!****************************************************************
!*                                                              *
!*      CORREL :    Correlate two IFF images as a scattergram   *
!*                                                              *
!*                  Version 1.1    2 Nov 1987                   *
!*                                                              *
!****************************************************************

%include "inc:util.imp"
%include "iffinc.imp"
%include "level1:graphinc.imp"

!J. Butler Jan 87

!Trivial IFF utilities demo - takes nominated files and correlates them
%begin
%string (255) in1, in2
%record (iffhdr fm) iffhdr1,iffhdr2
%owninteger a1,a2,i,k,rc
%constinteger marg=16

clear
printline("parameters?") %andstop %unless cli param -> in1.(",").in2
a1=0
rc = iff readin(in1, iffhdr1, a1)
printline("IFF connect: ".iff error(rc)) %and %stop %if rc#0
iff show header(iffhdr1, 1)  ;!display it

a2=0
rc = iff readin(in2, iffhdr2, a2)
printline("IFF connect: ".iff error(rc)) %and %stop %if rc#0
iff show header(iffhdr2, 1)

printline("Files not same size") %and %c
%stop %unless iffhdr1_ht=iffhdr2_ht %and iffhdr1_wid=iffhdr2_wid

newline
printline("X=First file colour values, Y=second file")

colour(yellow)
line(marg,marg, 511+marg,511+marg)
colour(red)
hline(0,511,marg)
vline(marg,0,511)
colour(white)

%for i=0,1,iffhdr1_wid*iffhdr1_ht-1 %cycle
   plot(byteinteger(a1+i)<<1+marg, byteinteger(a2+i)<<1+marg)
%repeat

heapput(a1)
heapput(a2)
%endofprogram