www.pudn.com > lianma.rar > intline.m, change:2004-12-16,size:1233b

```function [x, y] = intline(x1, x2, y1, y2)
%INTLINE Integer-coordinate line drawing algorithm.
%  [X, Y] = INTLINE(X1, X2, Y1, Y2) computes an
%  approximation to the line segment joining (X1, Y1) and
%  (X2, Y2) with integer coordinates.  X1, X2, Y1, and Y2
%  should be integers.  INTLINE is reversible; that is,
%  INTLINE(X1, X2, Y1, Y2) produces the same results as
%  FLIPUD(INTLINE(X2, X1, Y2, Y1)).

%   Copyright 1993-2002 The MathWorks, Inc.  Used with permission.
%   \$Revision: 1.4 \$  \$Date: 2003/11/21 14:38:20 \$

dx = abs(x2 - x1);
dy = abs(y2 - y1);

% Check for degenerate case.
if ((dx == 0) & (dy == 0))
x = x1;
y = y1;
return;
end

flip = 0;
if (dx >= dy)
if (x1 > x2)
% Always "draw" from left to right.
t = x1; x1 = x2; x2 = t;
t = y1; y1 = y2; y2 = t;
flip = 1;
end
m = (y2 - y1)/(x2 - x1);
x = (x1:x2).';
y = round(y1 + m*(x - x1));
else
if (y1 > y2)
% Always "draw" from bottom to top.
t = x1; x1 = x2; x2 = t;
t = y1; y1 = y2; y2 = t;
flip = 1;
end
m = (x2 - x1)/(y2 - y1);
y = (y1:y2).';
x = round(x1 + m*(y - y1));
end

if (flip)
x = flipud(x);
y = flipud(y);
end
```