ColourUtils.java

package advancedsystemsmanager.util;

public class ColourUtils
{
    public static String RGBtoHex(int r, int g, int b)
    {
        String val = Integer.toHexString(r << 16 | g << 8 | b);
        while (val.length() < 6) val = "0" + val;
        return val;
    }

    public static int[] HSBtoRGB(float hue, float saturation, float brightness)
    {
        int r = 0, g = 0, b = 0;
        if (saturation == 0)
        {
            r = g = b = (int)(brightness * 255.0f + 0.5f);
        } else
        {
            float h = hue * 6.0f;
            float f = h - (float)java.lang.Math.floor(h);
            float p = brightness * (1.0f - saturation);
            float q = brightness * (1.0f - saturation * f);
            float t = brightness * (1.0f - (saturation * (1.0f - f)));
            switch ((int)h % 6)
            {
                case 0:
                    r = (int)(brightness * 255.0f + 0.5f);
                    g = (int)(t * 255.0f + 0.5f);
                    b = (int)(p * 255.0f + 0.5f);
                    break;
                case 1:
                    r = (int)(q * 255.0f + 0.5f);
                    g = (int)(brightness * 255.0f + 0.5f);
                    b = (int)(p * 255.0f + 0.5f);
                    break;
                case 2:
                    r = (int)(p * 255.0f + 0.5f);
                    g = (int)(brightness * 255.0f + 0.5f);
                    b = (int)(t * 255.0f + 0.5f);
                    break;
                case 3:
                    r = (int)(p * 255.0f + 0.5f);
                    g = (int)(q * 255.0f + 0.5f);
                    b = (int)(brightness * 255.0f + 0.5f);
                    break;
                case 4:
                    r = (int)(t * 255.0f + 0.5f);
                    g = (int)(p * 255.0f + 0.5f);
                    b = (int)(brightness * 255.0f + 0.5f);
                    break;
                case 5:
                    r = (int)(brightness * 255.0f + 0.5f);
                    g = (int)(p * 255.0f + 0.5f);
                    b = (int)(q * 255.0f + 0.5f);
                    break;
            }
        }
        return new int[]{r, g, b};
    }

    public static void HextoHSV(int RGB, float[] values)
    {
        int r = RGB >> 16;
        int g = (RGB >> 8) & 0xFF;
        int b = RGB & 0xFF;
        RGBtoHSV(r, g, b, values);
    }

    public static void RGBtoHSV(int r, int g, int b, float[] values)
    {
        float hue, saturation, brightness;
        int cmax = (r > g) ? r : g;
        if (b > cmax) cmax = b;
        int cmin = (r < g) ? r : g;
        if (b < cmin) cmin = b;

        brightness = ((float)cmax) / 255.0f;
        if (cmax != 0)
            saturation = ((float)(cmax - cmin)) / ((float)cmax);
        else
            saturation = 0;
        if (saturation == 0)
            hue = 0;
        else
        {
            float redc = ((float)(cmax - r)) / ((float)(cmax - cmin));
            float greenc = ((float)(cmax - g)) / ((float)(cmax - cmin));
            float bluec = ((float)(cmax - b)) / ((float)(cmax - cmin));
            if (r == cmax)
                hue = bluec - greenc;
            else if (g == cmax)
                hue = 2.0f + redc - bluec;
            else
                hue = 4.0f + greenc - redc;
            hue = hue / 6.0f;
            if (hue < 0)
                hue = hue + 1.0f;
        }
        values[0] = hue;
        values[1] = saturation;
        values[2] = brightness;
    }
}