driveBpmLocked()

float animartrix_ring::SoundOrchestrator::driveBpmLocked ( fl::u32 nowMs, float manualSpeedScalar )

private

Definition at line 194 of file sound_orchestrator.cpp.

                                                                            {
    if (!mProcessor) return manualSpeedScalar;
 
    // Baseline speed scales gently with BPM so faster songs read faster.
    const float bpm = mProcessor->getBPM();
    // Normalize BPM to a 0.6..1.6 multiplier around the nominal 120 BPM.
    float bpmScale = 1.0f;
    if (bpm > 1.0f) {
        bpmScale = bpm / 120.0f;
        if (bpmScale < 0.6f) bpmScale = 0.6f;
        if (bpmScale > 1.6f) bpmScale = 1.6f;
    }
 
    // Pulse: kick/snare/downbeat events bump speed briefly and decay.
    // Downbeats hit hardest (palette-level event); kicks medium; snares light.
    auto pulseFromEvent = [&](fl::u32 t, float weight) -> float {
        if (t == 0) return 0.0f;
        const fl::u32 dt = nowMs - t;
        if (dt >= mCfg.pulseDecayMs) return 0.0f;
        const float k = 1.0f - (static_cast<float>(dt) / mCfg.pulseDecayMs);
        return weight * k * k;  // ease-out square
    };
    const float kickPulse     = pulseFromEvent(mLastKickMs,     0.50f);
    const float snarePulse    = pulseFromEvent(mLastSnareMs,    0.25f);
    const float downbeatPulse = pulseFromEvent(mLastDownbeatMs, 0.80f);
    float pulse = kickPulse + snarePulse + downbeatPulse;
    if (pulse > 1.5f) pulse = 1.5f;
 
    // measurePhase smoothly fills the inter-beat gap so visuals breathe
    // between pulses rather than freezing. Phase is 0..1 within the measure.
    const float phase = mProcessor->getMeasurePhase(); // 0..1
    // Sine bow so phase contributes gently throughout the measure.
    const float phaseBow = 0.15f * fl::sin(phase * 6.2831853f);
 
    float speed = mCfg.bpmLockedBaseSpeed * bpmScale + pulse + phaseBow;
    if (speed < 0.2f) speed = 0.2f;
    return speed * manualSpeedScalar;
}

References bpm(), mCfg, mLastDownbeatMs, mLastKickMs, mLastSnareMs, mProcessor, fl::sin(), speed, and t.

Referenced by tick().

Here is the call graph for this function:

Here is the caller graph for this function: