Backwards Compatibilty

Despite its new approach, XPMP2 shall be your drop-in replacement for the original library: The original header files are still provided with the same name. All original public functions are still there. The original XPCAircraft class is still there, now derived from XPMP2::Aircraft.

Changes

A few changes are there, though, for clarity and to be future-proof. Some few require simple code changes:

• All enumerations are now proper enum definitions, i.e. enum typeName {...} instead of typedef int typeName.
• Type XPMPPlaneID is now just an unsigned, no longer a pointer type, so it can be used directly as modeS_id in the new TCAS override approach. Initialisation with NULL or nullptr will not compile, initialise with 0 instead.
• A number of functions and the class XPCAircraft are explicitly marked [[deprecated]], which will raise a few warnings, if your compiler is configured to show them. Just a gentle reminder to update your plugin at some point in time...
• XPMPMultiplayerInitLegacyData will in turn call XPMPMultiplayerInit, and XPMPLoadCSLPackage. The correct future-proof way of initialising the library is to call XPMPMultiplayerInit and then do one or more calls to XPMPLoadCSLPackage.
• Parameters of XPMPMultiplayerInit(LegacyData) have been reshaped and will require a code change. These parameters are needed now (see documentation of header file XPMPMultiplayer.h):
  • your plugin's name (replaces use of XPMP_CLIENT_NAME and XPMP_CLIENT_LONGNAME precompile macros),
  • the path to the resources directory (see here for details),
  • (optionally) a preferences callback function,
  • (optionally) the default aircraft type code,
  • (optionally) a short name / acronym used for logging into Log.txt.
• It is no longer necessary to define the compile-time macros XPMP_CLIENT_NAME and XPMP_CLIENT_LONGNAME. Instead, you can use the new parameter inPluginName in the call to XPMPMultiplayerInit or the function XPMPSetPluginName to set the plugin's name from within your plugin. XPMP2 tries to guess the plugin's name if no name is explicitely set. This allows using the provided libraries directly without the need to recompile.
• XPMPLoadCSLPackage walks directories hierarchically up to 5 levels until it finds an xsb_aircraft.txt file. This should not affect classic usages, where such a path was just one level away from the xsb_aircraft.txt file. It would just also search deeper if needed.
• Available configuration parameters have change, that will be queried in calls to the configuration function callback that you can provide in XPMPMultiplayerInit. Please see the header file documentation for XPMPIntPrefsFuncTy for details.

Backward compatibility is tested intensively with LiveTraffic. LiveTraffic has always used subclassing of XPCAircraft, so you can be very sure that similar implementations will work fine. There have been less tests with the direct C-style interface using XPMPCreatePlane() et al., mostly using the sample plugin included in the package.