swift - 从 SF Symbols 字体创建一个不同颜色的 SKSpriteNode

Question

我正在尝试SKSpriteNode使用 SF Symbols 字体创建一个图像，虽然我可以做到，但我似乎无法将其设为黑色以外的任何颜色。

这是我的代码：

let image = UIImage.init(systemName: "gear")
let colored = image!.withTintColor(.red)
let texture = SKTexture.init(image: colored)
let sprite = SKSpriteNode.init(texture: texture, size: CGSize.init(width: 32, height: 32))

不幸的是，生成的精灵总是以黑色（而不是红色）出现。

我究竟做错了什么？

Answer 1

我认为问题在于 UIImage 是矢量图形，只有 UIImageViews 才能正确处理它们。也许我们可以将它强制为位图图像以使其正常工作。

以下是一些您可以尝试的实验代码：

let image = UIImage(systemName: "gear").withTintColor(.red)

let data = image.pngData()
let newImage = UIImage(data:data) 
let texture = SKTexture(image: newImage)
let sprite = SKSpriteNode(texture: texture,size: CGSize(width: 32, height: 32))

Answer 2

你必须设置colorBlendFactor精灵。

func makeSprite(symbolName: String) -> SKSpriteNode {
    let image = Image(systemName: symbolName)

    // Thanks Oskar!
    // https://stackoverflow.com/a/69315037/1610473
    // See my adapted version of his code further down; I
    // think you won't need it if you're on iOS, meaning
    // using UIImage, but that's all black magic to me.
    let renderedByOskar = image.renderAsImage()!

    let texture = SKTexture(image: renderedByOskar)
    let sprite = SKSpriteNode(texture: texture)

    sprite.color = .green
    sprite.colorBlendFactor = 1 // <-- This

    return sprite
}

一个绿色符号，多亏了黑魔法：

非常感谢Oskar的渲染扩展，使我能够在 macOS 上执行此操作，这意味着，无需UIImage：

class NoInsetHostingView<V>: NSHostingView<V> where V: View {
    override var safeAreaInsets: NSEdgeInsets {
        return .init()
    }
}

extension Image {
    func renderAsImage() -> NSImage? {
        let view = NoInsetHostingView(rootView: self)
        view.setFrameSize(view.fittingSize)
        return view.bitmapImage()
    }
}

public extension NSView {
    func bitmapImage() -> NSImage? {
        guard let rep = bitmapImageRepForCachingDisplay(in: bounds) else {
            return nil
        }

        cacheDisplay(in: bounds, to: rep)

        guard let cgImage = rep.cgImage else {
            return nil
        }

        return NSImage(cgImage: cgImage, size: bounds.size)
    }
}