Scale SKShapeNode from center?

Question

I have a SKShapeNode, and a label under one generic SKNode. If I try to scale that node, its position changes for no reason!. If I try to scale only the nodes it contains under it, it scales properly but not from the center, so it grows out to the up and right.

What am I doing wrong? First before scale

After scale

Notice its position moves up. Can't figure out why, does it even if I do it as an action or not. Also, the position is not changing based on log, but it appears the frame got bigger (though that is expected)

Steps to recreate issue:

set height and width @h = 50 @w = 256

create rect with height and width CGRectMake(0, 0, @w, @h)

get path for rect UIBezierPath.bezierPathWithRect(rect).CGPath

create skshape node with path, set position

  antialiased: false,
  lineWidth: 1.0,
  strokeColor: SKColor.blackColor,
  fillColor: SKColor.whiteColor

Create sklabel, vertical center alignment, set position

create generic SKNode, no properties, add skshapenode and sklabel to it as children

Scale the generic SKNode.

can you add a picture to help describe your problem? Have you tried changing the anchor points ? — DogCoffee
There appears to be no anchor points for SKShapeNode, and SKNode. — AwDogsGo2Heaven
my code isn't objective c (rubymotion) but logic is same, I'll show the pseudo code. — AwDogsGo2Heaven

DogCoffee DogCoffee · Accepted Answer · 2013-10-04T03:19:45

Try this

SKLabelNode *labNode = [SKLabelNode labelNodeWithFontNamed:@"Arial"];
labNode.fontSize = 12.0f;
labNode.fontColor = [SKColor blackColor];
labNode.text = @"SMASH";


SKSpriteNode *topWithText = [SKSpriteNode spriteNodeWithColor:[SKColor greenColor] size:CGSizeMake(100, 30)];
topWithText.position = CGPointMake(100, 110);
[topWithText addChild:labNode];

SKSpriteNode *bottom = [SKSpriteNode spriteNodeWithColor:[SKColor redColor] size:CGSizeMake(100, 10)];
bottom.position = CGPointMake(100, 100);

[self addChild:topWithText];
[self addChild:bottom];

[topWithText runAction:[SKAction sequence:@[
                                      [SKAction waitForDuration:3.0],
                                      [SKAction scaleBy:3.0 duration:3]
                                      ]]];

Scale SKShapeNode from center?

2 Answers