The flux viewer now properly supports partial redraws.

src/gui2/fluxview.cc

@@ -78,9 +78,11 @@ class FluxViewImpl : public FluxView
 
         painter.setBrush(Qt::NoBrush);
 
-        for (int pixel = startPos / _nanosecondsPerPixel;
-            pixel < t.gradient.size();
-            pixel++)
+        int start = std::max(0, (int)(startPos / _nanosecondsPerPixel));
+        int end = std::min(
+            (int)t.gradient.size(), (int)(endPos / _nanosecondsPerPixel));
+
+        for (int pixel = start; pixel < end; pixel++)
         {
             int c = t.gradient[pixel] * 255;
             painter.setPen(QPen(QColor(0, c, c), 1.5));

src/gui2/fluxvisualiserwidget.cc

@@ -66,6 +66,7 @@ class FluxVisualiserWidgetImpl : public FluxVisualiserWidget
         _numTracks = 0;
         _totalDuration = 0;
         _fluxView = FluxView::create();
+        _fluxView->setScale(_nanosecondsPerPixel);
         repaint();
     }
 
@@ -95,14 +96,18 @@ class FluxVisualiserWidgetImpl : public FluxVisualiserWidget
         painter.setRenderHint(QPainter::Antialiasing);
         _viewNavigator->transform(painter);
 
+        QRectF world =
+            painter.worldTransform().inverted().mapRect(QRectF(event->rect()));
+        nanoseconds_t left = world.left() * _nanosecondsPerPixel;
+        nanoseconds_t right = world.right() * _nanosecondsPerPixel;
         painter.setPen(palette().color(QPalette::Text));
         painter.setBrush(Qt::NoBrush);
 
         for (int i = 0; i < _numTracks; i++)
         {
             painter.save();
-            painter.translate(HBORDER, VBORDER + VSCALE_TRACK_SIZE * i);
-            _fluxView->redraw(painter, 0, 100, i);
+            painter.translate(0, VSCALE_TRACK_SIZE * i);
+            _fluxView->redraw(painter, left, right, i);
             painter.restore();
         }
     }

src/gui2/viewnavigator.h

@@ -6,5 +6,5 @@ class ViewNavigator : public QObject
     static std::unique_ptr<ViewNavigator> create(QWidget* obj);
 
 public:
-    virtual void transform(QPainter& painter)  = 0;
+    virtual void transform(QPainter& painter) = 0;
 };