现在说一下cocos2d的手势识别的代码，其主要策略就是两点，记录接触点的起始位置和末尾位置，通过根据这两个点的位置计算来确定是左移、右移、下滑、点击四种手势

bool Teris::ccTouchBegan(CCTouch*touch,CCEvent*event) {
	if (containsTouchLocation(touch)) {
		CCPoint touchPoint = convertTouchToNodeSpace(touch);
		firstX = touchPoint.x;
		firstY = touchPoint.y;
		is_control = true;
		return true;
	} else {
		is_control = false;
	}
}

void Teris::ccTouchEnded(CCTouch*touch,CCEvent*event) {
	if (is_control) {
		CCPoint touchPoint = convertTouchToNodeSpace(touch);
		endX = firstX - touchPoint.x;
		endY = firstY - touchPoint.y;
		if (endX * endX + endY * endY < 2) {
			turn_();
			return;
		}
		if (abs(endX) > abs(endY)) {
			if (endX + 5 > 0) {
				move_left();
			} else {
				move_right();
			}
		} else {
			if (endY + 5 > 0) {
				move_down();
			}
		}
	}
}