How to show shadow or any glow effect for SKSpriteNode when it moved on screen only?

Question

I want to show any effects or animations for my SKSpriteNode when it was dragging on screen.

I gone through many sites but i didn't find relevant answer for my question.I have little bit knowledge on SKSpriteNode.

Can any one guide me to solve this issue.

Thanks.

Answer 1

Use a factory to make a shadow:

import SpriteKit

class MAKE {

    private static let view:SKView = SKView()

    static func makeShadow(from source: SKTexture, rgb: SKColor, a: CGFloat) -> SKSpriteNode {
        let shadowNode = SKSpriteNode(texture: source)
            shadowNode.colorBlendFactor = 0.5  // makes the following line more effective
            shadowNode.color = SKColor.gray // makes for a darker shadow. Off for "glow" shadow
        let textureSize = source.size()
        let doubleTextureSize = CGSize(width: textureSize.width * 2, height: textureSize.height * 2)
        let framer = SKSpriteNode(color: UIColor.clear, size: doubleTextureSize)
            framer.addChild(shadowNode)
        let filter = CIFilter(name: "CIGaussianBlur")
        let blurAmount = 10
        filter?.setValue(blurAmount, forKey: kCIInputRadiusKey)
        let effectsNode = SKEffectNode()
            effectsNode.filter = filter
            effectsNode.blendMode = .alpha
            effectsNode.addChild(framer)
            effectsNode.shouldRasterize = true
        let tex = view.texture(from: effectsNode)
        let shadow = SKSpriteNode(texture: tex)
            shadow.colorBlendFactor = 0.5
            shadow.color = rgb
            shadow.alpha = a
            shadow.zPosition = -1
    return shadow
    }
}

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Now make a button anyway you like, but make sure you have created a buttonTexture that's the exact same size and shape as your button, preferably a grey rendition of it. You'll need this to send to the blurring factory shadowmaker above, like this:

shadowSprite = MAKE.makeShadow(from: buttonTexture, rgb: myColor, a: 0.33)
        shadowSprite.position = CGPoint(x: self.frame.midX, y: self.frame.midY - 5)
        addChild(shadowSprite)

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You can see more details on how and why a factory, here: Create \(Use) SKView as \(in a) factory \(static class)