[seek-dev] change signature for convex hull actor
Matt Jones
jones at nceas.ucsb.edu
Wed Nov 24 15:25:13 PST 2004
Hi Jianting,
I took a look at your convex hull cpp code and I think we should make a
slight change to make the actor easier to use. Right now the actor
requires the number of points as input which is not necessary. Could
you change the function in HullMain.cpp:
int GISHull (char *pointDataFile, int numSitePoints, char *hullDataFile)
to
int GISHull (char *pointDataFile, char *hullDataFile)
This can be implemented by opening the file and reading it, allocating
memory for the points as you go andy dynamically resizing the space for
the Points structure. I would probably allocate space for 100 points at
a time, and then truncate once you know the total number of points read
when you reach EOF (fscanf will return the EOF when it encoutners it).
You can track the number of points as you read them in a counter and if
the points < 3 then return your error value (as you do now). This will
simplify calling the actor, and will make the GISHull function more
robust (because it current is fragile if the numSitePoints is greater
than the actual number of points in the file.
Could you make these changes? If there are analogous simplifications in
the rasterization and buffering actors it would be good to make those
too, but they are less important. Thanks,
Matt
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