1 files changed, 43 insertions, 1 deletions
diff --git a/src/ecs/entity.zig b/src/ecs/entity.zig
index 6131cff..2ad8556 100644
--- a/src/ecs/entity.zig
+++ b/src/ecs/entity.zig
@@ -1,3 +1,45 @@
 const std = @import("std");
 
-pub const Entity = struct {};
+pub const Entity = struct {
+    id: usize,
+};
+
+pub const EntityCollection = struct {
+    allocator: std.mem.Allocator,
+    next_id: usize,
+    entities: std.AutoHashMap(usize, Entity),
+
+    pub fn addEntity(self: *EntityCollection) !usize {
+        try self.entities.put(self.next_id, .{
+            .id = self.next_id,
+        });
+
+        self.next_id += 1;
+
+        return self.next_id - 1;
+    }
+
+    pub fn init(allocator: std.mem.Allocator) EntityCollection {
+        return .{
+            .allocator = allocator,
+            .next_id = 0,
+            .entities = std.AutoHashMap(usize, Entity).init(allocator),
+        };
+    }
+
+    pub fn deinit(self: *EntityCollection) void {
+        self.entities.deinit();
+    }
+};
+
+test "create entities" {
+    try std.testing.expect(true);
+
+    var ec = EntityCollection.init(std.testing.allocator);
+    defer ec.deinit();
+
+    for (0..128) |i| {
+        const id = ec.addEntity();
+        try std.testing.expectEqual(i, id);
+    }
+}