
                       DIGITAL FILTER PACKAGE

                          Release Notes




Release 1.0.1
=============
Release Date: 10.March.1997

The original DFP release (version 1.0) created all the DFP figures and
the GUI objects with their dimensions specified in pixels. Furthermore,
these dimensions in pixels were independent of the display resolution.
In developing DFP I worked with PCs with display resolution at 1024x768
and with SUN workstations with display resolution at 1152x900.  All the
absolute object dimensions in pixels were determined based on these two
resolutions.  A consequence of this approach was that DFP would specify
incorrect object dimensions if it is run on a computer with a lower 
display resolution (such as 800x600 or 640x480).  A more serious problem
was that at such lower resolution displays, DFP would calculate negative 
dimensions generating error conditions.  My initial assumption that
everyone was using computers with display hardware operating at
1024x768 or higher resolutions was obviously wrong.

    The DFP version 1.0.1 is a service release that addresses this problem. 
During start up DFP determines display resolution (get(0,'ScreenSize')).
On a PC, if DFP detects that the screen resolution is less than 1024x768
(on a non-PC less than 1152x900), then DFP calculates two scaling
parameters DFP_ScaleX and DFP_ScaleY which as global variables are
shared with other DFP functions.  During figure and GUI object creation
I scale all the pixel dimensions using these two parameters.  Thus,
the dimension of DFP windows and GUI objects remain essentially the same
irrespective of the display resolution.  There is an important exception
to this observation.  The scale parameters DFP_ScaleX and DFP_ScaleY are
always restricted to values between 0 and 1.  Thus, on a PC with display
resolution greater than 1024x768, the DFP objects will not be scaled up.
This will allow those lucky few who can operate their display hardware at 
higher resolutions to utilize the extra display area without it being taken 
up by DFP windows.

    Why did I specify all dimensions in pixels?  Wouldn't it have been
easier to specify all dimensions in relative units, which then would have 
avoided this problem from becoming a problem in the first place.  According 
to Mathworks documentation, it is faster to generate MATLAB figures with
GUI objects if their dimensions are specified in pixels.  Only after
defining and creating the DFP objects I changed their units to
"normalized".  You have to change the units to normalized in order for
the "resize' property to function as expected, i.e., as one resizes a
figure, all the objects in that figure window are also resized relative
to the figure window.  There was on other reason why I worked with
pixels:  I find it more intuitive to specify dimensions in pixels.


Release 1.0
===========
Release Date: 25.February.1997


===========================================================================

    Author: Mehmet Zeytinoglu (mzeytin@ee.ryerson.ca)
            Department of Electrical and Computer Engineering
            Ryerson Polytechnic University
            Toronto, Ontario, M5B 2K3 
            CANADA

    Copyright (c) 1997 Mehmet Zeytinoglu

    $Revision: 1.2 $
    $Date: 1997/03/11 13:39:22 $

