Remove SDL dependency

.vscode/launch.json

@@ -0,0 +1,17 @@
+{
+    // Use IntelliSense to learn about possible attributes.
+    // Hover to view descriptions of existing attributes.
+    // For more information, visit: https://go.microsoft.com/fwlink/?linkid=830387
+    "version": "0.2.0",
+    "configurations": [
+        {
+            "type": "lldb",
+            "request": "launch",
+            "name": "Launch",
+            "program": "${workspaceFolder}/build/HansTheGatherer",
+            "args": [],
+            "cwd": "${workspaceFolder}"
+        }
+
+    ]
+}

CMakeLists.txt

@@ -7,40 +7,24 @@ set(CMAKE_EXPORT_COMPILE_COMMANDS ON)
 # Option to switch real platform vs. SDL implementation...
 
 include(FetchContent)
-FetchContent_Declare(
-    SDL3
-    URL https://github.com/libsdl-org/SDL/releases/download/release-3.2.14/SDL3-3.2.14.tar.gz
-    OVERRIDE_FIND_PACKAGE
-)
-FetchContent_MakeAvailable(SDL3)
 
 FetchContent_Declare(
-    SDL3_ttf
-    URL https://github.com/libsdl-org/SDL_ttf/releases/download/release-3.2.2/SDL3_ttf-3.2.2.tar.gz
+    entt
+    URL https://github.com/skypjack/entt/archive/refs/tags/v3.15.0.tar.gz
     OVERRIDE_FIND_PACKAGE
 )
-FetchContent_MakeAvailable(SDL3_ttf)
-
-FetchContent_Declare(
-    flecs
-    URL https://github.com/SanderMertens/flecs/archive/refs/tags/v4.0.5.tar.gz
-    OVERRIDE_FIND_PACKAGE
-)
-FetchContent_MakeAvailable(flecs)
-
-find_package(SDL3 CONFIG REQUIRED)
-find_package(SDL3_ttf CONFIG REQUIRED)
-find_package(flecs CONFIG REQUIRED)
-find_package(spdlog CONFIG REQUIRED)
+FetchContent_MakeAvailable(entt)
+find_package(entt CONFIG REQUIRED)
 
 add_executable(HansTheGatherer
     src/main.cpp
     src/audio.cpp
     src/assets.cpp
+    src/level.cpp
     src/physics.cpp
     src/render.cpp
 )
 
-target_link_libraries(HansTheGatherer SDL3::SDL3 SDL3_ttf::SDL3_ttf flecs::flecs spdlog::spdlog)
+target_link_libraries(HansTheGatherer EnTT)
 
 set_property(TARGET HansTheGatherer PROPERTY CXX_STANDARD 20)

src/assets.cpp

@@ -1,9 +1,7 @@
 #include "assets.hpp"
 #include "audio.hpp"
-#include "definitions.hpp"
 
 #include <cstdint>
-#include <spdlog/spdlog.h>
 
 static constexpr uint8_t BACKGROUND_DATA[] = {
 #embed "../assets/images/jungle.bmp"
@@ -37,79 +35,90 @@ static constexpr uint8_t DEFAULT_FONT_DATA[] = {
 #embed "../assets/fonts/OpenTTD-Sans.ttf"
 };
 
-SDL_Texture* load_texture(uint8_t const* data, size_t size, SDL_Renderer* renderer)
+// SDL_Texture* load_texture(uint8_t const* data, size_t size, SDL_Renderer* renderer)
+// {
+//     auto* iostream = SDL_IOFromConstMem(data, size);
+//     SDL_Surface* surface = SDL_LoadBMP_IO(iostream, false);
+//     if (surface == nullptr)
+//     {
+//         // spdlog::error("Failed to load SDL surface!\nCause: {}", SDL_GetError());
+//     }
+
+//     SDL_Texture* texture = SDL_CreateTextureFromSurface(renderer, surface);
+//     if (texture == nullptr)
+//     {
+//         // spdlog::error("Failed to create texture from surface!\nCause: {}", SDL_GetError());
+//     }
+
+//     return texture;
+// }
+
+// AudioAsset load_audio(uint8_t const* data, size_t size)
+// {
+//     AudioAsset audio_asset;
+
+//     auto* iostream = SDL_IOFromConstMem(data, size);
+//     bool res = SDL_LoadWAV_IO(
+//         iostream, false, &audio_asset.spec, &audio_asset.buffer, &audio_asset.buffer_length);
+//     if (!res)
+//     {
+//         // spdlog::error("Failed to load audio file!\nCause: {}", SDL_GetError());
+//     }
+//     return audio_asset;
+// }
+
+// FontAsset load_font(uint8_t const* data, size_t size)
+// {
+//     FontAsset font_asset;
+
+//     auto* iostream = SDL_IOFromConstMem(data, size);
+//     auto* ttf = TTF_OpenFontIO(iostream, false, 20);
+
+//     font_asset.font = ttf;
+
+//     return font_asset;
+// }
+
+AssetModule::AssetModule(entt::registry& registry)
 {
-    auto* iostream = SDL_IOFromConstMem(data, size);
-    SDL_Surface* surface = SDL_LoadBMP_IO(iostream, false);
-    if (surface == nullptr)
-    {
-        spdlog::error("Failed to load SDL surface!\nCause: {}", SDL_GetError());
-    }
+    // auto renderer = registry.ctx().get<SdlHandles>().renderer;
 
-    SDL_Texture* texture = SDL_CreateTextureFromSurface(renderer, surface);
-    if (texture == nullptr)
-    {
-        spdlog::error("Failed to create texture from surface!\nCause: {}", SDL_GetError());
-    }
-
-    return texture;
-}
-
-AudioAsset load_audio(uint8_t const* data, size_t size)
-{
-    AudioAsset audio_asset;
-
-    auto* iostream = SDL_IOFromConstMem(data, size);
-    bool res = SDL_LoadWAV_IO(
-        iostream, false, &audio_asset.spec, &audio_asset.buffer, &audio_asset.buffer_length);
-    if (!res)
-    {
-        spdlog::error("Failed to load audio file!\nCause: {}", SDL_GetError());
-    }
-    return audio_asset;
-}
-
-FontAsset load_font(uint8_t const* data, size_t size)
-{
-    FontAsset font_asset;
-
-    auto* iostream = SDL_IOFromConstMem(data, size);
-    auto* ttf = TTF_OpenFontIO(iostream, false, 20);
-
-    font_asset.font = ttf;
-
-    return font_asset;
-}
-
-AssetModule::AssetModule(flecs::world& world)
-{
-    auto* renderer = world.get<SdlHandles>()->renderer;
-
-    auto* background = load_texture(BACKGROUND_DATA, sizeof(BACKGROUND_DATA), renderer);
+    // auto* background = load_texture(BACKGROUND_DATA, sizeof(BACKGROUND_DATA), renderer);
     TextureAtlasLayout background_layout = {.width = 866, .height = 510, .rows = 1, .columns = 1};
 
-    auto* fruits = load_texture(FRUITS_DATA, sizeof(FRUITS_DATA), renderer);
+    // auto* fruits = load_texture(FRUITS_DATA, sizeof(FRUITS_DATA), renderer);
     TextureAtlasLayout fruits_layout = {.width = 16, .height = 16, .rows = 6, .columns = 38};
 
-    auto* spiders = load_texture(SPIDERS_DATA, sizeof(SPIDERS_DATA), renderer);
+    // auto* spiders = load_texture(SPIDERS_DATA, sizeof(SPIDERS_DATA), renderer);
     TextureAtlasLayout spiders_layout = {.width = 16, .height = 16, .rows = 2, .columns = 4};
 
-    auto* basket = load_texture(BASKET_DATA, sizeof(BASKET_DATA), renderer);
+    // auto* basket = load_texture(BASKET_DATA, sizeof(BASKET_DATA), renderer);
     TextureAtlasLayout basket_layout = {.width = 16, .height = 16, .rows = 1, .columns = 1};
 
-    world.set<TextureAssets>(TextureAssets{
-        .background = Texture{.sdl_texture = background, .texture_atlas_layout = background_layout},
-        .fruits = Texture{.sdl_texture = fruits, .texture_atlas_layout = fruits_layout},
-        .spiders = Texture{.sdl_texture = spiders, .texture_atlas_layout = spiders_layout},
-        .basket = Texture{.sdl_texture = basket, .texture_atlas_layout = basket_layout}});
+    // registry.ctx().emplace<TextureAssets>(TextureAssets{
+    //     .background = Texture{.sdl_texture = background, .texture_atlas_layout =
+    //     background_layout}, .fruits = Texture{.sdl_texture = fruits, .texture_atlas_layout =
+    //     fruits_layout}, .spiders = Texture{.sdl_texture = spiders, .texture_atlas_layout =
+    //     spiders_layout}, .basket = Texture{.sdl_texture = basket, .texture_atlas_layout =
+    //     basket_layout}});
+    registry.ctx().emplace<TextureAssets>(
+        TextureAssets{.background = Texture{.texture_atlas_layout = background_layout},
+                      .fruits = Texture{.texture_atlas_layout = fruits_layout},
+                      .spiders = Texture{.texture_atlas_layout = spiders_layout},
+                      .basket = Texture{.texture_atlas_layout = basket_layout}});
 
-    auto background_music = load_audio(BACKGROUND_MUSIC_DATA, sizeof(BACKGROUND_MUSIC_DATA));
-    auto pickup_sound = load_audio(PICKUP_SOUND_DATA, sizeof(PICKUP_SOUND_DATA));
-    auto hit_sound = load_audio(HIT_SOUND_DATA, sizeof(HIT_SOUND_DATA));
-    world.set<AudioAssets>(AudioAssets{.background_music = background_music,
-                                       .pickup_sound = pickup_sound,
-                                       .hit_sound = hit_sound});
+    // auto background_music = load_audio(BACKGROUND_MUSIC_DATA, sizeof(BACKGROUND_MUSIC_DATA));
+    // auto pickup_sound = load_audio(PICKUP_SOUND_DATA, sizeof(PICKUP_SOUND_DATA));
+    // auto hit_sound = load_audio(HIT_SOUND_DATA, sizeof(HIT_SOUND_DATA));
+    registry.ctx().emplace<AudioAssets>(AudioAssets{
+        .background_music = {.buffer = BACKGROUND_MUSIC_DATA,
+                             .buffer_length = sizeof(BACKGROUND_MUSIC_DATA)},
+        .pickup_sound = {.buffer = PICKUP_SOUND_DATA, .buffer_length = sizeof(PICKUP_SOUND_DATA)},
+        .hit_sound = {.buffer = HIT_SOUND_DATA, .buffer_length = sizeof(HIT_SOUND_DATA)}});
+    // registry.ctx().emplace<AudioAssets>(AudioAssets{.background_music = background_music,
+    //                                                 .pickup_sound = pickup_sound,
+    //                                                 .hit_sound = hit_sound});
 
-    auto font = load_font(DEFAULT_FONT_DATA, sizeof(DEFAULT_FONT_DATA));
-    world.set<FontAssets>(FontAssets{.default_font = font});
+    // auto font = load_font(DEFAULT_FONT_DATA, sizeof(DEFAULT_FONT_DATA));
+    // registry.ctx().emplace<FontAssets>(FontAssets{.default_font = font});
 }

src/assets.hpp

@@ -2,9 +2,7 @@
 
 #include "audio.hpp"
 
-#include <SDL3/SDL.h>
-#include <SDL3_ttf/SDL_ttf.h>
-#include <flecs.h>
+#include <entt/entt.hpp>
 
 struct TextureAtlasLayout
 {
@@ -16,7 +14,7 @@ struct TextureAtlasLayout
 
 struct Texture
 {
-    SDL_Texture* sdl_texture;
+    // SDL_Texture* sdl_texture;
     TextureAtlasLayout texture_atlas_layout;
 };
 
@@ -35,17 +33,17 @@ struct AudioAssets
     AudioAsset hit_sound;
 };
 
-struct FontAsset
-{
-    TTF_Font* font;
-};
+// struct FontAsset
+// {
+//     TTF_Font* font;
+// };
 
-struct FontAssets
-{
-    FontAsset default_font;
-};
+// struct FontAssets
+// {
+//     FontAsset default_font;
+// };
 
 struct AssetModule
 {
-    AssetModule(flecs::world& world);
+    AssetModule(entt::registry& registry);
 };

src/audio.cpp

@@ -1,34 +1,31 @@
 #include "audio.hpp"
 #include "assets.hpp"
 
-AudioModule::AudioModule(flecs::world& world)
+AudioModule::AudioModule(entt::registry& registry)
 {
-    auto* audio_assets = world.get<AudioAssets>();
-    auto* music_stream = SDL_OpenAudioDeviceStream(
-        SDL_AUDIO_DEVICE_DEFAULT_PLAYBACK, &audio_assets->background_music.spec, NULL, NULL);
-    auto* sound_stream = SDL_OpenAudioDeviceStream(
-        SDL_AUDIO_DEVICE_DEFAULT_PLAYBACK, &audio_assets->pickup_sound.spec, NULL, NULL);
+    // auto const& audio_assets = registry.ctx().get<AudioAssets>();
+    // auto* music_stream = SDL_OpenAudioDeviceStream(
+    //     SDL_AUDIO_DEVICE_DEFAULT_PLAYBACK, &audio_assets.background_music.spec, NULL, NULL);
+    // auto* sound_stream = SDL_OpenAudioDeviceStream(
+    //     SDL_AUDIO_DEVICE_DEFAULT_PLAYBACK, &audio_assets.pickup_sound.spec, NULL, NULL);
 
-    SDL_ResumeAudioStreamDevice(music_stream);
-    SDL_ResumeAudioStreamDevice(sound_stream);
+    // SDL_ResumeAudioStreamDevice(music_stream);
+    // SDL_ResumeAudioStreamDevice(sound_stream);
 
-    world.set<AudioStreams>(
-        AudioStreams{.music_stream = music_stream, .sound_stream = sound_stream});
-
-    world.system<AudioStreams, AudioAssets>("FeedAudioStreams")
-        .term_at(0)
-        .singleton()
-        .term_at(1)
-        .singleton()
-        .each(
-            [](AudioStreams& audio_streams, AudioAssets& audio_assets)
-            {
-                if (SDL_GetAudioStreamQueued(audio_streams.music_stream) <
-                    static_cast<int>(audio_assets.background_music.buffer_length))
-                {
-                    SDL_PutAudioStreamData(audio_streams.music_stream,
-                                           audio_assets.background_music.buffer,
-                                           audio_assets.background_music.buffer_length);
-                }
-            });
+    // registry.ctx().emplace<AudioStreams>(
+    //     AudioStreams{.music_stream = music_stream, .sound_stream = sound_stream});
 }
+
+// void AudioModule::FeedAudioStreams(entt::registry& registry)
+// {
+//     auto audio_streams = registry.ctx().get<AudioStreams>();
+//     auto audio_assets = registry.ctx().get<AudioAssets>();
+
+//     if (SDL_GetAudioStreamQueued(audio_streams.music_stream) <
+//         static_cast<int>(audio_assets.background_music.buffer_length))
+//     {
+//         SDL_PutAudioStreamData(audio_streams.music_stream,
+//                                audio_assets.background_music.buffer,
+//                                audio_assets.background_music.buffer_length);
+//     }
+// }

src/audio.hpp

@@ -1,23 +1,23 @@
 #pragma once
 
-#include <SDL3/SDL.h>
 #include <cstdint>
-#include <flecs.h>
+#include <entt/entt.hpp>
 
 struct AudioAsset
 {
-    SDL_AudioSpec spec;
-    uint8_t* buffer;
+    // SDL_AudioSpec spec;
+    uint8_t const* buffer;
     uint32_t buffer_length;
 };
 
-struct AudioStreams
-{
-    SDL_AudioStream* music_stream;
-    SDL_AudioStream* sound_stream;
-};
+// struct AudioStreams
+// {
+//     SDL_AudioStream* music_stream;
+//     SDL_AudioStream* sound_stream;
+// };
 
 struct AudioModule
 {
-    AudioModule(flecs::world& world);
+    AudioModule(entt::registry& registry);
+    // static void FeedAudioStreams(entt::registry& registry);
 };

src/definitions.hpp

@@ -1,18 +1,16 @@
 #pragma once
 
-#include <SDL3/SDL.h>
-#include <SDL3_ttf/SDL_ttf.h>
 #include <random>
 
 static constexpr int WINDOW_WIDTH = 400;
 static constexpr int WINDOW_HEIGHT = 240;
 
-struct SdlHandles
-{
-    SDL_Window* window;
-    SDL_Renderer* renderer;
-    TTF_TextEngine* text_engine;
-};
+// struct SdlHandles
+// {
+//     SDL_Window* window;
+//     SDL_Renderer* renderer;
+//     TTF_TextEngine* text_engine;
+// };
 
 struct Game
 {

src/level.cpp

@@ -0,0 +1,123 @@
+#include "level.hpp"
+#include "input.hpp"
+
+void LevelModule::MoveBasket(entt::registry& registry)
+{
+    auto const& input = registry.ctx().get<ButtonInput>();
+    auto basket_view = registry.view<Position, Size const, Sprite const, Basket>();
+
+    for (auto [entity, pos, size, sprite] : basket_view.each())
+    {
+        if (input.pressed.contains(SDLK_LEFT))
+        {
+            pos.x -= 5;
+        }
+        if (input.pressed.contains(SDLK_RIGHT))
+        {
+            pos.x += 5;
+        }
+
+        pos.x = pos.x < 0 ? 0 : pos.x;
+        pos.x = pos.x > WINDOW_WIDTH - size.w ? WINDOW_WIDTH - size.w : pos.x;
+    }
+}
+
+void LevelModule::SpawnFruits(entt::registry& registry)
+{
+    auto& game = registry.ctx().get<Game>();
+    auto const& texture_assets = registry.ctx().get<TextureAssets>();
+
+    std::bernoulli_distribution spider_dist(0.25);
+    bool spider = spider_dist(game.random_engine);
+
+    std::binomial_distribution<> velocity_dist(3, 0.5);
+    int vel = velocity_dist(game.random_engine) + 1;
+
+    if ((game.ticks % 50) == 0)
+    {
+        auto item = registry.create();
+        std::uniform_int_distribution<> xpos_dist(32, WINDOW_WIDTH - 32);
+        int xpos = xpos_dist(game.random_engine);
+        if (!spider)
+        {
+            std::uniform_int_distribution<> index_dist(0, 228 - 1);
+            uint16_t index = index_dist(game.random_engine);
+
+            registry.emplace<Fruit>(item);
+            registry.emplace<WorldPosition>(item);
+            registry.emplace<Position>(item, Position{.x = xpos, .y = -16});
+            registry.emplace<Velocity>(item, Velocity{.x = 0, .y = vel});
+            registry.emplace<Sprite>(
+                item, Sprite{.texture = &texture_assets.fruits, .texture_atlas_index = index});
+            registry.emplace<Size>(item, Size{.w = 32, .h = 32});
+        }
+        else
+        {
+            std::uniform_int_distribution<> index_dist(0, 8 - 1);
+            uint16_t index = index_dist(game.random_engine);
+
+            registry.emplace<Spider>(item);
+            registry.emplace<WorldPosition>(item);
+            registry.emplace<Position>(item, Position{.x = xpos, .y = -16});
+            registry.emplace<Velocity>(item, Velocity{.x = 0, .y = vel});
+            registry.emplace<Sprite>(
+                item, Sprite{.texture = &texture_assets.spiders, .texture_atlas_index = index});
+            registry.emplace<Size>(item, Size{.w = 32, .h = 32});
+        }
+
+        auto collision_box = registry.create();
+        registry.emplace<Parent>(collision_box, item);
+        registry.emplace<WorldPosition>(collision_box);
+        registry.emplace<Position>(collision_box, Position{.x = 0, .y = 0});
+        registry.emplace<Size>(collision_box, Size{.w = 32, .h = 32});
+        registry.emplace<CollisionBox>(collision_box, item);
+    }
+}
+
+void LevelModule::CollectFruit(entt::registry& registry)
+{
+    auto& game = registry.ctx().get<Game>();
+    // auto const& audio_streams = registry.ctx().get<AudioStreams>();
+    auto const& audio_assets = registry.ctx().get<AudioAssets>();
+
+    auto view = registry.view<Position, Fruit, Collided>();
+    for (auto [entity, pos] : view.each())
+    {
+        game.score += 10;
+        pos.x += 1000;
+        // registry.destroy(entity);
+
+        // SDL_PutAudioStreamData(audio_streams.sound_stream,
+        //                        audio_assets.pickup_sound.buffer,
+        //                        audio_assets.pickup_sound.buffer_length);
+    }
+}
+
+void LevelModule::CollectSpider(entt::registry& registry)
+{
+    auto& game = registry.ctx().get<Game>();
+    // auto const& audio_streams = registry.ctx().get<AudioStreams>();
+    auto const& audio_assets = registry.ctx().get<AudioAssets>();
+
+    auto view = registry.view<Position, Spider, Collided>();
+    for (auto [entity, pos] : view.each())
+    {
+        game.score -= 50;
+        pos.x += 1000;
+        // registry.destroy(entity);
+
+        // SDL_PutAudioStreamData(audio_streams.sound_stream,
+        //                        audio_assets.hit_sound.buffer,
+        //                        audio_assets.hit_sound.buffer_length);
+    };
+}
+
+void LevelModule::DespawnItems(entt::registry& registry)
+{
+    auto view = registry.view<WorldPosition const, Item>();
+    for (auto [entity, pos] : view.each())
+    {
+        if (pos.y >= WINDOW_HEIGHT)
+            registry.destroy(entity);
+    }
+}

src/level.hpp

@@ -1,12 +1,14 @@
 #pragma once
 
 #include "definitions.hpp"
-#include "input.hpp"
 #include "physics.hpp"
 #include "sprite.hpp"
 
-#include <flecs.h>
-#include <spdlog/spdlog.h>
+#include <entt/entt.hpp>
+
+struct Background
+{
+};
 
 struct Fruit
 {
@@ -24,175 +26,44 @@ struct Basket
 {
 };
 
+struct BasketCollisionBox
+{
+};
+
 struct LevelModule
 {
-    LevelModule(flecs::world& world)
+    LevelModule(entt::registry& registry)
     {
-        auto const* texture_assets = world.get<TextureAssets>();
+        auto const* texture_assets = &registry.ctx().get<TextureAssets>();
 
-        world.component<Item>();
-        world.component<Fruit>().is_a<Item>();
-        world.component<Spider>().is_a<Item>();
+        auto background = registry.create();
+        registry.emplace<Position>(background, Position{.x = 0, .y = 0});
+        registry.emplace<Sprite>(
+            background, Sprite{.texture = &texture_assets->background, .texture_atlas_index = 0});
+        registry.emplace<Size>(background, Size{.w = WINDOW_WIDTH, .h = WINDOW_HEIGHT});
+        registry.emplace<Background>(background);
 
-        world.entity("Background")
-            .set<Position>(Position{.x = 0, .y = 0})
-            .set<Sprite>(Sprite{.texture = &texture_assets->background, .texture_atlas_index = 0})
-            .set<Size>(Size{.w = WINDOW_WIDTH, .h = WINDOW_HEIGHT});
+        auto basket = registry.create();
+        registry.emplace<WorldPosition>(basket);
+        registry.emplace<Position>(basket,
+                                   Position{.x = WINDOW_WIDTH / 2 - 32, .y = WINDOW_HEIGHT - 32});
+        registry.emplace<Sprite>(
+            basket, Sprite{.texture = &texture_assets->basket, .texture_atlas_index = 0});
+        registry.emplace<Size>(basket, Size{.w = 64, .h = 32});
+        registry.emplace<Basket>(basket);
 
-        auto basket =
-            world.entity("Basket")
-                .add<WorldPosition>()
-                .set<Position>(Position{.x = WINDOW_WIDTH / 2 - 32, .y = WINDOW_HEIGHT - 32})
-                .set<Sprite>(Sprite{.texture = &texture_assets->basket, .texture_atlas_index = 0})
-                .set<Size>(Size{.w = 64, .h = 32})
-                .add<Basket>();
-
-        world.entity()
-            .child_of(basket)
-            .add<WorldPosition>()
-            .set<Position>(Position{.x = 0, .y = 16})
-            .set<Size>(Size{.w = 64, .h = 16})
-            .add<CollisionBox>();
-
-        world.system<Game, TextureAssets const>("SpawnFruits")
-            .term_at(0)
-            .singleton()
-            .term_at(1)
-            .singleton()
-            .each(
-                [](flecs::iter& it, size_t index, Game& game, TextureAssets const& texture_assets)
-                {
-                    std::bernoulli_distribution spider_dist(0.25);
-                    bool spider = spider_dist(game.random_engine);
-
-                    std::binomial_distribution<> velocity_dist(3, 0.5);
-                    int vel = velocity_dist(game.random_engine) + 1;
-
-                    if ((game.ticks % 50) == 0)
-                    {
-                        flecs::entity e;
-                        std::uniform_int_distribution<> xpos_dist(32, WINDOW_WIDTH - 32);
-                        int xpos = xpos_dist(game.random_engine);
-                        if (!spider)
-                        {
-                            std::uniform_int_distribution<> index_dist(0, 228 - 1);
-                            uint16_t index = index_dist(game.random_engine);
-
-                            e = it.world()
-                                    .entity()
-                                    .add<Fruit>()
-                                    .add<WorldPosition>()
-                                    .set<Position>(Position{.x = xpos, .y = -16})
-                                    .set<Velocity>(Velocity{.x = 0, .y = vel})
-                                    .set<Sprite>(Sprite{.texture = &texture_assets.fruits,
-                                                        .texture_atlas_index = index})
-                                    .set<Size>(Size{.w = 32, .h = 32});
-                        }
-                        else
-                        {
-                            std::uniform_int_distribution<> index_dist(0, 8 - 1);
-                            uint16_t index = index_dist(game.random_engine);
-
-                            e = it.world()
-                                    .entity()
-                                    .add<Spider>()
-                                    .add<WorldPosition>()
-                                    .set<Position>(Position{.x = xpos, .y = -16})
-                                    .set<Velocity>(Velocity{.x = 0, .y = vel})
-                                    .set<Sprite>(Sprite{.texture = &texture_assets.spiders,
-                                                        .texture_atlas_index = index})
-                                    .set<Size>(Size{.w = 32, .h = 32});
-                        }
-                        it.world()
-                            .entity("CollisionBox")
-                            .child_of(e)
-                            .add<WorldPosition>()
-                            .set<Position>(Position{.x = 0, .y = 0})
-                            .set<Size>(Size{.w = 32, .h = 32})
-                            .add<CollisionBox>();
-                    }
-                });
-
-        // world.system<WorldPosition const, Item>("DespawnItems")
-        //     .kind(flecs::OnValidate)
-        //     .each(
-        //         [](flecs::entity e, WorldPosition const& pos, Item)
-        //         {
-        //             if (pos.y >= WINDOW_HEIGHT)
-        //                 e.destruct();
-        //         });
-
-        world.system<Game, AudioStreams, AudioAssets, Position, Fruit, Collided>("CollectFruit")
-            .term_at(0)
-            .singleton()
-            .term_at(1)
-            .singleton()
-            .term_at(2)
-            .singleton()
-            .each(
-                [](flecs::entity e,
-                   Game& game,
-                   AudioStreams& audio_streams,
-                   AudioAssets& audio_assets,
-                   Position& pos,
-                   Fruit,
-                   Collided)
-                {
-                    game.score += 10;
-                    pos.x += 1000;
-                    // e.destruct();
-
-                    SDL_PutAudioStreamData(audio_streams.sound_stream,
-                                           audio_assets.pickup_sound.buffer,
-                                           audio_assets.pickup_sound.buffer_length);
-                });
-
-        world.system<Game, AudioStreams, AudioAssets, Position, Spider, Collided>("CollectSpider")
-            .term_at(0)
-            .singleton()
-            .term_at(1)
-            .singleton()
-            .term_at(2)
-            .singleton()
-            .each(
-                [](flecs::entity e,
-                   Game& game,
-                   AudioStreams& audio_streams,
-                   AudioAssets& audio_assets,
-                   Position& pos,
-                   Spider,
-                   Collided)
-                {
-                    game.score -= 50;
-                    pos.x += 1000;
-                    // e.destruct();
-
-                    SDL_PutAudioStreamData(audio_streams.sound_stream,
-                                           audio_assets.hit_sound.buffer,
-                                           audio_assets.hit_sound.buffer_length);
-                });
-
-        world.system<ButtonInput const, Position, Size const, Sprite const, Basket>("MoveBasket")
-            .term_at(0)
-            .singleton()
-            .each(
-                [](ButtonInput const& input,
-                   Position& pos,
-                   Size const& size,
-                   Sprite const& sprite,
-                   Basket)
-                {
-                    if (input.pressed.contains(SDLK_LEFT))
-                    {
-                        pos.x -= 5;
-                    }
-                    if (input.pressed.contains(SDLK_RIGHT))
-                    {
-                        pos.x += 5;
-                    }
-
-                    pos.x = pos.x < 0 ? 0 : pos.x;
-                    pos.x = pos.x > WINDOW_WIDTH - size.w ? WINDOW_WIDTH - size.w : pos.x;
-                });
+        auto basket_cb = registry.create();
+        registry.emplace<WorldPosition>(basket_cb);
+        registry.emplace<Position>(basket_cb, Position{.x = 0, .y = 16});
+        registry.emplace<Size>(basket_cb, Size{.w = 64, .h = 16});
+        registry.emplace<CollisionBox>(basket_cb);
+        registry.emplace<Parent>(basket_cb, basket);
+        registry.emplace<BasketCollisionBox>(basket_cb);
     }
+
+    static void MoveBasket(entt::registry& registry);
+    static void SpawnFruits(entt::registry& registry);
+    static void CollectFruit(entt::registry &registry);
+    static void CollectSpider(entt::registry &registry);
+    static void DespawnItems(entt::registry &registry);
 };

src/main.cpp

@@ -5,114 +5,91 @@
 #include "physics.hpp"
 #include "render.hpp"
 
-#include <SDL3/SDL.h>
-#include <SDL3_ttf/SDL_ttf.h>
-#include <flecs.h>
-#include <spdlog/spdlog.h>
+#include <entt/entt.hpp>
+
+void increment_ticks(entt::registry& registry)
+{
+    auto& game = registry.ctx().get<Game>();
+    game.ticks += 1;
+
+    if (game.ticks % 60 == 0)
+    {
+        game.time = std::max(0, game.time - 1);
+    }
+}
 
 int main()
 {
-    spdlog::info("Initialize SDL...");
+    entt::registry registry;
 
-    SDL_SetHint(SDL_HINT_RENDER_VSYNC, "1");
+    registry.ctx().emplace<Game>(Game{.ticks = 0, .time = 60, .score = 0, .random_engine = {}});
+    registry.ctx().emplace<ButtonInput>(ButtonInput{});
 
-    if (!SDL_Init(SDL_INIT_VIDEO | SDL_INIT_AUDIO))
-    {
-        spdlog::critical("Failed to initialize SDL!\nCause: {}", SDL_GetError());
-        std::terminate();
-    }
-
-    TTF_Init();
-
-    auto* window = SDL_CreateWindow("HansTheGatherer", WINDOW_WIDTH, WINDOW_HEIGHT, 0);
-    if (window == nullptr)
-    {
-        spdlog::critical("Failed to create SDL window!\nCause: {}", SDL_GetError());
-    }
-
-    auto* renderer = SDL_CreateRenderer(window, nullptr);
-    if (renderer == nullptr)
-    {
-        spdlog::critical("Failed to create SDL renderer!\nCause: {}", SDL_GetError());
-    }
-
-    auto* text_engine = TTF_CreateRendererTextEngine(renderer);
-
-    flecs::world world;
-
-    world.set<Game>(Game{.ticks = 0, .time = 60, .score = 0, .random_engine = {}});
-    world.set<ButtonInput>(ButtonInput{});
-    world.set<SdlHandles>(
-        SdlHandles{.window = window, .renderer = renderer, .text_engine = text_engine});
-
-    world.import <AssetModule>();
-    world.import <AudioModule>();
-    world.import <RenderModule>();
-    world.import <PhysicsModule>();
-    world.import <LevelModule>();
-
-    world.system<Game, TranslateSystem>("IncrementTicks")
-        .term_at(0)
-        .singleton()
-        .term_at(1)
-        .singleton()
-        .each(
-            [](Game& game, TranslateSystem& translate_system)
-            {
-                game.ticks += 1;
-
-                if (game.ticks % 60 == 0)
-                {
-                    game.time = std::max(0, game.time - 1);
-                }
-
-                if (game.time == 0)
-                    translate_system.translate_system.disable();
-            });
+    AssetModule asset_module(registry);
+    AudioModule audio_module(registry);
+    RenderModule render_module(registry);
+    PhysicsModule physics_module(registry);
+    LevelModule level_module(registry);
 
     bool exit_gameloop = false;
     while (!exit_gameloop)
     {
-        auto* input = world.get_mut<ButtonInput>();
+        auto* input = &registry.ctx().get<ButtonInput>();
 
         // Clear just pressed/released
         input->just_pressed.clear();
         input->just_released.clear();
 
         // Input
-        SDL_Event event;
-        while (SDL_PollEvent(&event))
+        // SDL_Event event;
+        // while (SDL_PollEvent(&event))
+        // {
+        //     switch (event.type)
+        //     {
+        //     case SDL_EVENT_QUIT:
+        //         exit_gameloop = true;
+        //         break;
+        //     case SDL_EVENT_KEY_DOWN:
+        //         if (event.key.key == SDLK_ESCAPE)
+        //         {
+        //             exit_gameloop = true;
+        //         }
+        //         if (input->pressed.insert(event.key.key).second)
+        //         {
+        //             input->just_pressed.insert(event.key.key);
+        //         }
+        //         break;
+        //     case SDL_EVENT_KEY_UP:
+        //         if (input->pressed.erase(event.key.key) != 0)
+        //         {
+        //             input->just_released.insert(event.key.key);
+        //         }
+        //         break;
+        //     }
+        // }
+
+        // AudioModule::FeedAudioStreams(registry);
+
+        if (registry.ctx().get<Game>().time != 0)
         {
-            switch (event.type)
-            {
-            case SDL_EVENT_QUIT:
-                exit_gameloop = true;
-                break;
-            case SDL_EVENT_KEY_DOWN:
-                if (event.key.key == SDLK_ESCAPE)
-                {
-                    exit_gameloop = true;
-                }
-                if (input->pressed.insert(event.key.key).second)
-                {
-                    input->just_pressed.insert(event.key.key);
-                }
-                break;
-            case SDL_EVENT_KEY_UP:
-                if (input->pressed.erase(event.key.key) != 0)
-                {
-                    input->just_released.insert(event.key.key);
-                }
-                break;
-            }
+            increment_ticks(registry);
+            LevelModule::MoveBasket(registry);
+            LevelModule::SpawnFruits(registry);
+            LevelModule::CollectFruit(registry);
+            LevelModule::CollectSpider(registry);
+            // LevelModule::DespawnItems(registry);
         }
 
-        world.progress();
-    }
+        PhysicsModule::TranslatePhysicsObject(registry);
+        PhysicsModule::PropagatePosition(registry);
+        PhysicsModule::RemoveCollisionMarker(registry);
+        PhysicsModule::CollisionCheck(registry);
 
-    SDL_DestroyRenderer(renderer);
-    SDL_DestroyWindow(window);
-    SDL_Quit();
+        // SDL_RenderClear(sdl_handles.renderer);
+        RenderModule::RenderSprites(registry);
+        RenderModule::RenderScore(registry);
+        // SDL_RenderPresent(sdl_handles.renderer);
+    }
 
     return 0;
 }

src/physics.cpp

@@ -1,86 +1,68 @@
 #include "physics.hpp"
 #include "level.hpp"
 
-#include <spdlog/spdlog.h>
-
-PhysicsModule::PhysicsModule(flecs::world& world)
+void PhysicsModule::TranslatePhysicsObject(entt::registry& registry)
 {
-    auto translate_system = world.system<Position, Velocity const>("TranslatePhysicsObject")
-                                .each(
-                                    [](Position& pos, Velocity const& vel)
-                                    {
-                                        pos.x += vel.x;
-                                        pos.y += vel.y;
-                                    });
+    auto view = registry.view<Position, Velocity const>();
 
-    world.set<TranslateSystem>(TranslateSystem{translate_system});
+    for (auto [entity, pos, vel] : view.each())
+    {
+        pos.x += vel.x;
+        pos.y += vel.y;
+    }
+}
 
-    // Introduce phase that runs after OnUpdate but before OnValidate
-    flecs::entity propagate_phase = world.entity().add(flecs::Phase).depends_on(flecs::OnUpdate);
+void PhysicsModule::PropagatePosition(entt::registry& registry)
+{
+    auto root_transform_view = registry.view<Position const, WorldPosition>(entt::exclude<Parent>);
+    auto transform_view = registry.view<Position const, WorldPosition, Parent const>();
 
-    world.system<WorldPosition, Position const>("PropagatePosition")
-        .kind(propagate_phase)
-        .each(
-            [](flecs::entity e, WorldPosition& world_pos, Position const& local_pos)
+    for (auto [entity, pos, world_pos] : root_transform_view.each())
+    {
+        world_pos.x = pos.x;
+        world_pos.y = pos.y;
+    }
+
+    for (auto [entity, pos, world_pos, parent] : transform_view.each())
+    {
+        auto parent_pos = registry.get<WorldPosition const>(parent.parent);
+
+        world_pos.x = parent_pos.x + pos.x;
+        world_pos.y = parent_pos.y + pos.y;
+    }
+}
+
+void PhysicsModule::RemoveCollisionMarker(entt::registry& registry)
+{
+    auto view = registry.view<Collided const>();
+    for (auto [entity] : view.each())
+    {
+        registry.remove<Collided>(entity);
+    }
+}
+void PhysicsModule::CollisionCheck(entt::registry& registry)
+{
+    auto view = registry.view<WorldPosition const, Size const, Parent const, CollisionBox>(
+        entt::exclude<BasketCollisionBox>);
+    auto basket_cb_view = registry.view<WorldPosition const, Size const, BasketCollisionBox>();
+
+    for (auto [e, world_pos, size, parent] : view.each())
+    {
+        auto fruit = parent.parent;
+
+        for (auto [basket, basket_world_pos, basket_size] : basket_cb_view.each())
+        {
+            if (basket_world_pos.x + basket_size.w >= world_pos.x &&
+                basket_world_pos.x <= world_pos.x + size.w &&
+                basket_world_pos.y + basket_size.h >= world_pos.y &&
+                basket_world_pos.y <= world_pos.y + size.h)
             {
-                if (e.parent() != flecs::entity::null() && e.parent().has<WorldPosition>())
-                    return;
+                registry.emplace<Collided>(fruit);
+            }
+        }
+    }
+}
 
-                world_pos.x = local_pos.x;
-                world_pos.y = local_pos.y;
-
-                std::function<void(flecs::entity, WorldPosition const&)> propagate_to_children;
-                propagate_to_children = [&](flecs::entity parent, WorldPosition const& parent_pos)
-                {
-                    parent.children(
-                        [=](flecs::entity child)
-                        {
-                            auto local_pos = child.get<Position>();
-                            auto world_pos = child.get_mut<WorldPosition>();
-
-                            world_pos->x = parent_pos.x + local_pos->x;
-                            world_pos->y = parent_pos.y + local_pos->y;
-
-                            propagate_to_children(child, *world_pos);
-                        });
-                };
-
-                propagate_to_children(e, world_pos);
-            });
-
-    auto basket_query = world.query<Basket>();
-
-    world.system<Collided>("RemoveCollisionMarker")
-        .kind(flecs::PreUpdate)
-        .each([](flecs::entity e, Collided) { e.remove<Collided>(); });
-
-    world.system<WorldPosition const, Size const, CollisionBox>("CollisionCheck")
-        .kind(flecs::OnValidate)
-        .each(
-            [basket_query](
-                flecs::entity e, WorldPosition const& world_pos, Size const& size, CollisionBox)
-            {
-                if (e.parent().has<Basket>())
-                    return;
-
-                auto fruit = e.parent();
-                auto basket = basket_query.first();
-                basket.children(
-                    [fruit, world_pos, size](flecs::entity basket_child)
-                    {
-                        if (!basket_child.has<CollisionBox>())
-                            return;
-
-                        auto basket_child_pos = basket_child.get<WorldPosition>();
-                        auto basket_child_size = basket_child.get<Size>();
-
-                        if (basket_child_pos->x + basket_child_size->w >= world_pos.x &&
-                            basket_child_pos->x <= world_pos.x + size.w &&
-                            basket_child_pos->y + basket_child_size->h >= world_pos.y &&
-                            basket_child_pos->y <= world_pos.y + size.h)
-                        {
-                            fruit.add<Collided>();
-                        }
-                    });
-            });
+PhysicsModule::PhysicsModule(entt::registry& registry)
+{
 }

src/physics.hpp

@@ -1,6 +1,6 @@
 #pragma once
 
-#include <flecs.h>
+#include <entt/entt.hpp>
 
 struct WorldPosition
 {
@@ -26,6 +26,16 @@ struct Size
     int h;
 };
 
+struct Parent
+{
+    entt::entity parent;
+};
+
+struct Children
+{
+    std::vector<entt::entity> children;
+};
+
 struct CollisionBox
 {
 };
@@ -34,12 +44,12 @@ struct Collided
 {
 };
 
-struct TranslateSystem
-{
-    flecs::system translate_system;
-};
-
 struct PhysicsModule
 {
-    PhysicsModule(flecs::world& world);
+    PhysicsModule(entt::registry& registry);
+
+    static void TranslatePhysicsObject(entt::registry& registry);
+    static void PropagatePosition(entt::registry& registry);
+    static void RemoveCollisionMarker(entt::registry& registry);
+    static void CollisionCheck(entt::registry& registry);
 };

src/render.cpp

@@ -1,73 +1,72 @@
 #include "render.hpp"
 
 #include "definitions.hpp"
+#include "level.hpp"
 #include "physics.hpp"
 #include "sprite.hpp"
 
 #include <format>
 
-RenderModule::RenderModule(flecs::world& world)
+RenderModule::RenderModule(entt::registry& registry)
 {
-    world.system<SdlHandles>("RenderClear")
-        .term_at(0)
-        .singleton()
-        .kind(flecs::PreStore)
-        .each([](SdlHandles& sdl_handles) { SDL_RenderClear(sdl_handles.renderer); });
-
-    flecs::entity render_present_phase =
-        world.entity().add(flecs::Phase).depends_on(flecs::OnStore);
-
-    world.system<SdlHandles>("RenderPresent")
-        .term_at(0)
-        .singleton()
-        .kind(render_present_phase)
-        .each([](SdlHandles& sdl_handles) { SDL_RenderPresent(sdl_handles.renderer); });
-
-    world.system<SdlHandles const, Position const, Size const, Sprite const>("RenderSprites")
-        .kind(flecs::OnStore)
-        .term_at(0)
-        .singleton()
-        .each(
-            [](SdlHandles const& sdl_handles,
-               Position const& pos,
-               Size const& size,
-               Sprite const& sprite)
-            {
-                TextureAtlasLayout layout = sprite.texture->texture_atlas_layout;
-                uint8_t row = sprite.texture_atlas_index / layout.columns;
-                uint8_t column = sprite.texture_atlas_index % layout.columns;
-                SDL_FRect srcrect{static_cast<float>(column * layout.width),
-                                  static_cast<float>(row * layout.height),
-                                  static_cast<float>(layout.width),
-                                  static_cast<float>(layout.height)};
-
-                SDL_FRect dstrect{static_cast<float>(pos.x),
-                                  static_cast<float>(pos.y),
-                                  static_cast<float>(size.w),
-                                  static_cast<float>(size.h)};
-
-                SDL_RenderTexture(
-                    sdl_handles.renderer, sprite.texture->sdl_texture, &srcrect, &dstrect);
-            });
-
-    world.system<SdlHandles const, Game const, FontAssets const>("RenderScore")
-        .kind(flecs::OnStore)
-        .term_at(0)
-        .singleton()
-        .term_at(1)
-        .singleton()
-        .term_at(2)
-        .singleton()
-        .each(
-            [](SdlHandles const& sdl_handles, Game const& game, FontAssets const& font_assets)
-            {
-                auto score_string = std::format("Score: {}\nTime: {}", game.score, game.time);
-                auto text = TTF_CreateText(sdl_handles.text_engine,
-                                           font_assets.default_font.font,
-                                           score_string.c_str(),
-                                           score_string.length());
-                TTF_DrawRendererText(text, 0.0, 0.0);
-
-                TTF_DestroyText(text);
-            });
 }
+
+void RenderModule::RenderSprites(entt::registry& registry)
+{
+    // auto const& sdl_handles = registry.ctx().get<SdlHandles>();
+    auto const& game = registry.ctx().get<Game>();
+    auto sprites_view =
+        registry.view<Position const, Size const, Sprite const>(entt::exclude<Background>);
+    auto background_view = registry.view<Position const, Size const, Sprite const, Background>();
+
+    for (auto [entity, pos, size, sprite] : background_view.each())
+    {
+        TextureAtlasLayout layout = sprite.texture->texture_atlas_layout;
+        uint8_t row = sprite.texture_atlas_index / layout.columns;
+        uint8_t column = sprite.texture_atlas_index % layout.columns;
+        // SDL_FRect srcrect{static_cast<float>(column * layout.width),
+        //                   static_cast<float>(row * layout.height),
+        //                   static_cast<float>(layout.width),
+        //                   static_cast<float>(layout.height)};
+
+        // SDL_FRect dstrect{static_cast<float>(pos.x),
+        //                   static_cast<float>(pos.y),
+        //                   static_cast<float>(size.w),
+        //                   static_cast<float>(size.h)};
+
+        // SDL_RenderTexture(sdl_handles.renderer, sprite.texture->sdl_texture, &srcrect, &dstrect);
+    }
+
+    for (auto [entity, pos, size, sprite] : sprites_view.each())
+    {
+        TextureAtlasLayout layout = sprite.texture->texture_atlas_layout;
+        uint8_t row = sprite.texture_atlas_index / layout.columns;
+        uint8_t column = sprite.texture_atlas_index % layout.columns;
+        // SDL_FRect srcrect{static_cast<float>(column * layout.width),
+        //                   static_cast<float>(row * layout.height),
+        //                   static_cast<float>(layout.width),
+        //                   static_cast<float>(layout.height)};
+
+        // SDL_FRect dstrect{static_cast<float>(pos.x),
+        //                   static_cast<float>(pos.y),
+        //                   static_cast<float>(size.w),
+        //                   static_cast<float>(size.h)};
+
+        // SDL_RenderTexture(sdl_handles.renderer, sprite.texture->sdl_texture, &srcrect, &dstrect);
+    }
+}
+
+void RenderModule::RenderScore(entt::registry& registry)
+{
+    // auto const& sdl_handles = registry.ctx().get<SdlHandles>();
+    auto const& game = registry.ctx().get<Game>();
+    // auto const& font_assets = registry.ctx().get<FontAssets>();
+
+    auto score_string = std::format("Score: {}\nTime: {}", game.score, game.time);
+    // auto text = TTF_CreateText(sdl_handles.text_engine,
+    //                            font_assets.default_font.font,
+    //                            score_string.c_str(),
+    //                            score_string.length());
+    // TTF_DrawRendererText(text, 0.0, 0.0);
+    // TTF_DestroyText(text);
+}

src/render.hpp

@@ -1,8 +1,11 @@
 #pragma once
 
-#include <flecs.h>
+#include <entt/entt.hpp>
 
 struct RenderModule
 {
-    RenderModule(flecs::world& world);
+    RenderModule(entt::registry& registry);
+
+    static void RenderSprites(entt::registry& registry);
+    static void RenderScore(entt::registry& registry);
 };