CCSprite遵循一系列CGPoints

Question

我正在使用Cocos2D开发一个线图绘制游戏,类似于Flight Control,Harbor Master和appstore中的其他人.

对于这个游戏,我需要一个CCSprite来跟随用户绘制的一条线.我根据我在和消息中得到的点存储了一系列CGPoint结构.我现在有一个问题,如何让我的精灵跟随他们.NSArraytouchesBegintouchesMoved

我有一个tick方法,以帧速率调用.在该tick方法中,基于精灵的速度和当前位置,我需要计算它的下一个位置.有没有标准的方法来实现这一目标？

我当前的方法是计算最后一个"参考点"和下一个参考点之间的线,并计算该线中的下一个点.我遇到的问题是精灵"转"(从一段线移动到另一段).

任何提示将不胜感激.

Answer 1

为什么要编写自己的tick方法？你为什么不使用内置CCMoveTo方法？

(void) gotoNextWayPoint {
    // You would need to code these functions:
    CGPoint point1 = [self popCurrentWayPoint];
    CGPoint point2 = [self getCurrentWayPoint];

    // Calculate distance from last way point to next way point
    CGFloat dx = point2.x - point1.x;
    CGFloat dy = point2.y - point1.y;
    float distance = sqrt( dx*dx + dy*dy );

    // Calculate angle of segment
    float angle = atan2(dy, dx);

    // Rotate sprite to angle of next segment
    // You could also do this as part of the sequence (or CCSpawn actually) below
    // gradually as it approaches the next way point, but you would need the
    // angle of the line between the next and next next way point
    [mySprite setRotation: angle];

    CCTime segmentDuration = distance/speed;

    // Animate this segment, and afterward, call this function again
    CCAction *myAction = [CCSequence actions: 
          [CCMoveTo actionWithDuration: segmentDuration position: nextWayPoint], 
          [CCCallFunc actionWithTarget: self selector: @selector(gotoNextWayPoint)],
          nil];

    [mySprite runAction: myAction];
}