Passing SAFEARRAY type to Visio win32::ole object from Perl

[ketanh]

Dear Monks,

I'm trying to create a spline object in Visio using win32::OLE in perl. I'm struggling with converting the equivalent macro into perl code, especially the part where I have to pass an array of control points and knots for Visio to generate the spline.

The equivalent macro is:

Sub genSplineMy()
    Dim ControlPoints1(5) As Double
    Dim Knots1(3) As Double
    ControlPoints1(0) = 1.5
    ControlPoints1(1) = 10.25
    ControlPoints1(2) = 2.21642
    ControlPoints1(3) = 10.1541
    ControlPoints1(4) = 2.375
    ControlPoints1(5) = 9.875
    Knots1(0) = 0
    Knots1(1) = 0
    Knots1(2) = 0
    Knots1(3) = 2.66958

    Application.ActiveWindow.Page.DrawNURBS 3, 0, ControlPoints1, Knot
+s1
End Sub

My perl script that is trying to do this:

use strict;
use Win32::OLE qw(in with);
use Win32::OLE::Variant;
use Win32::OLE::Const 'Microsoft Visio';
$Win32::OLE::Warn = 3;

my $Visio = Win32::OLE->new('Visio.Application', 'Quit');
$Visio->{Visible}=1 ;

my $doc = $Visio->Documents->Open("c:\\work\\tools\\perl\\visio\\basic
+_template.vst");
$doc->SaveAs('c:\\work\\tools\\perl\\visio\\test.vdx');

my @controlpoints = (1.5,10.25,1.84606,10.3302,2.21642,10.1541,2.375,9
+.875);
my @knots = (0,0,0,0,2.66958);

my $variant_controlpoints = Win32::OLE::Variant->new(VT_R8|VT_ARRAY|VT
+_BYREF, @controlpoints);
my $variant_knots = Win32::OLE::Variant->new(VT_R8|VT_ARRAY|VT_BYREF, 
+@knots);

$Visio->Application->ActiveWindow->Page->DrawNURBS(3, 0, $variant_cont
+rolpoints, $variant_knots);

$doc->SaveAs('c:\\work\\tools\\perl\\visio\\test.vdx');
$doc->Close;

I get this error when i run the perl script:
OLE exception from "test.vdx - Microsoft Visio":
An exception occurred.
Win32::OLE(0.1709) error 0x86db0898
in METHOD/PROPERTYGET "DrawNURBS" at visio_test.pl line 19

I used the variant type as recommended in the DrawNURBS documentation here: http://msdn.microsoft.com/en-us/library/office/aa224588(v=office.11).aspx
I've tried a bunch of different ways to create that variant and pass it into the DrawNURBS method, but I'm struggling to get it to work.

I can draw a line just fine in Visio using this command

$Visio->Application->ActiveWindow->Page->DrawLine(3.1875, 8.75, 4.875,
+ 7.5);

It's just the spline and the array argument that's evading me.

Would appreciate any perl wisdom I could be offered here.