WritableBitmap.fs

 
type ColorF(r : float, g : float, b : float) = 
    new(r : byte, g : byte, b : byte) = ColorF(float r / 255.0, float g / 255.0, float b / 255.0)
    member __.R = r
    member __.G = g
    member __.B = b
    member color.RGBA = 
        let r = int (r * 255.0)
        let g = int (g * 255.0)
        let b = int (b * 255.0)
        (255 <<< 24) ||| (r <<< 16) ||| (g <<< 8) ||| b


let writeableBitmap = WriteableBitmap(1024, 1024, 96.0, 96.0, PixelFormats.Bgra32, null)
do writeableBitmap.Lock()
let backbuffer = NativePtr.ofNativeInt<int> writeableBitmap.BackBuffer
let stride = writeableBitmap.BackBufferStride
let plot_pixel x y (color:ColorF) = NativePtr.set backbuffer (x + ((stride / 4) * y)) (color.RGBA)
//Set some pixels using plot_pixel function
do writeableBitmap.AddDirtyRect(Int32Rect(0, 0, 1024, 1024))
do writeableBitmap.Unlock()