color lib

[Manu via Digitalmars-d]

On 10 October 2016 at 23:41, Andrea Fontana via Digitalmars-d
<digitalmars-d at puremagic.com> wrote:
> On Monday, 10 October 2016 at 13:25:07 UTC, Manu wrote:
>>
>> On 10 October 2016 at 23:00, Andrea Fontana via Digitalmars-d
>> <digitalmars-d at puremagic.com> wrote:
>>>
>>> On Monday, 10 October 2016 at 08:44:49 UTC, Manu wrote:
>>>
>>> From doc:
>>> colorFromString Create a color from a string. May be a hex color in the
>>> standard forms: (#/$)rgb/argb/rrggbb/aarrggbb May also be the name of any
>>> color from the Colors enum.
>>>
>>> It seems it reads just rgb. (+ enum)
>>>
>>> I think that:
>>> colorFromString("red");
>>> colorFromString!"rgb"("#3212ff");
>>> colorFromString!"bgra"("#ff1232dd");
>>>
>>> makes more sense.
>>>
>>> Andrea
>>
>>
>> Why? I see no value in that function being a template... It's not like you
>> can confuse "#FF0080" and "LightGoldenrodYellow". As far as I know, there's
>> no possible ambiguity in colour strings, so why make them separate
>> functions?
>
>
> But it would be useful to create rgb, bgr, argb, bgra, or other color space
> using a string.

Give the preferred format as template arg?

> If a third party library or source gives me code in rgba, I have to
> preprocess it to convert as argb and then pass it to your library.

Sorry, what are we talking about? My lib supports basically every
format or arrangement I've ever encountered... you can work with
practically any data format you can think of.

> Anyway, I don't know if a code with letters a-f can be composed. In that
> case an ambiguity exists.

It must also be exactly 3,4,6,8 letters long, and begin with the
letter '#' or '$' ;)


I'm not sure why it matters what format the colour you have is...
Strings are in the form #RRGGBB, or #AARRGGBB. That is all.
It's the standard I've seen used everywhere ever, including the web,
which is a pretty good precedent :P
If you support swizzled forms of strings, then ambiguity exists.
Better not to allow it.

If you want a BGR from a string, use: colorFromString!BGR8("#FF0000");
If you want Lab: colorFromString!(Lab!float)("#FF0000");