# HG changeset patch
# User Hasan Yavuz ÖZDERYA <hy@ozderya.net>
# Date 2018-09-25 16:38:30
# Node ID 7dd5ac90961fb227543dce5a696f054816bd9334
# Parent  2541096f1ba6bbdbedd6ceaf538f63fa2b7a8a12

optimized search for findIndex

diff --git a/src/framebuffer.h b/src/framebuffer.h
--- a/src/framebuffer.h
+++ b/src/framebuffer.h
@@ -61,4 +61,24 @@ class WFrameBuffer : public ResizableBuf
     virtual void clear() = 0;
 };
 
+/**
+ * Abstract base class for X buffers.
+ *
+ * These buffers only contain increasing or equal (to previous) values.
+ */
+class XFrameBuffer : public ResizableBuffer
+{
+public:
+    enum Index {OUT_OF_RANGE = -1};
+
+    /**
+     * Finds index for given value.
+     *
+     * If given value is bigger than max or smaller than minimum
+     * returns `OUT_OF_RANGE`. If it's in between values, smaller
+     * index is returned (not closer one).
+     */
+    virtual int findIndex(double value) const = 0;
+};
+
 #endif // FRAMEBUFFER_H
diff --git a/src/indexbuffer.cpp b/src/indexbuffer.cpp
--- a/src/indexbuffer.cpp
+++ b/src/indexbuffer.cpp
@@ -1,5 +1,5 @@
 /*
-  Copyright © 2017 Hasan Yavuz Özderya
+  Copyright © 2018 Hasan Yavuz Özderya
 
   This file is part of serialplot.
 
@@ -47,3 +47,15 @@ Range IndexBuffer::limits() const
 {
     return Range{0, _size-1.};
 }
+
+int IndexBuffer::findIndex(double value) const
+{
+    if (value < 0 || value > size() - 1)
+    {
+        return OUT_OF_RANGE;
+    }
+    else
+    {
+        return value;
+    }
+}
diff --git a/src/indexbuffer.h b/src/indexbuffer.h
--- a/src/indexbuffer.h
+++ b/src/indexbuffer.h
@@ -26,15 +26,16 @@
 /// sample value.
 ///
 /// @note This buffer isn't for storing data.
-class IndexBuffer : public ResizableBuffer
+class IndexBuffer : public XFrameBuffer
 {
 public:
     IndexBuffer(unsigned n);
 
-    unsigned size() const;
-    double sample(unsigned i) const;
-    Range limits() const;
-    void resize(unsigned n);
+    unsigned size() const override;
+    double sample(unsigned i) const override;
+    Range limits() const override;
+    void resize(unsigned n) override;
+    int findIndex(double value) const override;
 
 private:
     unsigned _size;
diff --git a/src/stream.cpp b/src/stream.cpp
--- a/src/stream.cpp
+++ b/src/stream.cpp
@@ -31,7 +31,8 @@ Stream::Stream(unsigned nc, bool x, unsi
     _hasx = x;
     if (x)
     {
-        xData = new RingBuffer(ns);
+        // TODO: implement XRingBuffer (binary search)
+        Q_ASSERT(false);
     }
     else
     {
@@ -118,7 +119,8 @@ void Stream::setNumChannels(unsigned nc,
     {
         if (x)
         {
-            xData = new RingBuffer(_numSamples);
+            // TODO: implement XRingBuffer (binary search)
+            Q_ASSERT(false);
         }
         else
         {
@@ -191,7 +193,9 @@ void Stream::feedIn(const SamplePack& pa
     unsigned ns = pack.numSamples();
     if (_hasx)
     {
-        static_cast<RingBuffer*>(xData)->addSamples(pack.xData(), ns);
+        // TODO: implement XRingBuffer (binary search)
+        Q_ASSERT(false);
+        // static_cast<RingBuffer*>(xData)->addSamples(pack.xData(), ns);
     }
 
     // modified pack that gain and offset is applied to
diff --git a/src/stream.h b/src/stream.h
--- a/src/stream.h
+++ b/src/stream.h
@@ -93,7 +93,7 @@ private:
     bool _paused;
 
     bool _hasx;
-    ResizableBuffer* xData;
+    XFrameBuffer* xData;
     QList<StreamChannel*> channels;
 
     ChannelInfoModel _infoModel;
diff --git a/src/streamchannel.cpp b/src/streamchannel.cpp
--- a/src/streamchannel.cpp
+++ b/src/streamchannel.cpp
@@ -20,7 +20,7 @@
 #include <limits>
 #include "streamchannel.h"
 
-StreamChannel::StreamChannel(unsigned i, const FrameBuffer* x,
+StreamChannel::StreamChannel(unsigned i, const XFrameBuffer* x,
               FrameBuffer* y, ChannelInfoModel* info)
 {
     _index = i;
@@ -38,15 +38,19 @@ unsigned StreamChannel::index() const {r
 QString StreamChannel::name() const {return _info->name(_index);};
 QColor StreamChannel::color() const {return _info->color(_index);};
 bool StreamChannel::visible() const {return _info->isVisible(_index);};
-const FrameBuffer* StreamChannel::xData() const {return _x;}
+const XFrameBuffer* StreamChannel::xData() const {return _x;}
 const FrameBuffer* StreamChannel::yData() const {return _y;}
 FrameBuffer* StreamChannel::yData() {return _y;}
 const ChannelInfoModel* StreamChannel::info() const {return _info;}
-void StreamChannel::setX(const FrameBuffer* x) {_x = x;};
+void StreamChannel::setX(const XFrameBuffer* x) {_x = x;};
+
+#include <QtDebug>
 
 double StreamChannel::findValue(double x) const
 {
-    int index = findIndex(x);
+    // int index = findIndex(x);
+    int index = _x->findIndex(x);
+    qDebug() << x << ":" << index;
     if (index >= 0)
         return _y->sample(index);
     else
diff --git a/src/streamchannel.h b/src/streamchannel.h
--- a/src/streamchannel.h
+++ b/src/streamchannel.h
@@ -35,7 +35,7 @@ public:
      * @param info channel info model
      */
     StreamChannel(unsigned i,
-                  const FrameBuffer* x,
+                  const XFrameBuffer* x,
                   FrameBuffer* y,
                   ChannelInfoModel* info);
     ~StreamChannel();
@@ -44,18 +44,18 @@ public:
     QString name() const;
     QColor color() const;
     bool visible() const;
-    const FrameBuffer* xData() const;
+    const XFrameBuffer* xData() const;
     FrameBuffer* yData();
     const FrameBuffer* yData() const;
     const ChannelInfoModel* info() const;
-    void setX(const FrameBuffer* x);
+    void setX(const XFrameBuffer* x);
 
     /// Returns sample value for closest X
     double findValue(double x) const;
 
 private:
     unsigned _index;
-    const FrameBuffer* _x;
+    const XFrameBuffer* _x;
     FrameBuffer* _y;
     ChannelInfoModel* _info;