// 把贪吃蛇头部增加一格
head = (WormLink)worm.lastElement();
head.increaseLength();
// 如果没有吃到食物则尾部减少一格
if (!hasEaten) {
WormLink tail;
tail = (WormLink)worm.firstElement();
int tailX = tail.getX();
int tailY = tail.getY();
// 如果尾部块长度为0就删除
tail.decreaseLength();
if (tail.getLength() == 0) {
worm.removeElement(tail); }
// 尾部减少一格
g.setColor(WormPit.ERASE_COLOUR);
drawLink(g, tailX, tailY, tailX, tailY, 1);
} else {
// 如果吃到食物就不删除尾部
hasEaten = false; }
needUpdate = false;
// 确认是否在边界中
if (!WormPit.isInBounds(head.getEndX(), head.getEndY())) {
// 如果不在,就死了
throw new WormException("over the edge"); }
headX = (byte)head.getEndX();
headY = (byte)head.getEndY();
//贪吃蛇的头部增加一格
g.setColor(WormPit.DRAW_COLOUR);
drawLink(g, headX, headY, headX, headY, 1);
// 判断是否吃到自己
for (int i = 0; i < worm.size()-1; i++) {
sl = (WormLink)worm.elementAt(i);
if (sl.contains(headX, headY)) {
throw new WormException("you ate yourself"); } } |