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, generation of such a map is a relatively easy task (as compared to later games which had true 3D engines, thus making it difficult to render a map automatically).

The map shows all segs (segments of wall) the player has seen since entering the level. Therefore, while it is possible to walk around in automap mode, 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. As the Doom instruction manual notes, playing in automap mode is a dubious long-term strategy, since monsters cannot be seen.

The lines in the automap are color-coded. Red lines indicate solid walls. Yellow lines indicate changes in ceiling height (e.g. doors). Brown lines indicate changes in floor height. Light grey lines indicate areas which have not yet been visited (made visible by the computer map powerup).

Editing
During the design of a level, lines can be flagged by the authors of levels so as not to appear on the automap even if the computer map powerup is obtained. However, the iddt cheat code will display all lines.

To avoid giving away secrets, concealed doors can also be marked so as to initially appear red on the map, as though they were solid walls.

Keys
Several keys perform actions inside the automap:


 * F: Toggles follow mode; if follow mode is on, the map follows the player, and if not, it is possible to browse around the map freely using the arrow keys.
 * M: Marks the current position with a flag. (In Doom95, this function is extremely buggy and may even cause the program to crash.)
 * 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.