PTCell-class: The PTCell class

Description

The PTCell class is the smallest possible element of a PTPattern table. It holds all information on which note to play, at which frequency, with which effect and what kind of triggers or jumps should be applied.

Arguments

Slots

data

A vector of class raw of length 4. The raw data is stored identical to the way it is stored in a ProTracker module file. The character representation is easier to understand, and with the ProTrackR package it shouldn't be necessary to manipulate the raw data directly.

The structure is illustrated with an example. Let's start with a character representation of a PTCell as an example: "C-3 1B A08". The left-hand part of this string shows that this cell will play note "C" in octave 3. The middle part shows that PTSample number 0x1B = 27 will be played. The right-hand part of the string shows that effect "A08" will be applied (which is a volume slide down).

The raw representation of this example would be "10 d6 ba 08", or when I replace the actual values with symbols: "sp pp se ee". Where "ss" represents the sample number, "eee" represents the effect() code and "ppp" represents the period value. The correct note and octave can be derived by looking up the period value in the period_table (which is also implemented in the following methods: note(), octave() and periodToChar()). The period value 0x0d6 = 214 corresponds with note "C" in octave 3.

Author

Pepijn de Vries

Details

The PTCell class consists of a vector of four raw values, as specified in the 'Slots' section. A cell will tell which PTSample is to be played at which frequency (corresponding to a note and octave). If no octave or note is specified, nothing will be played, or if a sample was started to play on the same PTTrack, this sample will continue playing. The PTCell can also hold effect() codes which can be used to add audio effects to the sample being played, change the speed/tempo at which patterns are played, or trigger jumps to other positions within a PTPattern or to other positions in the patternOrder table.

Examples

Run this code

data("mod.intro")

## get the PTCell from mod.intro at
## PTPattern #1, PTTrack #1 and row #1:

cell <- PTCell(mod.intro, 1, 1, 1)

## get the note of this cell:
note(cell)

## get the octave of this cell:
octave(cell)

## get the sampleNumber of this cell:
sampleNumber(cell)

## get the effect code of this cell:
effect(cell)

## get the raw data of this cell:
as.raw(cell)

## get the character representation of this cell:
as.character(cell)