> > Color white - (Color white alpha:0) = Color white > Color white - (Color white alpha:0.5) = Color gray. > Color white - (Color white alpha:1.0) = Color black. > For what do you need the color arithmetic ? > Maybe there are already other operations defined on Color that you can > used instead.
That is too complicated :) The idea was to have one-line fix that just leaves the behaviour as it was before, simply makes it not produce garbage. Basically there should be a long discussion after pharo 4 is released. How it is now: (Color white alpha: 0) = Color transparent => false Color white - (Color white alpha: 0) = Color black => true >From logical point of view is should not be black. But from mathematical point of view Color is just a vector and operations with it should be the same or almost the same as with vectors. For what do you need the color arithmetic ? I wanted to get linear discrete transformation from one color to another to use it in animation Cheers, Alex On Sun, Mar 22, 2015 at 1:54 PM, Marcus Denker <[email protected]> wrote: > > On 22 Mar 2015, at 13:35, Nicolai Hess <[email protected]> wrote: > > > > 2015-03-22 12:43 GMT+01:00 Nicolai Hess <[email protected]>: > >> >> >> 2015-03-21 15:51 GMT+01:00 Eliot Miranda <[email protected]>: >> >>> Why not take the average of alpha in all cases? >>> >>> Eliot (phone) >>> >>> On Mar 21, 2015, at 6:32 AM, Aliaksei Syrel <[email protected]> >>> wrote: >>> >> >> >> Or weight the argument by its alpha and don't change the alpha of the >> receiver: >> Color white - (Color white alpha:0) = Color white >> Color white - (Color white alpha:0.5) = Color gray. >> Color white - (Color white alpha:1.0) = Color black. >> >> For what do you need the color arithmetic ? >> Maybe there are already other operations defined on Color that you can >> used instead. >> >> As the arithmetic operations on Color doesn't work (for years?), maybe we >> should remove >> the operation now, and replace them with a more verbose api >> addRGB/ addRGBA/ subRGBA .... >> >> nicolai >> >> > Ah, this issue is already closed. That was a rather short discussion. And > #/ and #* still don't work > for colors. > > > Yes… I think we have a problem that there is no “this is ready for > integration” check. > > We need to get more careful… > > Marcus >
