ios - 用户触摸时如何更改 Sprite 颜色

Question

我是 iOS 开发和 SpriteKit 的新手。 我正在制作游戏，我需要在用户触摸时更改 Sprite 颜色。 实际上，我有三种确定的颜色。 Sprite 开始时是红色的。当用户触摸它时，它会变成蓝色。如果用户再次触摸它会变黑。如果用户再次触摸它，它会再次变红。

在 touchbegan 方法中，我正在尝试类似的方法:

if (playerBar.color == [SKColor redColor]) {
    playerBar.color = [SKColor blueColor];
} else if (playerBar.color == [SKColor blueColor] {
    playerBar.color = [SKColor blackColor];
} else if (playerBar.color == [SKColor blackColor]) {
    playerBar.color = [SKColor redColor];
}

谁能帮帮我？ 非常感谢。

Answer 1

!!!抱歉回答这么长，在底部你可以找到 Swift 和 Objective-C 的完整解决方案

您可以使用动画更改 SKSpriteNode 的颜色，使用这种方法看起来会更好:

objective-C :

   SKAction *changeColorAction = [SKAction colorizeWithColor:[SKColor blueColor] colorBlendFactor:1.0 duration:0.5];
   [myLabel runAction:changeColorAction];

swift :

   let changeColorAction = SKAction.colorizeWithColor(SKColor.blueColor(), colorBlendFactor: 1.0, duration: 0.5)
   playerBar.runAction(changeColorAction)

这是针对您的问题的 Swift 完整解决方案，包括触摸检查、颜色比较和更改。实际上，您检查节点当前颜色是否等于 SKColor 的方法不正确。因此，下面我将向您展示我的解决方案，这可能不是很好，但很有效。

首先，在你初始化 playerBar Sprite 节点的地方，给它起一个像这样的名字:

  playerBar.name = "playerBar"

之后，使用下面的代码进行 SKColor 比较(不是很准确，但对于这种情况有效)，还用于检查节点和颜色变化的触摸。

  func isEqualColor(color: SKColor, toColor: SKColor) -> Bool {
    let color1Components = CGColorGetComponents(color.CGColor)
    let color2Components = CGColorGetComponents(toColor.CGColor)

    if ((color1Components[0] != color2Components[0]) || //red
       (color1Components[1] != color2Components[1]) || //green
       (color1Components[2] != color2Components[2]) || //blue
       (color1Components[3] != color2Components[3])) { //alpha
        return false
    }

    return true
  }

  override func touchesBegan(touches: NSSet, withEvent event: UIEvent) {
        /* Called when a touch begins */

      for touch: AnyObject in touches {
        let location = touch.locationInNode(self)

        let nodes = self.nodesAtPoint(location) as [SKNode]

        for node in nodes {
          if node.name == "playerBar" {
            let spriteNode = node as SKSpriteNode
            var color = SKColor.redColor()

            if isEqualColor(spriteNode.color, toColor: SKColor.redColor()) {
              color = SKColor.blueColor()
            } else if isEqualColor(spriteNode.color, toColor: SKColor.blueColor()) {
              color = SKColor.blackColor()
            }

            let changeColorAction = SKAction.colorizeWithColor(color, colorBlendFactor: 1.0, duration: 0.5)
            spriteNode.runAction(changeColorAction) {
              spriteNode.color = color //On completion of action, we set color so after in comparison method not have conflicts while comparing color components
            }
          }
        }
      }
    }

如果没有 Obejctive-C 解决方案，我不能离开你 :) 因此，您需要在初始化时再次为您的 playerBar SpriteNode 命名。

playerBar.name = "playerBar";

在将此方法用于您的完整解决方案之后:

- (BOOL)isEqualColor:(SKColor *)color1 toColor:(SKColor *)color2
{
  const CGFloat* color1Components = CGColorGetComponents([color1 CGColor]);
  const CGFloat* color2Components = CGColorGetComponents([color2 CGColor]);

  if ((color1Components[0] != color2Components[0]) || //red
      (color1Components[1] != color2Components[1]) || //green
      (color1Components[2] != color2Components[2]) || //blue
      (color1Components[3] != color2Components[3])) { //alpha
    return NO;
  }

  return YES;
}

- (void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event {
    /* Called when a touch begins */

    for (UITouch *touch in touches) {
      CGPoint location = [touch locationInNode:self];

      NSArray *nodes = [self nodesAtPoint:location];

      for (SKNode *node in nodes) {
        if ([node.name isEqualToString:@"playerBar"]) {
          SKSpriteNode *spriteNode = (SKSpriteNode *)node;
          SKColor *color = [SKColor redColor];

          if ([self isEqualColor:spriteNode.color toColor:[SKColor redColor]]) {
            color = [SKColor blueColor];
          } else if ([self isEqualColor:spriteNode.color toColor:[SKColor blueColor]]) {
            color = [SKColor blackColor];
          }

          SKAction *changeColor = [SKAction colorizeWithColor:color colorBlendFactor:1.0 duration:0.5];
          [spriteNode runAction:changeColor completion:^{
            spriteNode.color = color; //On completion of action, we set color so after in comparison method not have conflicts while comparing color components
          }];
        }
      }
    }
}