Added a parseChunk function for parsing chunk strings like w080n40.

src/Lib/Geometry/util.cxx

@@ -8,6 +8,7 @@
 
 #include <simgear/debug/logstream.hxx>
 #include <simgear/math/sg_geodesy.hxx>
+#include <simgear/misc/exception.hxx>
 
 #include <Polygon/polygon.hxx>
 
@@ -144,4 +145,38 @@ makePolygon (const Line &line, int width, FGPolygon &polygon)
 }
 
 
+Rectangle
+parseChunk (const string &s)
+{
+  Rectangle bounds;
+  int x_factor;
+  int y_factor;
+
+  if (s.size() != 7)
+    throw sg_exception(string("Bad length for chunk specifier: ") + s);
+
+  if (s[0] == 'w')
+    x_factor = -1;
+  else if (s[0] == 'e')
+    x_factor = 1;
+  else
+    throw sg_exception(string("Chunk specifier must begin with 'e' or 'w': "
+			      + s));
+
+  if (s[4] == 's')
+    y_factor = -1;
+  else if (s[4] == 'n')
+    y_factor = 1;
+  else
+    throw sg_exception("Second part of chunk specifier must begin with 's' or 'n': " + s);
+
+  
+  double x = atoi(s.substr(1,3).c_str()) * x_factor;
+  double y = atoi(s.substr(5).c_str()) * y_factor;
+  bounds.setMin(Point3D(x, y, 0));
+  bounds.setMax(Point3D(x + 10, y + 10, 0));
+
+  return bounds;
+}
+
 // end of util.cxx

src/Lib/Geometry/util.hxx

@@ -14,6 +14,9 @@
 #include <simgear/compiler.h>
 #include <simgear/math/point3d.hxx>
 
+#include <string>
+SG_USING_STD(string);
+
 #include <Polygon/polygon.hxx>
 
 #include "line.hxx"
@@ -84,4 +87,13 @@ void makePolygon (const Point3D &p, int width, FGPolygon &polygon);
 void makePolygon (const Line &line, int width, FGPolygon &polygon);
 
 
+/**
+ * Parse a chunk string (like "w080n40") into a rectangle.
+ *
+ * @param s The string.
+ * @return A rectangle containing the bounds.
+ */
+Rectangle parseChunk (const string &s);
+
+
 #endif // __UTIL_HXX