Bubbles from Fractal Forest

gistfile1.fs

// just a tiny tweak on the Fractal Forest dojo:
// https://github.com/c4fsharp/Dojo-Fractal-Forest

open System
open System.Drawing
open System.Windows.Forms

let width, height = 500, 500         
let form = new Form(Width = width, Height = height)
let box = new PictureBox(BackColor = Color.White, Dock = DockStyle.Fill)
let image = new Bitmap(width, height)
let graphics = Graphics.FromImage(image)
graphics.SmoothingMode <- System.Drawing.Drawing2D.SmoothingMode.HighQuality
let brush = new SolidBrush(Color.FromArgb(0, 0, 0))

box.Image <- image
form.Controls.Add(box) 

let endpoint x y angle length =
    x + length * cos angle,
    y + length * sin angle

let flip x = (float)height - x

let drawCircle (target : Graphics) (brush : Brush) 
             (x : float) (y : float) 
             (angle : float) (length : float) (width : float) =
    let x_end, y_end = endpoint x y angle length
    let origin = new PointF((single)x, (single)(y |> flip))
    let destination = new PointF((single)x_end, (single)(y_end |> flip))
    let pen = new Pen(brush, (single)width)
    target.DrawEllipse(pen, int x, int y, int length, int length) 

let draw x y angle length width = 
    drawLine graphics brush x y angle length width

let pi = Math.PI

let bubblify depth =
    let rec bubbles (x:float) (y:float) angle length width depth =  
        drawCircle graphics brush x y angle length width |> ignore
        if depth > 0 then 
            for i in 1 .. 7 do
                let i' = float i
                let angle = angle + 0.2 * i'
                let length = length * 0.4
                let width = width * 0.8
                let x1, y1 =  endpoint x y angle (length * 1.4 * i')
                bubbles x1 y1 angle length width (depth - 1)
             
    bubbles 250. 50. (pi*(0.5)) 100. 4. depth 

bubblify 6

form.ShowDialog()