The AGAST Script Language looks similar to the C language, but it has the completely different purpose of directing the flow of an adventure game. Like C, it allows one to declare and modify variables, define and call functions (called scripts in AGAST), and code loops and branches of execution. Unlike C, it has many special-purpose constructs for adventure game scripting. Such features include an event-driven model, concurrent script execution, and object-based (but not oriented) programming.

Conventions

Here are some general conventions and concepts of the AGAST script language.

• Overview of Script Elements
• File and Directory Organization
  • [ Game Directory ]
  • [ Scene Directories ]
• Scope
• Identifiers
• Comments
• Handlers

Declarations

Script files are the actual text files that are translated by the compiler, and they contain definitions for events, scripts, objects, variables, etc.

• Variables
  • [ What is a variable? ]
  • [ Game and Scene Scope ]
  • [ Static and Automatic Script Variables ]
  • [ Initialization ]
  • [ Variable Arrays ]
  • [ Logical Values ]
• Objects
  • [ Object Classes ]
  • [ Object Member Variables ]
  • [ Using Member Variables and Classes ]
• Scripts
• Events
  • [ Main ]
  • [ Enter ]
  • [ Click ]
  • [ Object-on-Object ]
  • [ Default-on-Object ]
  • [ Click-Object ]
  • [ Default-on-Default ]
  • [ Object-on-Default ]
  • [ Key Event ]
  • [ Paint-Object ]
  • [ Animate-Object ]
  • [ Mouse-Over-Object ]
  • [ Mouse-Off-Object ]
• Resources ^Updated
• Constants
• Strings
• Parser/Scanner Word Declarations
  • [ Ignore Word ]
  • [ Word ]

Statements

Statements are commands that appear inside a declaration's code block. Each statement performs some simple action. Statements are executed one after the other until the script ends.

• Assignment
  • [ Simple Assignment ]
  • [ Abbreviated Assignment ]
  • [ Increment/Decrement Variable ]
• Control
  • [ Enter-Statement ]
  • [ Start-Statement ]
  • [ Delay-Statement ]
  • [ Return-Statement ]
• Branching
  • [ If/Unless-Statement ]
  • [ Switch-Statement ]
• Looping
  • [ While/Until-Statement ]
  • [ Do While/Until-Statement ]
  • [ For-Statement ]
  • [ Loop-Statement ]
• Objects
• Scripts and Functions
  • [ Start vs. Call ]
  • [ Function Calls ]
• Print

Expressions

Most statements may include one or more expressions. Expressions are evaluated according to operator precedence and return a single integer value.

• Operators
  • [ Operator Precedence ]
• Literals
  • [ Integers ]
  • [ Strings ]
  • [ Characters ]
  • [ Floating-point values ]
• Objects
• Resources
• Calls
• Key Codes
• Bit Access
• Counters
  • [ Up Counter ]
  • [ Down Counter ]
  • [ Flip Counter ]
• Parse Masks
  • [ Sentence Masks ]
  • [ Phrase Masks ]
  • [ Prefix Masks ]
  • [ Suffix Masks ]
  • [ Empty Masks ]
  • [ Input Masks ]

Predefined Functions and Properties

Predefined functions and properties are used to control all aspects of the interpreter's operation. They fall into these categories:

• Interpreter System
• General Utility Functions
• Object Manipulation and Direction
• Midnight GUI System ^New
• Inventory Management and Display
• Dialog System
• Background Screen
• Event Data and Control
• Message Printing System
• String Manipulation Functions
• Menu System
• Drawing Functions
• User Input
• Key Code Conversion Functions
• Resource File Information
• Floating-Point Math Functions
• File Input and Output
• Vertex Buffer ^New
• Scanning and Parsing Input
• Index/Quick Reference