From 93a7f31757881fa15c1d86b6389108d1c8c9d495 Mon Sep 17 00:00:00 2001
From: NukeBird <nukebird.dev@gmail.com>
Date: Thu, 20 Mar 2025 18:12:46 +0300
Subject: [PATCH] make/destroy world/entities

---
 CMakeLists.txt |  4 +--
 tests/zecsy.c  | 47 +++++++++++++++++++++++++++--
 zecsy.h        | 81 ++++++++++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 128 insertions(+), 4 deletions(-)

diff --git a/CMakeLists.txt b/CMakeLists.txt
index 8b50986..ee5e299 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -8,7 +8,7 @@ set(CMAKE_C_STANDARD_REQUIRED ON)
 set(CMAKE_EXPORT_COMPILE_COMMANDS ON)
 option(BUILD_ZECSY_TESTS "Build tests?" ON)
 
-add_library(zecsy STATIC zecsy.h)
+add_library(zecsy STATIC zecsy.h stb_ds.h)
 set_target_properties(zecsy PROPERTIES LINKER_LANGUAGE C)
 
 if(${BUILD_ZECSY_TESTS})
@@ -21,5 +21,5 @@ if(${BUILD_ZECSY_TESTS})
     FetchContent_MakeAvailable(clove-unit)
 
     add_executable(tests tests/zecsy.c)
-    target_link_libraries(tests clove-unit)
+    target_link_libraries(tests clove-unit zecsy)
 endif()
diff --git a/tests/zecsy.c b/tests/zecsy.c
index f6c9067..05b4087 100644
--- a/tests/zecsy.c
+++ b/tests/zecsy.c
@@ -1,9 +1,52 @@
+#include <stdlib.h>
 #define CLOVE_IMPLEMENTATION
 #include <clove-unit.h>
 
-CLOVE_TEST(oh_hi_mark)
+#define ZECSY_IMPLEMENTATION
+#include "../zecsy.h"
+
+CLOVE_TEST(make_and_delete_empty_world)
 {
-    CLOVE_IS_TRUE(true);
+    world* w = NULL;
+    make_world(&w);
+    
+    CLOVE_NOT_NULL(w);
+    CLOVE_SIZET_EQ(RESERVED_ENTITY_ID + 1, w->entity_id_counter);
+    CLOVE_SIZET_EQ(0, w->alive_entities);
+
+    destroy_world(&w);
+    CLOVE_NULL(w);
+}
+
+CLOVE_TEST(pass_null_to_world_free)
+{
+    world* w = NULL;
+    destroy_world(&w);
+
+    CLOVE_NULL(w);
+}
+
+CLOVE_TEST(alive_entities)
+{
+    world* w = NULL;
+    make_world(&w);
+
+    entity_id e = make_entity(w);
+    CLOVE_SIZET_NE(e, RESERVED_ENTITY_ID);
+    CLOVE_IS_TRUE(world_has_entity(w, e));
+    destroy_world(&w);
+}
+
+CLOVE_TEST(dead_entities)
+{
+    world* w = NULL;
+    make_world(&w);
+
+    entity_id e = make_entity(w);
+    destroy_entity(w, e);
+    CLOVE_IS_FALSE(world_has_entity(w, e));
+
+    destroy_world(&w);
 }
 
 CLOVE_RUNNER()
diff --git a/zecsy.h b/zecsy.h
index 5fad448..aedaee5 100644
--- a/zecsy.h
+++ b/zecsy.h
@@ -1,8 +1,89 @@
 #ifndef __ZECSY_H
 #define __ZECSY_H
 
+#define STB_DS_IMPLEMENTATION
+#include "stb_ds.h"
+#include <stdlib.h>
+#include <stddef.h>
+
+#define RESERVED_ENTITY_ID 0
+typedef size_t entity_id;
+
+typedef struct
+{
+    struct{entity_id key; int value;}* entity_map; 
+    entity_id entity_id_counter;
+    entity_id alive_entities;
+} world;
+
+void make_world(world** w);
+void destroy_world(world** w);
+
+entity_id make_entity(world* w);
+void destroy_entity(world* w, entity_id e);
+
+int world_has_entity(world* w, entity_id e);
+
 #endif // !__ZECSY_H
 
+#define ZECSY_IMPLEMENTATION //TODO: REMOVE
 #ifdef ZECSY_IMPLEMENTATION
 
+void make_world(world** w)
+{
+    if(!w)
+        return;
+
+    (*w) = malloc(sizeof(world));
+
+    (**w) = (world)
+    {
+        .entity_map = NULL,
+        .entity_id_counter = RESERVED_ENTITY_ID + 1,
+        .alive_entities = 0,
+    };
+}
+
+void destroy_world(world** w)
+{
+    if(!w || !(*w))
+        return;
+
+    if((*w)->entity_map)
+        hmfree((*w)->entity_map);
+
+    free((*w));
+    (*w) = NULL;
+}
+
+entity_id make_entity(world* w)
+{
+    entity_id e = RESERVED_ENTITY_ID;
+    
+    if(w)
+    {
+        e = w->entity_id_counter++;
+        hmput(w->entity_map, e, 1);
+        w->alive_entities++;
+    }
+
+    return e;
+}
+
+void destroy_entity(world* w, entity_id e)
+{
+    if(w)
+        hmdel(w->entity_map, e);
+}
+
+int world_has_entity(world* w, entity_id e)
+{
+    if(w)
+    {
+        return hmgeti(w->entity_map, e) != -1;
+    }
+
+    return 0;
+}
+
 #endif // ZECSY_IMPLEMENTATION