pulp::playback::TransportPlayhead Struct Reference

Where the transport is, published for a reader that is not the audio thread. More...

#include <transport.hpp>

Public Member Functions
constexpr bool	operator== (const TransportPlayhead &) const =default

Public Attributes
std::uint64_t	sequence = 0
	Monotonic per publish.
std::uint64_t	playback_epoch = 0
	Identity of the continuous playback interval this reading belongs to.
timebase::TickPosition	position {}
	Position of the FIRST frame of the published block.
LoopRegion	loop {}
double	tempo_bpm = 120.0
bool	is_playing = false
	True whenever the position advances on its own.
bool	scrubbing = false

Detailed Description

Where the transport is, published for a reader that is not the audio thread.

This is the counterpart to TransportSnapshot, and the difference is the lifetime of what it carries. A snapshot borrows const CompiledTempoMap* from the compiled program, which is correct for a block renderer that consumes it inside the callback that produced it, and unsafe for a view that keeps a copy across frames while the engine may adopt a different program underneath. Every field here is a value, so a retained reading goes stale, never invalid.

The vocabulary is the transport's own. Projecting a reading into the UI vocabulary a timeline editor speaks is the job of whoever implements that seam, because playback's dependency floor excludes the editor rung.

Member Function Documentation

operator==()

bool pulp::playback::TransportPlayhead::operator== ( const TransportPlayhead & ) const

constexprdefault

Member Data Documentation

is_playing

bool pulp::playback::TransportPlayhead::is_playing = false

True whenever the position advances on its own.

Mirrors TransportSnapshot::is_playing, so it is also true while scrubbing and a reader asking only "does the playhead move" needs no scrub branch.

loop

LoopRegion pulp::playback::TransportPlayhead::loop {}

playback_epoch

std::uint64_t pulp::playback::TransportPlayhead::playback_epoch = 0

Identity of the continuous playback interval this reading belongs to.

A change means continuity broke, so a reader interpolating between two readings must not interpolate across one.

position

timebase::TickPosition pulp::playback::TransportPlayhead::position {}

Position of the FIRST frame of the published block.

That frame has not left the device yet, so it is the least-ahead-of-audible position the transport can state; publishing the block's end would put every reading one buffer into the future.

scrubbing

bool pulp::playback::TransportPlayhead::scrubbing = false

sequence

std::uint64_t pulp::playback::TransportPlayhead::sequence = 0

Monotonic per publish.

Two readings with the same value are the same reading, which is how a reader skips redundant work. Zero means nothing has been published yet. reset() deliberately does not restart it: a restarted counter would make a new reading indistinguishable from one a reader already acted on.

tempo_bpm

double pulp::playback::TransportPlayhead::tempo_bpm = 120.0

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

• /home/runner/work/pulp/pulp/core/playback/include/pulp/playback/transport.hpp