代码如下:
function [x, y] = Cooline(x1, x2, y1, y2)
%CooLINE Integer-coordinate line drawing algorithm.
% [X, Y] = CooLINE(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
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
end