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Text File | 1995-10-18 | 12.1 KB | 283 lines

TRELLIS - The Adventure Interpreter (c) copyright 1991-4 Soft Rock Software Putting It On The Computer -------------------------- With the map and initial notes drawn up, you can now start thinking about transferring the information onto the computer. Trellis needs this data in the form of 5 text files, each of which contains a different part of the data:- Titles - contains the game title and some brief instructions Rooms - contains information about each location Words - contains lists of words the player can enter as commands Objects - contains information about each object Script - contains the main controlling program These files can be created in !Edit or your favourite word processor (provided it can save !Edit format files). Before describing the format of these files, it is necessary to explain how to set Trellis up to use them. Make a copy of your !Trellis application on another disk. Rename this copy as appropriate to the name of your game (eg !Wanderer). Open this application directory, and you will see the following:- files: !Boot !Run Licence directories: DataFiles Program The files !Boot and !Run, and the directory Program should not be touched. The directory DataFiles contains the files that you need to change/create in order to write your game. It contains the files described below, and a file called !Sprites. The !Sprites file contains a sprite called !Trellis, and is displayed by RISC OS when the !Trellis application is seen in a filer window. Since you have renamed your copy of the application, it will no longer use this. Load the !Sprites file into !Paint and rename the sprite !Trellis so that it has the same name as your application directory, and redesign it to suit your game. Do the same with sm!Trellis - renaming it as appropriate. Now we can look at the other files:- In the main, the format of each of these files differs from the others. However, there are certain similarities which can be explained as a whole instead of repeating it with the description of each file. First of all, what is meant by a line should be clarified: a line is all the text/data entered until the return key is pressed - which can be more than what you might see as a line on the screen. In practice, a line can be up to approximately 240 characters long. In an 80 column mode, such as modes 12 or 15, this is three 'screen' lines using the system font. So, wherever you see the word 'line' in these instructions, you should remember that it can be anything up to roughly 240 characters or three screen lines. If you are using a screen that is wider than 80 characters, using !Edit you can set the 'display width' to 80. The lines you type in must then be less than three lines in the edit window. To confuse matters slightly, there is a case where a line must not be longer than 40 characters in length. This will be referred to in these instructions as a 'short line'. Another thing that should be explained is what is meant by a 'blank line'. This is a line on which you press the return key at the very start of the line without typing in anything else - not even spaces. All of the Trellis files start off in the same way. You may type in a number of lines of text that will be ignored. These initial 'comment' lines can be used to put a title and copyright message at the start of the files, or whatever information you choose. The end of these comments is marked by a blank line. After the blank line comes the data that is needed by Trellis. Note: if you prefer not to put any comments at the start of your data files, you must still include the blank line as Trellis seeks this out as a marker for the start of the data. --The Titles File-- This is the simplest file needed by Trellis. It contains some basic information about the game that is displayed on the title screen. After the comment lines and blank line (as mentioned above), the file must contain the following, each on a separate short line:- The title of the game, eg Dark Mountain The name of the author, eg Vince M Hudd The year the game was written, eg 1994 The name of the company that owns the copyright, eg Soft Rock Software The next six short lines should contain brief instructions about the game, or some other comment that you wish to make. If you do not want to include anything on any or all of these lines you must include blank lines instead since Trellis expects all six lines to be present. --The Words File-- This file contains lists of words & alternatives that the player can use when playing your game. After the initial comment lines and blank line (mentioned above) you must put a number; the number of lines of words that follow. After this come the actual word lists. Each line in the file consists of a series of words, separated by commas, that mean the same thing and is called a word list. Note: The last word on the line must have a comma following it as well. For example:- FIGHT,ATTACK,KILL, The first word in each list (the first word on each line) is called a keyword. This is the word you must use in your TScript program whenever you want to refer to that list - eg to see if the player has entered a word. If the word list represents an object, for example:- SWORD,WEAPON, then the keyword must also be used in the objects file as part of the definition for that object. This will be explained as part of the Object file instructions. Additionally, there are a number of words and alternatives already defined within Trellis that, therefore, DO NOT have to be included in your Words file. These are:- NORTH, EAST, SOUTH, WEST, UP, DOWN, GET,TAKE,GRAB,LIFT,PICK,STEAL,PINCH, DROP,LEAVE,ABANDON, INV, EXAMINE,STUDY,CHECK,DESCRIBE, LOOK,SEARCH, QUIT,END,FINISH,TERMINATE,STOP, HELP,SUPPORT,AID, Although these words are not part of the Words file, you may treat them as if they are. In other words, the first word on each of the above lines is a keyword which can be used by you in your TScript files. --The Objects File-- This file is used to tell the software what objects there are in the game, and other information it needs to know about them. After the initial comment lines and blank lines the definitions start. The first line after the blank line must be a number, this tells Trellis how many objects there are. Following this are the definitions for each object. For each object there will be 6 lines, as follows:- Line 1 - ignored. This can be a comment, or can be left blank, or whatever. My own preference is to use a line of asterisks (*), broken up in the center by the number of the object. Eg:- ******************************* 1 ********************************* Note: this number is not used, as such, by the software and is not part of the definition. I use it only for my own reference. Line 2 - the keyword. This is a word that is used to refer to this object in the script file, in respect of the player's commands. It is also used, if there are alternatives that the player can type in, as the first word on a line in the words file. For example, if the object is a sword this would appear in the objects file:- SWORD (and the line in the words file, therefore, might be SWORD,WEAPON,) Line 3 - the definition. This is a short description of the object, usually two words. For example:- a sword When the software tells the player what he/she can see, it is this description that is displayed on screen. Line 4 - the room number. This is a number that tells Trellis what room the object is in at the start of the game. If you don't want the object to start off in a room (perhaps the object may magically appear at the appropriate time) you can set this to -1. Note: if an object is in room 0 it is being carried by the player. Line 5 - the weight. This tells Trellis how heavy the object is. The player can be given a weight limit, and the total weights of all the objects he/she carries can't exceed this. If you don't want to use a weight limit simply set all the object weights to zero. If there is something in the game that, although the player can't pick up, may be usefully treated as an object for the purposes of examining it, etc., then give it a weight higher than the weight limit. This technique has been employed in the game !Pyramid, wherein a statue and a pedestal are objects that the player can't carry. Line 6 - the description. This line will be displayed by Trellis whenever the player wants to examine the object. It enables a more detailed description of the object than the one on line 2, and may include clues about what the object may be used for. It could even include an advertisement for another game! --The Rooms File-- The rooms file contains descriptions of each location in the game and information that tells Trellis how the player can move between them. As with the other files, it starts off with the comments and blank line. After this comes a number (the number of rooms), then the actual data. Each room's definition has three lines:- Line 1 - ignored. This line can be used for comments, left blank, or whatever. Similarly to the objects file, my own preference is to use it for numbering the rooms via a line of asterisks and a number. For example:- *************************** 1 ***************************** Line 2 - description. This line contains the text that is displayed for the location. For example:- You are on a high cliff-side path. It is cold here, and the strong wind makes it difficult to maintain your balance. You may find, if you are making your descriptions very detailed, that the line limit of 240 characters is not enough. It is possible, however, to add more to the description via the script file. This will be explained at the appropriate point in these instructions. Line 3 - Light Flag & Exits. This line tells Trellis if the room is light or dark, and what (automatic) exits there are. All the different items on this line should be separated by commas. If the room is light the first character on this line must be L. If it is dark the L can be left out. What this actually tells Trellis is the conditions under which the location's description can be shown on screen. If the L is present (ie. the room is light) the description will always be shown. However, if no L is present (the room is dark) the description will only be shown if the player is carrying a light source (such as a torch), otherwise the software will show the message 'It is dark.' In order to tell Trellis that the player is carrying a light source the contents of a store must be set accordingly. This will be detailed in the section on stores. The exits are detailed by including the first letter of the direction followed by the number of the room the direction leads to. This may seem a little unclear, so to use an example:- L,N14,S15,W16 If this is part of the definition for room 13, it says that the room is light (L), moving North leads to room 14 (N14), moving South leads to room 15 (S15) and moving West to room 16 (W16). There is no E, U, or D so the player can't go East, Up or Down - unless you allow him/her to do so via a section of the script file. This is dealt with later in the section on puzzles. --The Script File-- This file contains a program (or script) that Trellis must follow in order to run your adventure game. Depending on what is needed for your game, the script file can be as simple or as complicated as you like. The basic format of the file starts off as with the others, with the comments and blank line. After the blank line are the commands. Each command should be on a separate line. Leading spaces are ignored, so you can easily indent sections of the script. Blank lines are also ignored. The language that Trellis recognises is called TScript, and is currently in version 2 (though this version number can be ignored - it is the Trellis version number that is important This is found on the loading screen). Part 4 of these instructions describes the commands available with TScript. Before that, however, the subject of stores in Trellis needs to be explained. This is dealt with in the next part.