LinearXform.g

Code

The code for this and other example scripts can be found in the DataHub distribution archive, typically at one of these locations: C:\Program Files\Cogent\OPC DataHub\scripts\ C:\Program Files\Cogent\Cascade DataHub\scripts\ Please refer to Section 3.1, “How to Run a Script” for more information on using scripts.

/* This script creates a class that performs linear
   transformation functions on DataHub points. */

class LinearXform
{
    verbose;
}

method LinearXform.cbLinearXform (dst, value, mult, add)
{
    if (.verbose)
        princ ("xform ", dst, " = ", value, " * ", mult, " + ", add, "\n");
    if (number_p(value))
        set (dst, value * mult + add);
    else
        set (dst, value);
}

method LinearXform.AddLinearXform (app, src, dst, mult, add, bidirectional_p?=nil)
{
    datahub_command (string ("(create \"", src, "\" 1)"));
    datahub_command (string ("(create \"", dst, "\" 1)"));
    app.OnChange (src, `(@self).cbLinearXform (#@dst, value, @mult, @add));
    if (bidirectional_p && mult != 0)
    {
        allow_self_reference (src, 1);
        allow_self_reference (dst, 1);
        app.OnChange (dst, `(@self).cbLinearXform (#@src, value, @(1/mult), @(-add/mult)));
    }
}