op::sdk::timing Namespace Reference

Musical subdivision constants and clock/timing helpers. More...

Functions
uint32_t	beats_to_ticks (float beats, uint32_t bpm)
	Convert musical beats at a given tempo into microseconds.
uint32_t	subdivision_us (uint8_t subdiv, uint32_t bpm)
	Microseconds per single subdivision at the given tempo.
uint32_t	quantize_to_grid (uint32_t tick_us, uint32_t subdiv_us)
	Round a tick value down to the nearest grid boundary.
int32_t	swing_offset (uint32_t tick_us, uint8_t swing_percent, uint32_t subdiv_us)
	Microsecond offset to apply to "every other" subdivision to create swing feel.

Variables
constexpr uint8_t	kSubdiv1 = 0
	Whole note subdivision (4 beats in 4/4).
constexpr uint8_t	kSubdiv_2 = 1
	Half note subdivision.
constexpr uint8_t	kSubdiv_4 = 2
	Quarter note subdivision (one beat).
constexpr uint8_t	kSubdiv_8 = 3
	Eighth note subdivision.
constexpr uint8_t	kSubdiv_16 = 4
	Sixteenth note subdivision.
constexpr uint8_t	kSubdiv_32 = 5
	Thirty-second note subdivision.
constexpr uint8_t	kSubdivTripletQuarter = 6
	Quarter-note triplet (three notes per half-note).
constexpr uint8_t	kSubdivTripletEighth = 7
	Eighth-note triplet (three notes per quarter-note).
constexpr uint8_t	kSubdivTripletSixteenth = 8
	Sixteenth-note triplet (three notes per eighth-note).

Detailed Description

Musical subdivision constants and clock/timing helpers.

Function Documentation

beats_to_ticks()

uint32_t op::sdk::timing::beats_to_ticks ( float beats, uint32_t bpm )

inline

Convert musical beats at a given tempo into microseconds.

Parameters

beats	Fractional beat count.
bpm	Tempo in beats per minute (must be non-zero).

Returns

Duration in microseconds, or 0 if bpm == 0.

quantize_to_grid()

uint32_t op::sdk::timing::quantize_to_grid ( uint32_t tick_us, uint32_t subdiv_us )

inline

Round a tick value down to the nearest grid boundary.

Parameters

tick_us	Microsecond timestamp.
subdiv_us	Grid step in microseconds (typically from subdivision_us).

Returns

Largest multiple of subdiv_us that is <= tick_us.

tick_us unchanged when subdiv_us == 0.

subdivision_us()

uint32_t op::sdk::timing::subdivision_us ( uint8_t subdiv, uint32_t bpm )

inline

Microseconds per single subdivision at the given tempo.

Parameters

subdiv	One of the kSubdiv* constants.
bpm	Tempo in beats per minute (must be non-zero).

Returns

Duration of one step of that subdivision, or 0 for unknown input.

Reference (120 BPM): quarter = 500'000us, eighth = 250'000us, triplet eighth = 166'666us.

Safe for bpm in [1, ...]. The result fits uint32_t for all bpm >= 1 (the worst case, kSubdiv1 at bpm == 1, is 240'000'000us, well within the uint32_t range).

swing_offset()

int32_t op::sdk::timing::swing_offset ( uint32_t tick_us, uint8_t swing_percent, uint32_t subdiv_us )

inline

Microsecond offset to apply to "every other" subdivision to create swing feel.

Parameters

tick_us	Target tick (used to decide whether we are on an even or odd subdivision).
swing_percent	0..100. 50 is "no swing" (straight feel). Higher values delay the off-beat subdivision proportionally.
subdiv_us	Duration of one grid step (see subdivision_us).

Returns

Signed microsecond offset to add to the off-beat's nominal time, 0 on the on-beat or when subdiv_us == 0.

Pass a grid-quantized tick_us (see quantize_to_grid) so the even/odd subdivision classification lands on true grid-step boundaries. An unquantized tick_us near a boundary can flip parity under integer truncation.