Update README.md

README.md

@@ -1,9 +1,77 @@
 # asl-help
 Welcome!
 
+## Purpose
+asl-help was created to aid auto splitter authors in writing scripts for games that use the Mono framework, specifically the Unity fork. It is packaged as a .NET Framework library that can be loaded at runtime from an auto splitter script, and uses code generation to allow for the creation of more streamlined, human-readable, and update-resilient pointer paths.
+
+## Usage 
+### Development Setup
+Download the `asl-help` file located in the `lib` directory of this repository and place it in LiveSplit's components folder. This is only necessary for development — the file will be downloaded automatically for end users, provided that you configure your auto splitter correctly (see [Publishing](#publishing)).
+
+### Loading Asl-Help
+Use the following snippet to load the asl-help binary in your auto splitter. This and the following examples will assume that the game runs on the Unity engine.
+```cs
+startup {
+    Assembly.Load(File.ReadAllBytes("Components/asl-help")).CreateInstance("Unity");
+}
+```
+
+### TryLoad
+All pointers must be declared inside of a function that is assigned to the `TryLoad` member of the auto-generated `Helper` variable. This should be done inside the `init` block. If this function returns `true`, then asl-help has been successfully initialized.
+```cs
+init {
+    vars.Helper.TryLoad = (Func<dynamic, bool>)(mono => {
+        // Declare your pointers here.
+        return true;
+    });
+}
+```
+Because the `mono` variable is scoped to the anonymous function, it cannot be accessed outside of the function. Do not store a reference to it that could outlive said function.
+
+### Pointers
+Pointers in asl-help are declared with the following syntax inside of the TryLoad function.
+```cs
+vars.Helper["WatcherName"] = mono.Make<Type>("Classname", "FieldName", offset1, offset...);
+```
+`WatcherName` is the name that will be used to access the MemoryWatcher.  
+`ClassName` is the name of the class that owns the field that is to be accessed.  
+`Type` is the datatype of the value that is to be read from memory.  
+`FieldName` is the name of a **static** field on the class. It can also be replaced by a number representing that field's offset in the static field table. asl-help will print all the static fields of any classes used to the debug output, wich can be used to ensure the name of the field matches said output.  
+`offset`, `offset2`, etc. are optional additional pointer offsets that work just like a normal pointer declaration.
+
+### Accessing Pointers
+The value of pointers declared this way can be accessed just like pointers declared in the state block: using `current` and `old`. Alternatively, the MemoryWatchers themselves can be accessed from the `vars.Helper` variable.
+```cs
+// The following two lines are equivalent.
+return current.Level != old.Level;
+return vars.Helper["Level"].Current != vars.Helper["Level"].Old;
+```
+
+### Inheritance
+Sometimes, a class's parent class has a static field that must be accessed. This is very common when dealing with singletons, which are often implemented like so:
+```cs
+abstract class Singleton<T> {
+    static T instance;
+}
+
+class Manager : Singleton<Manager> {
+    // other fields
+}
+```
+To access a field like this, specify a number indicating how many classes in the inheritance tree to go up when declaring the pointer.
+```cs
+vars.Helper["Manager"] = mono["Manager", 1].Make<IntPtr>("instance");
+```
+
+### Publishing
+When publishing an auto splitter that depends on asl-help, add the following to the auto splitter's entry in the master XML document inside of the `<URLs>` tag to ensure that it will be automatically downloaded along with the script.
+```xml
+<URL>https://github.com/just-ero/asl-help/raw/main/lib/asl-help</URL>
+```
+
 ---
 ##### Third Party Notice
 This repository is not responsible for scripts malfunctioning due to issues that are not caused by asl-help.
 We reserve the right to immediately close any issues which report problems out of our control.
 
-Instead, please either open an issue in the repository of the script's creator, or ask a question in the [Speedrun Tool Development Discord server](https://discord.gg/cpYsxz7).
+Instead, please either open an issue in the repository of the script's creator, or ask a question in the [Speedrun Tool Development Discord server](https://discord.gg/cpYsxz7).