Method renderSample

src/core/SampledAudioNode.cpp:299–437

    }

    bool SampledAudioNode::renderSample(ContextRenderLock& r, Scheduled& schedule, size_t destinationSampleOffset, size_t frameSize)
    {
        std::shared_ptr<AudioBus> srcBus = m_sourceBus->valueBus();
        AudioBus* dstBus = output(0)->bus(r);
        size_t dstChannelCount = dstBus->numberOfChannels();
        size_t srcChannelCount = srcBus->numberOfChannels();
        ASSERT(dstChannelCount == srcChannelCount);

        float* buffer = dstBus->channel(0)->mutableData();
        float rate = totalPitchRate(r);
        if (fabsf(rate - 1.f) < 1e-3f)
        {
            // no pitch modification
            int write_index = (int) destinationSampleOffset;
            while (write_index < AudioNode::ProcessingSizeInFrames)
            {
                int count = AudioNode::ProcessingSizeInFrames - write_index;
                int remainder = schedule.grain_end - schedule.cursor;
                bool ending = remainder < count;
                count = std::min(count, remainder);

                for (int i = 0; i < srcChannelCount; ++i)
                {
                    float* buffer = dstBus->channel(i)->mutableData();
                    VectorMath::vadd(srcBus->channel(i)->data() + schedule.cursor, 1, 
                                     buffer + write_index, 1, buffer + write_index, 1, count);
                }

                schedule.cursor += count;
                write_index += count;

                if (ending)
                {
                    schedule.cursor = schedule.grain_start; // reset to start

                    if (schedule.loopCount > 0)
                        schedule.loopCount--;
                    else if (schedule.loopCount < 0)
                    {
                        // infinite looping
                    }
                    else
                    {
                        schedule.loopCount = -3;    // signal retirement of the schedule
                        break;                      // and stop the write loop
                    }
                }
            }
        }
        else
        {
            while (schedule.resampler.size() < srcBus->numberOfChannels())
            {
                // samplers are expensive to allocate, so if there's one to recycle, use it
                if (_resamplers.size())
                {
                    auto resampler = _resamplers.back();
                    schedule.resampler.push_back(resampler);