tempo-plotter Changeset - 6b58eb9e9a3c · protofusion repositories

Changeset - 6b58eb9e9a3c

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Hasan Yavuz ÖZDERYA - 10 years ago 2015-08-15 09:26:15
hy@ozderya.net

re-implemented FrameBuffer as a better ring buffer

2 files changed with 79 insertions and 35 deletions:

framebuffer.cpp

framebuffer.h

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framebuffer.cpp

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@@ @@ -19,80 +19,119 @@ @@
 #include "framebuffer.h"
 FrameBuffer::FrameBuffer(size_t size) :
     data(size, 0.)
 FrameBuffer::FrameBuffer(size_t size)
+{
     _size = size;
     data = new double[_size]();
     headIndex = 0;
+}
 FrameBuffer::~FrameBuffer()
+{
     delete data;
+}
 void FrameBuffer::resize(size_t size)
+{
     size_t old_size = this->size();
     size_t new_size = size;
     int offset = size - _size;
     if (offset == 0) return;
     double* newData = new double[size];
     if (new_size < old_size)
     // move data to new array
     int fill_start = offset > 0 ? offset : 0;
     for (int i = fill_start; i < int(size); i++)
+    {
-        data.remove(0, old_size - new_size);
+        newData[i] = _sample(i - offset);
+    }
     else if (new_size > old_size)
     // fill the beginning of the new data
     if (fill_start > 0)
+    {
         // This is seriously inefficient!
         for (size_t i = old_size; i < new_size; i++)
         for (int i = 0; i < fill_start; i++)
+        {
-            data.prepend(0);
+            newData[i] = 0;
+        }
+    }
     // data is ready, clean and re-point
     delete data;
     data = newData;
     headIndex = 0;
     _size = size;
+}
 void FrameBuffer::addSamples(QVector<double> samples)
+{
     int offset = size() - samples.size();
     if (offset < 0)
     unsigned shift = samples.size();
     if (shift < _size)
+    {
         // new samples exceed the size of frame buffer
         // excess part (from beginning) of the input will be ignored
         for (unsigned int i = 0; i < size(); i++)
         unsigned x = _size - headIndex; // distance of `head` to end
         if (shift <= x) // there is enough room at the end of array
+        {
             data[i] = samples[i - offset];
             for (size_t i = 0; i < shift; i++)
+            {
                 data[i+headIndex] = samples[i];
+            }
             if (shift == x) // we used all the room at the end
+            {
                 headIndex = 0;
+            }
             else
+            {
                 headIndex += shift;
+            }
+        }
         else // there isn't enough room
+        {
             for (size_t i = 0; i < x; i++) // fill the end part
+            {
                 data[i+headIndex] = samples[i];
+            }
             for (size_t i = 0; i < (shift-x); i++) // continue from the beginning
+            {
                 data[i] = samples[i+x];
+            }
             headIndex = shift-x;
+        }
+    }
     else if (offset == 0) // input is the same size as the framebuffer
+    {
         data = samples;
+    }
     else // regular case; input is smaller than framebuffer
     else // number of new samples equal or bigger than current size
+    {
         // shift old samples
         int shift = samples.size();
         for (int i = 0; i < offset; i++)
         int x = shift - _size;
         for (size_t i = 0; i < _size; i++)
+        {
-            data[i] = data[i + shift];
+            data[i] = samples[i+x];
+        }
         // place new samples
         for (int i = 0; i < samples.size(); i++)
+        {
             data[offset + i] = samples[i];
+        }
         headIndex = 0;
+    }
+}
 void FrameBuffer::clear()
+{
-    data.fill(0);
+    for (size_t i=0; i < _size; i++) data[i] = 0.;
+}
 size_t FrameBuffer::size() const
+{
-    return (size_t) data.size();
+    return _size;
+}
 QPointF FrameBuffer::sample(size_t i) const
+{
-    return QPointF(i, data[i]);
+    return QPointF(i, _sample(i));
+}
 QRectF FrameBuffer::boundingRect() const
+{
     return qwtBoundingRect(*this);
+}
 double FrameBuffer::_sample(size_t i) const
+{
     size_t index = headIndex + i;
     if (index >= _size) index -= _size;
     return data[index];
+}

framebuffer.h

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Show inline comments

@@ @@ -28,6 +28,7 @@ class FrameBuffer : public QwtSeriesData @@
+{
 public:
     FrameBuffer(size_t size);
     ~FrameBuffer();
     void resize(size_t size);
     void addSamples(QVector<double> samples);
@@ @@ -39,7 +40,11 @@ public: @@
     QRectF boundingRect() const;
 private:
     QVector<double> data;
     size_t _size; // size of `data`
     double* data;
     size_t headIndex; // indicates the actual `0` index of the ring buffer
     double _sample(size_t i) const;
 };
 #endif // FRAMEBUFFER_H

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