RingBuffer.h

/**
 * Simple ring buffer which is always the same length
 * for keeping a stream of float input values
 * Designed to give a snapshot in time 
 *
 * TODO: use vector queue to store values instead of array pointer
 */

class RingBuffer
{
public:
    RingBuffer (int bufferSize) : bufferSize (bufferSize), count (0), head (0), buffer (nullptr), readBuffer (nullptr)
    {
        buffer     = new float[bufferSize];        
        readBuffer = new float[bufferSize];    
    }

    ~RingBuffer() 
    {
        delete buffer;
        delete readBuffer;
    }
    
    void push (float value)
    {
        if (count < bufferSize && head == 0)
        {
            buffer[count++] = value;
        }
        else if (count >= bufferSize)
        {
            if (head >= bufferSize)
            {
                head = 0;
            }
            buffer[head++] = value;
        }
    }

    /**
     * Return a snapshot of the buffer as a continous array
     */
    const float* getSnapshot () 
    {
         // Set up read buffer as continuous stream
         int readIndex = head;
         for (int i = 0; i < count; i++)
         {
             readBuffer[i] = buffer[readIndex];
             readIndex = (readIndex + 1) % bufferSize;
         }
         return readBuffer;
    }
    
private:
    int bufferSize, head, count;
    float* buffer;
    float* readBuffer;
};

Hello Adam
in push:
If bufferSize is 256 and head is 255:
buffer[head++] = value; // sets value to element 255 and increase head to 256

in getSnapshot:
head and readIndex will be 256
readBuffer[i] = buffer[readIndex]; // read element 256 which is outside the buffer !

Could this solve the problem:

void push (float value)
    {
        if (count < bufferSize && head == 0)  {
            buffer[count++] = value;
        }     else if (count >= bufferSize) {
            buffer[head++] = value;
            if (head >= bufferSize) {
                head = 0;
            }
        }
    }

Regards, Oliver

Thanks for spotting that! I'll test and update accordingly. The code could also be improved by using memcpy in getSnapshot instead of the for loop. I still haven't gotten around to that!