Re: OpenGL in Ada

[BrianG <briang000@gmail.com>]

Shark8 wrote:
> On Jul 9, 9:11 am, Gene <gene.ress...@gmail.com> wrote:
>> On Jul 7, 10:42 pm, Shark8 <onewingedsh...@gmail.com> wrote:
>>> Hello everyone,
>>> I posted about wanting to write an OS in Ada a while ago and, as part
>>> of that effort I've taken to translating the OpenGL API. No, I don't
>>> mean JUST running the headers through ato-Ada converter but actually
>>> translating the API into a more Ada-natural form.
>>> As an example, here is the glColor-'family' of functions:
...
>>> which was rewritten as:
>>>  -- Color Formats
>>>  Procedure Color    ( red, green, blue : in Byte );
>>>  Procedure Color    ( v : RGB_Byte_Vector );
>>>  Procedure Color    ( red, green, blue : in double );
>>>  Procedure Color    ( v : RGB_Double_Vector );
>>>  Procedure Color    ( red, green, blue : in float );
>>>  Procedure Color    ( V : RGB_Float_Vector );
>>>  Procedure Color    ( red, green, blue : int );

One problem you'll have is if a user wants to make a call with all 
literals, i.e. Color(1, 2, 3) or Color(1.0, 2.0, 3.0), the compiler 
won't know which version to use.  The best solution I've found (besides 
making users specify a type) is to have a second name which is defined 
for int and float only (or whatever the default is), but I've come up 
with no good format for the second name:  Color_Literal, Color_L, 
Color1, ...?

(I've tried starting a similar effort, but never got very far.  I was 
using the OpenGL "red book" as a basis; I find it interesting that the 
OpenGL definition recognizes that "some languages like Ada and C++" 
could implement names this way, but every Ada library I've seen follows 
the C naming scheme.)