Tag: C++

Modding Monster Train – Harmony Reverse Patches

digm520admin / / C#, Harmony, Modding, MonsterTrain, Programming
July 14, 2021

Modding with Harmony

Monster Train

Title:
Harmony ParDeike – Reverse Patch

By:
Harmony


Harmony – Documentation

Description:
Harmony documentation on patching with the Reverse Patch.

Overview

I was investigating ways to use Harmony to access private methods and fields from classes within the Unity target game itself, Monster Train in this case. One of the first direct options I came across was using reverse patches.

Basics of the Reverse Patch

“A reverse patch is a stub method in your own code that ‘becomes’ the original or part of the original method so you can use that yourself.”

    Typical use cases:

  • easily call private methods
  • no reflection, no delegate, native performance
  • you can cherry-pick part of the original method by using a transpiler
  • can give you the unmodified original
  • will freeze the implementation to the time you reverse patch

Implementation

After seeing its first use case being calling private methods, I thought this would be a perfect tool to use. As far as I have found, it appears to need a reference to an instance of the object that the private method belongs to. This has proved rather troublesome. While the setting up of the reverse patch has appeared to work and run, it is running into other issues that require further research.

The class I am trying to access is a Unity Scriptable Object, and has no easy way to directly access the existing instance (that I have found so far). I tried circumventing this by creating my own instance to work from, but that has its own issues. The new instance, if it is even being generated properly, is not intialized in any way and is missing integral references, such as to the AllGameData, which are also difficult to inject into the instance. This is again because it is a Unity Scriptable Object, so most fields are private but serialized, so they are very protected and only exposed in the Unity Inspector to make the necessary references I am missing in a newly generated instance.

via Blogger http://stevelilleyschool.blogspot.com/2021/07/modding-monster-train-harmony-reverse.html

Observer Pattern in Unity with C# – by Jason Weimann

digm520admin / / C#, DesignPattern, Events, Programming, Tutorial, Unity
April 22, 2021

Observer Pattern

Game Dev Patterns

Title:
Observer Pattern – Game Programming Patterns in Unity & C#

By:
Jason Weimann


Youtube – Tutorial

Description:
Introduction to the observer pattern and implementing it in Unity through C#.

Overview

This tutorial covers the basics of the observer pattern in game development with two ways of implementing it in Unity. The first approach is relatively simple just to establish the concept, whereas the second approach uses events with C# to create a more flexible system.

Observer Pattern Basics

An object, called the subject, maintains a list of its dependents, called observers, and notifies them automatically of any state changes (usually by calling one of their methods)

Example Uses in Games:

UI elements updating when data behind them changes

Achievement systems

Implementation #1: Inheriting Observer and Subject Classes

Observer Class:

Abstract class your observers will inherit from

OnNotify() method that accepts a value and notification type


Subject Class:

Abstract class your subjects will inherit from

Hold information on their list of observers they report to

RegisterObserver() method to add Observers to list of those reporting to

Notify() passes a value and notification type on to all the observers they report to in their list, in turn calling their OnNotify methods with the passed on data

This example gets the point across, but is not particularly well suited for Unity or C# projects. Requires a base class on all observers and subjects (although could possibly be changed to using an interface system).

Implementation #2: Using Events

Subject objects create a ‘static event Action‘, which they then call when the requirements are met.

Observer objects have their own methods to perform when those same requirements are met, and they are connected by having the observers subscribe their relevant methods to that same ‘static event’.

This reduces the direct coupling between the observers and subjects, as well as any other objects involved. Should profile this as calling events every frame can start to lead to performance loss. As always, also need to be careful to properly unsubscribe methods from events when needed (such as when deactivating or destroying objects).

via Blogger http://stevelilleyschool.blogspot.com/2021/04/observer-pattern-in-unity-with-c-by.html

Basics of Bits and Bytes with C++: Operands and Manipulation

digm520admin / / BitsBytes, C++, Memory, Tutorial
March 26, 2021

Manipulating Bits and Bytes

C++

Title:
Wikipedia – Bitwise Operation


Wikipedia – Bitwise Operation

Description:
Wikipedia’s page on bitwise operations.

Title:
Bitwise Operators in C/C++


GeeksforGeeks – Bitwise Operators

Description:
The basics of bitwise operators and using them in C and C++ with some guidance on more involved usage.

Title:
sizeof operator


cppreference – sizeof operator

Description:
Definition of the sizeof operator used in C++ to find the size of an something in bytes.

Title:
Bit Manipulation

By:
Make School


Youtube – Tutorial #1

Description:
Basic introduction to bit operators as well as how to use them together for simple manipulation.

Summary

These are several of the more encompassing sources I came across recently on the basics of working with bits and bytes, especially in C++. More directy memory management and bit manipulation is not something I come across often using C# in Unity, but it still seems good to understand as it does come up every now and then. Unity uses bit maps for instance with their layer masks, which reading these sources greatly helped me understand better. I am also starting to do more work in Unreal, which uses C++ as its primary language, where I feel like this type of work is done more often.

via Blogger http://stevelilleyschool.blogspot.com/2021/03/basics-of-bits-and-bytes-with-c.html