storyscript.md

Storyscript

Introduction and Design Ideas

Storygscript is a scripting system for expressing AVG stories and is one of the official modules of AVG.js. Similar to the scripting system of other AVG engines, it is executed in the order of text; grammatically, it is quite similar to BKEngine's scripting system, but simpler.

The previous AVG script, including the entire programming logic, but unlike Lua, Javasciprt and other mature programming language, the command-style language grammar is very out of date, using it to writing a game system is often a big trouble.

AVG.js separates game system programming from script writting, and the rest of script writting is only storytelling, which is the origin of the name Storyscript.

Storyscript aims to reduce the difficulty of learning, so that non-programmers can fully grasp their use, so that designers and other personnel can complete the entry of game content on their own and reduce unnecessary communication links.

Syntax

StoryScript consists of Content Script and Logical Script.

Content script: changes in the game plot, such as print dialogue text, display characters, switch the background picture, play sound, etc.

Logic Script: Controls the direction of the game plot or provides convenient programming logic such as variable assignment, conditional branching, loops, etc.

Content Script

Basic

[command flag param="value"]

For example

[bgm autoplay loop file="abc.ogg" volume=100]

Will be parsed as

{
  command: 'bgm',
  flags: ['autoplay', 'loop'],
  params: {
    file: "abc.ogg",
    volume: 100
  }
}

Logical Script

Statement

LET

#let foo = 123  // standard way
#bar = 456      // omit let
#let foobar     // can not assign value (value will be null), thus `let` can not be omitted

If

#if foo > bar
// do something
#elseif foo == bar
// do something
#else
// do something
#end

Among them, elseif andelse are optional.

While

#while i < 10
// do something
#end

Currently break andcontinue are not supported, but they are in TODO list :)

Foreach

#foreach child in children
// do something
#end

children is an array, there are some special circumstances, please read on.

Variables

Support for simple variable assignment and modify operations, and to meet the needs of AVG, different variables in the archive have different treatment.

Global Archive Variables

Variables that begin with $ will be treated as global archive variables, meaning that once assigned, they will be read in any case, either by reading a new archive or by using a previous archive. You can use it to control the unlock CG appreciation, or support New Game+.

#let $gameclear = true;

Single archive variable

Variables that start with % are treated as single archive variables, meaning that they will only be valid in certain archives and will be overwritten when other archives are read. Usually used to control the route or favorability.

#let %girl_favor_num = 1;

Common variables

In other cases, the variable name is a normal variable, in the archive, only the archive point where the "block" and the parent "block" common variables will be saved (see below). Common variables are used only for single-file use. Do not use them to save favorability.

#let x = 0;

Scopes

Global archive variables and single archive variables are valid at any location, and are therefore considered global variables.

(NOTE: The global archive variable is completely unrelated to the global variable, the former is about how it is saved in the archive, while the other is about where it can be access in the game script)

For a normal variable, its scope is "block", such as an IF branch or the contents of the While statement, are a "block." The largest "block" is the "file", that is, even if you do not declare variables such as IF While, but outside of them, variables in the scope of the work is limited to the current script file.