OS/2 Professional/OS2PRO194.ISO/os2/prgramer/mirrors/mirrors.txt

Text File | 1993-01-18 | 8.1 KB | 183 lines

MICROGRAFX MIRRORS

Micrografx Mirrors is a set of development tools that enables
Windows applications to be ported quickly to the OS/2 2.0 operating
system.  An application can be maintained for both platforms with
one set of source code.

DEMONSTRATION FILES

In order to use the demonstration programs that accompany this text,
copy the files to a directory on your hard drive and decompress them
using the PKUNZIP utility.  The Windows version was intentionally compiled
as a Windows 3.0 application so it would be compatible with OS/2's
seamless Windows and compatibility box.

You should have the following files:

WINLIFE.EXE    A Microsoft Windows version of the popular Life algorithm.

PMLIFE.EXE     A Presentation Manager version of the Life algorithm,
               created using the same code as WINLIFE, except that it
               is linked against the MIRRORS DLL.

MIRRORS.DLL    This is a 32-bit OS/2 DLL.  It is this DLL that emulates
               the Windows environment for your source code.

WINLIFE.HLP    This is the Windows help file that accompanies the Life
               program.

PMLIFE.HLP     This PM help file was created using the same source as that
               used for the Windows version.  It was converted automatically
               using the MIRHLP conversion utility.  Help for your
               application would be converted similarly.


HOW MIRRORS WORKS

Applications for Windows and OS/2 are similar in nature. Applications in
both environments typically consist of code that processes event-
generated messages. Applications in both environments access system
resources (e.g., file system, graphics system) via function calls to system
dynamic link libraries (also called DLLs). In both environments
application resources, such as icons, bitmaps and help files, are located
in separate files which are bound to the executable code.

Although a Presentation Manager application cannot directly use
Windows resources, translating the resources from one
form into another is relatively simple. Because Windows and OS/2 are
similar and because DLLs separate system resources from the
application, Mirrors is able to emulate the Windows application
programming interface (API) on OS/2.

The Mirrors conversion utilities convert Windows resources into
native Presentation Manager resources; the Mirrors DLLs provide Windows
emulation.  The Windows application that has been ported to OS/2 2.0
using Mirrors continues to make calls to what appears to be Windows
system DLLs. In reality, these calls are intercepted by the Mirrors DLLs
and are either passed on to the appropriate OS/2 system DLLs or to
Mirrors emulation functions written using the Presentation Manager
API.  For example, Windows dialog boxes and control classes are
implemented entirely by Mirrors.

MIRRORS COMPONENTS

The Mirrors tool kit contains a 32-bit dynamic link library that enables
a Windows application to be ported virtually unchanged to the
Presentation Manager interface. Mirrors acts as a filter between the
application code and the Presentation Manager interface. Mirrors
emulates Windows by defining all of the necessary Windows functions
in the Mirrors DLL. When an application calls a Windows function,
Mirrors accepts the call and its parameters and then implements that
function using other functions available  in the OS/2 system DLLs.

The second important part of Mirrors is the conversion utilities.
Resources, icons, help files, definition files, bitmaps, and
cursors must be converted before they can be used in the OS/2 environment.
The conversion of these is done statically using Mirrors.  That is,
conversion is done once, when the application is being ported to
Presentation Manager.  Static conversion improves the performance
of ported applications  tremendously.  After this conversion,
these resources may be used like PM resources.  They are accessed with
the same speed that native PM resources are used.

The Mirrors conversion utilities are easy to use.  They simply accept the
Windows resource, icons, cursors, and definition files as input and
output an object or file that is compatible with the OS/2 environment.

BENEFITS OF MIRROR

Mirrors provides tools that allow developers to quickly and easily port
their Windows application to the OS/2 2.0 operating system. In
particular, Mirrors

* allows developers to maintain a single set of source code for Windows and
  OS/2 versions of their application

* leverages existing Windows application development

* significantly reduces the costs of porting a Windows application
  to OS/2

* enables developers to quickly move existing Windows applications to OS/2



OVERVIEW OF PORTING WITH MIRRORS

Porting a Windows application to Presentation Manager is simply a
matter of linking the application with the Mirrors DLLs and
the converted resources.  Special modifications of the source code are
rarely necessary.

If the code you intend to port has conformed to good Windows coding
practices, you should be able to port the application code with little
effort.  However, if undocumented DOS function calls or other
questionable coding practices have been used, you may need to
rework this.  You also may need to modify code which uses function
calls provided by a particular compiler's libraries that may not be a part
of the OS/2 development libraries.  That code must be changed to be
more independent of a specific development environment; a utility is
included with Mirrors to help identify non-portable code.

The Mirrors Host Independent API supports INT 21 and the
DOS3CALL routine supplied with Windows 3.0.  Services for these
functions are provided in the OS/2 environment by the Mirrors DLL.
These functions supply the same operations that the original DOS
interrupts performed under Windows.

Porting a Windows application to the Presentation Manager using
Mirrors involves only a few steps:

You must translate the Windows application resource files (.RC),
definition file (.DEF), and icons into formats compatible with the OS/2
resource compiler and the OS/2 LINK program.  This is accomplished
using the conversion utilities provided with Mirrors.

Mirrors supplies its own resource compiler, called MIRRC.  This
resource compiler must be run on the resource file that your application
will use.

The existing object modules, created by compiling the code for the
application, must be relinked, replacing the Windows libraries with
MIRRORS.LIB.  This is generally performed exactly as it would be for
Windows using a make utility, compiler and linker.

The final step is to produce the executable application by binding the
linked .EXE file with the converted resources.

If you want to use the help files that were written for your application to
run under Windows, they may also be converted using the help
conversion utilities provided with Mirrors.

CONTRACTS

Micrografx has ported a number of large, well-known applications
from Windows to OS/2.  These include WordPerfect's word processing
application and IBM's multimedia application, Columbus.  Micrografx
has also ported its own award winning graphics applications, Draw!
and Designer to OS/2 using Mirrors.  These porting contracts
are negotiated individually.  For more information,
contact us at [phone].

PRICE AND AVAILABILITY

Micrografx Mirrors is available directly from Micrografx. The
list price for Mirrors is $495.00 (U.S.).  For a limited time, developers
can purchase Mirrors for $345.00 (U.S.).

Developers who purchase Mirrors receive six months of free technical
support and royalty-free distribution rights for any applications
developed with Mirrors.

To place an order, fax or call Micrografx.
Phone [phone].
FAX   [phone].

Mirrors is a trademark of Micrografx, Inc. Micrografx Mirrors is not
affiliated with Softklone Distributing Corporation or Softklone's
MIRROR data communications products.

Other brand and product names are trademarks or registered
trademarks of their respective holders.