Dumb question about Desktop pixels

[John Montenigro]

Among other things, one goal is to test the color of a particular pixel of the DESKTOP.

I can see how to apply the GRAPHICS statements in GRAPHICS windows that I create in my program and it's cool stuff! However, I haven't been able to tell if there's a way to apply them to the DESKTOP. Is it possible?

I've read everything in the Help about GRAPHICS, I've examined the Sample programs, I've searched the Forums, but I have not come close to figuring this one out.

I'm currently trying to overlay the Desktop with my own graphics window, which will have transparent foreground and background pixels, and read the Desktop pixel color through that... I have no idea if that will work, but at least I'm trying!

[Chris Holbrook]

see getpixel in the Win32 Programmers Reference or MSDN.

[Michael Mattias]

Window style WS_EX_TRANSPARENT?

(Don't know if that's allowed on a GRAPHIC WINDOW NEW but let me look at help...nah, doesn't look like you get a style... Maybe GRAPHIC CLEAR with color %NULL will be "transparent?")

Then again, there's always CreateWindowEx...

MCM

[John Montenigro]

...still reading, testing, etc...

...while trying to get the suggestions to work, I'm trying to figure out whether or not the Desktop meets the criteria of being a "device context"... While it makes sense it would have a Bitmap and a Region, I have a hunch it might not have a Brush, Font, or Pen...

OK, off to do more reading! ...A guy could lose a whole football game trying to read the MSDN!

[Paul Dixon]

John,
if this what you're after?
Paul.

#INCLUDE "win32api.inc"

FUNCTION PBMAIN () AS LONG

DO
    DeskTopDC&=GetDc(0)  'get the DC of the desktop
   
    FOR x& = 1 TO 100
        FOR y& = 1 TO 100
            PixelColour&= getpixel(DeskTopDC&,x&,y&)   'find the colour of the pixel at position x,y
            setpixel(DeskTopDC&,100+x&,100+y&,PixelColour&) 'copy that pixel to somewhere else on the desktop
        NEXT
        
    NEXT

    ReleaseDC(0,DeskTopDC&)

    SLEEP 1000
LOOP UNTIL INSTAT

       
WAITKEY$

END FUNCTION

[John Montenigro]

Indeed it is, and a lot more! Thank you!

I was getting closer, but still had a long way to go. I had started out mistakenly giving getpixel a handle and not a device context handle. Further reading got me tinkering with GetDC, but I had gotten sidetracked into trying to see if GetObjectType was needed...

I expected to see the copied area remain visible on the desktop, but it vanished after I cycled through open windows and closed them...

I have SOOooooo much more to learn about this.

Meanwhile, I'm good to go. This was a BIG help in my first venture into the world of GRAPHICS.