Implemented event bus.

src/Makefile

@@ -4,6 +4,7 @@ CORE_SOURCES := \
   vector2d.c \
   inputs.c \
   asset_manager.c \
+  event_bus.c \
   ecs.c \
   display.c \
   main.c

src/asset_manager.c

@@ -10,12 +10,6 @@
 
 int create_asset(asset_t *asset, va_list args)
 {
-    if(!asset)
-    {
-        error_printf("Failed to allocate memory : %d", errno);
-        return EXIT_FAILURE;
-    }
-
     asset->type = va_arg(args, asset_type_t);
     asset->nb_refs = 0;
 

src/ecs.c

@@ -6,12 +6,6 @@
 
 int create_component(component_t *component, va_list args)
 {
-    if(!component)
-    {
-        error_printf("Component cannot be NULL");
-        return EXIT_FAILURE;
-    }
-
     component->type = va_arg(args, component_type_t);
 
     switch(component->type)
@@ -41,12 +35,6 @@ int create_component(component_t *component, va_list args)
 
 inline int destroy_component(component_t *component)
 {
-    if(!component)
-    {
-        error_printf("Component cannot be NULL");
-        return EXIT_FAILURE;
-    }
-
     if(component->deleter(component)) return EXIT_FAILURE;
 
     return EXIT_SUCCESS;
@@ -54,12 +42,6 @@ inline int destroy_component(component_t *component)
 
 int create_entity(entity_t *entity, va_list args)
 {
-    if(!entity)
-    {
-        error_printf("Entity cannot be NULL");
-        return EXIT_FAILURE;
-    }
-
     entity->id = va_arg(args, size_t);
     entity->draw_priority = 0;
 
@@ -70,12 +52,6 @@ int create_entity(entity_t *entity, va_list args)
 
 inline int destroy_entity(entity_t *entity)
 {
-    if(!entity)
-    {
-        error_printf("Entity cannot be NULL");
-        return EXIT_FAILURE;
-    }
-
     if(linked_list_exit(&entity->components)) return EXIT_FAILURE;
 
     return EXIT_SUCCESS;
@@ -85,6 +61,7 @@ component_t *entity_new_component(entity_t *entity, component_type_t component_t
 {
     elem_t *component_elem = create_elem(&entity->components, component_type);
     if(!component_elem) return NULL;
+
     component_t *component = component_elem->data;
 
     component->entity = entity;
@@ -118,6 +95,7 @@ inline component_t *entity_get_component(const entity_t *entity, component_type_
 static inline int action_update_component(elem_t *elem, va_list args __attribute__((unused)))
 {
     component_t *component = elem->data;
+
     if(component->update(component)) return EXIT_FAILURE;
 
     return EXIT_SUCCESS;
@@ -135,6 +113,7 @@ inline int update_entity(entity_t *entity)
 static inline int action_draw_component(elem_t *elem, va_list args __attribute__((unused)))
 {
     component_t *component = elem->data;
+
     if(component->draw) if(component->draw(component)) return EXIT_FAILURE;
 
     return EXIT_SUCCESS;

src/event_bus.c

@@ -0,0 +1,118 @@
+#include "event_bus.h"
+
+#include <stdlib.h>
+#include "linked_list.h"
+#include "memory_alloc.h"
+
+// Args : void *payload
+int create_event(event_t *event, va_list args)
+{
+    event->payload = va_arg(args, void *);
+
+    return EXIT_SUCCESS;
+}
+
+int destroy_event(event_t *event)
+{
+    free(event->payload);
+
+    return EXIT_SUCCESS;
+}
+
+// Args : callback_t callback
+int create_subscription(subscription_t *subscription, va_list args)
+{
+    subscription->callback = va_arg(args, callback_t);
+
+    return EXIT_SUCCESS;
+}
+
+// Args : size_t id, size_t max_history_size
+int create_topic(topic_t *topic, va_list args)
+{
+    topic->id = va_arg(args, size_t);
+    topic->max_history_size = va_arg(args, size_t);
+
+    linked_list_init(&topic->events, sizeof(event_t), (allocator_t)create_event, (deleter_t)destroy_event);
+    linked_list_init(&topic->subscriptions, sizeof(subscription_t), (allocator_t)create_subscription, NULL);
+
+    if(linked_list_reserve(&topic->events, topic->max_history_size)) return EXIT_FAILURE;
+
+    return EXIT_SUCCESS;
+}
+
+int destroy_topic(topic_t *topic)
+{
+    if(linked_list_exit(&topic->events)) return EXIT_FAILURE;
+    if(linked_list_exit(&topic->subscriptions)) return EXIT_FAILURE;
+
+    return EXIT_SUCCESS;
+}
+
+int event_bus_init(event_bus_t *event_bus)
+{
+    linked_list_init(&event_bus->topics, sizeof(topic_t), (allocator_t)create_topic, (deleter_t)destroy_topic);
+
+    return EXIT_SUCCESS;
+}
+
+int event_bus_exit(event_bus_t *event_bus)
+{
+    if(linked_list_exit(&event_bus->topics)) return EXIT_FAILURE;
+
+    return EXIT_SUCCESS;
+}
+
+int event_bus_new_topic(event_bus_t *event_bus, size_t id, size_t max_history_size)
+{
+    if(!create_elem(&event_bus->topics, id, max_history_size)) return EXIT_FAILURE;
+
+    return EXIT_SUCCESS;
+}
+
+// Args : size_t id
+static inline bool condition_is_topic_id(elem_t *elem, va_list args)
+{
+    return ((topic_t *)elem->data)->id == va_arg(args, size_t);
+}
+
+int event_bus_remove_topic(event_bus_t *event_bus, size_t id)
+{
+    if(linked_list_remove_if(&event_bus->topics, condition_is_topic_id, id)) return EXIT_FAILURE;
+
+    return EXIT_SUCCESS;
+}
+
+// Args : void *payload
+static inline int action_execute_callback(elem_t *elem, va_list args)
+{
+    subscription_t *subscription = elem->data;
+
+    if(subscription->callback(va_arg(args, void *))) return EXIT_FAILURE;
+
+    return EXIT_SUCCESS;
+}
+
+int event_bus_publish(event_bus_t *event_bus, size_t id, void *payload)
+{
+    elem_t *topic_elem = linked_list_get_if(&event_bus->topics, condition_is_topic_id, id);
+    if(!topic_elem) return EXIT_FAILURE;
+
+    topic_t *topic = topic_elem->data;
+    if(!create_elem(&topic->events, payload)) return EXIT_FAILURE;
+
+    if(linked_list_for_each(&topic->subscriptions, action_execute_callback, payload)) return EXIT_FAILURE;
+
+    return EXIT_SUCCESS;
+}
+
+int event_bus_subscribe(event_bus_t *event_bus, size_t id, callback_t callback)
+{
+    elem_t *topic_elem = linked_list_get_if(&event_bus->topics, condition_is_topic_id, id);
+    if(!topic_elem) return EXIT_FAILURE;
+
+    topic_t *topic = topic_elem->data;
+    if(!create_elem(&topic->subscriptions, callback)) return EXIT_FAILURE;
+
+    return EXIT_SUCCESS;
+}

src/headers/event_bus.h

@@ -0,0 +1,45 @@
+#ifndef EVENT_BUS_H
+#define EVENT_BUS_H
+
+#include <stdarg.h>
+#include "linked_list.h"
+
+typedef int (*callback_t)(void *payload);
+
+typedef struct event_t {
+    void *payload;
+} event_t;
+
+int create_event(event_t *event, va_list args);
+int destroy_event(event_t *event);
+
+typedef struct subscription_t {
+    callback_t callback;
+} subscription_t;
+
+int create_subscription(subscription_t *subscription, va_list args);
+
+typedef struct topic_t {
+    size_t id;
+    linked_list_t events;
+    linked_list_t subscriptions;
+    size_t max_history_size;
+} topic_t;
+
+int create_topic(topic_t *topic, va_list args);
+int destroy_topic(topic_t *topic);
+
+typedef struct event_bus_t {
+    linked_list_t topics;
+} event_bus_t;
+
+int event_bus_init(event_bus_t *event_bus);
+int event_bus_exit(event_bus_t *event_bus);
+
+int event_bus_new_topic(event_bus_t *event_bus, size_t id, size_t max_history_size);
+int event_bus_remove_topic(event_bus_t *event_bus, size_t id);
+
+int event_bus_publish(event_bus_t *event_bus, size_t id, void *payload);
+int event_bus_subscribe(event_bus_t *event_bus, size_t id, callback_t callback);
+
+#endif // EVENT_BUS_H

src/headers/game.h

@@ -19,7 +19,7 @@
 typedef struct game_t {
     asset_manager_t asset_manager;
     entity_manager_t entity_manager;
-    events_t events;
+    inputs_t events;
 
     float delta_time_ms;
     bool is_running;

src/headers/inputs.h

@@ -5,20 +5,19 @@
 #include "vector2d.h"
 #include "keycodes.h"
 
-#define EVENT_KEY_UP SDL_EVENT_KEY_UP
-#define EVENT_KEY_DOWN SDL_EVENT_KEY_DOWN
-#define EVENT_QUIT SDL_EVENT_QUIT
+#define INPUT_EVENT_KEY_UP SDL_EVENT_KEY_UP
+#define INPUT_EVENT_KEY_DOWN SDL_EVENT_KEY_DOWN
+#define INPUT_EVENT_QUIT SDL_EVENT_QUIT
 
-typedef struct event_t {
+typedef struct input_event_t {
     uint32_t type;
     SDL_Scancode key;
-} event_t;
+} input_event_t;
 
-int pollevent(event_t *event);
+int poll_event(input_event_t *event);
 
-typedef struct events_t {
-    vector2d_t cursor_pos;
+typedef struct inputs_t {
     bool keys[MAX_KEYCODES];
-} events_t;
+} inputs_t;
 
 #endif // KEYBOARD_H

src/headers/linked_list.h

@@ -258,7 +258,7 @@ elem_t *linked_list_get_if(const linked_list_t *linked_list, const condition_t c
  * @param condition     Condition to verify
  * @param ...           Argument to pass to the condition
  *
- * @return Pointer to element, NULL if no element verify the condition or if an error occurred.
+ * @return EXIT_SUCCESS, EXIT_FAILURE on error.
 */
 int linked_list_remove_if(linked_list_t *linked_list, const condition_t condition, ...);
 

src/inputs.c

@@ -2,7 +2,7 @@
 
 #include <SDL3/SDL_events.h>
 
-inline int pollevent(event_t *event)
+inline int poll_event(input_event_t *event)
 {
     SDL_Event sdl_event;
     int ret = SDL_PollEvent(&sdl_event);