Re: Mainstream Ada

["Joachim Schröer" <joachim.schroeer@dornier.eads.net>]

Al Mole wrote:

> Would you say it was advisable to attempt a games engine in Ada using the
> OpenGL bindings ?
> 


Why not? I think it has been done already. There were some threads
on CLA concerning this topic.
My experience is mainly 2D with a few 3D components you need for
flight instruments (except this XEarth variant published on the link I 
gave yesterday).
The key abstractions I made may be implemented in each OO language as
there is: incorporate the state of a rigid body
(3D position and 3D attitude) in the object; push/pop the modelview
matrix before translate/rotate using that state. So you may implement
modular graphical objects using relative coordinate systems.
But in Ada besides finding errors early you have some benefits, e.g.:
Neither in the Win32 nor in the GLUT implementation I got these bloody
timers to work. So I implemented animation by an extra task. Or:
A C-program generated from a Simulink aircraft model feeds the OpenGL
program with the actual aircraft state which is used to drive the
instruments. The flight model runs with a fixed frequency that is
dictated to stabilize the simulator control loops. The OpenGL program
runs as fast as the actual OpenGL HW allows. A protected object
synchronizes the access to this data. I newer used semaphores or so
to solve those kind of problems. You just don't need to care about this
low level stuff. And the Java guys with their synchronized and thread
classes may impress a C++ programmer but no Ada95 one.

Best regards


> "Joachim Schr�er" <joachim.schroeer@dornier.eads.net> wrote in message
> news:3C8601CB.6050906@dornier.eads.net...
> 
>>Kevin Cline wrote:
>>
>>
>>>Hyman Rosen <hyrosen@mail.com> wrote in message
>>>
> news:<3C78943B.9030600@mail.com>...
> 
>>>>Richard Riehle wrote:
>>>>
>>>>
>>>>>At present, functional requirements overshadow non-functional
>>>>>
>>>>>requirements in the world of commercial software. That is,
>>>>>features are easier to sell than quality.
>>>>>
>>>>You know we usually fight over Ada vs. C++ issues, but I think
>>>>I'm going to take Ada's side here. I don't like Ada all that
>>>>much, but it's mostly for stylistic reasons. I believe, however,
>>>>that an Ada programmer can pound out features just as well, and
>>>>just as quickly, as a Java or C++ programmer. Are you really
>>>>suggesting that commercial software developers who choose Ada
>>>>will have to forego adding features to their software?
>>>>
>>>>
>>>The fundamental problem continues to be the lack of high-quality
>>>bindings to non-Ada facilities, e.g. OpenGL, Qt, relational databases,
>>>
> etc.
> 
>>>This does indeed make it much more difficult to add features
>>>to Ada applications.
>>>
>>>
>>There are bindings to nearly all important libraries. I developed the
>>instrument displays of flight simulators in Ada on top of OpenGL.
>>The kernel of the class library is free and can be found on
>>www.adapower.com/schroer
>>There is also the possibility to generate your own bindings e.g.
>>with C2Ada.
>>
>>
>>Best regards
>>J. Schr�er
>>
>>
> 
>