Talk:Backwards Compatibility Initiative

• http://wiki.flightgear.org/index.php/Simplifying_Aircraft_Deployment#Feature-based_version_tracking
• http://www.mail-archive.com/flightgear-devel@lists.sourceforge.net/msg20774.html
• "Another thing to bear in mind is that no consideration is given to backwards compatibility in FG development"
• http://www.mail-archive.com/flightgear-devel@lists.sourceforge.net/msg24114.html
• http://www.mail-archive.com/flightgear-devel@lists.sourceforge.net/msg24167.html
• http://www.mail-archive.com/flightgear-devel@lists.sourceforge.net/msg24183.html
• http://flightgear.org/forums/viewtopic.php?f=2&t=7064

Requirements for a flexible Compatibility Scheme in FG

Exposing modifications to internal APIs via the property tree enables FlightGear resources such as XML files or Nasal scripts to dynamically adjust to the runtime environment:

• expose library versions (OSG, SimGear ...) and build/config settings via property tree
• expose full list of fgfs startup parameters and runtime variables via property tree
• expose supported OpenGL extensions via property tree /sim/opengl-extensions/GL_ARB_multitexture
• expose available fgcommands via property tree ( /sim/fgcommands/has-loadxml=true
• expose available Nasal API functions via property tree
• if necessary expose versioning info for API calls (fgcommands/nasal) /sim/fgcommands/loadxml/version
• start versioning SGSubsystems and require changes to be communicated by increasing the version number
• start using feature-based version tracking by communicating new/modified features using the property tree