[AD] Skater + AllegroGL

[Milan M. <mil...@gm...>]

I'm proud to announce that the Skater demo now can work with AllegroGL, 
using hardware acceleration if available, without a single OpenGL 
command in the game code.

The only modification to the game code consist of:
- added code for AGL initialization (mandatory)
- added new gfx update driver (mandatory)
- convert all bitmaps to video bitmaps on load (not mandatory, but the 
whole thing losses sense without this)
- added support for AGL fonts support (quite extensive modification) [1]
- used
  rectfill(buffer, 0, 0, buffer->w, fixtoi(lowy) + 1, getpixel(cloud, 0, 
0));
  instead of:
  set_clip_rect(buffer, 0, 0, buffer->w, fixtoi(lowy));
  clear_to_color(buffer, getpixel(cloud, 0, 0));
  set_clip_rect(buffer, 0, 0, buffer->w, buffer->h);
  to workaround a AGL bug.  (not a big deal)
- other really minor things.

I think I didn't miss anything.


Differences to non-AGL Skater that I can notice:
- higher FPS and less CPU time used :)
- the "transition" animation looks a bit broken
- the grass (the surface where our hero is skating) contains pink 
pixels. That's because 3D polygons with masked textures are not 
supported by AGL and probably will never be. I am asking here if I can 
change the grass sprite the use sky-blue at those spots? It's all blue 
background anyways.


With this I'm trying to show you that AGL's gfx driver is becoming 
mature for more serious usage. I think it is ready for 4.3 branch.


To try it out:

- get AllegroGL from SVN:
svn co https://allegrogl.svn.sourceforge.net/svnroot/allegrogl/trunk allegro

Compile & install AGL.


- get Skater from SVN:
svn co https://alleg.svn.sourceforge.net/svnroot/alleg/demos/skater skater

- apply the attached patch to Skater.
cd skater/
patch -p0 <skater_agl.diff

Compile Skater using "scons" command. If you wish to build Skater with 
disabled AllegroGL support remove the two related defines from 
SConstruct file.


[1] If SKATER_USE_ALLEGRO_GL_FONT is defined (default) Skater will use 
AGL fonts. These are faster then regular Allegro fonts but currently 
cannot be drawn
onto video bitmaps, thus text will not display during the "transition" 
animation which lasts for 0.3 seconds by the way. Regular Allegro fonts 
could be
used instead, they which can be drawn onto video bitmaps and do not 
require modification of the existing code... The only drawback is that 
they are very slow. To try it out with regular Allegro fonts undefine 
ALLEGRO_USE_ALLEGRO_GL_FONT in SConstruct file.

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