Colour operations using CyberShadow's graphics library

[Phil via Digitalmars-d-learn]

Brilliant, thanks a lot.

That works a treat, allowing me to use c1 + c2 when c1 :: RGB and 
c2 :: ChangeChannelType!(RGB, int), say.

It's not happy with doubles atm, but presumably this is sorted in 
your push. Thanks again :-)

On Monday, 19 January 2015 at 21:11:34 UTC, Vladimir Panteleev 
wrote:
> Hi Phil,
>
> The Color template implements opCast for types with the same 
> set of fields, so you should be able to just cast a struct with 
> ubyte fields to one with double fields (or use std.conv.to). 
> The only restriction is that the fields must have the same 
> order.
>
> You can use the ChangeChannelType template to create a Color 
> type from an existing one but a different type for the channel 
> fields, for example this assert will hold:
>
> static assert(is(ChangeChannelType!(RGB, ushort) == RGB16));
>
> To create a view with double-typed channels from an RGB view, 
> you can use colorMap:
>
> alias doubleTypedView = colorMap!(c => 
> cast(ChangeChannelType!(typeof(c), double))c);
>
> You can use this as with any other view transform:
>
> auto i = onePixel(L8(1));
> auto d = i.doubleTypedView();
> assert(d[0, 0].l == 1.0);
>
> By the way, as I've never tried using floating-point types, the 
> code didn't quite work with them as it is, as some templates 
> expected integral types in a few places. I guess you've fixed 
> things on your side? Anyhow, I've now pushed a commit which 
> fixes and adds tests for FP types.