Enabled SDL_image's support for PNG and TIFF files and improved the

AssetManager with a hashing function, a linked list structure to store
the hashes as well as a reference counter to support multiple users
sharing the same asset.

src/GameEngine.c

@@ -8,25 +8,29 @@
 #include "SDL_image.h"
 #include "SDL_pixels.h"
 #include "SDL_render.h"
+#include "SDL_timer.h"
 #include "Window.h"
 #include "constants.h"
 #include "engine_build_config.h"
 #include "reusable_ids.h"
+#include <SDL2/SDL_mixer.h>
 #include <stdbool.h>
+#include <stdint.h>
 #include <stdlib.h>
 
 #ifdef DEBUG_ENGINE
 #include <stdio.h>
 #endif /* DEBUG_ENGINE */
 
-INTERNAL struct game {
+INTERNAL struct game_engine {
   bool running;
   float delta;
+  uint64_t last_time;
   Window window;
   SDL_Event event;
   ObjectStore *object_store;
   AssetManager *asset_manager;
-} Game;
+} GameEngine;
 
 bool init_game(const char *game_name, int window_width, int window_height,
                SDL_Color window_background_color, bool full_screen) {
@@ -40,11 +44,15 @@ bool init_game(const char *game_name, int window_width, int window_height,
     return false;
   }
 
-  if (IMG_Init(IMG_INIT_PNG) != IMG_INIT_PNG) {
+  uint32_t img_flags = IMG_INIT_PNG | IMG_INIT_TIF;
+  if ((IMG_Init(img_flags) & img_flags) != img_flags) {
+#ifdef DEBUG_ENGINE
+    printf("Failed to initialise SDL. Error: %s\n", IMG_GetError());
+#endif /* DEBUG_ENGINE */
     initialisation_complete = false;
   }
 
-  if (!init_window(&(Game.window), game_name, window_width, window_height,
+  if (!init_window(&(GameEngine.window), game_name, window_width, window_height,
                    window_background_color, full_screen)) {
 #ifdef DEBUG_ENGINE
     printf("Failed to initialise window\n");
@@ -53,15 +61,15 @@ bool init_game(const char *game_name, int window_width, int window_height,
     initialisation_complete = false;
   }
 
-  Game.object_store = create_object_store();
+  GameEngine.object_store = create_object_store();
 
-  if (!(Game.object_store)) {
+  if (!(GameEngine.object_store)) {
     initialisation_complete = false;
   }
 
-  Game.asset_manager = create_asset_manager();
+  GameEngine.asset_manager = create_asset_manager();
 
-  if (!(Game.asset_manager)) {
+  if (!(GameEngine.asset_manager)) {
     initialisation_complete = false;
   }
 
@@ -71,9 +79,9 @@ bool init_game(const char *game_name, int window_width, int window_height,
     return false;
   }
 
-  Game.running = true;
-  // Game.delta = 0.0f;
-  Game.delta = 1.0f / 60.0f;
+  GameEngine.running = true;
+  GameEngine.delta = 0.0f;
+  GameEngine.last_time = SDL_GetTicks64();
 
 #ifdef DEBUG_ENGINE
   printf("Game initialised successfully\n");
@@ -82,31 +90,32 @@ bool init_game(const char *game_name, int window_width, int window_height,
   return true;
 }
 
-bool game_running() { return Game.running; }
+bool game_running() { return GameEngine.running; }
 
 ObjectID add_object(void *object, EventHandlerPtr event_handler,
                     UpdateFuncPtr update_func, RenderFuncPtr render_func) {
-  if (!(Game.running) || !(Game.object_store)) {
+  if (!(GameEngine.running) || !(GameEngine.object_store)) {
     return -1;
   }
 
-  return add_object_to_store(Game.object_store, object, event_handler,
+  return add_object_to_store(GameEngine.object_store, object, event_handler,
                              update_func, render_func);
 }
 
-void remove_object(ObjectID id) {
-  if (!(Game.running) || !(Game.object_store)) {
+void remove_object(ObjectID *id) {
+  if (!(GameEngine.running) || !(GameEngine.object_store)) {
     return;
   }
 
-  remove_object_from_store(Game.object_store, id);
+  remove_object_from_store(GameEngine.object_store, id);
 }
 
 AssetID load_asset(const char *path, AssetType type) {
   return type == ASSET_TYPE_IMAGE
-             ? load_asset_to_manager(Game.asset_manager, path, type,
-                                     Game.window.renderer)
-             : load_asset_to_manager(Game.asset_manager, path, type, NULL);
+             ? load_asset_to_manager(GameEngine.asset_manager, path, type,
+                                     GameEngine.window.renderer)
+             : load_asset_to_manager(GameEngine.asset_manager, path, type,
+                                     NULL);
 }
 
 void render_texture_asset(AssetID id, float x, float y, float w, float h) {
@@ -114,69 +123,79 @@ void render_texture_asset(AssetID id, float x, float y, float w, float h) {
     return;
   }
 
-  SDL_Texture *texture = get_texture(Game.asset_manager, id);
+  SDL_Texture *texture = get_texture(GameEngine.asset_manager, id);
 
-  render_texture(Game.window.renderer, texture, x, y, w, h);
+  render_texture(GameEngine.window.renderer, texture, x, y, w, h);
 }
 
-void close_asset(AssetID id) {
-  remove_asset_from_manager(Game.asset_manager, id);
+void close_asset(AssetID *id) {
+  remove_asset_from_manager(GameEngine.asset_manager, id);
 }
 
 void handle_events() {
-  if (!(Game.running)) {
+  if (!(GameEngine.running)) {
     return;
   }
 
-  while (SDL_PollEvent(&(Game.event))) {
-    switch (Game.event.type) {
+  while (SDL_PollEvent(&(GameEngine.event))) {
+    switch (GameEngine.event.type) {
     case SDL_QUIT:
-      Game.running = false;
+      GameEngine.running = false;
       break;
     }
 
-    if (!Game.object_store) {
+    if (!GameEngine.object_store) {
       break;
     }
 
-    handle_all_objects_events(Game.object_store, &(Game.event));
+    handle_all_objects_events(GameEngine.object_store, &(GameEngine.event));
   }
 }
 
 void update() {
-  if (!(Game.running) || !(Game.object_store)) {
+  if (!(GameEngine.running) || !(GameEngine.object_store)) {
     return;
   }
 
-  update_all_objects(Game.object_store, Game.delta);
+  uint64_t current_time = SDL_GetTicks64();
+
+  // Get the delta time in seconds since the SDL_GetTicks64() returns the
+  // time in milliseconds
+  GameEngine.delta = (current_time - GameEngine.last_time) / 1000.0f;
+
+  update_all_objects(GameEngine.object_store, GameEngine.delta);
+
+  GameEngine.last_time = current_time;
 }
 
 void render() {
-  if (!(Game.running)) {
+  if (!(GameEngine.running)) {
     return;
   }
 
-  clear_window(&(Game.window));
+  clear_window(&(GameEngine.window));
 
-  if (Game.object_store) {
-    render_all_objects(Game.object_store);
+  if (GameEngine.object_store) {
+    render_all_objects(GameEngine.object_store);
   }
 
-  swap_render_buffers(&(Game.window));
+  swap_render_buffers(&(GameEngine.window));
 }
 
 void close_game() {
-  destroy_asset_manager(Game.asset_manager);
-  Game.asset_manager = NULL;
+  destroy_asset_manager(GameEngine.asset_manager);
+  GameEngine.asset_manager = NULL;
 
-  destroy_object_store(Game.object_store);
-  Game.object_store = NULL;
+  destroy_object_store(GameEngine.object_store);
+  GameEngine.object_store = NULL;
 
-  destroy_window(&(Game.window));
+  destroy_window(&(GameEngine.window));
 
-  Game.delta = 0.0f;
+  GameEngine.last_time = 0.0f;
 
-  Game.running = false;
+  GameEngine.delta = 0.0f;
+
+  GameEngine.running = false;
 
   IMG_Quit();