GP Script has been enhanced significantly for GP4. Apart from numerous new functions, it is now possible to create scripts associated with individual songs, a gigwide gigscript and scriptlets (MIDI processing plugins written with GPScript)
Unfortunately, to accommodate these significant enhancements, there have been a few changes that may cause GP3 scripts to fail or otherwise not compile under GP4 and they will require some minor tweaks to get them working again.
- GPScript handles (associated with plugin blocks) are case-sensitive. GP3 scripts ignored case but in GP4, plugin variables declared in a script must match the plugin handle including case.
- The On Beat callback now properly reports the current bar and beat. In GP3 the beat just incremented continuously and it was necessary to do your own calculations to determine the actual bar. Such calculations are no longer necessary but if you have such calculations, they will need to be removed as they will no longer return correct values.
- The words Song and Songpart are now reserved as they are used by the On Song and On Songpart callbacks (available in song scripts). If you were using either of these words as variable names (for example), you will need to rename them to something else.