Initial commit

src/engine/entity.h

@@ -0,0 +1,70 @@
+#ifndef JNR_ENTITY_H
+#define JNR_ENTITY_H
+
+#include <stdbool.h>
+#include <stdint.h>
+#include "config.h"
+#include "engine/physics.h"
+#include "engine/animation.h"
+#include "util/vec2.h"
+
+/* Forward declarations */
+typedef struct Tilemap Tilemap;
+typedef struct Camera Camera;
+
+typedef enum EntityType {
+    ENT_NONE = 0,
+    ENT_PLAYER,
+    ENT_ENEMY_GRUNT,
+    ENT_ENEMY_FLYER,
+    ENT_PROJECTILE,
+    ENT_PICKUP,
+    ENT_PARTICLE,
+    ENT_TYPE_COUNT
+} EntityType;
+
+/* Entity flags */
+#define ENTITY_INVINCIBLE  (1 << 0)
+#define ENTITY_FACING_LEFT (1 << 1)
+#define ENTITY_DEAD        (1 << 2)
+
+typedef struct Entity {
+    EntityType   type;
+    bool         active;
+    Body         body;
+    Animation    anim;
+    int          health;
+    int          max_health;
+    int          damage;
+    uint32_t     flags;
+    float        timer;          /* general-purpose timer       */
+    void        *data;           /* type-specific data pointer  */
+} Entity;
+
+/* Function pointer types for entity behaviors */
+typedef void (*EntityUpdateFn)(Entity *self, float dt, const Tilemap *map);
+typedef void (*EntityRenderFn)(Entity *self, const Camera *cam);
+typedef void (*EntityDestroyFn)(Entity *self);
+
+typedef struct EntityManager {
+    Entity entities[MAX_ENTITIES];
+    int    count;
+    /* dispatch tables */
+    EntityUpdateFn  update_fn[ENT_TYPE_COUNT];
+    EntityRenderFn  render_fn[ENT_TYPE_COUNT];
+    EntityDestroyFn destroy_fn[ENT_TYPE_COUNT];
+} EntityManager;
+
+void    entity_manager_init(EntityManager *em);
+Entity *entity_spawn(EntityManager *em, EntityType type, Vec2 pos);
+void    entity_destroy(EntityManager *em, Entity *e);
+void    entity_update_all(EntityManager *em, float dt, const Tilemap *map);
+void    entity_render_all(EntityManager *em, const Camera *cam);
+void    entity_manager_clear(EntityManager *em);
+
+/* Register behavior functions for an entity type */
+void entity_register(EntityManager *em, EntityType type,
+                     EntityUpdateFn update, EntityRenderFn render,
+                     EntityDestroyFn destroy);
+
+#endif /* JNR_ENTITY_H */