public class anemom
    {
        int x0, y0, w, val;
        int r, rc, ds, d, xm, ym, xv, yv, xc, yc, i, j;
        double ar, a, ai;

        System.Drawing.Graphics zona_des;
        System.Drawing.Pen creion_a = new System.Drawing.Pen(System.Drawing.Color.Gray);
        System.Drawing.Pen creion_r = new System.Drawing.Pen(System.Drawing.Color.Red);
        System.Drawing.Bitmap img;
        System.Drawing.Bitmap ims;

        public void setval(int i_vant, int dir_v)
        {
            val = i_vant;// intensitatea vantului -- maxim diam/2
            ai = dir_v;
            if (w > 0)
            {
                // pun grid
                img = new Bitmap(ims);

                // fascicul de raze
                Graphics g = Graphics.FromImage(img);
                for (a = ai; a < (ai + 30); a += 360 / 120)
                {
                    ar = a * Math.PI / 180;
                    xm = System.Convert.ToInt16(xc + r * Math.Sin(ar));
                    ym = System.Convert.ToInt16(yc - r * Math.Cos(ar));
                    g.DrawLine(creion_a, xc, yc, xm, ym);
                    if (val <= w / 2)
                    {
                        xv = System.Convert.ToInt16(xc + val * Math.Sin(ar));
                        yv = System.Convert.ToInt16(yc - val * Math.Cos(ar));
                        g.DrawLine(creion_r, xc, yc, xv, yv);
                    }
                }
            }
            // afisez
            zona_des.DrawImage(img, x0, y0);
        }
        public anemom(System.Drawing.Graphics desen, int pozx, int pozy, int diam)
        {
            x0 = pozx;
            y0 = pozy;
            w = diam;
            r = w / 2 - 1;
            ds = Convert.ToInt32(2 * r / 10.0); // distanta dintre cercuri
            xc = w / 2;
            yc = w / 2;
            rc = 0;
            double ar, a;
            zona_des = desen;
            img = new Bitmap(w + 4, w + 4, zona_des);
            if (w > 0)
            {
                ims = new Bitmap(w + 4, w + 4, zona_des);
                Graphics g = Graphics.FromImage(ims);

                // sterg imaginea

                for (j = 0; j <= w + 3; j++)
                {
                    for (i = 0; i <= w + 3; i++)
                    {
                        ims.SetPixel(i, j, System.Drawing.Color.White);
                    }
                }

                // cercuri concentrice

                rc = 0;
                int k = 0;
                for (d = 2 * r; d >= 0; d -= ds)
                {
                    g.DrawEllipse(creion_a, rc, rc, d, d);
                    k++;
                    rc = Convert.ToInt32(k * (ds / 2.0));
                }

                //raze in cerc

                for (a = 0; a < 360; a += 360 / 12)
                {
                    ar = a * Math.PI / 180;
                    xm = System.Convert.ToInt16(xc + r * Math.Sin(ar));
                    ym = System.Convert.ToInt16(yc - r * Math.Cos(ar));
                    g.DrawLine(creion_a, xc, yc, xm, ym);
                }
            }
        }
    }