The Goonies

The collision maps

Each scene is a list of rectangles of eight kinds

The picture on screen is only scenery. What a Goonie can stand on is a list of rectangles kept beside each scene's code, between 22 and 53 of them ($11F7), each with a kind and four edges. When a scene starts, load_scene_tables ($1189) points the collision tests at its five lists through a table of ten words per list ($1201).

Every rectangle of the scene's lists, from the game's bytes, drawn over a screenshot of the scene. Edges across are in units of two pixels and lines count from the top of the play area, one character row below the status line. A dashed outline is a rectangle whose kind has bit 7 set, which the collision test skips: the lists as they stand in the saved game, where scene 1's fire has not been put out. Hover over a row of the table to find its rectangle.

Each pass, move_object ($0CFD) moves an object by its speeds and then looks for every rectangle its new box overlaps, noting one of each kind. The kind decides what happens next:

Kind	What it does to a Goonie	Where
0	a wall met moving left: the Goonie stops with its left edge on the rectangle's	`$0F3A`
1	a wall met moving right: stops it against the rectangle's left edge	`$0F4B`
2	a ceiling, met moving up	`$0F7C`
3	a floor, met moving down: the Goonie stands on its top	`$0FA5`
4	a floor that is also a ladder's top: stand on it, or climb down through it	`$0E64`
5	a ladder: up climbs it, and the Goonie is centred on it	`$0F63`
6	water, which slows a fall	`$0F05`
7	a bar: up holds on, gravity stops, and left or right jumps off	`$0E31`

A wall works from one side only. A kind 0 rectangle stops a Goonie moving left and a kind 1 stops one moving right, so each solid block on the map is drawn as a pair of thin walls, and a Goonie inside one walks out freely.

Moving parts

Doors and bridges are rectangles switched on and off

Nothing in a scene's picture moves the collision map. The scene's own routine changes the lists while it plays, most often by setting or clearing bit 7 of a rectangle's kind.

Scene	What changes	Where
1	the fire's rectangle is out of use while it burns and becomes a ladder's top when the tank puts it out	`$7CF3`
2	the three weights' rectangles move with them, and the float is a rectangle the Goonies ride	`$75D4`, `$76A4`
3	the floor at the burst pipe goes out of use	`$8ACD`
4	floor gaps open under a Goonie, and the planks' wall goes when the last plank does	`$1859`, `$1948`
5	the egg pile's top rises with each egg, and the bones switch the lava bridges	`$E08A`, `$E0B7`
6	thirteen platforms are solid or not by the pattern of pads held down, eight patterns in all	`$F413`
7	the flipper turns a rectangle into water, and the fallen crate becomes a floor	`$96EE`, `$97D6`
8	each porthole's two rectangles change with its lever, and the lift's floor follows it	`$A17E`, `$A049`

Scenes 4, 5, and 7 keep a second list for the things that roll, the rocks, the eggs, and the crate, and swap it in while one of them moves ($1B34, $E427, $98DA). A rock rolls on its own floors, which the Goonies never touch.

The order

Scenes 2 and 3 are stored the other way round

The game numbers its scenes by an index ($12B9), which picks the scene's lists, its routines, its tune, and its picture on the disk. The play order is not the index order: each exit stores the index of the next scene, and scene 1's exit jumps to index 2.

Scene	1	2	3	4	5	6	7	8	ending	title
Index	0	2	1	3	4	5	6	7	8	9

The attract mode shows the scenes in index order ($93F3), so its demonstration of the pipes comes before the lake.