The Gig Performer scripting language, which we have rather unimaginatively named GPScript, is a special purpose procedural language designed to add programmable and responsive functionality to Gig Performer, our plugin host for live performing musicians. While its original purpose was to enable the development team to experiment with ideas that might later be integrated into the main Gig Performer application (as has in fact happened quite a few times), the team recognized that users with some programming language experience might find GP Script to be of interest in its own right and created this manual to help such users become familiar with the basic concepts behind GP Script.
For example, you can write scripts with code that can respond to incoming MIDI note events and then transpose them, make chords out of them constrained to a scale, or use them to change widget values or to directly control parameters of a plugin (keyboard tracking, anyone?). Script code can be triggered in response to your moving a knob, slider or button. There are also time generators that can be used as LFOs (with varying shapes) or as ADSRs.
Up until Gig Performer 3, you could only create and associate a script with each rackspace in a gig file. As of Gig Performer 4 you can create and associate scripts with individual rackspaces, individual songs, scriptlet plugins and a single "gig file" level script, that last providing some very useful control mechanisms.
This document is solely intended to be a reference manual for the GP Script language itself. Beyond the language itself, there exists an extensive run-time library of system functions available and we encourage users interested in working with GP Script to review carefully these system functions.
We assume that users interested in working with GP Script either already have some experience with programming language concepts such as variables, types, statements, function calls, callbacks and so forth or have access to resources through which they can gain some basic programming knowledge. This document is not a tutorial and does not attempt to teach any programming concepts. Users are welcome to ask questions through the scripting section of the Gig Performer community forums but should understand that Deskew Technologies, LLC cannot offer any formal support to teach users how to write programs with GP Script.
More in this chapter:
Events and callbacks
Different kinds of scripts