C4Image create with CGImageRef

ViewController

import UIKit
import C4UI
import C4Core
import C4Animation

public struct PixelData {
    var a:UInt8
    var r:UInt8
    var g:UInt8
    var b:UInt8

    public init() {
        a = 255
        r = 0
        g = 0
        b = 0
    }
}

class ViewController: C4CanvasController {

    override func setup() {
        var pixels = [PixelData]()
        for x in 0..<256 {
            for y in 0..<256 {
                var pixel = PixelData()
                pixel.r = UInt8(x)
                pixel.b = UInt8(y)
                pixels.append(pixel)
            }
        }

        let rgbColorSpace = CGColorSpaceCreateDeviceRGB()
        let bitmapInfo:CGBitmapInfo = CGBitmapInfo(CGImageAlphaInfo.PremultipliedFirst.rawValue)
        let bitsPerComponent:Int = 8
        let bitsPerPixel:Int = 32
        let width : Int = 256
        let height : Int = 256

        assert(pixels.count == Int(width * height))

        var data = pixels // Copy to mutable []
        let providerRef = CGDataProviderCreateWithCFData(
            NSData(bytes: &data, length: data.count * sizeof(PixelData))
        )

        let cgim = CGImageCreate(
            width,
            height,
            bitsPerComponent,
            bitsPerPixel,
            width * Int(sizeof(PixelData)),
            rgbColorSpace,
            bitmapInfo,
            providerRef,
            nil,
            true,
            kCGRenderingIntentDefault
        )

        let img = C4Image(cgimage: cgim)
        canvas.add(img)
    }
}