MCC::ScalePattern Class Reference

Root-independent scale structure: up to twelve ascending degrees. More...

#include <ScalePattern.h>

Collaboration diagram for MCC::ScalePattern:

Public Member Functions
constexpr	ScalePattern () noexcept
	Creates the invalid pattern (SPEC-ERR-2).
constexpr bool	IsValid () const noexcept
	Returns true unless this is the invalid pattern.
MCC_CONSTEXPR14 uint8_t	DegreeCount () const noexcept
	Returns the number of degrees, or 0 for the invalid pattern.
MCC_CONSTEXPR14 Interval	DegreeInterval (int32_t degree) const noexcept
	Returns the ascending interval from the root to degree (1-based), or the invalid interval outside [1, DegreeCount()].
MCC_CONSTEXPR14 bool	ContainsSemitone (int32_t semitones) const noexcept
	Returns true when a degree lies semitones (reduced modulo 12) above the root.

Static Public Member Functions
static constexpr ScalePattern	Invalid () noexcept
	Returns the invalid pattern.
static MCC_CONSTEXPR14 ScalePattern	FromFormula (const char *formula) noexcept
	Builds a pattern from a degree formula such as "1 2 b3 4 5 b6 b7".

Static Public Attributes
static constexpr uint8_t	MaximumDegrees = 12
	Largest number of degrees: every chromatic semitone.

Friends
struct	Detail::ScalePatternStorage
MCC_CONSTEXPR14 bool	operator== (const ScalePattern &a, const ScalePattern &b) noexcept
	Compares degrees, including their written steps.
MCC_CONSTEXPR14 bool	operator!= (const ScalePattern &a, const ScalePattern &b) noexcept
	Negation of operator==.

Detailed Description

Root-independent scale structure: up to twelve ascending degrees.

Each degree stores its diatonic steps (0-6) and semitones (0-11) above the root, so a scale spelled from any root keeps its written letters: the third degree of a major pattern is always a third (SPEC-SCL-2). Semitones are strictly ascending and the first degree is the perfect unison (SPEC-SCL-1).

A pattern is eight bytes, trivially copyable and allocation-free, so the same representation is stored in the flash catalog (SPEC-EMB-5). Default construction and every malformed input produce the single invalid pattern (SPEC-ERR-1..3).

Member Function Documentation

FromFormula()

MCC_CONSTEXPR14 ScalePattern MCC::ScalePattern::FromFormula ( const char * formula )

inlinestaticnoexcept

Builds a pattern from a degree formula such as "1 2 b3 4 5 b6 b7".

Each space-separated token is an optional run of b or # followed by a degree number from 1 to 7, read against the major scale. The formula must start with 1 and its semitones must be strictly ascending inside one octave; otherwise the invalid pattern is returned.

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The documentation for this class was generated from the following file:

• src/MCC/Scale/ScalePattern.h