include <imhdr.h>

procedure select_obj(in,cx,cy)
# Allows the user to select a location of the display.
# This procedure either computed the centroid of a selected region,
# or it uses the value of a single point.
pointer in
int cx,cy
real wx1, wx2, wy1, wy2, temp
int wcs, key
char strval[SZ_LINE]
int nx, ny, xp, yp
pointer imgs2r()
int halfwidth
int junk, clgcur()

begin
        call printf("PLEASE SELECT AN OBJECT. \n")
        call printf("Select first corner, press the x key (s for single point)\n")
        junk = clgcur ("imcur",wx1,wy1,wcs,key,strval,SZ_LINE)

        if(key!='s') {
                call printf("Select second corner, press the x key\n")
                junk = clgcur ("imcur",wx2,wy2,wcs,key,strval,SZ_LINE)

                if(wx2<wx1) {
                        temp=wx1
                        wx1=wx2
                        wx2=temp
                }
                if(wy2<wy1) {
                        temp=wy1
                        wy1=wy2
                        wy2=temp
                }
        }
        else {
                wx2 = wx1
                wy2 = wy1
        }
        halfwidth = 10 


        nx = nint(wx2 - wx1 + 1)
        ny = nint(wy2 - wy1 + 1)

        if(nx<2 || ny <2) {
        # Discard window
                halfwidth=0     
        #Fix range to fit inside the image
                wx1 = max (wx1 - halfwidth, 1.)
                wx2 = min (wx2 + halfwidth, real(IM_LEN(in,1)))
                wy1 = max (wy1 - halfwidth, 1.) 
                wy2 = min (wy2 + halfwidth, real(IM_LEN(in,2)))
                nx = nint(wx2 - wx1 + 1)
                ny = nint(wy2 - wy1 + 1)
        }
        if (halfwidth != 0) {
                call printf("Computing centroid\n")
                call find_centroid (Memr[imgs2r(in,nint(wx1),nint(wx2),nint(wy1),nint(wy2))], nx, ny, xp, yp)
                cx = nint(wx1) + xp - 1
                cy = nint(wy1) + yp - 1
                call printf("Centroid=(%d,%d)\n")
                        call pargi(cx)
                        call pargi(cy)
        }
        else {
                cx = wx1
                cy = wy1
        }
end