From 9b4b52bc9f20d3caed809908f381caee6dfa48ef Mon Sep 17 00:00:00 2001
From: NukeBird <nukebird.dev@gmail.com>
Date: Thu, 13 Feb 2025 18:55:56 +0300
Subject: [PATCH] Add dinkyecs.hpp

---
 dinkyecs.hpp | 156 +++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 156 insertions(+)
 create mode 100644 dinkyecs.hpp

diff --git a/dinkyecs.hpp b/dinkyecs.hpp
new file mode 100644
index 0000000..c8dc3bc
--- /dev/null
+++ b/dinkyecs.hpp
@@ -0,0 +1,156 @@
+#pragma once
+
+#include <functional>
+#include <typeindex>
+#include <typeinfo>
+#include <unordered_map>
+#include <any>
+#include <tuple>
+#include <queue>
+#include "dbc.hpp"
+
+namespace DinkyECS {
+  typedef unsigned long Entity;
+
+  using EntityMap = std::unordered_map<Entity, std::any>;
+
+  struct Event {
+    int event = 0;
+    Entity entity = 0;
+    std::any data;
+  };
+
+  typedef std::queue<Event> EventQueue;
+
+  struct World {
+    unsigned long entity_count = 0;
+    std::unordered_map<std::type_index, EntityMap> $components;
+    std::unordered_map<std::type_index, std::any> $facts;
+    std::unordered_map<std::type_index, EventQueue> $events;
+    std::vector<Entity> $constants;
+
+    Entity entity() {
+      return ++entity_count;
+    }
+
+    void clone_into(DinkyECS::World &to_world) {
+      to_world.$constants = $constants;
+      to_world.$facts = $facts;
+      to_world.entity_count = entity_count;
+
+      for(auto eid : $constants) {
+        for(const auto &[tid, eid_map] : $components) {
+          auto& their_map = to_world.$components[tid];
+          if(eid_map.contains(eid)) {
+            their_map.insert_or_assign(eid, eid_map.at(eid));
+          }
+        }
+      }
+    }
+
+    void make_constant(DinkyECS::Entity entity) {
+        $constants.push_back(entity);
+    }
+
+    template <typename Comp>
+      EntityMap& entity_map_for() {
+        return $components[std::type_index(typeid(Comp))];
+      }
+
+    template <typename Comp>
+      EventQueue& queue_map_for() {
+        return $events[std::type_index(typeid(Comp))];
+      }
+
+    template <typename Comp>
+      void remove(Entity ent) {
+        EntityMap &map = entity_map_for<Comp>();
+        map.erase(ent);
+      }
+
+    template <typename Comp>
+      void set_the(Comp val) {
+        $facts.insert_or_assign(std::type_index(typeid(Comp)), val);
+      }
+
+    template <typename Comp>
+      Comp &get_the() {
+        auto comp_id = std::type_index(typeid(Comp));
+        dbc::check($facts.contains(comp_id),
+            fmt::format("!!!! ATTEMPT to access world fact that hasn't been set yet: {}", typeid(Comp).name()));
+
+        // use .at to get std::out_of_range if fact not set
+        std::any &res = $facts.at(comp_id);
+        return std::any_cast<Comp&>(res);
+      }
+
+    template <typename Comp>
+      bool has_the() {
+        auto comp_id = std::type_index(typeid(Comp));
+        return $facts.contains(comp_id);
+      }
+
+    template <typename Comp>
+      void set(Entity ent, Comp val) {
+        EntityMap &map = entity_map_for<Comp>();
+        map.insert_or_assign(ent, val);
+      }
+
+    template <typename Comp>
+      Comp &get(Entity ent) {
+        EntityMap &map = entity_map_for<Comp>();
+        // use .at for bounds checking
+        std::any &res = map.at(ent);
+        return std::any_cast<Comp&>(res);
+      }
+
+    template <typename Comp>
+      bool has(Entity ent) {
+        EntityMap &map = entity_map_for<Comp>();
+        return map.contains(ent);
+      }
+
+    template<typename Comp>
+      void query(std::function<void(const Entity&, Comp&)> cb) {
+        EntityMap &map = entity_map_for<Comp>();
+        for(auto& [entity, any_comp] : map) {
+          Comp &res = std::any_cast<Comp&>(any_comp);
+          cb(entity, res);
+        }
+      }
+
+    template<typename CompA, typename CompB>
+      void query(std::function<void(const Entity&, CompA&, CompB&)> cb) {
+        EntityMap &map_a = entity_map_for<CompA>();
+        EntityMap &map_b = entity_map_for<CompB>();
+
+        for(auto& [entity, any_a] : map_a) {
+          if(map_b.contains(entity)) {
+            CompA &res_a = std::any_cast<CompA&>(any_a);
+            CompB &res_b = get<CompB>(entity);
+            cb(entity, res_a, res_b);
+          }
+        }
+      }
+
+    template<typename Comp>
+      void send(Comp event, Entity entity, std::any data) {
+        EventQueue &queue = queue_map_for<Comp>();
+        queue.push({event, entity, data});
+      }
+
+    template<typename Comp>
+      Event recv() {
+        EventQueue &queue = queue_map_for<Comp>();
+        Event evt = queue.front();
+        queue.pop();
+        return evt;
+      }
+
+    template<typename Comp>
+      bool has_event() {
+        EventQueue &queue = queue_map_for<Comp>();
+        return !queue.empty();
+      }
+  };
+}