public class manom
    {
        System.Drawing.Pen creion_lg, creion_rad, creion_g, creion_r;
        System.Drawing.SolidBrush pens_a, pens_r, pens_rad;
        System.Drawing.Font font_arial;
        System.Drawing.Graphics zona_des;
        System.Drawing.Bitmap img;
        Graphics g;
        int x0, y0, xi, xe, xm, xgr, xgm, xtx, w, val_m, diam_i, diam_e, diam_m, diam_gr, diam_gm, diam_tx;
        int gr; 			//grosimea arcului de cerc
        bool af_grd; 		// se afiseaza gradatii
        public void setval(int val)
        {
            int vl = val;
            int alfa = 360 * vl / val_m;

            // sterg interiorul
            g.FillEllipse(pens_rad, xe-1, xe-1, diam_e+2, diam_e+2);

            // trasez arc de cerc
            g.DrawArc(creion_lg, xm, xm, diam_m, diam_m, 90, alfa);
            if ((w >= 150) && af_grd)
            {
                g.DrawEllipse(creion_g, xi, xi, diam_i, diam_i);
                g.DrawEllipse(creion_g, xe, xe, diam_e, diam_e);
            }
            g.DrawString(vl.ToString(), font_arial, pens_r, (w - gr) / 2 - gr / 3, (w - gr) / 2 - 3*gr / 5);
            g.DrawString("/" + val_m.ToString(), font_arial, pens_a, (w - gr) / 2 - gr / 3, (w - gr) / 2 + gr / 2);
            // afisez imaginea
            zona_des.DrawImage(img, x0, y0);
        }
        public manom(System.Drawing.Graphics desen, int pozx, int pozy, bool af_gradatii, int diam, int val_max)
        {
            x0 = pozx;                      // pozitia pe x a instrumentului
            y0 = pozy;                      // pozitia pe y a instrumentului
            if(diam>99)
                w = diam;                   // latimea instrumentului
            else
                w = 100;                    // minima latimea instrumentului
            gr = w/11;                      // grosimea arcului de cerc
            af_grd = af_gradatii;           // afisare gradatii
            diam_i = diam - 7 * gr;         // diametrul cercului interior
            diam_e = diam_i + 2 * gr;       // diametrul cercului exterior
            diam_m = (diam_e + diam_i) / 2; // diametrul cercului mediu pentru arcul de cerc
            diam_gr = diam_e + 2 * gr / 3;  // diametrul cercului pentru gradatii
            diam_gm = diam_e + 4 * gr / 3;  // diametrul cercului pentru gradatii mari
            diam_tx = diam_e + 3 * gr;      // diametrul cercului pentru texte
            val_m = val_max;                // valoarea maxima afisata
            xi = (w - diam_i) / 2;          // coordonata pentru cercul interior
            xe = (w - diam_e) / 2;          // coordonata pentru cercul exterior
            xm = (w - diam_m) / 2;          // coordonata pentru cercul mediu
            xgr = (w - diam_gr) / 2;        // coordonata pentru cercul gradatiilor mici
            xgm = (w - diam_gm) / 2;        // coordonata pentru cercul gradatiilor mari
            xtx = (w - diam_tx)/2-gr/3;     // coordonata pentru cercul valorilor
            creion_lg = new System.Drawing.Pen(System.Drawing.Color.LightGray, gr);
            creion_rad = new System.Drawing.Pen(System.Drawing.Color.White, gr);
            creion_g = new System.Drawing.Pen(System.Drawing.Color.Gray);
            creion_r = new System.Drawing.Pen(System.Drawing.Color.Blue);
            font_arial = new System.Drawing.Font("Arial", 10);
            pens_a = new System.Drawing.SolidBrush(System.Drawing.Color.Gray);
            pens_r = new System.Drawing.SolidBrush(System.Drawing.Color.Red);
            pens_rad = new System.Drawing.SolidBrush(System.Drawing.Color.White);
            zona_des = desen;
            img = new Bitmap(w, w, zona_des);
            g = Graphics.FromImage(img);
            g.FillRectangle(pens_rad, 0, 0, w + 2, w + 2);
            int k = 0;
            double grd; 	// grade hexazecimale

            // trasez gradatii si valori
            for (grd = 630; grd > 270; grd -= 3.6)
            {
                double rad = 2 * System.Math.PI * grd / 360;
                int x1 = Convert.ToInt16(xe + (diam_e / 2) + (diam_e / 2) * System.Math.Cos(rad));
                int y1 = Convert.ToInt16(xe + (diam_e / 2) - (diam_e / 2) * System.Math.Sin(rad));
                int x2 = Convert.ToInt16(xgr + (diam_gr / 2) + (diam_gr / 2) * System.Math.Cos(rad));
                int y2 = Convert.ToInt16(xgr + (diam_gr / 2) - (diam_gr / 2) * System.Math.Sin(rad));
                int x3 = Convert.ToInt16(xgm + (diam_gm / 2) + (diam_gm / 2) * System.Math.Cos(rad));
                int y3 = Convert.ToInt16(xgm + (diam_gm / 2) - (diam_gm / 2) * System.Math.Sin(rad));
                int x4 = Convert.ToInt16(xtx + (diam_tx / 2) + (diam_tx / 2) * System.Math.Cos(rad));
                int y4 = Convert.ToInt16(xtx + (diam_tx / 2) - (diam_tx / 2) * System.Math.Sin(rad));
                if ((w >= 150) && af_grd)
                {
                    if (k % 10 != 0)
                    {
                        if(w>=200)
                        g.DrawLine(creion_g, x1, y1, x2, y2);
                    }
                    else
                    {
                        g.DrawLine(creion_r, x1, y1, x3, y3);
                        g.DrawString((k * val_m / 100).ToString(), font_arial, pens_a, x4 - gr / 2, y4);
                    }
                    k++;
                }
            }
        }
    }