Re: ANN: OpenGLAda 0.3 and OpenCLAda 0.1 released

[Felix Krause <usenet@flyx.org>]

On 2013-12-26 18:03:26 +0000, Marius Amado-Alves said:

> It builds and runs, but I'd like to sanitize the process.
> The project
> 
>    with "OpenGLAda-0.3/opengl-glfw";
>    project Test is
>       for Main use ("test");
>    end Test;
> 
> gives error: gl.ali not found, gl.adb must be compiled.

I also stumbled upon this problem. I don't know what's the cause, but 
it seems like this is a problem with gnatmake. gl.ali should be copied 
into OpenGLAda-0.3/lib (where GNAT searches for it), but it is not for 
some reason. If you compile the project with gprbuild instead, it works 
as expected. Perhaps someone with more knowledge about 
gnatmake/gprbuild can comment on that?

> If we tell GNAT where they are
> 
>    with "OpenGLAda-0.3/opengl-glfw";
>    project Test is
>       for Object_Dir use "OpenGLAda-0.3/obj";
>       for Main use ("test");
>    end Test;
> 
> it works, but a few problems (my poor command of the GNAT Project 
> language no doubt):
> 
> 1.
> Why do we have to tell GNAT the "OpenGLAda-0.3/obj" path? shouldn't the 
> OpenGLAda project files know that?

What happens when you do that is that GNAT does not need the gl.ali 
file in the OpenGLAda-0.3/lib directory, because it's available 
directly in the directory where the object files of your code are 
placed into. This is a *very* dirty hack and I don't think it's 
guaranteed to work.

> 2.
> The executable gets created inside that path, whereas I wanted it in 
> the base project dir.

You can set "Exec_Dir", which defaults to "Object_Dir" if you don't set it.

> 3.
> The OpenGlAda project files expect external scenario parameters; I am 
> using command line options -X
>     gnatmake -Ptest -Xwindowing_system=windows -Xglfw_version=3
> is it possible to set these params in the project file (test.gpr)?
> (Two avoid having options in two places, command line, project file.)

Currently not. I admit that it was a bad decision to take the GLFW 
version as scenario parameter, and I will revise this in the next 
release. As GLFW 2 and 3 are completely incompatible, the decision 
which one will be used is made in the development stage, not in the 
compilation stage. Therefore, there should be two projects, 
opengl-glfw2.gpr and opengl-glfw3.gpr.

On the other hand, Windowing_System is about platform independence. If 
you set it in your project file (you actually cannot do that, btw), 
your project will only compile on the platform you chose. Therefore, it 
is a scenario variable so that the platform can be chosen when 
compiling the project.

-- 
Felix Krause
http://flyx.org/