| Chapter 9: Elements of a Script |
| About Script Elements |
 |
Scripts are made up of what are called segments. There are eleven different
segments which you can use in your scripts. They all fit into three different
categories: Data, Code and Compiler Directives. |
| Data Segments |
| local |
The local variables of the script are declared in the local segment.
Each variable is 16 bit, meaning it can have a value from -32,768
to 32,767. Variable arrays are also supported.
(local
score // no value set, will set later
maxScore = 100 // value of 100 set
anArrayOfValues[40] // an array of 40 variables totalling 80 bytes
)
For more information on the local segment, refer to the section
in the SCI Studio Help File. |
| string |
The strings in your script can be declared in the string segment.
Each string begins with a label identifying it, followed by either
the size, a string of text, or both.
(string // A simple string.
SomeString = "This is a string"
// Numbers can be inserted into the strings.
AnotherString = ("H" "ELL" "O" $20 "There!" 0)
// This allocates 40 bytes of an empty string.
StringBuffer[40]
// This allocates 20 bytes of string. The first five bytes are filled with "Hello".
YetAnotherString[20] = "Hello"
)
For more information on the string segment, refer to the section
in the SCI Studio Help File.
|
| synonyms |
The synonyms in your script can be declared in the synonyms segment.
Each synonym consists of two vocab words. This is one of the least
used segments, and you will probably never use it in your game.
(synonyms
'grab' = 'get'
)
For more information on the synonyms segment, refer to the section
in the SCI Studio Help File.
|
| Code Segments |
| class |
SCI, being object orientated, is structured completely around objects.
Each class segment defines a class object. Class objects are the
most powerful types of objects.
(class SomeClass of AnotherClass
(properties
aProperty 1
anotherProperty 2
)
(method (someMethod aParam anotherParam)
= aProperty 10
)
)
Classes are discussed in detail in the next chapter. For even
more information on classes, refer to the section in the SCI
Studio Help File. |
| instance |
Instances are objects derived from classes. They have slightly
more limited functionality, but are very well suited for general
purpose objects.
(instance SomeInstance of SomeClass
(properties
aProperty 1
anotherProperty 2
)
(method (someMethod aParam anotherParam)
= aProperty 10
)
)
Instances are discussed in detail in the next chapter.
For even more information on instances, refer to the section
in the SCI Studio Help
File
. |
| procedure |
Procedures are blocks of code. They operate identical
to methods, but are not tied to objects. This being the case,
they can be used by any object or other procedure, and accomplish
any task.
(procedure ( someProc aParam anotherParam)
= aParam 10
)
For more information on procedures, refer to
the section in the
SCI Studio Help File
.
|
| Compiler Directives |
| script |
Every script must have it's script number specified.
The script segment tells the compiler which number the current
script is (from 0-999). In the following example, it tells
the compiler that it's compiling the file script.123.
(script 123)
|
| define |
Define is a very frequently used segment.
It allows you to label immediate values. The script header
(.sh) files are built of these statements.
(define A_NUMBER 123)
For more information on defines, refer to
the section in the SCI
Studio Help File
.
|
| include |
The include statement tells the compiler
to use the specified header with the current script.
(include "sci.sh")
For more information on the include
statement and header files, refer to the section in the
SCI
Studio Help File
.
|
| use |
The use statement tells the compiler
that the current script uses other script's classes (and in
the case of main.sc, variables as well). Each script which
is compiled generates a .sco file. The following example means
that the script uses the obj.sc script, and reads the obj.sco
file.
(use "obj")
For more information on use statements, refer to the section
in the SCI Studio Help File.
|
| preload text |
Some scripts use text resource to print all/some of it's text.
In this case, it will access the text resource corresponding to
the script resource (ie.script.123 would use text.123). If you
are contantly accessing the text from text resources, you should
use the preload text statement. It loads the text into memory for quicker
access.
(preload text)
|
|
That sums up the segments of a script. If you don't fully understand
them yet, don't worry. Continue on with the tutorial, doing the step by
step examples. When done, you should have a good grasp on them. If you
still do not, come back to this chapter and read it again, and look at
the links to the help file.
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