From 55b38f1678c9df281b8a913f3f424b5d54fd94a7 Mon Sep 17 00:00:00 2001
From: NorbiPeti <szatmari.norbert.peter@gmail.com>
Date: Mon, 26 Apr 2021 03:12:22 +0200
Subject: [PATCH] Start working on FlyCam and create an overcomplicated struct

Just some native code that's totally unnecessary
---
 GamecraftModdingAPI/FlyCam.cs               | 26 ++++++
 GamecraftModdingAPI/OptionalRef.cs          | 99 +++++++++++++++++++++
 GamecraftModdingAPI/Players/FlyCamEngine.cs | 28 ++++++
 3 files changed, 153 insertions(+)
 create mode 100644 GamecraftModdingAPI/FlyCam.cs
 create mode 100644 GamecraftModdingAPI/OptionalRef.cs
 create mode 100644 GamecraftModdingAPI/Players/FlyCamEngine.cs

diff --git a/GamecraftModdingAPI/FlyCam.cs b/GamecraftModdingAPI/FlyCam.cs
new file mode 100644
index 0000000..15a6aa5
--- /dev/null
+++ b/GamecraftModdingAPI/FlyCam.cs
@@ -0,0 +1,26 @@
+using GamecraftModdingAPI.Players;
+using Svelto.ECS.EntityStructs;
+using Unity.Mathematics;
+
+namespace GamecraftModdingAPI
+{
+    public class FlyCam
+    {
+        private static FlyCamEngine Engine;
+        
+        public uint Id { get; }
+
+        public FlyCam(uint id) => Id = id;
+
+        public unsafe float3 Position
+        {
+            get => Engine.GetComponent<PositionEntityStruct>(Id).Map(pos => &pos->position);
+            set => Engine.GetComponent<PositionEntityStruct>(Id).Map(pos => &pos->position).Set(value);
+        }
+
+        public static void Init()
+        {
+            Engine = new FlyCamEngine();
+        }
+    }
+}
\ No newline at end of file
diff --git a/GamecraftModdingAPI/OptionalRef.cs b/GamecraftModdingAPI/OptionalRef.cs
new file mode 100644
index 0000000..a1b09cd
--- /dev/null
+++ b/GamecraftModdingAPI/OptionalRef.cs
@@ -0,0 +1,99 @@
+using System;
+using System.Collections;
+using System.Collections.Generic;
+using System.Linq;
+using System.Linq.Expressions;
+using GamecraftModdingAPI.Blocks;
+using Svelto.DataStructures;
+using Svelto.ECS;
+
+namespace GamecraftModdingAPI
+{
+    public struct OptionalRef<T> where T : unmanaged
+    {
+        private bool exists;
+        private NB<T> array;
+        private uint index;
+
+        private unsafe T* pointer;
+
+        public OptionalRef(NB<T> array, uint index)
+        {
+            exists = true;
+            this.array = array;
+            this.index = index;
+            unsafe
+            {
+                pointer = null;
+            }
+        }
+
+        public OptionalRef(ref T value)
+        {
+            unsafe
+            {
+                fixed(T* p = &value) pointer = p;
+            }
+
+            exists = true;
+            array = default;
+            index = default;
+        }
+
+        public ref T Get()
+        {
+            unsafe
+            {
+                if (pointer != null && exists)
+                    return ref *pointer;
+            }
+
+            if (exists)
+                return ref array[index];
+            throw new InvalidOperationException("Calling Get() on an empty OptionalRef");
+        }
+
+        public T Value
+        {
+            get
+            {
+                unsafe
+                {
+                    if (pointer != null && exists)
+                        return *pointer;
+                }
+
+                if (exists)
+                    return array[index];
+                return default;
+            }
+        }
+
+        public unsafe void Set(T value) //Can't use properties because it complains that you can't set struct members
+        {
+            if (pointer != null && exists)
+                *pointer = value;
+        }
+
+        public bool Exists => exists;
+
+        public static implicit operator T(OptionalRef<T> opt) => opt.Value;
+
+        public static implicit operator bool(OptionalRef<T> opt) => opt.exists;
+
+        public delegate ref TR Mapper<TR>(ref T component) where TR : unmanaged;
+        public unsafe delegate TR* PMapper<TR>(T* component) where TR : unmanaged;
+
+        /*public OptionalRef<TR> Map<TR>(Mapper<TR> mapper) where TR : unmanaged =>
+            exists ? new OptionalRef<TR>(ref mapper(ref Get())) : new OptionalRef<TR>();*/
+
+        /*public OptionalRef<TR> Map<TR>(Expression<Func<T, TR>> expression) where TR : unmanaged
+        {
+            if (expression.Body.NodeType == ExpressionType.MemberAccess)
+                Console.WriteLine(((MemberExpression) expression.Body).Member);
+        }*/
+        
+        public unsafe OptionalRef<TR> Map<TR>(PMapper<TR> mapper) where TR : unmanaged =>
+            exists ? new OptionalRef<TR>(ref *mapper(pointer)) : new OptionalRef<TR>();
+    }
+}
\ No newline at end of file
diff --git a/GamecraftModdingAPI/Players/FlyCamEngine.cs b/GamecraftModdingAPI/Players/FlyCamEngine.cs
new file mode 100644
index 0000000..b8f8cf4
--- /dev/null
+++ b/GamecraftModdingAPI/Players/FlyCamEngine.cs
@@ -0,0 +1,28 @@
+using GamecraftModdingAPI.Engines;
+using Svelto.ECS;
+using Techblox.FlyCam;
+
+namespace GamecraftModdingAPI.Players
+{
+    public class FlyCamEngine : IApiEngine
+    {
+        public void Ready()
+        {
+        }
+
+        public EntitiesDB entitiesDB { get; set; }
+        public void Dispose()
+        {
+        }
+
+        public string Name => "TechbloxModdingAPIFlyCamEngine";
+        public bool isRemovable => false;
+
+        public OptionalRef<T> GetComponent<T>(uint id) where T : unmanaged, IEntityComponent
+        {
+            if (entitiesDB.TryQueryEntitiesAndIndex<T>(id, Techblox.FlyCam.FlyCam.Group, out uint index, out var array))
+                return new OptionalRef<T>(array, index);
+            return new OptionalRef<T>();
+        }
+    }
+}
\ No newline at end of file