source: 2017/30/MikkoH/Sq/Sq/Sq/Sq.cs @ 9441

using System;
using System.Collections.Generic;
using Jypeli;

public class Sq : Game
{   
    double glmin = 0.5, glmax = 3; bool glrev;
    List<Square> sqs = new List<Square>();

    public override void Begin()
    {
        Window.Height = 800; Window.Width = 1200;
        Mouse.IsCursorVisible = true; Level.Background.Color = Color.Black;

        sqs.Add(new Square(new Vector(0,0), 1, 400, 10, glrev, new Vector(-30, 30)));
    }      

    protected override void Paint(Canvas c)
    {
        if (sqs.Count == 0) Exit();
        for (int i = 0; i < sqs.Count; i++)
        {
            sqs[i].mag += sqs[i].magc = (glmin+(sqs[i].maxmag-sqs[i].mag) / // scales change to [glmin,glmax]
                (sqs[i].maxmag)*(glmax-glmin)) * Math.Sign(sqs[i].magc);    // and reduces current magnitude

            int d = (int)(sqs[i].mag / (sqs[i].maxmag+glmax - sqs[i].minmag) * 254);
            c.BrushColor = new Color(d, 100, 0); // scales color change from magnitude change, TODO: something interesting

            for (int j = 0; j < sqs[i].Count; j++)
                c.DrawLine(sqs[i][j % sqs[i].Count] * sqs[i].mag + sqs[i].pos,
                           sqs[i][(j + sqs[i].Count / 4) % sqs[i].Count] * sqs[i].mag + sqs[i].pos);

            if (sqs[i].mag < sqs[i].minmag)
            {
                if (sqs[i].n == 0) { sqs.Remove(sqs[i]); continue; } // number of pts reached
                sqs[i].magc = -sqs[i].magc; // reverse squeeze
                for (int k = 0; k < 2; k++)
                    sqs.Add(new Square(RandomGen.NextVector(Level.Left, Level.Bottom, Level.Right, Level.Top),
                                       sqs[i].minmag, sqs[i].maxmag/1.5, sqs[i].n - 1, glrev = !glrev, sqs[i].off));
                sqs.Remove(sqs[i]);
            } else if (sqs[i].mag > sqs[i].maxmag) sqs[i].magc = -sqs[i].magc; // reverse squeeze

            sqs[i].Rotate(Time.SinceLastUpdate.TotalSeconds);
        } base.Paint(c);
    }
}

class Square : List<Vector>
{
    public double n, mag, minmag , maxmag, magc, lim;
    public Vector pos, off; public bool rev;

    // position, min and max magnitude, d = number of pts/side
    // sqs are always collections of unit vectors centered around origin, offset from origin is indicated by pos
    public Square(Vector p, double min, double max, double d, bool r, Vector o)
    {
        n = d; mag = minmag = magc = min; maxmag = max; lim = 2/(d+1);
        pos = p; rev = r; off = o;
        for (double i = -1; i < 1; i += lim) Add(new Vector(-1, i));
        for (double i = -1; i < 1; i += lim) Add(new Vector(i, 1));
        for (double i = 1; i > -1; i -= lim) Add(new Vector(1, i));
        for (double i = 1; i > -1; i -= lim) Add(new Vector(i, -1));       
    }

    public void Rotate(double d)
    {
        if (rev) d = -d;
        for (int i = 0; i < Count; i++)
            this[i] = new Vector(this[i].X * Math.Cos(-d) - this[i].Y * Math.Sin(-d),
                                 this[i].X * Math.Sin(-d) + this[i].Y * Math.Cos(-d));
    }
}
















//List<Vector> crc;
//double rad = 50, radc = 0.01, pts = 150, minrad = 1, maxrad = 200;

//crc = CreateCircle(rad, pts);

// r = radius, n = number of pts
//List<Vector> CreateCircle(double r, double n)
//{
//    List<Vector> crc = new List<Vector>();
//    for (int i = 0; i <= n; i++)
//        crc.Add(new Vector(Math.Sin(i) * r, Math.Cos(i) * r));
//    return crc;
//}
//c.BrushColor = Color.Blue;

////draws and squeezes the circle
//for (int i = 0; i < crc.Count; i++)
//{
//    c.DrawLine(crc[i % crc.Count], crc[(i + 2) % crc.Count]);
//    crc[i] = new Vector(Math.Sin(i) * rad, Math.Cos(i) * rad);
//    if (rad < minrad || rad > maxrad) radc = -radc;
//    rad -= radc;
//}

//foreach (Square sq in sqs)  //Rotate(crc, true);