Looking for help in C# with RGB color cross fade

Question

Ok, I made an app in C# that polls info from my screen for ambilight SFX using an external LED controller. My question is, what is the code or how do I go about making a color cross fade type thing where I get a fade from red to green to blue and out put the RGB values as

red = CODE;
green = CODE; 
blue = CODE;

I have done this long ago in C++ using "Interpolation(FadeSteps, Delay, Array)", I just don't have a clue how in C#

Think of drawing a 2D box and have it fade from one color to the next that's the idea.

I just want to be able to set speed of the fade
Idea as to what it's controlling

Answer 1

Ok, If I understand you right, you want to fade from Red, to green to blue?

Starting off with a struct and an enum to hold our color data and state.

public enum PrimaryColor
{
    Red,
    Green,
    Blue
}

public struct Color
{
    public byte r;
    public byte g;
    public byte b;

    public Color(byte r, byte g, byte b)
    {
        this.r = r;
        this.g = g;
        this.b = b;
    }
}

We then make some variables to hold our state data, including an array of which we will traverse.

Color ActualColor = new Color(255, 0, 0);
int State = 0;
PrimaryColor[] Order = { PrimaryColor.Red, PrimaryColor.Green, PrimaryColor.Blue };

Then, in your update function (say a timer, or while loop, etc.) we add a little switch statement to update colors, check for byte underflow and change states.

switch (Order[State])
{
    case PrimaryColor.Red:
        ActualColor.r++;
        if(ActualColor.g > 0) ActualColor.g--;
        if (ActualColor.b > 0) ActualColor.b--;
        if (ActualColor.r == 255 && ActualColor.g == 0 && ActualColor.b == 0) State++;
        break;
    case PrimaryColor.Green:
        ActualColor.g++;
        if (ActualColor.r > 0) ActualColor.r--;
        if (ActualColor.b > 0) ActualColor.b--;
        if (ActualColor.r == 0 && ActualColor.g == 255 && ActualColor.b == 0) State++;
        break;
    case PrimaryColor.Blue:
        ActualColor.b++;
        if (ActualColor.g > 0) ActualColor.g--;
        if (ActualColor.r > 0) ActualColor.r--;
        if (ActualColor.r == 0 && ActualColor.g == 0 && ActualColor.b == 255) State++;
        break;
    default:
        break;
}
if (State == Order.Length) State = 0;

//Send color data to your controller