From ba8cb4fcea09190bbe6e80c45ef59314feea8600 Mon Sep 17 00:00:00 2001
From: kdx <kikoodx@paranoici.org>
Date: Fri, 17 Mar 2023 10:51:17 +0100
Subject: [PATCH] simple entity system

---
 CMakeLists.txt |  4 +++-
 src/entity.h   | 28 ++++++++++++++++++++++++++++
 src/game.c     | 49 +++++++++++++++++++++++++++++++++++++++++++++++++
 src/game.h     | 15 +++++++++++++++
 src/main.c     | 15 +++++++++++++++
 src/player.c   | 25 +++++++++++++++++++++++++
 src/player.h   | 10 ++++++++++
 7 files changed, 145 insertions(+), 1 deletion(-)
 create mode 100644 src/entity.h
 create mode 100644 src/game.c
 create mode 100644 src/game.h
 create mode 100644 src/player.c
 create mode 100644 src/player.h

diff --git a/CMakeLists.txt b/CMakeLists.txt
index 74aa891..28424ad 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -10,8 +10,10 @@ include(Fxconv)
 find_package(Gint 2.9 REQUIRED)
 
 set(SOURCES
-  src/main.c
+  src/game.c
   src/lzy.c
+  src/main.c
+  src/player.c
 )
 
 set(ASSETS
diff --git a/src/entity.h b/src/entity.h
new file mode 100644
index 0000000..9f5861c
--- /dev/null
+++ b/src/entity.h
@@ -0,0 +1,28 @@
+#pragma once
+#include "player.h"
+#include <stdbool.h>
+
+struct Game;
+
+typedef enum {
+	ET_NONE,
+	ET_PLAYER
+} EntityType;
+
+typedef struct Entity Entity;
+struct Entity {
+	unsigned long uuid;
+	void (*update)(Entity *this, struct Game *g);
+	void (*draw)(Entity *this, struct Game *g);
+	unsigned int type;
+	int id;
+	int pos[2];
+	double vel[2];
+	double rem[2];
+	int width;
+	int height;
+	bool solid;
+	union {
+		Player player;
+	};
+};
diff --git a/src/game.c b/src/game.c
new file mode 100644
index 0000000..2a3ceeb
--- /dev/null
+++ b/src/game.c
@@ -0,0 +1,49 @@
+#include "game.h"
+#include <string.h>
+
+void
+game_init(Game *this)
+{
+	memset(this, 0, sizeof(*this));
+}
+
+void
+game_deinit(Game *this)
+{
+	(void)this;
+}
+
+void
+game_update(Game *this)
+{
+	for (int i = 0; i < MAX_ENTITIES; i++) {
+		Entity *const e = &this->entities[i];
+		if (e->type != ET_NONE && e->update != NULL)
+			e->update(e, this);
+	}
+}
+
+void
+game_draw(Game *this)
+{
+	for (int i = 0; i < MAX_ENTITIES; i++) {
+		Entity *const e = &this->entities[i];
+		if (e->type != ET_NONE && e->draw != NULL)
+			e->draw(e, this);
+	}
+}
+
+Entity *
+game_create_entity(Game *this)
+{
+	Entity *e = &this->entities[MAX_ENTITIES - 1];
+	for (int i = 0; i < MAX_ENTITIES; i++)
+		if (this->entities[i].type == ET_NONE) {
+			e = &this->entities[i];
+			break;
+		}
+	e->type = ET_NONE;
+	e->uuid = this->uuid;
+	this->uuid += 1;
+	return e;
+}
diff --git a/src/game.h b/src/game.h
new file mode 100644
index 0000000..185c89b
--- /dev/null
+++ b/src/game.h
@@ -0,0 +1,15 @@
+#pragma once
+#include "entity.h"
+
+enum { MAX_ENTITIES = 64 };
+
+typedef struct Game {
+	unsigned int uuid;
+	Entity entities[MAX_ENTITIES];
+} Game;
+
+void game_init(Game *this);
+void game_deinit(Game *this);
+void game_update(Game *this);
+void game_draw(Game *this);
+Entity *game_create_entity(Game *this);
diff --git a/src/main.c b/src/main.c
index 03b612f..744c96b 100644
--- a/src/main.c
+++ b/src/main.c
@@ -1,4 +1,8 @@
 #include "lzy.h"
+#include "game.h"
+#include "player.h"
+#include <stdio.h>
+#include <stdlib.h>
 
 int main(void)
 {
@@ -8,6 +12,15 @@ int main(void)
 		return 1;
 	}
 
+	Game *const game = malloc(sizeof(Game));
+	if (game == NULL) {
+		LZY_Log("malloc failed");
+		LZY_Quit();
+		return 1;
+	}
+	game_init(game);
+	player_init(game_create_entity(game));
+
 	while (!LZY_ShouldQuit()) {
 		LZY_CycleEvents();
 
@@ -17,6 +30,8 @@ int main(void)
 		LZY_DrawEnd();
 	}
 
+	game_deinit(game);
+	free(game);
 	LZY_Quit();
 	return 0;
 }
diff --git a/src/player.c b/src/player.c
new file mode 100644
index 0000000..d751857
--- /dev/null
+++ b/src/player.c
@@ -0,0 +1,25 @@
+#include "player.h"
+#include "entity.h"
+#include "game.h"
+#include <string.h>
+
+static void
+player_update(Entity *this, Game *g)
+{
+	(void)this, (void)g;
+}
+
+static void
+player_draw(Entity *this, Game *g)
+{
+	(void)this, (void)g;
+}
+
+void
+player_init(Entity *this)
+{
+	memset(this, 0, sizeof(*this));
+	this->type = ET_PLAYER;
+	this->update = player_update;
+	this->draw = player_draw;
+}
diff --git a/src/player.h b/src/player.h
new file mode 100644
index 0000000..a6fe6c9
--- /dev/null
+++ b/src/player.h
@@ -0,0 +1,10 @@
+#pragma once
+
+typedef struct {
+	int _;
+} Player;
+
+struct Entity;
+struct Game;
+
+void player_init(struct Entity *this);