Tile
Tile refers, broadly, to any distinct element within the world of Chip's Challenge. For example, Chip himself, the iconic computer chips, locked doors, and pushable blocks are all tiles.
Other uses of the term include:
- Elements like the toggle door, which are really a collection of multiple tiles (the "open" and "closed" states are internally distinct in every Chip's Challenge game), but which act like a single entity that changes state.
- An element and its facing direction, especially when editing for the DAT format, which encodes such combinations as single bytes. For example, a west-facing glider is an available DAT tile, corresponding to the byte
0x51. - A combination of tiles that functions as a single unit, especially if it alters the behavior of its parts. For example, a "fireball cloner" is really a fireball on top of a clone machine (which prevents the fireball from moving), and a "no green keys" sign is really a green key beneath a no sign (which prevents the key from being picked up).
- One of the square positions within the grid of a level, which may contain multiple elements. For example, "invalid tile" can refer to a stack of tiles expressible in a DAT level but that would be impossible on the original Lynx game. More pedantically known as a cell.
- One individual square of artwork used by any version of the game, known more generally in game development as a sprite.
Types of tile
Tiles can be informally grouped into several categories, based on their behavior.
- Terrain — static tiles that cannot move
- Acting floor — the floor tile specifically, and others that allow free passage
- Acting wall — the wall tile specifically, and others that can't be moved into
- Locked doors
- Buttons
- Items — tiles that can be picked up; may or may not be considered terrain, depending on ruleset
- Actors — tiles that can move
Layers
Tiles can also be grouped based on whether two different tiles can coexist in the same cell. If two tiles cannot, they are said to exist on the same layer. The set of layers is defined by a combination of ruleset and file format.
Lynx
The original game was designed around having two layers:
- Static tiles — including both terrain and items
- Actors — everything that can move
The game's internal data structure defined a level as a single 32×32 layer of static tiles, plus one optional actor per cell. It was thus impossible to create otherwise intuitive combinations like a key on top of gravel, because both the key and the gravel would have had to occupy the same space.
This format was restricted to the Atari Lynx game itself. Emulators have generally needed to load levels in the DAT format, which
MS
Strictly speaking, MSCC was only designed to play the original levels, so it was likely intended to obey the same layering restrictions as Lynx. However, it takes an unusual approach to layering: each cell is a stack of any two tiles. Internally, a gravel tile looks like this:
 Gravel
|
 Floor (nothing)
|
If Chip then steps into this cell, the gravel moves down, and he takes its place:
 Chip
|
| Gravel
|
When he leaves, the gravel will move back up and a floor tile will fill the empty space, returning things to the first diagram.
The DAT format invented for MSCC inadvertently exposes this arrangement to level designers, allowing a level to have any two tiles stacked atop one another. The game wasn't designed to handle two actors or two static tiles in the same cell, so various unusual effects may occur. Combinations of tiles that are technically possible to create in a DAT level, but could not have been represented in the original Atari Lynx game, are called invalid tiles.
Steam
Steam rules are designed for the much more expansive set of tiles available in Chip's Challenge 2 and introduced much greater flexibility in layering. From bottom to top, the layers are:
- Terrain
- Item — includes both kinds of bomb and all three time modifiers
- Item mod — only the no sign
- Actor
- Swivel door — only the revolving part; the base counts as terrain
- Thin wall
- Canopy
Each cell must have a terrain tile — in fact, CC2's C2M level format enforces it — but every other layer is optional.
(Internally, it may be the case that thin walls and canopies are part of the same tile and thus the same layer, as they're encoded together in C2M. From the perspective of players and designers, they behave as separate tiles.)
For Chip's Challenge 1 tiles, the most notable improvements are the ability to place an item on top of any kind of terrain and the ability to place thin walls, in any combination, atop anything else at all. The other new layers are dedicated to new CC2 tiles: the no sign (which combines with an item underneath), swivel doors, and canopies (which are specifically for hiding everything below).
Chip's Challenge 1 tiles
MS also has the clone block, used to indicate the direction of a block cloner. This is a tile in the sense that it can be placed within a level, but it exists as an editing trick and is not intended as a distinct game element. In all other rulesets, dirt blocks have a direction like every other moving object, so a separate clone block is unnecessary.
Invalid tiles
These tiles are possible to place in a level due to quirks of the DAT format, and may have interesting properties, but only exist as accidents and aren't defined within the normal rules of the game.
Fake exit
Swimming Chip
Drowned Chip
Burned Chip- The Combination tile
- Three unused tiles
One of the unused tiles found new life in the "pgchip" patch for MSCC, which replaced it with the ice block from CC2.
See also
- The MSCC tileset (in the sense of spritesheet)
