Task snapshot (Text path)
snapshot (0, 0, 640, 480, path) @

Task snapshot (Int xul, Int yul, Int dx, Int dy, Text path)
//
// xul: x-coordinate of upper-left corner of the region to be captured
// xul: x-coordinate of upper-left corner of the region to be captured
// dx: horizontal size (in pixels) of the region to be captured
// dy: vertical size (in pixels) of the region to be captured
// path: path to the file onto which the image is to be stored
//
Int2 head[]={0, 0, 118, 40, 0, 0, 0, 0, 0, 1000, 1000, 0, 0}
Int r[]={0,  0,  0,  0,128,128,128,192,128,  0,  0,  0,255,255,255,255}
Int g[]={0,  0,128,128,  0,  0,128,192,128,  0,255,255,  0,  0,255,255}
Int b[]={0,128,  0,128,  0,128,  0,192,128,255,  0,255,  0,255,  0,255}
Int zz
size=8*((dx-1)/8+1)
head[0]=size
head[4]=dx
head[5]=dy
head[6]=4*65536L+1
command="write "+path
Open g (command)
Write binary g (66)
Write binary g (77)
Do k=0,12
   +zz_=(head_[k_])&0xff;
   Write binary g (zz)
   +zz_=(head_[k_]>>8)&0xff;
   Write binary g (zz)
   +zz_=(head_[k_]>>16)&0xff;
   Write binary g (zz)
   Write binary g (0)
Loop
Do k=0,15
   Write binary g (b[k])
   Write binary g (g[k])
   Write binary g (r[k])
   Write binary g (0)
Loop
Do y=dy-1,0
   Do x=0,size/2-1
      z=16*getpixel(xul+2*x,yul+y)+getpixel(xul+2*x+1,yul+y)
      Write binary g (z)
   Loop
Loop
Close g