Question

我正在开发SpriteKit上的Scrabble游戏，并且一直停留在Zooming和Scrolling Scrabble Board上。首先让我解释游戏背后的工作：在我的GameScene上我有：

一个名为GameBoard Layer（名为NAME_GAME_BOARD_LAYER）的SKNode子类，包含以下子项：
```
A SKNode subclass for Scrabble Board named NAME_BOARD.
A SKNode subclass for Letters Tile Rack named NAME_RACK.
```
The Letters Tiles从Tile Rack中挑出并放在Scrabble Board上。

这里的问题是，我需要模仿UIScrollView可以实现的缩放和滚动，我认为不能在SKNode上添加。我需要模仿的功能是：

放大用户双击的精确位置
向左滚动（尝试PanGestures，以某种方式产生拖拽瓦片的问题）
将Zoomed SKNode保留在特定区域（与UIScrollView一样，将缩放的内容保留在scrollView边界内）

以下是我用于缩放的代码，使用UITapGestures：

在我的GameScene.m

中

- (void)didMoveToView:(SKView *)view {
UITapGestureRecognizer *tapGesture = [[UITapGestureRecognizer alloc] initWithTarget:self
                                                                             action:@selector(handleTapGesture:)];
tapGesture.numberOfTapsRequired = 2;
tapGesture.numberOfTouchesRequired = 1;
[self.scene.view addGestureRecognizer:tapGesture];
}

- (void)handleTapGesture:(UITapGestureRecognizer*)recognizer {
if ([self childNodeWithName:NAME_GAME_BOARD_LAYER]) {
    GameBoardLayer *gameBoardLayer = (GameBoardLayer*)[self childNodeWithName:NAME_GAME_BOARD_LAYER];

    SKNode *node = [Utils nodeAt:[recognizer locationInView:self.view]
                        withName:NAME_BOARD
                   inCurrentNode:gameBoardLayer];

    if ([node.name isEqualToString:NAME_BOARD]) {
        [gameBoardLayer handleDoubleTap:recognizer];
    }

}
}

在我的GameBoardLayer节点中：

- (void)handleDoubleTap:(UITapGestureRecognizer*)recognizer {
Board *board = (Board*)[self childNodeWithName:NAME_BOARD];
if (isBoardZoomed)
{
    [board runAction:[SKAction scaleTo:1.0f duration:0.25f]];
    isBoardZoomed = NO;
}
else
{
    isBoardZoomed = YES;
    [board runAction:[SKAction scaleTo:1.5f duration:0.25f]];
}
}

有人会指导我如何实现此功能？

谢谢大家。

Answer 1

这就是我要这样做的方式：

设定：

创建一个GameScene作为游戏的rootNode。（SKScene的孩子）
将BoardNode作为子节点添加到场景（SKNode的子节点）
将CameraNode作为子级添加到Board（SKNode的子级）
添加LetterNodes作为董事会成员

保持相机节点居中：

// GameScene.m
- (void) didSimulatePhysics
{
     [super didSimulatePhysics];
     [self centerOnNode:self.Board.Camera];
}

- (void) centerOnNode:(SKNode*)node
{
    CGPoint posInScene = [node.scene convertPoint:node.position fromNode:node.parent];
    node.parent.position = CGPointMake(node.parent.position.x - posInScene.x, node.parent.position.y - posInScene.y);
}

通过移动BoardNode来平移视图（记住防止平移越界）

// GameScene.m
- (void) handlePan:(UIPanGestureRecognizer *)pan
{
    if (pan.state == UIGestureRecognizerStateChanged)
    {
        [self.Board.Camera moveCamera:CGVectorMake([pan translationInView:pan.view].x, [pan translationInView:pan.view].y)];
    }
}

// CameraNode.m
- (void) moveCamera:(CGVector)direction
{
    self.direction = direction;
}

- (void) update:(CFTimeInterval)dt
{
    if (ABS(self.direction.dx) > 0 || ABS(self.direction.dy) > 0)
    {
        float dx = self.direction.dx - self.direction.dx/20;
        float dy = self.direction.dy - self.direction.dy/20;
        if (ABS(dx) < 1.0f && ABS(dy) < 1.0f)
        {
            dx = 0.0;
            dy = 0.0;
        }
        self.direction = CGVectorMake(dx, dy);
        self.Board.position = CGPointMake(self.position.x - self.direction.dx, self.position.y + self.direction.dy);
    }
}

// BoardNode.m
- (void) setPosition:(CGPoint)position
{
    CGRect bounds = CGRectMake(-boardSize.width/2, -boardSize.height/2, boardSize.width, boardSize.height);

    self.position = CGPointMake(
        MAX(bounds.origin.x, MIN(bounds.origin.x + bounds.size.width, position.x)),
        MAX(bounds.origin.y, MIN(bounds.origin.y + bounds.size.height, position.y)));
}

通过设置GameScene的大小来缩放：

// GameScene.m
- (void) didMoveToView:(SKView*)view
{
    self.scaleMode = SKSceneScaleModeAspectFill;
}

- (void) handlePinch:(UIPinchGestureRecognizer *)pinch
{
    switch (pinch.state)
    {
        case UIGestureRecognizerStateBegan:
        {
            self.origPoint = [self GetGesture:pinch LocationInNode:self.Board];
            self.lastScale = pinch.scale;
        } break;

        case UIGestureRecognizerStateChanged:
        {
            CGPoint pinchPoint = [self GetGesture:pinch LocationInNode:self.Board];
            float scale = 1 - (self.lastScale - pinch.scale);

            float newWidth = MAX(kMinSceneWidth, MIN(kMaxSceneWidth, self.size.width / scale));
            float newHeight = MAX(kMinSceneHeight, MIN(kMaxSceneHeight, self.size.height / scale));

            [self.gameScene setSize:CGSizeMake(newWidth, newHeight)];                
            self.lastScale = pinch.scale;

        } break;

        default: break;
    }
}

如果意外拖动你的LetterNodes会出现平移问题，我通常会实现一个TouchDispatcher（通常在GameScene类中）来记录所有的触摸。然后，TouchDispatcher决定哪个节点应该响应触摸（以及以何种顺序）。

在SpriteKit中缩放和滚动SKNode

1 个答案: