-//
-// interpolater.hxx -- routines to handle linear interpolation from a table of
-// x,y The table must be sorted by "x" in ascending order
-//
+/**
+ * \file interpolater.hxx
+ * Routines to handle linear interpolation from a table of x,y The
+ * table must be sorted by "x" in ascending order
+ */
+
// Written by Curtis Olson, started April 1998.
//
// Copyright (C) 1998 Curtis L. Olson - curt@me.umn.edu
#include <simgear/compiler.h>
+#include <vector>
+SG_USING_STD(vector);
+
#include STL_STRING
SG_USING_STD(string);
-#define MAX_TABLE_SIZE 32
-
+/**
+ * A class that provids a simple linear 2d interpolation lookup table.
+ * The actual table is expected to be loaded from a file. The
+ * independant variable must be strictly ascending. The dependent
+ * variable can be anything.
+ */
class SGInterpTable {
+
+ struct Entry
+ {
+ Entry ()
+ : ind(0.0L), dep(0.0L) {}
+ Entry (double independent, double dependent)
+ : ind(independent), dep(dependent) {}
+ double ind;
+ double dep;
+ };
+
int size;
- double table[MAX_TABLE_SIZE][2];
+ vector<Entry> table;
public:
- // Constructor -- loads the interpolation table from the specified
- // file
+ /**
+ * Constructor. Creates a new, empty table.
+ */
+ SGInterpTable();
+
+ /**
+ * Constructor. Loads the interpolation table from the specified file.
+ * @param file name of interpolation file
+ */
SGInterpTable( const string& file );
- // Given an x value, linearly interpolate the y value from the table
- double interpolate(double x);
- // Destructor
- ~SGInterpTable( void );
+ /**
+ * Add an entry to the table, extending the table's length.
+ *
+ * @param ind The independent variable.
+ * @param dep The dependent variable.
+ */
+ void addEntry (double ind, double dep);
+
+
+ /**
+ * Given an x value, linearly interpolate the y value from the table.
+ * @param x independent variable
+ * @return interpolated dependent variable
+ */
+ double interpolate(double x) const;
+
+ /** Destructor */
+ ~SGInterpTable();
};