示例#1
0
        public static Color HsbToRgb(HsbColor hsbColor)
        {
            /* Gray (zero saturation) is a special case.We simply
            * set RGB values to HSB Brightness value and exit. */

            // Gray: Set RGB and return
            if (hsbColor.S == 0.0)
            {
                return(Color.FromArgb((byte)(hsbColor.A * 255),
                                      (byte)(hsbColor.B * 255),
                                      (byte)(hsbColor.B * 255),
                                      (byte)(hsbColor.B * 255)
                                      ));
            }

            /* Now we process the normal case. */
            var h = (hsbColor.H == 360) ? 0 : hsbColor.H / 60;

            //var i = (int)(Math.Truncate(h));

            //var i = (int)(Math.Round(h));
            if (double.IsNaN(h))
            {
                return(Color.FromArgb((byte)(hsbColor.A * 255),
                                      (byte)(hsbColor.B * 255),
                                      (byte)(hsbColor.B * 255),
                                      (byte)(hsbColor.B * 255)
                                      ));
            }


            int i = Convert.ToInt32(Math.Floor(h));
            var f = h - i;

            var p = hsbColor.B * (1.0 - hsbColor.S);
            var q = hsbColor.B * (1.0 - (hsbColor.S * f));
            var t = hsbColor.B * (1.0 - (hsbColor.S * (1.0 - f)));

            double r, g, b;

            switch (i)
            {
            case 0:
                r = hsbColor.B;
                g = t;
                b = p;
                break;

            case 1:
                r = q;
                g = hsbColor.B;
                b = p;
                break;

            case 2:
                r = p;
                g = hsbColor.B;
                b = t;
                break;

            case 3:
                r = p;
                g = q;
                b = hsbColor.B;
                break;

            case 4:
                r = t;
                g = p;
                b = hsbColor.B;
                break;

            default:
                r = hsbColor.B;
                g = p;
                b = q;
                break;
            }


            // Set return value
            return(Color.FromArgb((byte)(hsbColor.A * 255),
                                  (byte)(r * 255),
                                  (byte)(g * 255),
                                  (byte)(b * 255)
                                  ));
        }
示例#2
0
        public static HsbColor RgbToHsb(Color rgbColor)
        {
            /* Hue values range between 0 and 360. All
             * other values range between 0 and 1. */

            // Create HSB color object
            var hsbColor = new HsbColor();

            // Get RGB color component values
            var r = (int)rgbColor.R;
            var g = (int)rgbColor.G;
            var b = (int)rgbColor.B;
            var a = (int)rgbColor.A;

            // Get min, max, and delta values
            double min   = Math.Min(Math.Min(r, g), b);
            double max   = Math.Max(Math.Max(r, g), b);
            double delta = max - min;

            /* Black (max = 0) is a special case. We
             * simply set HSB values to zero and exit. */

            // Black: Set HSB and return
            if (max == 0.0)
            {
                hsbColor.H = 0.0;
                hsbColor.S = 0.0;
                hsbColor.B = 0.0;
                hsbColor.A = a / 255;
                return(hsbColor);
            }

            /* Now we process the normal case. */

            // Set HSB Alpha value
            var alpha = (double)a;

            hsbColor.A = alpha / 255;

            // Set HSB Hue value
            if (r == max)
            {
                hsbColor.H = (g - b) / delta;
            }
            else if (g == max)
            {
                hsbColor.H = 2 + (b - r) / delta;
            }
            else if (b == max)
            {
                hsbColor.H = 4 + (r - g) / delta;
            }
            hsbColor.H *= 60;
            if (hsbColor.H < 0.0)
            {
                hsbColor.H += 360;
            }

            // Set other HSB values
            hsbColor.S = delta / max;
            hsbColor.B = max / 255;

            // Set return value
            return(hsbColor);
        }