Better world

18 files changed, 539 insertions, 45 deletions

diff --git a/src/assets.c b/src/assets.c
new file mode 100644
index 0000000..1f0c95b
--- /dev/null
+++ b/src/assets.c
@@ -0,0 +1,39 @@
+#include "assets.h"
+
+const char textureAssetPaths[TEXTURE_ASSET_COUNT][ASSET_PATH_MAX] = {
+	"/home/nathan/Documents/KillaFacsista/assets/icon.png",
+	"/home/nathan/Documents/KillaFacsista/assets/icon128.png",
+	"/home/nathan/Documents/KillaFacsista/assets/icon64.png"
+};
+
+const char modelAssetPaths[MODEL_ASSET_COUNT][ASSET_PATH_MAX] = {
+	"/home/nathan/Documents/KillaFacsista/assets/antifaShip.obj"
+};
+
+void LoadAssets(Assets * assets) {
+	int i;
+
+	// Textures.
+	for (i = 0; i < TEXTURE_ASSET_COUNT; ++i)
+		assets->textures[i] = LoadTexture(textureAssetPaths[i]);
+
+	// Models.
+	for (i = 0; i < MODEL_ASSET_COUNT; ++i)
+		assets->models[i] = LoadModel(modelAssetPaths[i]);
+
+	TraceLog(LOG_INFO, "Assets loaded");
+}
+
+void unloadAssets(Assets * assets) {
+	int i;
+
+	// Textures.
+	for (i = 0; i < TEXTURE_ASSET_COUNT; ++i)
+		UnloadTexture(assets->textures[i]);
+
+	// Models.
+	for (i = 0; i < MODEL_ASSET_COUNT; ++i)
+		UnloadModel(assets->models[i]);
+
+	TraceLog(LOG_INFO, "Assets unloaded");
+}
diff --git a/src/assets.h b/src/assets.h
new file mode 100644
index 0000000..f28ddb8
--- /dev/null
+++ b/src/assets.h
@@ -0,0 +1,37 @@
+#include "gameCommon.h"
+
+#ifndef ASSETS_H
+#define ASSETS_H
+
+#define ASSET_PATH_MAX 255
+
+#define TEXTURE_ASSET_COUNT 3
+#define MODEL_ASSET_COUNT 1
+
+// Paths to assets.
+extern const char textureAssetPaths[TEXTURE_ASSET_COUNT][ASSET_PATH_MAX];
+extern const char modelAssetPaths[MODEL_ASSET_COUNT][ASSET_PATH_MAX];
+
+typedef int32_t AssetId;
+
+// Texture asset ids.
+enum {
+	ICON_ASSET,
+	ICON128_ASSET,
+	ICON64_ASSET
+};
+
+// Model asset ids.
+enum {
+	ANTIFA_SHIP_ASSET
+};
+
+typedef struct Assets {
+	Texture2D textures[TEXTURE_ASSET_COUNT];
+	Model models[MODEL_ASSET_COUNT];
+} Assets;
+
+void LoadAssets(Assets * assets);
+void unloadAssets(Assets * assets);
+
+#endif
diff --git a/src/entities/antifaShip.c b/src/entities/antifaShip.c
index 1944053..f43a7df 100644
--- a/src/entities/antifaShip.c
+++ b/src/entities/antifaShip.c
@@ -1,28 +1,21 @@
 #include "antifaShip.h"
-#include <raylib.h>
+#include "game.h"
 
-void initAntifaShip(Entity * entity) {
-	entity->model = LoadModel("/home/nathan/Documents/KillaFacsista/assets/antifaShip.obj");
+void initAntifaShip(Entity * entity, Game * game) {
+	entity->model = &game->assets.models[ANTIFA_SHIP_ASSET];
 
 	entity->useAcceleration = true;
 	entity->acceleration = (EntityAcceleration){
 		.speedUp = 30.0,
 		.speedDown = 15,
-		.rotationUp =   (Vector3){0.6, 0.6, 0.6},
-		.rotationDown = (Vector3){0.6, 0.6, 0.6}
+		.rotation = (Vector3){0.7, 0.7, 0.7}
 	};
 }
 
 void closeAntifaShip(Entity * entity) {
-	UnloadModel(entity->model);
 }
 
 void updateAntifaShip(Game * game, Entity * entity, EntityId id) {
-}
-
-void drawAntifaShip(Game * game, Entity * entity, EntityId id) {
-	entityDraw(entity);
-
 	Vector3 stick = (Vector3){
 		GetGamepadAxisMovement(0, 1),
 		-GetGamepadAxisMovement(0, 0),
@@ -33,3 +26,7 @@ void drawAntifaShip(Game * game, Entity * entity, EntityId id) {
 
 	entityJoystickControl(entity, stick, fabs(GetGamepadAxisMovement(0, 3) * 300.0));
 }
+
+void drawAntifaShip(Game * game, Entity * entity, EntityId id) {
+	entityDraw(entity);
+}
diff --git a/src/entities/antifaShip.h b/src/entities/antifaShip.h
index 15e9009..a1b97d2 100644
--- a/src/entities/antifaShip.h
+++ b/src/entities/antifaShip.h
@@ -4,7 +4,7 @@
 #ifndef ANTIFA_SHIP_H
 #define ANTIFA_SHIP_H
 
-void initAntifaShip(Entity * entity);
+void initAntifaShip(Entity * entity, Game * game);
 void closeAntifaShip(Entity * entity);
 void updateAntifaShip(Game * game, Entity * entity, EntityId id);
 void drawAntifaShip(Game * game, Entity * entity, EntityId id);
diff --git a/src/entities/soldato.c b/src/entities/soldato.c
new file mode 100644
index 0000000..c1903d4
--- /dev/null
+++ b/src/entities/soldato.c
@@ -0,0 +1,18 @@
+#include "soldato.h"
+#include "game.h"
+
+void initSoldato(Entity * entity, Game * game) {
+	entity->model = &game->assets.models[ANTIFA_SHIP_ASSET];
+	entity->velocity.angularVelocity = (AxisAngle){(Vector3){1.0, 1.0, 1.0}, 1.0};
+}
+
+void closeSoldato(Entity * entity) {
+}
+
+void updateSoldato(Game * game, Entity * entity, EntityId id) {
+	entityUpdateRotation(entity);
+}
+
+void drawSoldato(Game * game, Entity * entity, EntityId id) {
+	entityDraw(entity);
+}
diff --git a/src/entities/soldato.h b/src/entities/soldato.h
new file mode 100644
index 0000000..4069b26
--- /dev/null
+++ b/src/entities/soldato.h
@@ -0,0 +1,12 @@
+#include "gameCommon.h"
+#include "entity.h"
+
+#ifndef SOLDATO_H
+#define SOLDATO_H
+
+void initSoldato(Entity * entity, Game * game);
+void closeSoldato(Entity * entity);
+void updateSoldato(Game * game, Entity * entity, EntityId id);
+void drawSoldato(Game * game, Entity * entity, EntityId id);
+
+#endif
diff --git a/src/entity.c b/src/entity.c
index c88c767..f4066b5 100644
--- a/src/entity.c
+++ b/src/entity.c
@@ -1,9 +1,11 @@
 #include "entity.h"
 #include "entities/antifaShip.h"
+#include "entities/soldato.h"
 
 // This fucker is used for creating entities.
 const EntityTypeInfo entityTypeInfo[ENTITY_TYPE_COUNT] = {
-	(EntityTypeInfo){initAntifaShip, closeAntifaShip, updateAntifaShip, drawAntifaShip}
+	(EntityTypeInfo){initAntifaShip, closeAntifaShip, updateAntifaShip, drawAntifaShip},
+	(EntityTypeInfo){initSoldato, closeSoldato, updateSoldato, drawSoldato}
 };
 
 EntityVelocity entityVelocityIdentity() {
@@ -32,7 +34,7 @@ Vector3 accelerateVector3(Vector3 value, Vector3 lastValue, Vector3 up, Vector3
 	};
 }
 
-Entity createEntity(EntityType type) {
+Entity createEntity(EntityType type, Game * game) {
 	EntityTypeInfo info = entityTypeInfo[type];
 
 	// Set defaults.
@@ -49,7 +51,7 @@ Entity createEntity(EntityType type) {
 	};
 
 	// Init.
-	info.initCb(&entity);
+	info.initCb(&entity, game);
 
 	return entity;
 }
@@ -60,10 +62,10 @@ void closeEntity(Entity * entity) {
 
 // Basic wireframe drawing.
 void entityDraw(Entity * entity) {
-	entity->model.transform = QuaternionToMatrix(entity->rotation);
+	entity->model->transform = QuaternionToMatrix(entity->rotation);
 
 	DrawModelWires(
-		entity->model,
+		*entity->model,
 		entity->position,
 		1,
 		GREEN
@@ -110,8 +112,8 @@ void entityJoystickControl(Entity * entity, Vector3 stick, float speed) {
 		st = accelerateVector3(
 			stick,
 			entity->lastVelocity.stick,
-			Vector3Scale(entity->acceleration.rotationUp, t),
-			Vector3Scale(entity->acceleration.rotationDown, t)
+			Vector3Scale(entity->acceleration.rotation, t),
+			Vector3Scale(entity->acceleration.rotation, t)
 		);
 	}
 
diff --git a/src/entity.h b/src/entity.h
index 7d27258..128365f 100644
--- a/src/entity.h
+++ b/src/entity.h
@@ -19,6 +19,7 @@ enum {
 
 typedef int8_t EntityType;
 typedef int16_t EntityId; // Id in world.
+typedef uint32_t EntityFingerprint;
 
 // Callbacks.
 typedef void (*EntityUpdateCb)(Game * game, Entity * entity, EntityId id);
@@ -26,8 +27,7 @@ typedef void (*EntityDrawCb)(Game * game, Entity * entity, EntityId id);
 
 // Acceleration indeed hehehe.
 typedef struct EntityAcceleration {
-	Vector3 rotationUp;
-	Vector3 rotationDown;
+	Vector3 rotation;
 	float speedUp;
 	float speedDown;
 } EntityAcceleration;
@@ -46,8 +46,10 @@ EntityVelocity entityVelocityIdentity();
 
 // This fucker is a entity.
 typedef struct Entity {
+	EntityId id;
+	EntityFingerprint fingerprint;
 	EntityType type;
-	Model model;
+	Model * model;
 
 	Vector3 position;
 	Quaternion rotation;
@@ -65,7 +67,7 @@ typedef struct Entity {
 	void * data;
 } Entity;
 
-typedef void (*EntityInitCb)(Entity * entity);
+typedef void (*EntityInitCb)(Entity * entity, Game * game);
 typedef void (*EntityCloseCb)(Entity * entity);
 
 // Info for each entity type.
@@ -79,7 +81,7 @@ typedef struct EntityTypeInfo {
 const extern EntityTypeInfo entityTypeInfo[ENTITY_TYPE_COUNT];
 
 // Do I need a fucking comment?
-Entity createEntity(EntityType type);
+Entity createEntity(EntityType type, Game * game);
 void closeEntity(Entity * entity);
 
 // Helper functions for updating and drawing.
diff --git a/src/game.c b/src/game.c
index 2e966f2..bffc6b5 100644
--- a/src/game.c
+++ b/src/game.c
@@ -4,23 +4,81 @@ void initGame(Game * game) {
 	// Window.
 	InitWindow(WINDOW_WIDTH, WINDOW_HEIGHT, "Killa Facsista");
 
+	// Assets.
+	LoadAssets(&game->assets);
+
 	// Screen id.
 	game->screenId = SCREEN_GAME;
 
+	// Main menu.
+	initMainMenu(game);
+
 	// Camera.
 	initPlayerCamera(&game->playerCamera);
 
-	// Ship test.
-	game->ship = createEntity(ENTITY_ANTIFA);
-
 	SetTargetFPS(60);
 	//DisableCursor();
+	
+	// World.
+	initWorld(&game->world);
+
+	// Debug.
+	// Add player.
+	addEntityToWorld(
+		&game->world,
+		createEntity(ENTITY_ANTIFA, game)
+	);
+
+	// Test entity.
+	Entity soldato = createEntity(ENTITY_SOLDATO, game);
+	soldato.position = (Vector3){10.0, 10.0, 10.0};
+	addEntityToWorld(&game->world, soldato);
+
+	soldato = createEntity(ENTITY_SOLDATO, game);
+	soldato.position = (Vector3){20.0, 20.0, 20.0};
+	addEntityToWorld(&game->world, soldato);
+
+	soldato = createEntity(ENTITY_SOLDATO, game);
+	soldato.position = (Vector3){30.0, 30.0, 30.0};
+	addEntityToWorld(&game->world, soldato);
+
+	printf("%d\n", removeEntityFromWorld(&game->world, 2));
+	printf("%d\n", removeEntityFromWorld(&game->world, 3));
+
+	soldato = createEntity(ENTITY_SOLDATO, game);
+	soldato.position = (Vector3){-30.0, -30.0, -30.0};
+	addEntityToWorld(&game->world, soldato);
+
+
+	puts("v");
+
+	for (int i = 0; i < game->world.vacantIdsCount; ++i)
+		printf("%d\n", game->world.vacantIds[i]);
+
+	puts("l");
+
+	for (int i = 0; i < game->world.lookUpSize; ++i) {
+		printf("%d\n", game->world.lookUp[i]);
+
+		Entity * e = getEntityFromWorld(game->world, i);
+
+		if (e == NULL) {
+			puts("null");
+			continue;
+		}
+
+		if (e->id == i)
+			printf("good %x\n", e->fingerprint);
+		else
+			printf("bad %d\n", e->id);
+	}
 }
 
 void closeGame(Game * game) {
-	// Close ship test.
-	closeEntity(&game->ship);
+	unloadAssets(&game->assets);
+	freeWorld(&game->world);
 
+	// Close window last.
 	CloseWindow();
 }
 
diff --git a/src/game.h b/src/game.h
index f875b62..e1f318a 100644
--- a/src/game.h
+++ b/src/game.h
@@ -3,6 +3,8 @@
 #include "gameScreen.h"
 #include "playerCamera.h"
 #include "entity.h"
+#include "assets.h"
+#include "world.h"
 
 #ifndef GAME_H
 #define GAME_H
@@ -17,8 +19,8 @@ typedef struct Game {
 	MainMenu mainMenu;
 	GameScreen gameScreen;
 	Camera3D playerCamera;
-
-	Entity ship;
+	Assets assets;
+	World world;
 } Game;
 
 void initGame(Game * game);
diff --git a/src/gameCommon.h b/src/gameCommon.h
index 0d18d32..08ce5fe 100644
--- a/src/gameCommon.h
+++ b/src/gameCommon.h
@@ -22,13 +22,6 @@ typedef struct Entity Entity;
 #define WINDOW_WIDTH 960
 #define WINDOW_HEIGHT 540
 
-// Bit shit.
-#define SET_BIT(b, n) (b | (0x1 << n))
-#define CLEAR_BIT(b, n) (b & ~(0x1 << n))
-#define IS_BIT_SET(b, n) ((b >> n) & 0x1)
-#define TOGGLE_BIT(b, n) (b ^ (0x1 << n))
-#define HAS_FLAG(v, f) ((v & f) == f)
-
 // Memory management.
 #define KF_MALLOC(size) malloc(size)
 #define KF_CALLOC(nmemb, size) calloc(nmemb, size)
diff --git a/src/gameScreen.c b/src/gameScreen.c
index 893da0c..1eb6b55 100644
--- a/src/gameScreen.c
+++ b/src/gameScreen.c
@@ -1,7 +1,12 @@
 #include "gameScreen.h"
 #include "game.h"
+#include "world.h"
 
 void updateGameScreen(Game * game) {
+
+	// Update world.
+	updateWorld(&game->world, game);
+
 	ClearBackground(BLACK);
 
 	// Camera.
@@ -11,7 +16,8 @@ void updateGameScreen(Game * game) {
 
 	DrawGrid(500, 25.0);
 
-	game->ship.drawCb(game, &game->ship, 0);
+	// Draw world.
+	drawWorld(&game->world, game);
 
 	EndMode3D();
 }
diff --git a/src/mainMenu.c b/src/mainMenu.c
index 10f293a..fc67972 100644
--- a/src/mainMenu.c
+++ b/src/mainMenu.c
@@ -1,14 +1,46 @@
 #include "mainMenu.h"
 #include "game.h"
 
+void initMainMenu(Game * game) {
+	game->mainMenu = (MainMenu){
+		.startButton = (Rectangle){0, 0, 100, 50},
+		.logoTexture = &game->assets.textures[ICON128_ASSET]
+	};
+
+	resizeMainMenu(game);
+}
+
 void updateMainMenu(Game * game) {
+	MainMenu * mainMenu = &game->mainMenu;
 	ClearBackground(RAYWHITE);
 
-	bool start = GuiButton(
-		(Rectangle){10, 10, 100, 50},
-		"Start"
+	// Logo.
+	DrawTextureV(
+		*mainMenu->logoTexture,
+		mainMenu->logoPosition,
+		WHITE
 	);
 
+	// Start button.
+	bool start = GuiButton(mainMenu->startButton, "Start");
+
 	if (start)
 		game->screenId = SCREEN_GAME;
+
+	if (IsWindowResized())
+		resizeMainMenu(game);
+}
+
+void resizeMainMenu(Game * game) {
+	MainMenu * mainMenu = &game->mainMenu;
+
+	// Logo.
+	mainMenu->logoPosition = (Vector2){
+		(GetScreenWidth() / 2.0) - (mainMenu->logoTexture->width / 2.0),
+		(GetScreenHeight() / 2.0) - (mainMenu->logoTexture->height * 1.50)
+	};
+
+	// Start button.
+	mainMenu->startButton.x = (GetScreenWidth() / 2.0) - (mainMenu->startButton.width / 2.0);
+	mainMenu->startButton.y = (GetScreenHeight() / 2.0) - (mainMenu->startButton.height / 2.0);
 }
diff --git a/src/mainMenu.h b/src/mainMenu.h
index 7dd5036..10ce855 100644
--- a/src/mainMenu.h
+++ b/src/mainMenu.h
@@ -4,8 +4,14 @@
 #define MAIN_MENU_H
 
 typedef struct MainMenu {
+	Vector2 logoPosition;
+	Texture2D * logoTexture;
+
+	Rectangle startButton;
 } MainMenu;
 
+void initMainMenu(Game * game);
 void updateMainMenu(Game * game);
+void resizeMainMenu(Game * game);
 
 #endif
diff --git a/src/playerCamera.c b/src/playerCamera.c
index d84d6d3..df2cce4 100644
--- a/src/playerCamera.c
+++ b/src/playerCamera.c
@@ -13,10 +13,12 @@ void initPlayerCamera(Camera3D * camera) {
 }
 
 void updatePlayerCamera(Camera3D * camera, Game * game) {
+	Entity * player = &game->world.entities[0];
+
 	//UpdateCamera(camera, CAMERA_FIRST_PERSON);
-	camera->target = game->ship.position;
+	camera->target = player->position;
 
-	Matrix m = QuaternionToMatrix(QuaternionInvert(game->ship.rotation));
+	Matrix m = QuaternionToMatrix(QuaternionInvert(player->rotation));
 	Vector3 pos = (Vector3){0.0, CAMERA_DIS/2, -CAMERA_DIS};
 
 	camera->position = (Vector3){
@@ -25,7 +27,7 @@ void updatePlayerCamera(Camera3D * camera, Game * game) {
 		m.m8 * pos.x + m.m9 * pos.y + m.m10 * pos.z
 	};
 
-	camera->position = Vector3Add(camera->position, game->ship.position);
+	camera->position = Vector3Add(camera->position, player->position);
 	camera->up = (Vector3){
 		m.m1 + m.m2,
 		m.m5 + m.m6,
diff --git a/src/util.h b/src/util.h
index 94a9dd6..c769488 100644
--- a/src/util.h
+++ b/src/util.h
@@ -3,6 +3,13 @@
 #ifndef UTIL_H
 #define UTIL_H
 
+// Bit shit.
+#define SET_BIT(b, n) (b | (0x1 << n))
+#define CLEAR_BIT(b, n) (b & ~(0x1 << n))
+#define IS_BIT_SET(b, n) ((b >> n) & 0x1)
+#define TOGGLE_BIT(b, n) (b ^ (0x1 << n))
+#define HAS_FLAG(v, f) ((v & f) == f)
+
 typedef struct AxisAngle {
 	Vector3 axis;
 	float angle;
diff --git a/src/world.c b/src/world.c
index ea50eca..d76a2d3 100644
--- a/src/world.c
+++ b/src/world.c
@@ -1 +1,251 @@
 #include "world.h"
+#include "game.h"
+
+void initWorld(World * world) {
+	world->entities = NULL;
+	world->entitiesCount = 0;
+
+	world->lookUp = NULL;
+	world->lookUpSize = 0;
+
+	world->vacantIds = NULL;
+	world->vacantIdsCount = 0;
+
+	// Set current fingerprint.
+	SetRandomSeed(time(NULL));
+
+	world->currentFingerprint = GetRandomValue(
+		FINGERPRINT_START_RANGE_MIN,
+		FINGERPRINT_START_RANGE_MAX 
+	);
+}
+
+void freeWorld(World * world) {
+	int i;
+
+	if (world->entities == NULL)
+		return;
+
+	// Close entities.
+	for (i = 0; i < world->entitiesCount; ++i)
+		closeEntity(&world->entities[i]);
+
+	KF_FREE(world->entities);
+	KF_FREE(world->lookUp);
+
+	if (world->vacantIds != NULL)
+		KF_FREE(world->vacantIds);
+}
+
+// Not for direct use.
+KfError pushVacantId(World * world, EntityId id) {
+	++world->vacantIdsCount;
+
+	// Allocate.
+	if (world->vacantIds == NULL)
+		world->vacantIds = (EntityId*)KF_CALLOC(1, sizeof(EntityId));
+	else
+		world->vacantIds = (EntityId*)KF_REALLOCARRAY(
+			world->vacantIds,
+			world->vacantIdsCount, 
+			sizeof(EntityId)
+		);
+
+	if (world->vacantIds == NULL) {
+		ALLOCATION_ERROR;
+		return KFERROR;
+	}
+
+	world->vacantIds[world->vacantIdsCount - 1] = id;
+	return KFSUCCESS;
+}
+
+// Not for direct use.
+EntityId popVacantId(World * world) {
+	EntityId id;
+
+	// Already empty.
+	if (world->vacantIds == NULL)
+		return ENTITY_ID_NONE;
+
+	id = world->vacantIds[world->vacantIdsCount - 1];
+
+	// Decrease count.
+	--world->vacantIdsCount;
+
+	// Free or recallocate.
+	if (world->vacantIdsCount == 0) {
+		KF_FREE(world->vacantIds);
+		world->vacantIds = NULL;
+	} else {
+		world->vacantIds = (EntityId*)KF_REALLOCARRAY(
+			world->vacantIds,
+			world->vacantIdsCount, 
+			sizeof(EntityId)
+		);
+	}
+
+	return id;
+}
+
+Entity * getEntityFromWorld(World world, EntityId id) {
+	if (world.entities == NULL || id < 0 || id >= world.lookUpSize)
+		return NULL;
+
+	int pos = world.lookUp[id];
+
+	if (pos == ENTITY_ID_NONE)
+		return NULL;
+
+	return &world.entities[pos];
+}
+
+EntityId addEntityToWorld(World * world, Entity entity) {
+	EntityId id;
+	EntityId poppedId;
+
+	Entity entityCopy = entity;
+
+	// Set fingerprint.
+	entityCopy.fingerprint = world->currentFingerprint;
+	++world->currentFingerprint;
+
+	// Not allocated.
+	if (world->entities == NULL) {
+		// Allocate.
+		world->entities = (Entity*)KF_CALLOC(1, sizeof(Entity));
+		world->lookUp = (EntityId*)KF_CALLOC(1, sizeof(EntityId));
+		world->entitiesCount = 1;
+		world->lookUpSize = 1;
+
+		if (world->entities == NULL || world->lookUp == NULL) {
+			ALLOCATION_ERROR;
+			return ENTITY_ID_NONE;
+		}
+
+		// Set entity and id.
+		world->entities[0] = entityCopy;
+		world->entities[0].id = 0;
+		world->lookUp[0] = 0;
+		return 0;
+	}
+
+	++world->entitiesCount;
+
+	// Resize.
+	world->entities = (Entity*)KF_REALLOCARRAY(
+		world->entities,
+		world->entitiesCount,
+		sizeof(Entity)
+	);
+
+	if (world->entities == NULL) {
+		ALLOCATION_ERROR;
+		return ENTITY_ID_NONE;
+	}
+
+	// Set entity.
+	world->entities[world->entitiesCount - 1] = entityCopy;
+
+	// Set look up.
+	poppedId = popVacantId(world);
+
+	// Got popped id.
+	if (poppedId != ENTITY_ID_NONE) {
+		world->lookUp[poppedId] = world->entitiesCount - 1;
+		world->entities[world->entitiesCount - 1].id = poppedId;
+		return poppedId;
+	}
+
+	++world->lookUpSize;
+
+	world->lookUp = (EntityId*)KF_REALLOCARRAY(
+		world->lookUp,
+		world->lookUpSize,
+		sizeof(EntityId)
+	);
+
+	if (world->lookUp == NULL) {
+		ALLOCATION_ERROR;
+		return ENTITY_ID_NONE;
+	}
+
+	// Set id.
+	id = world->lookUpSize - 1;
+	world->entities[world->entitiesCount - 1].id = id;
+	world->lookUp[id] = world->entitiesCount - 1;
+	return id;
+}
+
+KfError removeEntityFromWorld(World * world, EntityId id) {
+	int i;
+	int pos;
+
+	if (world->entitiesCount == 1)
+		return KFERROR;
+
+	// Get position in list.
+	pos = world->lookUp[id];
+
+	if (pos == ENTITY_ID_NONE)
+		return KFSUCCESS;
+
+	// Close entity.
+	closeEntity(&world->entities[pos]);
+
+	// Push id.
+	if (pushVacantId(world, id) != KFSUCCESS)
+		return KFERROR;
+
+	// Move back entities.
+	for (i = pos; i < world->entitiesCount - 1; ++i)
+		world->entities[i] = world->entities[i + 1];
+
+	// Update lookup.
+	for (i = id + 1; i < world->lookUpSize; ++i)
+		--world->lookUp[i];
+
+	world->lookUp[id] = ENTITY_ID_NONE;
+
+	// Resize entities.
+	--world->entitiesCount;
+
+	world->entities = (Entity*)KF_REALLOCARRAY(
+		world->entities,
+		world->entitiesCount,
+		sizeof(Entity)
+	);
+
+	if (world->entities == NULL) {
+		ALLOCATION_ERROR;
+		return KFERROR;
+	}
+
+	return KFSUCCESS;
+}
+
+void updateWorld(World * world, Game * game) {
+	int i;
+	Entity * entity;
+
+	for (i = 0; i < world->entitiesCount; ++i) {
+		entity = &world->entities[i];
+
+		// Call update callback.
+		if (entity->updateCb != NULL)
+			entity->updateCb(game, entity, i);
+	}
+}
+
+void drawWorld(World * world, Game * game) {
+	int i;
+	Entity * entity;
+
+	for (i = 0; i < world->entitiesCount; ++i) {
+		entity = &world->entities[i];
+
+		// Call draw callback.
+		if (entity->drawCb != NULL)
+			entity->drawCb(game, entity, i);
+	}
+}
diff --git a/src/world.h b/src/world.h
index 379b920..b075301 100644
--- a/src/world.h
+++ b/src/world.h
@@ -4,4 +4,35 @@
 #ifndef WORLD_H
 #define WORLD_H
 
+#define FINGERPRINT_START_RANGE_MIN 0xf
+#define FINGERPRINT_START_RANGE_MAX 0xff
+
+typedef struct World {
+	Entity * entities;
+	size_t entitiesCount;
+
+	// For getting entity id;
+	EntityId * lookUp;
+	size_t lookUpSize;
+
+	EntityId * vacantIds;
+	size_t vacantIdsCount;
+
+	// Used for making fingerprints for entities.
+	EntityFingerprint currentFingerprint;
+} World;
+
+void initWorld(World * world);
+void freeWorld(World * world);
+
+#define ENTITY_ID_NONE -1
+
+// ENTITY_ID_NONE on error.
+Entity * getEntityFromWorld(World world, EntityId id);
+EntityId addEntityToWorld(World * world, Entity entity);
+KfError removeEntityFromWorld(World * world, EntityId id);
+
+void updateWorld(World * world, Game * game);
+void drawWorld(World * world, Game * game);
+
 #endif