ios - 拖动通过 SKPhysicsJoints 连接的 Sprite 的最佳方式？

Question

我在移动通过 SKPhysicsJoint 连接的 Sprite 时遇到问题。我有一个如下所示的 touchesMoved 方法:

- (void)touchesMoved:(NSSet *)touches withEvent:(UIEvent *)event {
    UITouch *touch = [touches anyObject];
    CGPoint positionInScene = [touch locationInNode:self];
    CGPoint previousPosition = [touch previousLocationInNode:self];
    CGPoint translation = CGPointMake(positionInScene.x - previousPosition.x, positionInScene.y - previousPosition.y);
    CGPoint newPosition = CGPointMake(_selectedNode.position.x + translation.x, _selectedNode.position.y + translation.y);
    [_selectedNode runAction:[SKAction moveTo:newPosition duration:0]];
}

它有点管用，但如果我将重力设置得非常低，它似乎只能将 Sprite 移动到它应该移动的 25%，然后如果我将重力设置为默认。我很困惑，可能有很多事情，但我在想也许我只需要设置速度或其他东西，但如果是这样，什么是合适的设置？

Answer 1

这应该可以解决问题，我还建议您在抓取 Sprite 时关闭物理效果，并在您释放时再次打开。

- (void)touchesMoved:(NSSet *)touches withEvent:(UIEvent *)event {

    UITouch *touch = [touches anyObject];
    CGPoint positionInScene = [touch locationInNode:self];
    CGPoint previousPosition = [touch previousLocationInNode:self];
    CGPoint translation = CGPointMake(positionInScene.x - previousPosition.x, positionInScene.y - previousPosition.y);
    //_selectedNode.physicsBody.dynamic = NO;
    [_selectedNode setPosition:CGPointMake(_selectedNode.position.x + translation.x, _selectedNode.position.y + translation.y)];
}

如果你想再次开启物理学

- (void) touchesEnded:(NSSet *)touches withEvent:(UIEvent *)event
{
    _selectedNode.physicsBody.dynamic = YES;
}