colorizeWithColor and SKLabelNode

Question

The SKAction colorizeWithColor: does as per the docs only work with SKSpriteNode, so what do we do with SKLabelNode? SKLabelNode does have both color and colorBlendFactor properties that can be set statically. Is there some way to animate this with SKAction?

My current approach is to render a SKLabelNode to a texture using SKView's instance method textureFromNode, but just get nil texture out of that atm :-(

Update: What do you know. I think I found out the problem with the texture rendering. It's not possible to redner a texture in the init method of SKScene, because self.view is nil at that point. So I tried it in didMoveToView and voila, texture rendered. Thanks anyway :-)

Answer 1

Maybe somebody will find this useful.

   func changeColorForLabelNode(labelNode: SKLabelNode, toColor: SKColor, withDuration: NSTimeInterval) {
    labelNode.runAction(SKAction.customActionWithDuration(withDuration, actionBlock: {
      node, elapsedTime in

      let label = node as SKLabelNode

      let toColorComponents = CGColorGetComponents(toColor.CGColor)
      let fromColorComponents = CGColorGetComponents(label.fontColor.CGColor)

      let finalRed = fromColorComponents[0] + (toColorComponents[0] - fromColorComponents[0])*CGFloat(elapsedTime / CGFloat(withDuration))
      let finalGreen = fromColorComponents[1] + (toColorComponents[1] - fromColorComponents[1])*CGFloat(elapsedTime / CGFloat(withDuration))
      let finalBlue = fromColorComponents[2] + (toColorComponents[2] - fromColorComponents[2])*CGFloat(elapsedTime / CGFloat(withDuration))
      let finalAlpha = fromColorComponents[3] + (toColorComponents[3] - fromColorComponents[3])*CGFloat(elapsedTime / CGFloat(withDuration))

      labelNode.fontColor = SKColor(red: finalRed, green: finalGreen, blue: finalBlue, alpha: finalAlpha)
    }))
  }

You can even check the result of this function in use in this demo: https://www.youtube.com/watch?v=ZIz8Bn0-hUA&feature=youtu.be

I decided to write here a short nice solution, but if you need more details, check this question: SKAction.colorizeWithColor makes SKLabelNode disappear

Answer 2

SKLabelNode also has a fontColor property that you can set. However, it does not respond to the colorizeWithColor method.

Yet, you can still get it to dynamically change the color of the text by syncing it with another SKSpriteNode color. If you call colorizeWithColor on your sprite, the font color changes with it. And that includes color transitions over the specified duration. Example:

    [_tileCountLabel runAction:[SKAction repeatActionForever:
                            [SKAction customActionWithDuration:COLOR_TRANSITION_SPEED actionBlock:^(SKNode *node, CGFloat elapsedTime) {
    _tileCountLabel.fontColor = _tileLayer0.color;
}]]];

Also, I tried using SKCropNode mask to try setting the font color through a parent SKSpriteNode. The colorizeWithColor method on the SKSpriteNode worked, but the font was badly mangled and chunky. So, not useful.