Programming Web Graphics with Perl and GNU Softwar

Name

vertices( ) — get all the vertices in a polygon

Synopsis

GD::Polygon::vertices()

This method returns all the vertices as a list. Thus, for a list of returned vertices called @vertices, $vertices[0][0] refers to the x value of the first point, and $vertices[1][1] refers to the y value of the second point. You may want to convert this list into a portable string of x, y pairs separated by white space as in the addPt( ) example:

# Save a list of vertices as a string
#
my (@vertices, $polyPoints);

# Get the list of vertices as a two dimensional array
#
@vertices = $polywolly->vertices();

# Iterate over each coordinate pair
#
foreach (@vertices) {
    # Delimit each x, y pair with a comma and each point with a single space
    #
    $polyPoints .= join(join ",", @$_)." ";
}

print "Here's all the points in polywolly: $polyPoints\n";