Module: Musa::Datasets::DeltaD

Includes:
Delta
Included in:
GDVd
Defined in:
lib/musa-dsl/datasets/delta-d.rb

Overview

Delta events with flexible duration encoding.

DeltaD (Delta Duration) extends Delta events with three different ways to specify duration changes in delta-encoded sequences. This provides flexibility for efficient encoding of musical sequences.

Duration Encoding Modes

:abs_duration - Absolute duration override

Sets duration to an absolute value, regardless of previous duration. Use when duration changes to a completely different value.

{ abs_duration: 2.0 }
# Sets duration to 2.0, ignoring previous

:delta_duration - Incremental duration change

Adds or subtracts from the previous duration value. Use for small adjustments to duration.

{ delta_duration: 0.5 }   # Add 0.5 to previous
{ delta_duration: -0.25 } # Subtract 0.25 from previous

:factor_duration - Multiplicative duration factor

Multiplies previous duration by a factor. Use for proportional changes (doubling, halving, etc.).

{ factor_duration: 2 }    # Double previous duration
{ factor_duration: 0.5 }  # Half previous duration

Natural Keys

  • :abs_duration: Absolute duration value
  • :delta_duration: Duration increment/decrement
  • :factor_duration: Duration multiplication factor

Only one duration key should be present at a time.

Usage in Delta Encoding

Used by GDVd for efficient delta encoding of musical sequences:

Examples:

Different duration encoding modes

previous = { duration: 1.0 }

# Absolute: set to specific value
delta1 = { abs_duration: 2.0 }.extend(DeltaD)
# Result: duration becomes 2.0

# Delta: add to previous
delta2 = { delta_duration: 0.5 }.extend(DeltaD)
# Result: duration becomes 1.5 (was 1.0)

# Factor: multiply previous
delta3 = { factor_duration: 2 }.extend(DeltaD)
# Result: duration becomes 2.0 (was 1.0)

Neuma notation representation

# Absolute duration
{ abs_duration: 1.5 } => "1.5"

# Delta duration
{ delta_duration: 0.5 }  => "+0.5"
{ delta_duration: -0.5 } => "-0.5"

# Factor duration
{ factor_duration: 2 } => "*2"

See Also:

Constant Summary collapse

NaturalKeys =

Natural keys for delta duration encoding.

Only one of these keys should be present in a delta event.

Returns:

  • (Array<Symbol>) —

    natural duration keys

[:abs_duration, # absolute duration
               :delta_duration, # incremental duration
               :factor_duration # multiplicative factor duration
].freeze

Instance Method Summary collapse

Instance Method Details

#valid? ⇒ Boolean Originally defined in module E

Checks if event is valid.

Base implementation always returns true. Subclasses should override to implement specific validation logic.

Examples:

event.valid?  # => true

Returns:

  • (Boolean) —

    true if valid

#validate! ⇒ void Originally defined in module E

This method returns an undefined value.

Validates event, raising if invalid.

Examples:

event.validate!  # Raises if invalid

Raises:

  • (RuntimeError) —

    if event is not valid