Function MixResamplePolyphase

engine/sound/src/sound.cpp:1438–1467

    }

    static inline void MixResamplePolyphase(const MixContext* mix_context, SoundInstance* instance, uint32_t channels, uint64_t delta, float* mix_buffer[], uint32_t mix_buffer_count, uint32_t avail_framecount)
    {
        DM_PROFILE(__FUNCTION__);
        static_assert(SOUND_MAX_MIX_CHANNELS == 2, "this code assumes 2 mix channels");

        PrepTempBufferState(instance, channels);

        float scale_l[SOUND_MAX_DECODE_CHANNELS], scale_r[SOUND_MAX_DECODE_CHANNELS];
        float scale_dl[SOUND_MAX_DECODE_CHANNELS], scale_dr[SOUND_MAX_DECODE_CHANNELS];
        GetRampDelta(channels, mix_context, instance->m_ScaleL, mix_buffer_count, scale_l, scale_dl);
        GetRampDelta(channels, mix_context, instance->m_ScaleR, mix_buffer_count, scale_r, scale_dr);

        uint64_t frac = instance->m_FrameFraction;

        if (channels == 1)
        {
            frac = MixAndResampleMonoToStereo_Polyphase(mix_buffer, g_SoundSystem->GetDecoderBufferBase(0), mix_buffer_count, frac, delta, scale_l[0], scale_r[0], scale_dl[0], scale_dr[0]);
        }
        else
        {
            assert(channels == 2);
            frac = MixAndResampleStereoToStereo_Polyphase(mix_buffer, g_SoundSystem->GetDecoderBufferBase(0), g_SoundSystem->GetDecoderBufferBase(1), mix_buffer_count, frac, delta, scale_l[0], scale_r[0], scale_dl[0], scale_dr[0],
                                                                                                                                                                                    scale_l[1], scale_r[1], scale_dl[1], scale_dr[1]);
        }

        uint32_t next_index = (uint32_t)(frac >> RESAMPLE_FRACTION_BITS);
        instance->m_FrameFraction = frac & ((1U << RESAMPLE_FRACTION_BITS) - 1U);

        SaveTempBufferState(instance, avail_framecount, next_index, channels);
    }

    static inline void MixResample(const MixContext* mix_context, SoundInstance* instance, const dmSoundCodec::Info* info, uint64_t delta, float* mix_buffer[], uint32_t mix_buffer_count, uint32_t avail_framecount)
    {