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 Page 4 Maps and Legends 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. Page 5 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 Page 6 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. Page 7 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. Page 8 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 Page 9 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. Page 10 Maps and Legends 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. Page 11