function setimage(newimg, pos, clip)
%SETIMAGE Set and display the global variable I.
%
%    SETIMAGE(NEWIMAGE, XYPOS, CLIP)
%
%    SETIMAGE copies the image NEWIMAGE to the global variable I
%    and redisplays the image. XYPOS specifies the X and Y position
%    to which the NEWIMAGE will be copied (Default pos=[1 1]).
%    The NEWIMAGE can be smaller than the current image. In this case, only
%    part of the image will be changed. If pos is outside the
%    image border, the NEWIMAGE will be cropped to fit inside the
%    borders.
%    If CLIP is 1 (Default), the Clipboard and the Undofun are set;
%    if it is 0, the Cliboard is not set.
%    ALWAYS USE THIS FUNCTION TO MODIFY I.
%
%    See also SHOWIMAGE, IMAGE, UNDO.

%
% Copyright (c) 1995 by Claudio Rivetti and Mark Young
% claudio@alice.uoregon.edu,    mark@alice.uoregon.edu
%


global I Undofun isModify

if nargin < 1
  error('Too few input arguments.');
end

if nargin==2
  clip=1;
end

if nargin==1
  pos=[1 1];
  clip=1;
end

f=watchon;

if clip
  setclipboard(I);
  Undofun='setimage(getclipboard,inf,0);setclipboard([]);';
end

if pos~=inf
  pos=round(pos);
  imgr=size(I,1);
  imgc=size(I,2);
  newimgr=size(newimg,1);
  newimgc=size(newimg,2);

  if pos(2)>imgr | pos(1)>imgc | (pos(2)+newimgr)<1 | (pos(1)+newimgc)<1
    return;
  end

  if pos(1)<1
    newimg=newimg(:,abs(pos(1))+1:newimgc);
    pos(1)=1;
    newimgc=size(newimg,2);
  end

  if pos(1)+newimgc > imgc
    newimg=newimg(:,1:imgc-pos(1)+1);
    newimgc=size(newimg,2);
  end

  if pos(2)+newimgr > imgr
    newimg=newimg(1:imgr-pos(2)+1, :);
    newimgr=size(newimg,1);
  end

  if pos(2)<1
    newimg=newimg(abs(pos(2))+1:newimgr, :);
    pos(2)=1;
    newimgr=size(newimg,2);
  end

  I(pos(2):pos(2)+newimgr-1,  pos(1):pos(1)+newimgc-1)=newimg;
else
  I=newimg;
end

showimage;
isModify=isModify+1;
watchoff(f);
return