sprite-kitskshapenodesktextureskview

Create \(Use) SKView as \(in a) factory \(static class)


I want to make an SKView I can use as a factory to make SKShapeNodes and "render" them to textures.

But I can't find how I would initialise such a thing, and am having no luck, at all.

How do I make a standalone SKView for this purpose?

Or is there a better way to do this that avoids using the gamescene?

Here's my FUTILE Effort at making a factory, this complains that texture(from: ) is ambiguous. I have no idea what that means.

import SpriteKit

class Make: SKView{

static func circle() -> SKSpriteNode {
    let myShapeNode = SKShapeNode(circleOfRadius: 100)
    myShapeNode.fillColor = SKColor.lightGray
    myShapeNode.strokeColor = SKColor.gray
    let tex = texture(from: myShapeNode)
    return SKSpriteNode(texture: tex)
    }

required init?(coder aDecoder: NSCoder) {
    fatalError("init(coder:) has not been implemented")
    }   
}

Update

After more futile time on google, I tried searching for initialisation of a UIView, and found and added this piece of code, that initialises to a frame that seems imaginary... but it works! I don't know why... but I can't use it as a factory method, only as an instance method, this way:

import Foundation
import SpriteKit

class Make: SKView{

    // added randomly found UIView initialisation "code"...
    override init(frame: CGRect) {
        super.init(frame: frame)
    }

    func circle() -> SKSpriteNode {
        let myShapeNode = SKShapeNode(circleOfRadius: 100)
        myShapeNode.fillColor = SKColor.lightGray
        myShapeNode.strokeColor = SKColor.gray
        let tex = texture(from: myShapeNode)
        return SKSpriteNode(texture: tex)
    }

    required init?(coder aDecoder: NSCoder) {
        fatalError("init(coder:) has not been implemented")
    }
}

Solution

  • It's not quite clear what you mean by "how I would initialise such a thing". How is dependent upon technique and what the factory does overall. Some factories do not need external input for initialization while others do. Here is are a couple of really crude examples. These are perhaps overly simplistic and have not been tested at all.

    One uses the concept of a static class whilst the other is a singleton. None of this is to serve as "this is better than that". Nor is it to open Pandora's Box on which is better, etc. There are other threads which go over those details. Rather they are just a couple of approaches to get you going.

    Here is a static class version

    // static class version
    class SpriteFactory1 {
        private static let view:SKView = SKView()
    
        static func spriteFromShape(shape:SKShapeNode) -> SKSpriteNode? {
            guard let tex = view.texture(from:shape) else {
                return nil
            }
    
            return SKSpriteNode(texture:tex)
        }
    }
    

    Here is a singleton version. Adding your circle code from above ...

    // singleton version
    class SpriteFactory2 {
        static let sharedInstance = SpriteFactory2()
    
        private let view:SKView = SKView()
    
        func spriteFromShape(shape:SKShapeNode) -> SKSpriteNode? {
            guard let tex = view.texture(from:shape) else {
                return nil
            }
    
            return SKSpriteNode(texture:tex)
        }
    
        func circle() -> SKSpriteNode {
            let myShapeNode = SKShapeNode(circleOfRadius: 100)
            myShapeNode.fillColor = SKColor.lightGray
            myShapeNode.strokeColor = SKColor.gray
            let tex = texture(from: myShapeNode)
            return SKSpriteNode(texture: tex)
        }
    }
    

    You'll also note the code is more or less the same. However in the case of the static, the class variables must be static as well.

    Usage would look something like:

    // Test shape
    let shape = SKShapeNode()
    // Pretend shape is constructed as desired
    
    let sprite1 = SpriteFactory1.spriteFromShape(shape: shape)    
    let sprite2 = SpriteFactory2.sharedInstance.spriteFromShape(shape: shape)
    let circle = SpriteFactory2.sharedInstance.circle()