如何通过触摸spriteKit来旋转图像/精灵？

Question

我试着用一根手指来旋转一个精灵。老实说，我不知道该怎么做，这是spriteKit的新鲜事。有什么想法吗？

Answer 1

这将使雪碧旋转到你使用动作触摸的地方。如果你想让它在拖动手指的时候旋转。您应该删除该操作并在touchesMoved:上进行计算。

-(void)didMoveToView:(SKView *)view {
    sprite = [SKSpriteNode spriteNodeWithImageNamed:@"Spaceship"];

    sprite.xScale = 0.5;
    sprite.yScale = 0.5;
    sprite.position = CGPointMake(self.frame.size.width / 2, self.frame.size.height/2);

    [self addChild:sprite];
}

-(void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event {
    for (UITouch *touch in touches) {
        CGPoint location = [touch locationInNode:self];


        float dY = sprite.position.y - location.y;
        float dX = sprite.position.x - location.x;
        float angle = atan2f(dY, dX) + 1.571f;
        [sprite runAction:[SKAction rotateToAngle:angle duration:0.5 shortestUnitArc:YES]];
        return;
    }
}

或者：(记住从touchesBegan:中删除代码)

- (void)touchesMoved:(NSSet *)touches withEvent:(UIEvent *)event{
    for (UITouch *touch in touches) {
        CGPoint location = [touch locationInNode:self];

        float dY = sprite.position.y - location.y;
        float dX = sprite.position.x - location.x;
        float angle = (atan2f(dY, dX)) + 1.571f;
        sprite.zRotation = angle;
    }
}