Automap



The automap is a map displayed when the user presses the tab key. As all levels in Doom are flat when viewed from above this is a relatively easy task, compared to later games which were true 3D and so difficult to render a map automatically for.

The map shows all segs (segments of wall) the player has seen. Therefore while it is possible to walk around with the automap function turned on, the map itself will not update: the lines shown in the map are marked by the rendering process, which does not occur while the automap is turned on.

The lines in the automap are color-coded. Red indicates a solid wall. Yellow indicates a change in ceiling height (e.g. a door). Brown indicates a change in floor height. Light grey indicates an area which has not yet been visited (made visible by the computer map powerup).

Editing
Lines can be flagged by the authors of levels so as not to appear on the automap. Such lines are not displayed even if the computer map powerup is picked up. However, the IDDT cheat code will display all lines.

To avoid giving away secrets, secret doors can also be marked so as to appear red on the map like a solid wall.

Keys
Several keys perform actions inside the automap:


 * F: Toggles follow mode; if follow mode is on, the map follows the player, otherwise it is possible to browse around the map freely using the arrow keys.
 * M: Marks the current position with a flag
 * C: Clears all marked positions
 * G: Toggles grid on/off
 * +: Zooms in
 * -: Zooms out
 * 0: Zooms out fully
 * Tab: Exits automap and returns to normal view

Trivia
The IDDT cheat code can be used to display all items on the map. Zooming in closely on the player while this is active shows the letters "ddt", a reference to Dave Taylor who wrote the automap code.

Boom modifies this: the letters "jff" are visible instead, a reference to Jim Flynn.