


                               Maps and Legends


                          3    USING MAPS AND LEGENDS

                            Selecting from the Menu

              The Maps and Legends menu tree is shown in Figure 2.


              ---------------------------------------------------

                     Figure 2. Maps and Legends menu tree.
         Desk
         About Maps...Version and Copyright Notice
                       Source Code Message
                       User Notes and Hints
         File         Load... Item Selector
                       Save
                       Save As... Name Dialog
         Abandon
         Quit
         Options
                       Drawing tools... Pen, Eraser, Fill
                                        Fine, Medium, Broad
         Erase Map
         Text mode
         Locate mode
         Graticule
         State Boundaries
         Azimuthal Eqd... Input Dialog
         Conical... Input Dialog
         Cylindrical... Input Dialog
         Orthographic... Input Dialog
         Perspective... Input Dialog
         World Maps... Selection and Input Dialog
         Color
                       Color Selection Menu
         Pattern
                       Fill Pattern Selection Menu
              --------------------------------------------------

              Most  of  the  program functions can be reached from the
         menu tree. The menu bar at the top of the screen contains the
         five selections:


         Desk  File  Options  Color  Pattern

              Use  Desk  to  obtain  the  version and copyright of the
         program  by  selecting  About  Maps...,  and  to use the desk
         accessories  such  as  the  Control  Panel  for  changing the
         sixteen  colors  on  the  Color  menu,  Install  Printer  for
         changing  the  setup  for  your graphics printer, and ST Font
         Loader to install a new text font.


              File  is  to  save  and retrieve maps to and from a data



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         disk,  and  to  quit  the  program  and  go  back  to the GEM
         Desktop.


              Use  Options  to select a map projection, to make a tool
         selection  to  draw,  fill,  or  annotate text on the map, to
         select  graticules and state boundaries for the map, to erase
         a  map  from  the  screen,  and to select the locate and text
         modes.


              Color  allows  you  to  select the color before drawing,
         filling or annotating the map.


              Pattern  allows  you  to  select  a  fill pattern before
         filling in an area of the map.


                                 Entering Data

              Most  of  the projections need some input data to define
         the  area  of  the  world  to  be  drawn  on the map. Data is
         requested  by  a dialog box that appears on the screen. These
         dialogs  have  lines  of text that you can type in or modify.
         When  a  dialog appears with an editable text field, the text
         cursor  (vertical  line) appears showing where the characters
         you  type  will  appear.  A line shows the length of the text
         field.  You don't have to use all of the available length for
         your  entries.  Cursor  movement in an editable text field is
         controlled by the keyboard keys as described in Figure 3.


              ---------------------------------------------------

              Figure 3. Cursor movement in a GEM Dialog.


         Left-arrow:     Moves  the  text  cursor one character to the
         left without deleting characters.

         Right-arrow:    Moves  the  text  cursor one character to the
         right without deleting characters.

         Tab  or  down-arrow:   Moves  the cursor to the next editable
         field.

         Up-arrow:  Moves the cursor to the previous editable field.

         Delete:   Deletes the character to the right of the cursor.

         Backspace:      Deletes  the  character  to  the  left of the
         cursor  and  moves the remainder of the text string one space
         to the left.




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                               Maps and Legends


         Escape:    Moves  the  text  cursor  to  the beginning of the
         current  field and erases all of the characters in the field.
         Also  halts a map in the process of drawing and returns mouse
         control to you.

          -----------------------------------------------------------

              Be  sure  that  you  don't  press [Return] until you are
         ready to exit from the dialog. [Return] activates the default
         exit button which is normally the "OK" button.


                           Latitudes and Longitudes

              Latitude is a measure of distance north and south of the
         Earth's  equator  along  a  meridian  (a  great circle on the
         earth's  surface  passing through the north and south poles),
         expressed  in  degrees. A circle around the world at constant
         latitude  is  called a parallel. Distance along a parallel is
         also   measured  in  degrees  and  is  called  longitude.  By
         international  agreement the meridian that passes through the
         Royal Observatory in Greenwich, England, is used as the prime
         meridian.  The  longitude  of any place on that meridian is 0
         (zero) degrees.


              For  the Maps and Legends program latitudes south of the
         equator are entered as negative numbers. Latitudes range from
         90  to  -90  degrees.  Longitudes  must  be  entered  as east
         longitudes,  i.e. the longitude measured in degrees east from
         Greenwich.  This will range from 0 to 360 degrees. Many maps,
         especially  those  of  the Western Hemisphere, are labeled in
         west  longitude.  This  may be entered into the programs as a
         negative  east longitude. To do that you type a minus sign in
         front  of the west longitude. Most atlases have maps labelled
         with  longitudes  and latitudes. You can use such an atlas or
         the Locate mode in the Maps and Legends program to obtain the
         input data you need for your maps.


                                Designing a Map

              Here's  a step-by-step guide for designing a sample map.
         If you are working with a monochrome monitor, simply skip the
         steps  that refer to color. Let's do a perspective projection
         of North America as seen from an altitude of 5000 miles above
         Washington, D.C.


              1. Select a color for the map contours.


              Drop  down  the Color menu and click on the box in front
         of the black color block. (Suggestion:  In low resolution use
         the  black  color  that  is the tenth block from the top. The



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                               Maps and Legends


         screen  border  is drawn with the black that is in the second
         color block from the top. A fill can intrude on the border if
         the same color register is used for the map and the border.)


              2.  Select Graticule to add a latitude-longitude grid to
         the map.


              Drop the Options menu and click on Graticule.


              3. Select the Perspective Projection.


              Drop  the  Options  menu again. Note that there is now a
         check  in front of Graticule to indicate that you have chosen
         that  option  for  your  map. The check will remain until you
         click on Graticule again.


              Click   on   Perspective...   to   start  a  perspective
         projection map.


              4.  Enter the data in the dialog box for the Perspective
         Projection.


              If  you are not sure how to enter data in the dialog box
         see the section Entering Data above.


         Enter the following values:
                  Center longitude: -77 deg
                  Center latitude: 39 deg
                  Altitude: 5000 mi Azimuth 45 deg
                  then click on the "OK" button.

              In a few seconds a perspective map of North America will
         begin  to  appear  on the screen. When the bee disappears the
         map is complete. You can halt the drawing process any time by
         pressing the Esc key.


              5.   Now  let's  fill the oceans with blue and the space
         outside of the globe with black.


              Drop the Options menu and click on Drawing Tools...


              Then click on Fill.





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                               Maps and Legends


              Next click on OK.


              Note that the mouse cursor has changed to an open cross.
         This  symbol  is  used to warn you that the program is in the
         fill  mode.  The fill is performed at the exact center of the
         opening  in  the  cross.  You  can see the color of the pixel
         through  the  opening.  Be sure it is in the area you want to
         fill.


              Drop the Color menu and click on the box in front of the
         blue block, the fifth block from the top.


              Point  the  cross to any open spot in the Atlantic Ocean
         and press the left mouse button.


              Now  point  the  cross  to  any open spot in the Pacific
         Ocean  and  press the left mouse button. (Note: You can press
         the  Undo  key  to erase the last fill if you make a mistake.
         Try it once.)


              Drop the Color menu and click on the box in front of the
         black block, the tenth block from the top.


              Now point the cross to any spot outside of the globe and
         press the left mouse button. Do the same on the other side of
         the globe.


              6.  Let's annotate the names of the Atlantic and Pacific
         Oceans using yellow text.


              Drop the Options menu and click on Text mode.


              Drop  the  Options  menu  again  and  click  on  Drawing
         Tools...


              In  the Drawing Tools dialog click on "Pen" and click on
         "Medium."   (Text comes in three sizes corresponding with the
         three  pen sizes: fine, medium and broad.)  Click on the "OK"
         button.


              To select yellow for the text color, drop the Color menu
         and click on the box in front of the yellow block, the second
         block from the bottom.




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                               Maps and Legends



              Move the cross to an area of the Atlantic Ocean near the
         coast  of North America, and click once. The text cursor will
         appear.  Simply  type "Atlantic". You can use the [Backspace]
         key to erase any typing errors.


              Now  move  the  mouse  pointer  to the Pacific Ocean and
         click  once  at  the  location  for  the  first  letter. Type
         "Pacific".


              Finally  drop the Options menu and click on Text mode to
         terminate that mode.


              That  completes our sample map. Of course there are many
         more  possibilities  available  by  using  fill  patterns and
         drawing  custom  designs  on  the  screen  using  the pen and
         eraser.  You  also  have  the option of eliminating the state
         boundaries  for  the  United  States  by  clicking  on  State
         Boundaries  in  the Options menu. See the Hints Section below
         for other interesting ideas.


              Remember   to   choose   the  color  before  drawing  or
         annotating  your  maps  and  you  can press the [Undo] key to
         erase  any  mistakes  that you make when filling the map with
         colors.


                        Storing and Retrieving Your Map

              You  can save all of your maps on data disks. Be sure to
         have  a formatted disk with space available before working on
         your  map.  Maps  are  saved  in Degas file format and can be
         retrieved by that program for enhancement later.


              To  save  a map on disk, select Save As... from the File
         menu. Insert a formatted disk into your disk drive and type a
         filename  for  the  map  on  the line in the dialog. Finally,
         click on "OK".


              To  retrieve  a map from disk, insert the disk into your
         disk  drive  and  select  Load... from the File menu. An Item
         Selector  menu will appear. Click once on the filename of the
         map you wish to load. The name will appear under selection at
         the  right  of the dialog box. If the choice is correct click
         on  the  "OK"  button. If a map looks strange when its loaded
         you may be using the wrong screen resolution.


              If  you  load  a map and do some new work on it and then



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                               Maps and Legends


         decide  you  want  to start over, you can select Abandon from
         the  File  menu.  The original version of the map will reload
         from the disk and you can start over again.


              After  you  save or load a map, the filename for the map
         appears as the window title.


                               Printing Your Map

              To print your map on a graphics printer simply press the
         [Alternate]  and  [Help]  keys at the same time. Be sure your
         printer is properly installed. If the map does not fit on the
         page  try  the other Pixel/Line option on the Install Printer
         desk accessory.


                                   Draw Mode

              The  Draw mode is automatically selected when the Locate
         and  Text  modes  are  not  in effect. In this mode the mouse
         cursor  is  a solid cross. Select either pen or eraser, a pen
         size  and  a  color before drawing on the screen. You draw by
         holding  down  the  left  mouse button and moving the cursor.
         Fill  is  a special form of draw mode selected in the drawing
         tools window.


                                  Locate Mode

              Use  this  selection  from  the  Options  menu  to  read
         geographic coordinates from the map. A check appears in front
         of  Locate  Mode when that mode is selected. In this mode the
         mouse  cursor is an arrow. Point the mouse and click the left
         mouse  button  once  to  read  the location. For Cylindrical,
         Conical, and Mercator projections, the longitude and latitude
         are  printed  on  the  screen.  For the Azimuthal Equidistant
         projection  the  range and bearing from the center of the map
         are printed on the screen.


                                   Text Mode

              You  can  type  legends  and  annotations  on the map by
         selecting  Text  Mode from the Options menu. In this mode the
         mouse  cursor  is a text pointer. Point with the mouse to the
         position for the first letter and click once. The text cursor
         will  appear  at that location. Then type the annotation. You
         can erase the text that you have just entered by pressing the
         [Esc]  key.  To  type  at  another  location,  move the mouse
         pointer  to  the new position and click once. The text cursor
         will move to the new location. You can exit from Text mode by
         again  clicking  on  Text  Mode  on the Options menu. A check
         appears  in  front  of  Text Mode when that mode is selected.



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         When  Text  Mode  is  selected,  Locate Mode is automatically
         deselected.  If  you  have the ST Font Loader desk accessory,
         you can change the font as often as you wish while annotating
         a map.






















































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