Karya, built on Mon Jul 24 11:39:07 PDT 2017 (patch 33511aca01257b76b88de7c7a2763b7a965c084e)

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Derive.Scale.Scales

Contents

Description

Utilities for simple scales, which simply map pitch names to frequencies. Ok, so they also have octave structure, used by the input mechanism and to parse to Pitch.Pitches, but it can be set to the number of degrees in the scale if you don't have octaves.

Synopsis

Documentation

make_scale :: Pitch.ScaleId -> DegreeMap -> Text -> Doc.Doc -> Scale Source #

Make a simple scale where there is a direct mapping from input to note to nn.

empty_scale :: Pitch.ScaleId -> Text -> DocumentedCall -> Scale Source #

An empty scale that doesn't do anything.

types

data DegreeMap Source #

Constructors

DegreeMap 

Fields

degree_map Source #

Arguments

:: Pitch.PitchClass 
-> Pitch.Octave

The first Note is this Octave and PitchClass.

-> Pitch.PitchClass 
-> [Pitch.Note] 
-> [Pitch.NoteNumber] 
-> DegreeMap 

scale functions

transpose

non_transposing :: Transpose Source #

Transpose function for a non-transposing scale.

standard_transposers :: Set Control Source #

Indicate that this scale responds to the standard set of transpose signals. It still has to implement the support in its scale_note_to_call.

note_to_call

mapped_note_to_call :: DegreeMap -> BaseTypes.Scale -> Pitch.Note -> Maybe.Maybe ValCall Source #

A specialization of note_to_call that operates on scales with a DegreeMap, i.e. a static map from notes to degrees, and from degrees to NNs.

note_to_call :: Pitch.Semi -> BaseTypes.Scale -> SemisToNoteNumber -> (Pitch.Semi -> Maybe.Maybe Pitch.Note) -> ValCall Source #

Create a note call that respects chromatic and diatonic transposition. However, diatonic transposition is mapped to chromatic transposition, so this is for scales that don't distinguish.

input

input_to_note :: DegreeMap -> InputToNote Source #

Input to note for simple scales without keys.

mapped_input_to_nn :: DegreeMap -> InputToNn Source #

Input to NoteNumber for scales that have a direct relationship between Degree and NoteNumber.

direct_input_to_nn :: InputToNn Source #

An Input maps directly to a NoteNumber. This is an efficient implementation for scales tuned to 12TET.

This obeys Controls.octave but none of the other transposer controls. This is inconsistent with computed_input_to_nn, but trying to implement diatonic transposition would make this not so direct any more. And in any case, Cmd.MidiThru shouldn't let through any transposers other than octave.

computed_input_to_nn :: InputToNote -> (Pitch.Note -> Maybe.Maybe ValCall) -> InputToNn Source #

Convert input to nn by going through note_to_call. This works for complicated scales that retune based on the environment but is more work.

diatonic

lookup_kbd_to_scale :: Pitch.KbdType -> Pitch.PitchClass -> Pitch.PitchClass -> Pitch.Pitch -> Maybe.Maybe Pitch.Pitch Source #

Convert an absolute Pitch in the input keyboard's layout to a relative Pitch within a scale with the given number of diatonic steps per octave, or Nothing if that key should have no pitch.

piano_kbd_pitch :: Pitch.PitchClass -> Pitch.PitchClass -> Pitch.Pitch -> Maybe.Maybe Pitch.Pitch Source #

The MIDI kbd is absolute. This means that relative scales start on different keys rather than all starting on C. For example, in C major C produces the first scale degree, while in D major D produces the first scale degree.

In addition, if the scale octave is not an even multiple of the kbd octave (7), the extra notes produce Nothing. This check has to be done to the relative PitchClass. That way, a D on a 6 note scale starting on D is 1, and a C is Nothing. Thus, the returned Pitch is relative to the given tonic, so it should be formatted as-is, without the key.

ascii_kbd_pitch :: Pitch.PitchClass -> Pitch.Pitch -> Pitch.Pitch Source #

The ASCII kbd is relative. This means that relative scales always start on "C". So the tonic note of a key in a relative scale is irrelevant, C major and D major both start in the same place. Of course, they produce different frequencies, but that's the responsibility of scale_note_to_call.

Unlike absolute_to_pitch, if the scale octave is not an even multiple of the kbd octave (10), the extra notes wrap to the next highest octave.

adjust_octave :: Pitch.PitchClass -> Pitch.PitchClass -> Pitch.Octave -> Pitch.PitchClass -> (Pitch.Octave, Pitch.PitchClass) Source #

Try to fit a note from a keyboard into a scale. Round the note up to the nearest multiple of the keyboard octave and adjust the octave accordingly.

call_doc

DocumentedCall

prepend_doc :: Doc.Doc -> DocumentedCall -> DocumentedCall Source #

Prepend a bit of text to the documentation.

util

read_environ Source #

Arguments

:: (Typecheck.Typecheck a, ShowVal.ShowVal a) 
=> (a -> Maybe.Maybe val)

parse or Nothing

-> Maybe.Maybe val

if Just, a missing value gets this, otherwise it's an error

-> BaseTypes.Key 
-> BaseTypes.Environ 
-> Either BaseTypes.PitchError val 

Read and parse an environ value, or throw a ScaleError.

read_environ_default :: (Typecheck.Typecheck a, ShowVal.ShowVal a) => (a -> Maybe.Maybe val) -> Maybe.Maybe a -> BaseTypes.Key -> BaseTypes.Environ -> Either BaseTypes.PitchError val Source #

Like read_environ, except the default is given to the parse function.

parse_environ Source #

Arguments

:: Typecheck.TypecheckSymbol val 
=> Maybe.Maybe val

if Just, a missing value gets this, otherwise it's an error

-> BaseTypes.Key 
-> BaseTypes.Environ 
-> Either BaseTypes.PitchError val 

This is read_environ, but for instances of Typecheck.TypecheckSymbol.

keys

get_key :: key -> Map Pitch.Key key -> Maybe.Maybe Pitch.Key -> Either BaseTypes.PitchError key Source #

Find a key in a map, or throw a ScaleError.