kernel-shark: Add VirtBridge and VirtGap classes

The two simple plotting classes will be used to visualise the
guest->host data correlations.

Link: https://lore.kernel.org/linux-trace-devel/20201209134530.428368-10-y.karadz@gmail.com

Signed-off-by: Yordan Karadzhov (VMware) <y.karadz@gmail.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>

2 files changed, 69 insertions, 0 deletions

diff --git a/src/KsPlotTools.cpp b/src/KsPlotTools.cpp
index 9f983864..8d380094 100644
--- a/src/KsPlotTools.cpp
+++ b/src/KsPlotTools.cpp
@@ -1460,4 +1460,26 @@ void Graph::draw(float size)
 	}
 }
 
+void VirtGap::_draw(const Color &col, float size) const
+{
+	if (_entryPoint.x() - _exitPoint.x() < 4)
+		return;
+
+	Point p0(_exitPoint.x() + _size, _exitPoint.y());
+	Point p1(_exitPoint.x() + _size, _exitPoint.y() - _height);
+	Point p2(_entryPoint.x() - _size , _entryPoint.y());
+	Point p3(_entryPoint.x() - _size , _entryPoint.y() - _height);
+
+	Rectangle g;
+
+	g.setPoint(0, p0);
+	g.setPoint(1, p1);
+	g.setPoint(2, p2);
+	g.setPoint(3, p3);
+
+	g._color = {255, 255, 255}; // The virt. gap is always white.
+	g.setFill(false);
+	g.draw();
+}
+
 } // KsPlot
diff --git a/src/KsPlotTools.hpp b/src/KsPlotTools.hpp
index 4a7ca0a6..b9b93f37 100644
--- a/src/KsPlotTools.hpp
+++ b/src/KsPlotTools.hpp
@@ -578,6 +578,53 @@ private:
 	int	_firstBinOffset();
 };
 
+/**
+ * This class represents the graphical element visualizing how the execution
+ * goes from the host to the guest and back.
+ */
+class VirtBridge : public Polyline {
+public:
+	/** Create a default VirtBridge. */
+	VirtBridge() : Polyline(4) {}
+
+	/* Keep this destructor virtual. */
+	virtual ~VirtBridge() {}
+
+	/** Set the coordinates of the EntryHost point of the VirtBridge. */
+	void setEntryHost(int x, int y) {setPoint(0, x, y);}
+
+	/** Set the coordinates of the EntryGuest point of the VirtBridge. */
+	void setEntryGuest(int x, int y) {setPoint(1, x, y);}
+
+	/** Set the coordinates of the ExitGuest point of the VirtBridge. */
+	void setExitGuest(int x, int y) {setPoint(2, x, y);}
+
+	/** Set the coordinates of the ExitHost point of the VirtBridge. */
+	void setExitHost(int x, int y) {setPoint(3, x, y);}
+};
+
+/**
+ * This class represents the graphical element visualizing the time interval
+ * in the guest during which the execution has been returned to the host.
+ */
+class VirtGap : public Shape {
+public:
+	/** Create a VirtGap with height "h". */
+	VirtGap(int h) :_height(h) {}
+
+	/**  The point where the execution exits the VM. */
+	Point _exitPoint;
+
+	/** The point where the execution enters the VM. */
+	Point _entryPoint;
+
+private:
+	/** The vertical size (height) of the graphical element. */
+	int _height;
+
+	void _draw(const Color &col, float size) const;
+};
+
 }; // KsPlot
 
 #endif  /* _KS_PLOT_TOOLS_H */