A fading outline

Challenge 9 of 16

The outline has its own colour, and it is three numbers just the same. This ring has no fill at all, so the only thing fading is its edge.

Set the step to -4.

Your code JavaScript

Set the step to -4.

Console print() output

0 / 45 frames · 400×400

Target

Yours

Results

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Penalties: none this run

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Lesson Growing and Fading

Position was never special.

x = x + speed looked like it was about movement, but there is nothing about movement in it. It takes a number, adds another, and puts the answer back. Plug the result into a shape's third argument and you have a size; plug it into shapeColour and you have a colour that changes. The line does not know or care.

A colour is three numbers.

shapeColour(red, green, blue), each from 0 to 255, exactly as in "Colour by Numbers". Give one of them a variable and it can climb or drain a step at a time. Equal amounts of all three make a grey, which is why fading one number in all three places fades a shape to black. Keep them between 0 and 255 — above that a colour stops being a colour and the shape simply stops changing.

Seeing a number with nowhere to show.

A position you can watch. A colour number you cannot really read off the screen. print() writes a value into the console strip under your code — scroll down past the editor to find it — one line each time it runs, so you can see what your own number is actually doing. It shows your sketch's output, not the target's — it is for understanding your own work, not for finding the answer.