是否存在类似于中点圆算法的中点椭圆绘图算法?
我在google上搜索了一些示例,但是我发现任何一个都不起作用或者是填充椭圆,而不是绘制。此外,中点圆圈算法的维基百科页面指的是椭圆版本的存在,但有一个谷歌似乎无法帮助解决的死链接。
感谢任何帮助。
答案 0 :(得分:6)
最终在这里找到答案:
http://geofhagopian.net/sablog/Slog-october/slog-10-25-05.htm
转载和调整后更普遍适用于......
function ellipsePlotPoints (xc,yc, x, y)
{
setPixel (xc + x, yc + y);
setPixel (xc - x, yc + y);
setPixel (xc + x, yc - y);
setPixel (xc - x, yc - y);
}
function ellipse(xc,yc, a, b)
{
var a2 = a * a;
var b2 = b * b;
var twoa2 = 2 * a2;
var twob2 = 2 * b2;
var p;
var x = 0;
var y = b;
var px = 0;
var py = twoa2 * y;
/* Plot the initial point in each quadrant. */
ellipsePlotPoints (xc,yc, x, y);
/* Region 1 */
p = Math.round (b2 - (a2 * b) + (0.25 * a2));
while (px < py) {
x++;
px += twob2;
if (p < 0)
p += b2 + px;
else {
y--;
py -= twoa2;
p += b2 + px - py;
}
ellipsePlotPoints (xc,yc, x, y);
}
/* Region 2 */
p = Math.round (b2 * (x+0.5) * (x+0.5) + a2 * (y-1) * (y-1) - a2 * b2);
while (y > 0) {
y--;
py -= twoa2;
if (p > 0)
p += a2 - py;
else {
x++;
px += twob2;
p += a2 - py + px;
}
ellipsePlotPoints (xc,yc, x, y);
}
}