Controllers

Any information in a Modalys synthesis which can be changed over time by the user is specified by controllers. This is very important to the modular construction of Modalys because, after having created a complicated instrument, one can put the majority of detailed information in a “black box” and simply turn the knobs of certain controllers in order to make a sound. Controllers vary in dimension and “intelligence.” Single-dimension controllers are used to control a single value, whereas multi-dimensional controllers are needed to control more complex parameters, such as the (x, y) location of an access on a plate, just to give one practical example.

There are two general categories of controllers in Modalys: constant and dynamic.

Constant controllers are the simplest type of controller. They represent a “knob” or “slider” (or an array of them) which remains in one fixed position (a constant value) throughout an entire synthesis. In some cases constant controllers can be replaced with single numerical values as arguments. Generally, though, if a Modalys function calls for a controller, it is best to use a constant controller to set a fixed value for that controller. Some examples are shown on the constant controller's reference page.

Constant controllers are usually created with the following shorthand syntax:

Dynamic controllers are those whose values change over time. They can be as basic as an envelope defining a breakpoint function whose (time, value) pairs are expressed as a list of lists, and more complex controllers can be those which read MIDI files, outputting several values (dimensions) at a time. Some controllers can also themselves be composed of (programming code) functions which look at what is happening in the synthesis and make decisions about how its values should change.

All controllers have the following (text-based) syntax in common:

The dimension value must be provided by the user, even if its value seems obvious. Specific information on the subsequent arguments and parameters for each controller type is found on the controllers' reference pages, themselves.

The following pages contain the individual Modalys controller reference pages. The controllers are organized thematically in categories ranging roughly from basic to complex instead of being ordered alphabetically.

The following are the most basic and commonly used controllers:

• Constant Controller
• Envelope Controller

The following controllers get information from an access, interaction or other point from the Modalys synthesis environment:

• Access Speed Controller
• Access Position Controller
• Access Force Controller
• Connection State Controller
• Last Sample Controller (appears to be broken - does not cause errors, but outputs zero)

• Sound File Controller
• MIDI File Controller

• Dynamic Controller
• Send Message (used with the Dynamic Controller)
• Set Breakpoint (used with the Dynamic Controller) (semi-deprecated)
• Signal Controller

• Scale Controller
• Arithmetic Controller
• Expression Controller
• Foreign Call Controller (only available in the Lisp interface to Modalys)

• Sine Controller
• Random Controller (i.e. White Noise Controller)
• Band-Limited Noise Controller
• Noise Controller (i.e. Band-Limited Impulse Controller)

• Delay Controller
• Bilinear Filter (First Order IIR Filter)
• Biquadratic Filter (Second Order IIR FIlter)
• Constant Bandpass Filter Controller (appears to be broken...)
• Variable Bandpass Filter Controller

• Dimension-Mapping Controller
• Sum Controller
• Spread Controller

• (get-info 'value ... ) - obtain the current value of a controller