3 files changed, 131 insertions, 71 deletions
diff --git a/Djup.Native/src/Djup.Native.csproj b/Djup.Native/src/Djup.Native.csproj
index a581a58..f2a149b 100644
--- a/Djup.Native/src/Djup.Native.csproj
+++ b/Djup.Native/src/Djup.Native.csproj
@@ -9,7 +9,7 @@
   </PropertyGroup>
 
   <PropertyGroup>
-    <BuildDir>$(MSBuildThisFileDirectory)../../lib/build</BuildDir>
+    <BuildDir>$(MSBuildThisFileDirectory)../../lib/output</BuildDir>
   </PropertyGroup>
 
   <ItemGroup Condition=" '$(Configuration)'=='Release' ">
diff --git a/Djup.Native/src/LibDjup.cs b/Djup.Native/src/LibDjup.cs
index 4cd99f8..864f330 100644
--- a/Djup.Native/src/LibDjup.cs
+++ b/Djup.Native/src/LibDjup.cs
@@ -5,50 +5,62 @@ namespace Djup.Native;
 public static partial class LibDjup
 {
     const string LibraryName = "djup";
-    const string Prefix = "dp_";
 
-    [LibraryImport(LibraryName, EntryPoint = Prefix + nameof(hello_world))]
-    public static partial void hello_world();
+    [LibraryImport(LibraryName, EntryPoint = nameof(vec2_dot))]
+    public static partial Vec2 vec2_dot(Vec2 a, Vec2 b);
 
-    [LibraryImport(LibraryName, EntryPoint = Prefix + nameof(get_num))]
-    public static partial int get_num();
+    [LibraryImport(LibraryName, EntryPoint = nameof(vec2_length))]
+    public static partial float vec2_length(Vec2 v);
 
-    [LibraryImport(LibraryName, EntryPoint = Prefix + nameof(get_vec2))]
-    public static partial Vec2 get_vec2();
+    [LibraryImport(LibraryName, EntryPoint = nameof(vec2_normal))]
+    public static partial Vec2 vec2_normal(Vec2 v);
 
-    [LibraryImport(LibraryName, EntryPoint = Prefix + nameof(vec2_mul))]
-    public static partial Vec2 vec2_mul(Vec2 v, float scalar);
+    [LibraryImport(LibraryName, EntryPoint = nameof(sim_log_init))]
+    public static partial void sim_log_init(IntPtr simulation, [MarshalAs(UnmanagedType.FunctionPtr)] LoggerDelegate logger, [MarshalAs(UnmanagedType.FunctionPtr)] AssertDelegate assert);
 
-    [LibraryImport(LibraryName, EntryPoint = Prefix + nameof(vec2_normal))]
-    public static partial Vec2 vec2_normal(Vec2 v);
+    [LibraryImport(LibraryName, EntryPoint = nameof(sim_set_log_level))]
+    public static partial void sim_set_log_level(IntPtr simulation, LogLevel minLevel);
 
-    [LibraryImport(LibraryName, EntryPoint = Prefix + nameof(vec2_length))]
-    public static partial float vec2_length(Vec2 v);
+    [LibraryImport(LibraryName, EntryPoint = nameof(sim_create))]
+    public static partial IntPtr sim_create(int snapshots, int entities);
+
+    [LibraryImport(LibraryName, EntryPoint = nameof(sim_free))]
+    public static partial void sim_free(IntPtr simulation);
 
-    [LibraryImport(LibraryName, EntryPoint = Prefix + nameof(log_set_output))]
-    public static partial void log_set_output([MarshalAs(UnmanagedType.FunctionPtr)] LoggerDelegate logger);
+    [LibraryImport(LibraryName, EntryPoint = nameof(sim_get_snapshot))]
+    public unsafe static partial Snapshot* sim_get_snapshot(IntPtr simulation);
 
-    [LibraryImport(LibraryName, EntryPoint = Prefix + nameof(log_set_level))]
-    public static partial void log_set_level(LogLevel minLevel);
+    [LibraryImport(LibraryName, EntryPoint = nameof(sim_return_snapshot))]
+    public unsafe static partial void sim_return_snapshot(IntPtr simulation, Snapshot* snapshot);
 
-    [LibraryImport(LibraryName, EntryPoint = Prefix + nameof(physics_context_create))]
-    public static partial IntPtr physics_context_create(int snapshots, int players, int balls);
+    [LibraryImport(LibraryName, EntryPoint = nameof(sim_tick))]
+    public unsafe static partial void sim_tick(Snapshot* current, Snapshot* next);
 
-    [LibraryImport(LibraryName, EntryPoint = Prefix + nameof(physics_context_free))]
-    public static partial void physics_context_free(IntPtr context);
+    [LibraryImport(LibraryName, EntryPoint = nameof(snapshot_create_entity))]
+    public unsafe static partial EntityId snapshot_create_entity(Snapshot* snapshot);
 
-    [LibraryImport(LibraryName, EntryPoint = Prefix + nameof(physics_context_get_snapshot))]
-    public static partial IntPtr physics_context_get_snapshot(IntPtr context);
+    public enum ComponentAddError
+    {
+        None,
+        InvalidArg,
+        InvalidId,
+        EntityNotFound
+    }
 
-    [LibraryImport(LibraryName, EntryPoint = Prefix + nameof(physics_context_return_snapshot))]
-    public static partial void physics_context_return_snapshot(IntPtr context, IntPtr snapshot);
+    [LibraryImport(LibraryName, EntryPoint = nameof(snapshot_add_component))]
+    public unsafe static partial ComponentAddError snapshot_add_component(Snapshot* snapshot, EntityId entity, Component component, void* init);
 
-    [LibraryImport(LibraryName, EntryPoint = Prefix + nameof(physics_tick))]
-    public static partial int physics_tick(IntPtr currentSnapshot, double delta, IntPtr nextSnapshot);
+    public enum ComponentRemoveError
+    {
+        None,
+        InvalidArg,
+        InvalidId,
+        EntityNotFound
+    }
 
-    [LibraryImport(LibraryName, EntryPoint = Prefix + nameof(snapshot_put_player))]
-    public static unsafe partial int snapshot_put_player(IntPtr snapshot, int playerId, Player* player);
+    [LibraryImport(LibraryName, EntryPoint = nameof(snapshot_remove_components))]
+    public unsafe static partial ComponentRemoveError snapshot_remove_components(Snapshot* snapshot, EntityId entity, Components components);
 
-    [LibraryImport(LibraryName, EntryPoint = Prefix + nameof(snapshot_set_player_input))]
-    public static partial int snapshot_set_player_input(IntPtr snapshot, int playerId, byte input);
+    [LibraryImport(LibraryName, EntryPoint = nameof(snapshot_reset_entity))]
+    public unsafe static partial ComponentRemoveError snapshot_reset_entity(Snapshot* snapshot, EntityId entity);
 }
diff --git a/Djup.Native/src/Types.cs b/Djup.Native/src/Types.cs
index 3afce83..e9eb824 100644
--- a/Djup.Native/src/Types.cs
+++ b/Djup.Native/src/Types.cs
@@ -4,10 +4,84 @@ using System.Runtime.InteropServices;
 namespace Djup.Native;
 
 [StructLayout(LayoutKind.Sequential)]
+public struct EntityId
+{
+    public int Id { get; }
+
+    public static readonly EntityId Invalid = new(-1);
+
+    public EntityId(int id)
+    {
+        Id = id;
+    }
+
+    public bool IsInvalid => Id < 0;
+
+    public override string ToString() => $"#{Id}";
+
+    public override bool Equals(object? other)
+    {
+        if (other is EntityId id)
+        {
+            return this == id;
+        }
+        return false;
+    }
+
+    public override int GetHashCode() => Id.GetHashCode();
+
+    public static bool operator ==(EntityId a, EntityId b)
+    {
+        if (a < 0)
+            return b < 0;
+        if (b < 0)
+            return false;
+        return a.Id == b.Id;
+    }
+    public static bool operator !=(EntityId a, EntityId b) => !(a == b);
+    public static implicit operator int(EntityId entityId) => entityId.Id;
+    public static implicit operator EntityId(int id) => new(id);
+}
+
+public enum Component : int
+{
+    Exists,
+    Ball,
+    PlayerInput
+}
+
+[Flags]
+public enum Components : int
+{
+    Exists = 1 << Component.Exists,
+    Ball = 1 << Component.Ball,
+    PlayerInput = 1 << Component.PlayerInput
+}
+
+[StructLayout(LayoutKind.Sequential)]
+public unsafe struct OdinSlice<T>
+{
+    public void* Data { get; }
+    public nint Len { get; }
+
+    public Span<T> AsSpan() => new Span<T>(Data, Len.ToInt32());
+    public ReadOnlySpan<T> AsReadOnlySpan() => new ReadOnlySpan<T>(Data, Len.ToInt32());
+}
+
+[StructLayout(LayoutKind.Sequential)]
+public unsafe struct OdinString
+{
+    public sbyte* Data { get; }
+    public nint Len { get; }
+
+    public override string ToString() => new string(Data, 0, Len.ToInt32());
+}
+
+[StructLayout(LayoutKind.Sequential)]
 public struct Vec2
 {
-    public float X { get; }
-    public float Y { get; }
+    public float X { get; set; }
+    public float Y { get; set; }
 
     public Vec2(float x, float y)
     {
@@ -21,59 +95,32 @@ public struct Vec2
     public override string ToString() => $"({X}, {Y})";
 }
 
-public enum EntityState : byte
-{
-    Inactive = 0,
-    Active,
-    Removed,
-    Dead
-}
-
-public enum PlayerInput : byte
-{
-    Up = 1 << 0,
-    Down = 1 << 1,
-    Left = 1 << 2,
-    Right = 1 << 3
-}
-
 [StructLayout(LayoutKind.Sequential)]
-public struct Player
+public struct Ball
 {
-    public EntityState State { get; }
-    private byte input;
     public Vec2 Position { get; set; }
     public Vec2 Velocity { get; set; }
 }
 
 [StructLayout(LayoutKind.Sequential)]
-public struct Bullet
+public struct PlayerInput
 {
-    public EntityState State { get; set; }
-    public Vec2 Position { get; set; }
-    public Vec2 Velocity { get; set; }
+    public Vec2 Direction { get; set; }
 }
 
 [StructLayout(LayoutKind.Sequential)]
-public unsafe struct Snapshot
+public struct Snapshot
 {
-    private byte active;
+    private readonly byte active;
     public uint Tick { get; }
-    private int playersLength;
-    private Player* players;
-    private int bulletsLength;
-    private Bullet* bullets;
-
-    public ReadOnlySpan<Player> Players =>
-        new ReadOnlySpan<Player>(players, playersLength);
-
-    public ReadOnlySpan<Bullet> Bullets =>
-        new ReadOnlySpan<Bullet>(bullets, bulletsLength);
+    public OdinSlice<Components> Metadata { get; }
+    public OdinSlice<Ball> Balls { get; }
+    public OdinSlice<PlayerInput> PlayerInputs { get; }
+    private IntPtr ctx;
 }
 
 public enum LogLevel
 {
-    Trace,
     Debug,
     Info,
     Warn,
@@ -81,4 +128,5 @@ public enum LogLevel
     Fatal
 }
 
-public delegate void LoggerDelegate(LogLevel level, string source, int line, string message);
+public delegate void LoggerDelegate(LogLevel level, OdinString message, OdinString procedure, OdinString file, int line);
+public delegate void AssertDelegate(OdinString prefix, OdinString message, OdinString procedure, OdinString file, int line);