Initial feedback for std.experimental.image

[rikki cattermole via Digitalmars-d]

On Thursday, 9 July 2015 at 23:35:02 UTC, Vladimir Panteleev 
wrote:
> On Tuesday, 7 July 2015 at 03:39:00 UTC, Rikki Cattermole wrote:
>> I've been sold on the unsigned vs signed type issue for and 
>> only for the x and y coordinates.
>
> The first version of ae.utils.graphics had unsigned 
> coordinates. As I found out, this was a mistake.
>
> A rule of thumb I discovered is that any numbers you may want 
> to subtract, you should use signed types. Otherwise, operations 
> such as drawing an arc with its center point off-canvas (with 
> negative coordinates) becomes unreasonably complicated.

Canvas API != image library.
I'm quite happy for the canvas API to use signed integers. While 
the image library does not. After all the canvas API would just 
wrap how its being stored.
You lose the ability to have such large images as the CPU 
architecture can support but meh. Not my problem.

The canvas API being built on top should sanitise coordinates as 
need be. This is not unreasonable.

Little unknown fact is Devisualization.Util features a type 
called LineGraph which basically gets points based upon 
primitives such as lines and arcs. With support for deltas.
https://github.com/Devisualization/util/blob/master/source/core/devisualization/util/core/linegraph.d
Of course it was buggy but, I ran into the same issue you did. My 
view is definitely canvas should be signed. Just the underlying 
image storage type doesn't need to use it.