Method pullBuffer

src/backends/RtAudio/RtAudio.cpp:4299–4360

attempt to pull a buffer from the ring buffer from the current "out" index

    // attempt to pull a buffer from the ring buffer from the current "out" index
    bool pullBuffer(char * buffer, unsigned int bufferSize, RtAudioFormat format)
    {
        if (!buffer ||  // incoming buffer is NULL
            bufferSize == 0 ||  // incoming buffer has no data
            bufferSize > bufferSize_)  // incoming buffer too large
        {
            return false;
        }

        unsigned int relInIndex = inIndex_;
        unsigned int outIndexEnd = outIndex_ + bufferSize;
        if (relInIndex < outIndex_ && outIndexEnd >= bufferSize_)
        {
            relInIndex += bufferSize_;
        }

        // the "OUT" index CANNOT BEGIN at the "IN" index
        // the "OUT" index CAN END at the "IN" index
        if (outIndex_ <= relInIndex && outIndexEnd > relInIndex)
        {
            return false;  // not enough space between "out" index and "in" index
        }

        // copy buffer from internal to external
        int fromZeroSize = outIndex_ + bufferSize - bufferSize_;
        fromZeroSize = fromZeroSize < 0 ? 0 : fromZeroSize;
        int fromOutSize = bufferSize - fromZeroSize;

        switch (format)
        {
            case RTAUDIO_SINT8:
                memcpy(buffer, &((char *) buffer_)[outIndex_], fromOutSize * sizeof(char));
                memcpy(&((char *) buffer)[fromOutSize], buffer_, fromZeroSize * sizeof(char));
                break;
            case RTAUDIO_SINT16:
                memcpy(buffer, &((short *) buffer_)[outIndex_], fromOutSize * sizeof(short));
                memcpy(&((short *) buffer)[fromOutSize], buffer_, fromZeroSize * sizeof(short));
                break;
            case RTAUDIO_SINT24:
                memcpy(buffer, &((S24 *) buffer_)[outIndex_], fromOutSize * sizeof(S24));
                memcpy(&((S24 *) buffer)[fromOutSize], buffer_, fromZeroSize * sizeof(S24));
                break;
            case RTAUDIO_SINT32:
                memcpy(buffer, &((int *) buffer_)[outIndex_], fromOutSize * sizeof(int));
                memcpy(&((int *) buffer)[fromOutSize], buffer_, fromZeroSize * sizeof(int));
                break;
            case RTAUDIO_FLOAT32:
                memcpy(buffer, &((float *) buffer_)[outIndex_], fromOutSize * sizeof(float));
                memcpy(&((float *) buffer)[fromOutSize], buffer_, fromZeroSize * sizeof(float));
                break;
            case RTAUDIO_FLOAT64:
                memcpy(buffer, &((double *) buffer_)[outIndex_], fromOutSize * sizeof(double));
                memcpy(&((double *) buffer)[fromOutSize], buffer_, fromZeroSize * sizeof(double));
                break;
        }

        // update "out" index
        outIndex_ += bufferSize;