ApuCore

Class

Source: ApuCore.h

Description

Shared NES-style APU core used by every AudioScheduler.

Owns the 4 channels (2x PULSE, 1x TRIANGLE, 1x NOISE), the SPSC command queue and the music sequencer. Platform-specific schedulers (DefaultAudioScheduler, ESP32AudioScheduler, NativeAudioScheduler) are thin orchestrators that decide when generateSamples() runs; all synthesis, mixing and sequencing lives here to eliminate the three-way duplication that existed before.

Mixing curve: per channel: s_c = wave_c(phase) * volume_c * MIXER_SCALE sum: S = Σ s_c (bounded to [-1.6, 1.6]) compressor: y = S / (1 + |S| * MIXER_K) output: y * masterVolume * 32767, passed through a single-pole DC-blocker to remove offset + transient clicks.

On cores without an FPU (ESP32-C3) the integer-optimised path uses audio_mixer_lut which is pre-fitted to the same curve.

Methods

void init(int sampleRate)

bool submitCommand(const AudioCommand& cmd)

Returns: false if the SPSC queue was full.

void generateSamples(int16_t* stream, int length)

uint32_t getDroppedCommands() const

void setSequencerNoteLimit(size_t limit)

size_t getSequencerNoteLimit() const

size_t getDeferredNotes() const

bool isMusicPlaying() const

bool isMusicPaused() const

int getSampleRate() const

void reset()

void setPostMixMono(void (*fn)(int16_t* mono, int length, void* user), void* user)

void getAndResetProfileStats(ProfileEntry* out, uint8_t& count)