- Author name, copyright information and a general description of the levelset
- Compatibility with different rulesets
- Arbitrary text to be displayed before / after a level - typically to provide a storyline, additional hints or simply a brief description of the level
CCLP3 was the first levelset to use a .ccx file, and in fact, CCX files were originally conceived so that the CCLP3 storyline and author names could be read from within the game, without the necessity to refer to the documentation provided.
The author name is displayed in the message that appears on successful completion of a level. It may be specified either for the entire levelset or for each individual level.
The description and copyright information apply to the entire levelset, but are currently not visible anywhere within the game.
An individual level (or the levelset as a whole) may be flagged as being compatible or incompatible with the 3 different rulesets: MS, Lynx and pedantic Lynx. If a level is marked as not being compatible with a certain ruleset, an attempt to play the level under that ruleset will result in a warning message being shown. The message is only advisory in nature, and will not prevent playing the level, unless the level is unplayable for other reasons (for example, invalid tile combinations in Lynx mode).
Each level may incorporate a prologue and/or an epilogue. A prologue is displayed before a level commences, irrespective of the method used to reach that level. An epilogue is displayed only after its associated level is successfully completed. They may contain any number of pages of text, which can be formatted using HTML markup.
Prologues are the natural choice for displaying most information. Epilogues are useful for displaying concluding messages after the last level in a set, including "fake" last levels. After completion of a "fake" last level, its epilogue will play, but the prologue for the subsequent secret level will not play unless the level has been unlocked.
There are no other functions of a CCX file. The CCX file only provides meta-data, and does not alter the working of the game engine. As Tile World 2, CCLP3, and its CCX file were released within a short span of time, there have been misconceptions that the CCX file could also be used to control the view of the map during playback, as in You Can't Teach an Old Frog New Tricks. That is actually a peculiarity hardwired into the Tile World 2 program, as it would be very difficult to express such control in truly generic terms within a CCX file.
.ccx files should be placed in the "data" subdirectory of Tile World, irrespective of the location of the associated levelset file. Tile World 2 will read them, and earlier versions of Tile World will ignore them.
Although CCX files can be created using a plain text editor, their rather technical format makes it difficult for most designers to do so. Until recently, only CCEdit provided some amount of support for creating .ccx files, and only one levelset other than CCLP3 (geodave3) came with a .ccx file. However, some users have created CCX files for CCLP2 and CC1.
As of February 2013, Chip's Controls v.5.0 has incorporated a CCX editor for easy creation of CCX files.
Comparison with .dac files
Although .dac files were also designed with the intent of supplying additional configuration information about a levelset to Tile World, a new type of file (.ccx) was devised with the following rationale:
- Over a period of time, the use of .dac files has been relegated to the task of enabling a levelset to be played in both MS and Lynx modes, and thus there are usually two .dac files per levelset - usually created by the player rather than the designer.
- The format of the .dac file is - like an .ini file - designed for one-line configuration options, which is much too simple for storing complex information such as formatted multi-page text.