GetPixelValue

GetPixelValue$ function returns pixel color as "r g b" string (useful for JB) too useful function not to put it here! (hint: you can load any BMP and pick it's colors) Taken off a Tips room in JB forum. code by uncleBen, 16-bit add-on by tsh73
 * Warning.** Because it saves pixel to file on disk, it's pretty slow - my tests shows about 500 pixels per second on 3GGz box. Just be aware of it.

code format="thinbasic" 'GetPixelValue$ returns a string with the RGB values of the pixel 'in coordinates x and y in window/graphicbox names handle$ (e.g, "#main.graph") function GetPixelValue$(x, y, handle$)

'Grab a 1*1 bitmap #handle$, "getbmp gpv "; x; " "; y; " "; 1; " "; 1

'Save in a bmp file bmpsave "gpv", "getpvaluetemp.bmp"

'Open the file for string input and get it's full contents open "getpvaluetemp.bmp" for input as #gpv s$ = input$(#gpv, lof(#gpv)) close #gpv

'Check if user's display is 32-bit, and read the red-green-blue values 'If display 16 bit, then colors are masked. So some last (3 for red, 2 for green, 3 for blue) bits always 0 'That means that you did not get 255 255 255 for white - (248 252 248) instead. You have to experiment 'otherwise function returns nothing (support for other display types could be added (?)) bpp = asc(mid$(s$, 29, 1)) select case bpp case 32 red = asc(mid$(s$, 69, 1)) green = asc(mid$(s$, 68, 1)) blue = asc(mid$(s$, 67, 1)) case 16 bytes = asc(mid$( s$, 67, 1)) + 256*asc(mid$( s$, 68, 1)) red = (bytes AND 63488) /256       '0xF800 green = (bytes AND 2016) / 32 * 4  '0x7E0 blue = (bytes AND 31) * 8          '0x1F end select

'concatenate the return value, delete temporary file and free memory GetPixelValue$ = str$(red)+" "+str$(green)+" "+str$(blue) kill "getpvaluetemp.bmp" unloadbmp "gpv" end function code