I am trying to use a Canvas to display objects that have "world" location (rather than "screen" location). The canvas is defined like this:

<Canvas Background="AliceBlue">
    <ItemsControl Name="myItemsControl" ItemsSource="{Binding MyItems}">
        <ItemsControl.ItemTemplate>
            <DataTemplate>
                <Canvas>
                    <TextBlock Canvas.Left="{Binding WorldX}" Canvas.Top="{Binding WorldY}"
                               Text="{Binding Text}"
                               Width="Auto" Height="Auto" Foreground="Red" />
                </Canvas>
            </DataTemplate>
        </ItemsControl.ItemTemplate>
    </ItemsControl>
</Canvas>

MyItem is defined like this:

public class MyItem
{
    public MyItem(double worldX, double worldY, string text)
    {
        WorldX = worldX;
        WorldY = worldY;
        Text = text;
    }
    public double WorldX { get; set; }
    public double WorldY { get; set; }
    public string Text { get; set; }
}

In addition, I have a method to convert between world and screen coordinates:

Point worldToScreen(double worldX, double worldY)
{
    // return screen coordinates using the canvas properties and an internal MapData object
}

With the current implementation, the items are positioned in the wrong location, because their location is not converted to screen coordinates.

How can I apply the worldToScreen method on the MyItem objects before they are added to the canvas?