Cross-Compatibility

One of the main goals of S1API is to enable mod developers to write code that works seamlessly across both Mono and Il2Cpp builds of Schedule One. This guide explains how to achieve cross-compatibility in your mods.

The Challenge

Schedule One exists in two different build flavors:

1. Mono: The original build using Mono as the .NET runtime
2. Il2Cpp: A newer build where the .NET code has been converted to C++

These two builds handle many things differently, especially when it comes to:

• Type references and reflection
• Memory management
• Method pointers and delegates
• Native interop

Without S1API, mod developers would need to create separate versions of their mods for each build, duplicating effort and maintenance.

How S1API Enables Cross-Compatibility

S1API solves this problem by providing:

1. Unified Interfaces

S1API defines interfaces that work the same way regardless of the underlying implementation:

// Your code uses the same interface regardless of build type
var itemDefinition = ItemManager.GetItemDefinition("sword");
var productManager = ProductManager.DiscoveredProducts;
var timeInfo = TimeManager.CurrentDay;

2. Type Handling

S1API handles the differences in how types are represented through its internal CrossType utility:

// S1API handles the type differences internally
var npc = new NPC();
npc.CreateInternal(); // Works in both Mono and Il2Cpp

3. Reflection Alternatives

S1API provides reflection alternatives through internal utilities:

// Instead of direct reflection which works differently in each build
// Use S1API's components which handle the differences internally
var item = ItemManager.GetItemDefinition("some_item_id");

4. Serialization Support

S1API includes serialization utilities that work across both builds through its Saveable system:

// Define a class that extends Saveable
public class MyQuestData : Quest
{
    [SaveableField("QuestData")]
    private readonly QuestData _questData;
    
    // S1API handles the serialization differences internally
}

Best Practices for Cross-Compatible Mods

Follow these guidelines to ensure your mods work across both builds:

DO:

• ✅ Use S1API interfaces and classes instead of direct game references
• ✅ Use the provided manager classes (ItemManager, ProductManager, etc.)
• ✅ Extend built-in classes like Quest, PhoneApp, etc. for standard functionality
• ✅ Test your mod on both Mono and Il2Cpp if possible

DON'T:

• ❌ Reference game assemblies directly
• ❌ Use raw reflection on game types
• ❌ Make assumptions about memory layout or object references
• ❌ Use platform-specific code without proper conditional compilation

Conditional Compilation

In rare cases where you need platform-specific code, S1API provides preprocessor symbols:

#if (MONO)
// Mono-specific code
#elif (IL2CPP)
// Il2Cpp-specific code
#endif

However, this should be a last resort. Aim to use S1API's cross-platform abstractions whenever possible.