In this project you can click and drag the knobs to rotate them. When you do this it rotates the color effect on the cat's shirt or pants. The cat, the shirt, and the pants are all different sprites. I convert the angle of the knob sprite(s) from a number between -179 to 180 to a number between 0 and 200. Then I set the color effect to that number. There is some more detail if you see inside the project. I included a bunch of comments in there to explain what I was doing. The challenge here is that the color effect can take any numerical value, but it starts repeating itself in an unexpected way. Setting the Color Effect to 200 is the same as setting it to 0. Setting it to -1 is the same as setting it to 199. Additionally, the way angles work is that we end up with a number between -179 and 180. The easiest way to handle this is first make the angle be a positive angle by adding adding 360 to the number if its less than 180. This gives us an angle between 0 and 360. Then we need to divide the angle by 360 to get a number between 0 and 1. That's nice because we can multiply that by the color space (200). That way an angle of 0 will give us a color effect of 0 as expected, and the angle of 180 will give us the color effect value of 100, right in the middle. Similarly, an angle of -1 (or 359) gives us a color effect very close to 0. The way the color effect works also involves a smooth transition of colors so that even when you wrap around and the colors start repeating themselves they still look similar to the previous color. This uses a technique called Hue Rotation, which is really neat and I recommend you look it up. I also use the sensing "___ of ___" block so the shirt (and pants) can see what the rotation of the knob is.
