Appendix F — Glossary

One word for each idea, used the same way everywhere in the game and in this book.

Brush: The terrain chosen for painting (the Project Global brush).
Camp: The start cell (S). Maze Settings keeps its cell number in the column startCell, the algorithm’s own word.
Cell: One square of the map, numbered 0 to 119 in reading order. A Map Cell is the Object that draws one.
Cost: The price of entering a non-wall cell (Road 1, Forest 3, Mud 6).
Current cell: The cell the last Step settled (its Search Outline is white); none (-1) after a Reset.
Distance: The cheapest cost found so far from the camp to a cell.
Ending: How a trial ended: the Messages row End Trial shows (cheapestRoute, noRoute, invalidRoute, or the row of a broken input rule).
Find route: Run Step repeatedly on a named timer (searchTick) until done or paused. Find Route’s findRequested Modes are Start, Pause and Start Over.
Frontier: Reached, non-wall cells not yet settled.
Map: The 12 by 10 board of cells. The Object Map (no picture) lays it out when the Scene starts (Lay Out Map, and from Chapter 4 Lay Out Route Lines).
Map Place: The Data Structure in which a Map Cell or a Search Outline keeps its cell number (field cell).
Marker: The compass pawn that walks the finished route. The Project Global markerCell is the cell it stands on, or is sliding to once a move is committed.
Maze Rules: The Object that owns the trial and its live records in Maze Cells; buttons, cells and keys only ask it.
Mode: One of the ways an Event can run (Switch Mode, Turn On Mode, Turn Off Mode, Reset Modes).
Parent: The settled cell a cell’s best route came from.
Phase: Where the trial is: the Mode of Maze Rules’ stepRequested Event, one of Ready, Searching, Tracing, Replaying, Waiting For Marker, Finished.
Piece: One Object made for the map when the Scene starts: a Map Cell or a Search Outline (Lay Out Map), a Route Line or a Route Line Backing (Lay Out Route Lines).
Relax: Give a neighbor a smaller distance and a new parent, only when the new cost is strictly cheaper.
Reset: Clear the search and route, keeping the painted terrain.
Restore defaults: Put the supplied terrain back, then Reset.
Route: The chain of parents from the tower back to the camp, shown forward.
Route Cost: The sidebar text (the Cost readout) that shows the Route’s cost, the Tower’s distance, once the Tower is settled, and “--” before.
Route Line: The yellow line, over a dark Route Line Backing, that joins each two cells that follow each other on the Route.
Route Link: The Data Structure in which a Route Line or a Route Line Backing keeps the two cells it joins (fields cell and neighbor).
Search Outline: The ring over a cell that shows its place in the search: a thin cyan ring on the frontier, a thick blue ring once settled, thick white on the current cell, and from Chapter 4 thick yellow on the Route.
Selection: The ring around the selected cell, the cell the keyboard will paint (the Project Global selectedCell).
Settle: Choose the frontier cell with the smallest distance and mark it final.
Status: The sidebar line that says what the last Step did (the Project Global status); its words live only in Messages.
Step: One transition: settle one cell, trace one parent, or move the marker one cell.
Terrain: What a cell is: Road, Forest, Mud, or Wall (the rows of the Data Table Terrains).
Terrain Button: A sidebar button that shows one terrain’s name and cost and makes it the brush.
Terrain Preview: The terrain’s picture beside its button; activating it also makes that terrain the brush.
thisCell: Lay Out Route Lines’ Local Variable (Declare Variable, one cell’s run): the cell whose neighbors it is joining now; each new line takes cell = thisCell.
Tower: The goal cell (G). Maze Settings keeps its cell number in the column goalCell.
Trial: One run of Dijkstra’s algorithm on the terrain as it is: from Ready until it ends. Step Trial, Clear Trial, End Trial and Reset Trial are named for it.
Visited: The number of settled cells.
Wall: A cell that cannot be entered.