANSPARENT
	Else
		style :& ~WS_EX_TRANSPARENT
	EndIf
	SetWindowLong( hwnd, GWL_EXSTYLE, style)
EndFunction

Function BitmapFromPixmap32:Int( pix:TPixmap)
	pix = ConvertPixmap(pix,PF_BGRA8888)
	Return CreateBitmap( pix.Width, pix.Height, 1, 32, pix.Pixels)
EndFunction

Function UpdateBitmapFromPixmap( dc:Int, bmp:Int, pix:TPixmap)
	Local bi:BITMAPINFOHEADER = New BITMAPINFOHEADER
	bi.biSize = SizeOf(bi)
	bi.biWidth = pix.width
	bi.biHeight = -pix.height
	bi.biPlanes = 1
	bi.biBitCount = 32
	bi.biCompression = BI_RGB

	SetDIBits( dc, bmp, 0,pix.Height, pix.pixels, bi, DIB_RGB_COLORS)
EndFunction

And heres the image i used for testing: coca.png

EDIT: See Layered window per-pixel alpha + Max2D for a more advanced example.

Dan	(Posted 2017) [#15]

Iv just uploaded a Screen Mate/Desktop pets program on Emu.Zone

It uses GDI+ to display the Sprites on the screen, they are drag'able, with transparent background and self moving.

The Sourcecode is in AutoIt script, and is included in the download.

Maybe it can be usefull, as it shows how it is done in the function SetBitmap.