SVG to PNG [was: Ada_Arrays Project]

[Nick Roberts <nick.roberts@acm.org>]

M?rio Amado Alves wrote:

> I'm entertaining the idea of a generic package Ada_Arrays and children
> where Ada_Arrays is like Ada.Strings except the element type is
> generic instead of Character.
> 
> Anybody besides me foresees the great usefulness of Ada_Arrays?
> Anybody did it?

I think it's the sort of thing that has been done before by lots of people, 
generally not in a very organised or uniform way. I would guess the biggest 
problem would be that people would be reluctant to pay for this sort of 
thing; they would think "Crikey, I could just as easily write that myself," 
even if they actually were wrong.

> I'm considering doing it by program(med) transformation of existing
> source-code for Ada.Strings. My first studies indicate semantic
> analysis is required, so this might configure an ASIS application.

I suggest that much of the interfaces of the Ada.Strings.*_Strings packages 
are specific to the Character (component) type, and not sensibly applicable 
to a generic array interface. I think this sort of package would be sailing 
perilously close to the treacherous waters of the 'containers controversy'.

> (I'm also interested in this project as a test case for open source
> software licensing. I'd like to release it under a "commercial open
> source" license like one of those endorsed by the Software Developers
> Cooperative (www.softdevelcoop.org). Specially if done by way of
> program transformation from the GPLed GNAT, the licensing of
> Ada_Arrays is a complex issue.)

Allow me to suggest an alternative project, which I believe has a gap in 
the market at the moment, and could be commercially attractive.

I am not aware of any commercial program at the moment which can convert a 
standard SVG source file into a suitable image format file (I suggest PNG 
as the first target to aim at). There is the SVG viewer offered by Adobe, 
but it has problems (bugs, deviation from the standard, certain standard 
facilities not supported, slowness/inefficiency), and I'm not sure that it 
can actually genarate image files anyway. There may be some high-end 
products taht are very expensive, but if so that seems to leave a gap at 
the lower-cost end.

I think this would be a suitable product to be written in Ada, because it 
would require little or no platform-specific code, and it would suit Ada's 
strengths: efficiency and reliability. It would be impossible to 
accommodate any interactive features, of course, and animation would lead 
us to the complexities of animated GIFs or MNG files (but might be possible).

I understand there are some Ada XML packages available (I'm not sure on 
what terms), one of which could be used as a starting point for reading the 
SVG source files. I believe there is an Ada PNG package (again I'm not sure 
about its availablity).

There are further possibilities with conversions between HTML, XSL-FO, 
PS/EPS/PDF, and other presentation formats.

 > Anybody interested in collaborating?

If you're interested in something like this, Mario, I might be interested 
in collaborating. It would be important to plan the project carefully.

-- 
Nick Roberts