renpy_core

A Dart library that executes parsed Ren'Py scripts: a Python-subset evaluator, a script runner with callback-based I/O, and a screen-language interpreter. Depends on renpy_parser for the AST. This is an early-stage package (0.0.x); the API is broadly stable but may have breaking changes before 1.0.

Features

• RenPyRunner - step-by-step execution of a RenPyScript; drives dialogue, menus, images, and transitions through plain Dart callbacks, so it integrates with any UI framework
• RenPyPythonEvaluator - Python-subset evaluator covering variables, classes, inheritance, decorators, lambdas, list/dict/set comprehensions, augmented assignment, bare raise, and common builtins (len, range, sorted, isinstance, hasattr, getattr, setattr, zip, enumerate, etc.)
• Scoped variable storage via the RenPyPythonScope interface: store, persistent.*, config.*, and gui.* namespaces
• Screen-language runtime: evaluates screen displayable trees and fires RenPyScreenAction callbacks (Jump, Call, SetVariable, ToggleVariable, Function, SetField, ToggleField, and more)
• ATL (animation/transition language) skeleton, audio events, image resolver, layered-image resolver, transition resolver, styled-text parser
• .rpa archive reader (RenPyRpaArchive) for Ren'Py asset bundles
• Init-phase execution: init python: blocks and define statements run in priority/source order before gameplay begins, matching Ren'Py semantics
• Validated against the open-source game corpus shipped with Ren'Py

Installation

dependencies:
  renpy_core: ^0.0.2

Usage

import 'dart:io';
import 'package:renpy_core/renpy_core.dart';

Future<void> main() async {
  // 1. Parse.
  final source = await File('script.rpy').readAsString();
  final parseResult = RenPyParser().parse(source, 'script.rpy');

  // 2. Create runner and wire callbacks.
  final runner = RenPyRunner(parseResult.script);

  runner.onDialogue = (character, text) {
    print('${character ?? "narrator"}: $text');
  };

  runner.onImage = (scene, show, hide) {
    if (scene != null) print('[scene] $scene');
    if (show  != null) print('[show]  $show');
    if (hide  != null) print('[hide]  $hide');
  };

  runner.onMenu = (choices, onChoice, caption) {
    for (var i = 0; i < choices.length; i++) {
      print('  ${i + 1}. ${choices[i]}');
    }
    onChoice(0); // always pick first choice
  };

  // 3. Jump to the entry point and run.
  if (parseResult.script.findLabel('start') != null) {
    runner.jumpToLabel('start');
  }
  runner.run();

  // 4. Drive the execution loop.
  while (runner.state != RenPyRunnerState.complete &&
         runner.state != RenPyRunnerState.error) {
    if (runner.state == RenPyRunnerState.waitingForInput) {
      runner.continueExecution();
    }
  }

  if (runner.state == RenPyRunnerState.error) {
    print('Error: ${runner.errorMessage}');
  }
}

Key RenPyRunner members:

Repository

git.cypherstack.com/FiestaBerry/fiestavn

License

MIT