[AD] display option settings

[Milan Mimica <milan.mimica@xxxxxxxxxx>]

Hi.
There is a number of new display options I want to pull in (most of the ones 
listed at http://allegrogl.sourceforge.net/docs/group__settings.html), and 
originally I wanted to propose a completely new display settings API, but I'm 
hesitant about it. I don't like having a triplet of functions for each option, 
but I wouldn't like to change that now either, so I'll have to deal with it. :-/

So the problem remains: how to specify the new options? Originally I wanted 
something similar to what AllegroGL has, but with some semantics changed:
void al_set_new_display_option(option, val, suggest|request);
int al_get_display_option(option);

Must-have options are:
- The depth of each color component (RGBA) of the framebuffer. This would allow 
pixel formats incompatible with allegro, useful when the user wants to do his 
own drawing with OpenGL, in some custom pixel format.
- z depth - the depth of the z-buffer.
- Initial window position, for windowed mode (could go into multimonitor API if 
we'll have one some day).
- Something called AGL_SAMPLE_BUFFERS and AGL_SAMPLES in AllegroGL, which 
enables antialiasing.
- Something called AGL_FLOAT_COLOR and AGL_FLOAT_Z in AllegroGL, referring to 
floating point framebuffer and z-buffer (fancy things).
- Possibly some other options, because I don't know what does each and every 
option do.

Note that, for most of these options and the ones accepted by 
al_set_new_display_flags(), the user wouldn't want al_create_display() to fail 
if it can't set them. Display frequency is one of them too. "suggest|request" is 
the key feature which the current API is missing.

We could have void al_set_new_display_option(option, val, suggest|request)/
int al_get_display_option(option) in addition to what we have now. But that 
would be inconsistent.

I'm out of clever ideas.


--
Milan Mimica
http://sparklet.sf.net