Auto detect gfx card "speed"

[Jan Wassenberg]

• divide GPUs into several classes (i.e. crap, latest+greatest, shader capable, etc.)
• measure perf on one sample system from each class, and then compare with performance attained during a test run.
• if there is a test run, warn of a problem similar to what Nicolai experienced: lack of VIA 4in1 driver => AGP disabled => 5FPS when it should be much higher.

Could also use this to autodetect graphics settings based on what the user's system is capable of.

[fabio]

In 17338:

Enable GLSL by default on OpenGL 3+.

This doesn't override any user setting, it just changes the default when no preferglsl setting is specified.

Fixes #3641.
Refs #145.

[fabio]

This is mostly done. There is some detection code in ​hwdetect.js which can enable or disable some features based on specific cards/drivers combination.

• divide GPUs into several classes (i.e. crap, latest+greatest, shader capable, etc.)
• measure perf on one sample system from each class, and then compare with performance attained during a test run.
• Could also use this to autodetect graphics settings based on what the user's system is capable of.
  • this is currently done enabling GLSL on OpenGL3+ cards, while enabling everything[*] on OpenGL4+ cards. Actually only OpenGL2 is required for all features, however 3+ cards are newer and supposed to easily manage GLSL, while 4+ cards should be able to manage everything. This is somewhat arbitrary, since anyway a high end 3+ cards may manage some setting better than a low end 4+ cards, however users can still use the options menu to change their settings if needed; a finer tuning will require a lot of testing and could become obsolete when 0 A.D. renderer or drivers change;
  • there are also cards specific settings that can override the classes based on OpenGL versions.
• if there is a test run, warn of a problem similar to what Nicolai experienced: lack of VIA 4in1 driver => AGP disabled => 5FPS when it should be much higher.
  • there is some detection code that prints a warning when a software renderer is detected;
  • similarly, a warning is printed when a faulty nvidia driver version is detected.

[*] currently material quality setting is not forced, once there is a setting to let users change the default it may also enabled by default on OpenGL 4+ (see #2596).