Greetings all,

I am having a problem properly using the vgl_area function on a vgl_polygon< double> type.  Every time I call the function, it returns an area of 0.0.

Here is some example code that causes this problem for me:

    double x[ 4]= { 1.0, 20.0, 20.0, 1.0};
    double y[ 4]= { 1.0, 1.0, 20.0, 20.0};
    unsigned int size= 4;

    vgl_polygon< double> poly;
    poly.new_sheet();
    poly[ 0].resize( size);
    for( unsigned int ii= 0; ii< size; ++ii) {
        poly[ 0][ ii].set( x[ ii], y[ ii]);
    }

    double area= vgl_area( poly);  // Always returns 0.0
    double area2= vgl_area_signed( poly);  // Also always returns 0.0


I am using Microsoft Visual Studio 2008, with VXL version 1.14.0.  If anyone can let me know what I am doing wrong, I would be very grateful.

Thank you all for your time,

-Nate