Call Grid Generator

When you are satisfied with the arrangement of Spatial Domain Regions
(and possible Refinement Disks), the next step is to create
the OMEGA grid.  The program that translates the 2-D domain region information
into a full 3-D computational mesh is called the OMEGA Grid Generator
("gridgen").  

Since the gridgen program is independent of XOMEGA it needs to be called 
in a controlled way.  The mechanism for doing this is to use an intermediate
program called omega.  omega is the text based user interface to the OMEGA 
System.  Nearly all the functionality of using the OMEGA System may be
controlled by omega.  Please see the omega documentation for more information.
XOMEGA first calls omega, which then calls gridgen.  This chain of command
allows for cleaner file manipulations, better error control and a 
non-graphical backup redundant capability.

The Grid Generator first reads the file "grid.inp" to get information about 
the domain regions and levels.  The grid is then made by first gathering the 
requested data and "stitching" together the individual data sets
into a seamless block of terrain and shoreline data.  Next, a series of 
triangles is interpolated to the underlying data.  The interpolation process 
adds and deletes triangle vertices until all triangles are within the 
resolution range you requested.  The grid is now a single entity with varying 
resolution, but no distinct regions.  The regions are temporary boundaries 
used to specify desired resolution ranges and data set usage.

When you click on "Call Grid Generator" a small dialog box pops up.  This 
dialog consists of two sections: Status Message and a row of Action 
Buttons.

Note that if the Spatial Domain data has not been filled the 
Call Grid Generator dialog will not pop up.  Instead an error message will
pop up informing you of the error.  When you acknowledge the error by
clicking the "OK" button the Set Spatial Domain dialog will pop up.


Status Message

This is a simple line of text with the current status of the external program.


Action Buttons

Pause - This button will pause the currently running external process.
        When clicked the label will change to resume, the blinking icon
        will stop, and the Status Message will show that the process is 
        paused.  The continue the process click on Resume.

Cancel - When the external process is running this button will be inactive.  
         When the process is paused this button will be active.  Clicking on 
         Cancel will cancel the operation, and close the Grid Generator dialog.

Help - When the external process is running this button will be inactive.  
       When the process is paused this button will be active.  This button 
       will open the Help dialog and load this section.


Grid Generation Warning 

This dialog box is popped up when you try to Call the Grid Generator and a
valid grid file already exists.  The top part of the dialog contains
the warning message.  The bottom part has a row of three action buttons:

Overwrite - This button will Start the grid generation process.  All existing 
            output in the "grid/" sub-directory will be overwritten as 
            the new grid is made.  

Proceed - This button will accept the existing grid.  All existing grid 
          information is left untouched and the Call Grid Generator operation 
          is completed.
          The Grid Generation Warning dialog will be dismissed.

Cancel - This button will decline the existing grid.  All existing grid 
         information is left untouched and the Call Grid Generator operation 
         is NOT completed.
         The Grid Generation Warning dialog will be dismissed.

END Call Grid Generator