On Sun, Mar 22, 2015 at 8:17 PM, Nicolai Hess <nicolaihess@web.de> wrote:

Yes, but I think the operation were defined as the Color class did not contain the alpha value

Exactly

Ah, Ok. In that case I would not use the arithmetic operations at all. never :)

I wanted to solve the problem without actually solving it :)

In the image there is a general animation class that supports linear interpolation defined as:

(to - from) * delta + from

So it can theoretically work with all objects polymorphic with numbers in sense of math operations. I browsed Color class and surprisingly found that it is polymorphic with Number! What a lucky moment :) However when I tried I failed. Then I realized that color's value can't be negative, so

general solution will not work, since��(to - from)��can't be negative Color.��

That is why I had to interpolate each channel separately:

|r g b a|
r := (to red - from red) * delta + from red.
g := (to green - from green) * delta + from green.
b := (to blue - from blue) * delta + from blue.
a := (to alpha - from alpha) * delta + from alpha.
^ Color r: r g: g b: b alpha: a

I don't need math operations with colors anymore :) But having that feature doesn't work we should do something before release ;) That's why issue was opened. Feel free to make slice requests��

Cheers,

Alex