OpenEuphoria

Re: Need a way to get an image of screen

• Posted by Tommy Carlier <tommy.carlier at pandora.be> Jan 04, 2004
• 387 views

> I Need a way to get an image of the screen.
> It can be returned in Euphoria bitmap format or a sequence of colors(in 
> seqence or atom form)
> It needs to be fast, getPixel() is way too slow.
> For example something like:
> ret=getScreen(int startX, int startY,int endX,int endY)

If you need to do it in Windows, you could try my Shibby-library 
( download it from http://users.pandora.be/tommycarlier/eu/shibby.zip ). 
It allows you to manipulate 32-bit images in memory (should be fast as 
hell). To use it, you must also have Win32Lib 0.55.0 or better (no 
problem, i think).

---> <code>

include shibby.ew

constant my_win = create(Window, "My Window", 0, Default, Default, 240, 
250, 0)
Shibby_DIB my_dib
my_dib = newDIB(width, height) -- create a Shibby-bitmap with the 
specified width and height
copyBlt( my_dib[SHB_DIB_HANDLE], 0, 0, my_win ) -- copies image of my_win 
to the bitmap
copyBlt( my_dib[SHB_DIB_HANDLE], 0, 0, Screen ) -- copies image of screen 
to the bitmap

---> </code>

To read the pixels, you can access the memory directly:
start_address = my_dib[SHB_MEMORY]
width = my_dib[SHB_WIDTH]
pixel_address = start_address + ( y * width + x ) * 4 -- each pixel is 4 
bytes
color = peek( {pixel_address, 4} ) -- color is now {blue, green, red, 
alpha} -- each component is between 0 and 255
color = {0, 0, 255, 0} -- no blue + no green + full red = red
poke( pixel_address, color )

To display the image back on the window/pixmap/screen:
DrawBitmap( my_win, my_dib[SHB_DIB_HANDLE], 0, 0 ) -- draw bitmap on 
window my_win at position (0, 0)

I hope this helps.

--

Tommy Carlier
tommy online: http://users.pandora.be/tommycarlier