Quantize color channels

Workbook.cs

public static int Quantize(float value, int bits) {
    return (int)(value * (Math.Pow(2, bits) - 1));
}

public static int JoinColors(int maskWidth, params int[] colors) {
    int joined = colors[0];
    for (int i=1; i<colors.Length; ++i) {
        joined = JoinColor(joined, colors[i], i, maskWidth);
    }
    return joined;
}

public static int JoinColor(int joined, int color, int i, int maskWidth) {
    return joined |= color << (i * maskWidth);
}

public static float EncodeQuantized(int quantized, int maxValue) {
    return (float)quantized / ((float)maxValue - 1f);
}

public static int DecodeQuantized(float encoded, int maxValue) {
    return (int)(Math.Min(maxValue - 1, (int)(encoded * maxValue)));
}

public static int ExtractQuantized(int decoded, int num, int mask, int maskWidth) {
    return (decoded & (mask << (num * maskWidth))) >> (num * maskWidth);
}

public static float ToColor(int quantized, int bits) {
    return (float)quantized / ((int)Math.Pow(2, bits) - 1);
}

public static int GetMask(int bits) {
    int mask = 0;
    for (int i=0; i<bits; ++i) {
        mask |= (1 << i);
    }
    return mask;
}

public static float EncodeChannel(int channel, int colorBits, int maxBits, params Color[] colors) {
    int j = 0;
    for (int i=0; i<colors.Length; ++i) {
        int q = Quantize(colors[i][channel], colorBits);
        j = JoinColor(j, q, i, colorBits);
    }
    return EncodeQuantized(j, maxBits);
}

public static float DecodeChannel(float encodedChannel, int num, int maxBits, int colorBits, int channelMask) {
    int decoded = DecodeQuantized(encodedChannel, maxBits);
    int q = ExtractQuantized(decoded, num, channelMask, colorBits);
    return ToColor(q, colorBits);
}

public static string Bits(int value) {
    return Convert.ToString(value, 2).PadLeft(32, '0');
}

public static void PrintBits(string label, int value) {
    Console.WriteLine($"{label}: {Bits(value)}");
}

public static void Run() {
    int colorBits = 8;
    int numColors = 2;
    int channelMask = GetMask(colorBits);
    int maxBits = (int)Math.Pow(2, (numColors * colorBits));
    Console.WriteLine($"..channelMask: {Bits(channelMask)} dec : {channelMask}");

    // Create two colors
    Color a = new Color(1f, 0f, 0f);
    Color b = new Color(0f, 1f, 0f);
    
    // Encode each channel og both colors
    float encodedR = EncodeChannel((int)Channel.RED,   colorBits, maxBits, a, b);
    float encodedG = EncodeChannel((int)Channel.GREEN, colorBits, maxBits, a, b);
    float encodedB = EncodeChannel((int)Channel.BLUE,  colorBits, maxBits, a, b);
    Console.WriteLine($"Color a.r {a.r} b.r {b.r} : {encodedR}");
    Console.WriteLine($"Color a.g {a.g} b.g {b.g} : {encodedG}");
    Console.WriteLine($"Color a.b {a.b} b.b {b.b} : {encodedB}");

    // extract two colors
    float r0 = DecodeChannel(encodedR, 0, maxBits, colorBits, channelMask);
    Console.WriteLine($"...........r0: {r0}");
    float r1 = DecodeChannel(encodedR, 1, maxBits, colorBits, channelMask);
    Console.WriteLine($"...........r1: {r1}");

    float g0 = DecodeChannel(encodedG, 0, maxBits, colorBits, channelMask);
    Console.WriteLine($"...........g0: {g0}");
    float g1 = DecodeChannel(encodedG, 1, maxBits, colorBits, channelMask);
    Console.WriteLine($"...........g1: {g1}");

    float b0 = DecodeChannel(encodedB, 0, maxBits, colorBits, channelMask);
    Console.WriteLine($"...........b0: {b0}");
    float b1 = DecodeChannel(encodedB, 1, maxBits, colorBits, channelMask);
    Console.WriteLine($"...........b1: {b1}");
    
}