Wrap SDL event type enum (partially)

src/core/engine.cppm

@@ -7,13 +7,11 @@ module;
 export module core.engine;
 
 import config;
-import core.renderer;
+import core.render_server;
 import wrappers.sdl;
 
 export namespace core
 {
-    using Window = sdl::Window;
-
     class Engine
     {
         // Whether this class is currently instantiated (to prevent multiple instances)
@@ -22,13 +20,13 @@ export namespace core
         // If this is set to false, the application will exit
         bool keep_running_ = true;
 
-        Window window_;
-        Renderer renderer_;
+        sdl::Window window_;
+        RenderServer render_server_;
 
         // Private constructor
-        Engine(Window&& window, Renderer&& renderer)
+        Engine(sdl::Window&& window, sdl::Renderer&& renderer)
             : window_{std::move(window)},
-              renderer_{std::move(renderer)}
+              render_server_{std::move(renderer)}
         {
             instantiated_ = true;
         }
@@ -62,7 +60,7 @@ export namespace core
                 return std::unique_ptr<Engine>{
                     new Engine{
                         std::move(sdl_window),
-                        Renderer{std::move(sdl_renderer)}
+                        std::move(sdl_renderer)
                     }
                 };
             }
@@ -72,20 +70,20 @@ export namespace core
                 return keep_running_;
             }
 
-            Window& get_window()
+            sdl::Window& get_window()
             {
                 return window_;
             }
 
-            Renderer& get_renderer()
+            RenderServer& get_render_server()
             {
-                return renderer_;
+                return render_server_;
             }
 
             // Handles an SDL event. Returns true if the event has been handled.
             bool handle_event(const sdl::Event* event)
             {
-                if (event->type == SDL_EVENT_QUIT) {
+                if (event->type == sdl::EventType::Quit) {
                     // Exit the application
                     keep_running_ = false;
                     return true;

src/core/render_server.cppm

@@ -0,0 +1,81 @@
+module;
+
+#include <string>
+#include <utility>
+
+export module core.render_server;
+
+import core.resource_manager;
+import core.texture_loader;
+import wrappers.sdl;
+
+export namespace core
+{
+    using TextureID = unsigned int;
+    using TextureManager = ResourceManager<TextureID, sdl::Texture, TextureLoader>;
+
+    class RenderServer
+    {
+        sdl::Renderer renderer_;
+        TextureLoader texture_loader_;
+        TextureManager texture_manager_;
+
+        public:
+            RenderServer() = delete;
+
+            explicit RenderServer(sdl::Renderer&& renderer)
+                : renderer_{std::move(renderer)},
+                  texture_loader_{renderer_},
+                  texture_manager_{texture_loader_}
+            {}
+
+            // No copy or move operations
+            RenderServer(const RenderServer&) = delete;
+            RenderServer& operator=(const RenderServer&) = delete;
+            RenderServer(RenderServer&&) = delete;
+            RenderServer& operator=(RenderServer&&) = delete;
+
+            ~RenderServer() = default;
+
+            constexpr sdl::Renderer& get_renderer()
+            {
+                return renderer_;
+            }
+
+            /**
+             * Loads a texture from a file (if not loaded yet) and returns its texture ID.
+             */
+            constexpr TextureID load_texture(const std::string& filename)
+            {
+                return texture_manager_.load_resource_by_name(filename);
+            }
+
+            void start_frame() const
+            {
+                renderer_.clear();
+            }
+
+            void finish_frame() const
+            {
+                renderer_.present();
+            }
+
+            constexpr void render_texture(
+                const TextureID texture_id,
+                const sdl::FRect* src_rect,
+                const sdl::FRect* dest_rect
+            ) const
+            {
+                render_texture(texture_manager_.get_resource(texture_id), src_rect, dest_rect);
+            }
+
+            void render_texture(
+                const sdl::Texture& texture,
+                const sdl::FRect* src_rect,
+                const sdl::FRect* dest_rect
+            ) const
+            {
+                renderer_.render_texture(texture, src_rect, dest_rect);
+            }
+    };
+}

src/core/renderer.cppm

@@ -1,47 +0,0 @@
-module;
-
-#include <utility>
-
-export module core.renderer;
-
-import wrappers.sdl;
-
-export namespace core
-{
-    // TODO: Rename this class to RenderServer or something to distinguish it from sdl::Renderer?
-    class Renderer
-    {
-        sdl::Renderer sdl_renderer_;
-
-        public:
-            Renderer() = delete;
-
-            explicit Renderer(sdl::Renderer&& sdl_renderer)
-                : sdl_renderer_{std::move(sdl_renderer)}
-            {}
-
-            constexpr sdl::Renderer& get_sdl_renderer()
-            {
-                return sdl_renderer_;
-            }
-
-            void start_frame() const
-            {
-                sdl_renderer_.clear();
-            }
-
-            void finish_frame() const
-            {
-                sdl_renderer_.present();
-            }
-
-            void render_texture(
-                const sdl::Texture& texture,
-                const sdl::FRect* src_rect,
-                const sdl::FRect* dest_rect
-            ) const
-            {
-                sdl_renderer_.render_texture(texture, src_rect, dest_rect);
-            }
-    };
-}

src/core/resource_manager.cppm

@@ -0,0 +1,122 @@
+module;
+
+#include <cassert>
+#include <map>
+#include <optional>
+#include <string>
+#include <vector>
+
+export module core.resource_manager;
+
+export namespace core
+{
+    template <typename ResourceLoaderType, typename ResourceType>
+    concept IsResourceLoader = requires(ResourceLoaderType loader, const std::string& name)
+    {
+        { loader.load_resource(name) } -> std::same_as<ResourceType>;
+    };
+
+    template <
+        typename ResourceIDType,
+        typename ResourceType,
+        IsResourceLoader<ResourceType> ResourceLoaderType
+    >
+    class ResourceManager
+    {
+        // Resource loader
+        ResourceLoaderType& resource_loader_;
+
+        // Registry of loaded resources, array index is resource ID
+        std::vector<ResourceType> resource_registry_;
+
+        // Mapping of all loaded resources from (file) name to resource ID
+        std::map<std::string, ResourceIDType> resource_name_map_;
+
+        public:
+            ResourceManager() = delete;
+
+            explicit ResourceManager(ResourceLoaderType& resource_loader)
+                : resource_loader_{resource_loader}
+            {}
+
+            // No copy or move operations
+            ResourceManager(const ResourceManager&) = delete;
+            ResourceManager& operator=(const ResourceManager&) = delete;
+            ResourceManager(ResourceManager&&) = delete;
+            ResourceManager& operator=(ResourceManager&&) = delete;
+
+            ~ResourceManager() = default;
+
+            /**
+             * Adds a new resource to the registry and returns its ID.
+             */
+            ResourceIDType add_resource(ResourceType&& resource)
+            {
+                // Add resource to end of vector
+                resource_registry_.push_back(std::move(resource));
+
+                // Return the index of the newly added resource
+                return static_cast<ResourceIDType>(resource_registry_.size() - 1);
+            }
+
+            /**
+             * Adds a new resource to the registry, associates the name with it and returns its ID.
+             */
+            ResourceIDType add_resource(ResourceType&& resource, const std::string& name)
+            {
+                // Add resource
+                ResourceIDType resource_id = add_resource(std::move(resource));
+
+                // Associate name with resource ID for future access
+                resource_name_map_.emplace(name, resource_id);
+
+                return resource_id;
+            }
+
+            /**
+             * Gets the resource ID for a given resource name, or `std::nullopt` if the resource was not found.
+             */
+            std::optional<ResourceIDType> get_resource_id_by_name(const std::string& name) const
+            {
+                // Check if resource is already loaded
+                if (
+                    const auto search = resource_name_map_.find(name);
+                    search != resource_name_map_.end()
+                ) {
+                    // Return resource ID
+                    return search->second;
+                }
+
+                return std::nullopt;
+            }
+
+            /**
+             * Loads a resource (e.g. from a file) and adds it to the registry if it isn't loaded yet.
+             * Returns the resource ID.
+             */
+            ResourceIDType load_resource_by_name(const std::string& name)
+            {
+                // Check if resource is already loaded
+                if (
+                    auto resource_id = get_resource_id_by_name(name);
+                    resource_id.has_value()
+                ) {
+                    return resource_id.value();
+                }
+
+                // Load resource and add it to the registry
+                return add_resource(resource_loader_.load_resource(name), name);
+            }
+
+            /**
+             * Returns a reference to the resource with the given ID.
+             * The reference is not guaranteed to be valid after adding new resources to the registry.
+             * Assumes that the resource ID is valid.
+             */
+            const ResourceType& get_resource(const ResourceIDType resource_id) const
+            {
+                assert(resource_id < resource_registry_.size());
+                return resource_registry_[resource_id];
+            }
+    };
+}

src/core/texture_loader.cppm

@@ -0,0 +1,35 @@
+module;
+
+#include <string>
+
+export module core.texture_loader;
+
+import core.resource_manager;
+import wrappers.sdl;
+import wrappers.sdl_image;
+
+export namespace core
+{
+    class TextureLoader
+    {
+        sdl::Renderer& renderer_;
+
+        public:
+            explicit TextureLoader(sdl::Renderer& renderer)
+                : renderer_{renderer}
+            {}
+
+            // No copy or move operations (reference)
+            TextureLoader(const TextureLoader&) = delete;
+            TextureLoader& operator=(const TextureLoader&) = delete;
+            TextureLoader(TextureLoader&&) = delete;
+            TextureLoader& operator=(TextureLoader&&) = delete;
+
+            ~TextureLoader() = default;
+
+            sdl::Texture load_resource(const std::string& filename) const
+            {
+                return sdl_image::LoadTexture(renderer_, filename);
+            }
+    };
+}

src/game/game.cppm

@@ -2,12 +2,13 @@ module;
 
 #include <cassert>
 #include <memory>
+#include <vector>
 #include <SDL3/SDL.h>
 
 export module game.game;
 
 import core.engine;
-import core.renderer;
+import core.render_server;
 import game.sprite;
 import wrappers.sdl;
 import wrappers.sdl_image;
@@ -22,21 +23,18 @@ export namespace game
         // Reference to the engine
         core::Engine& engine_;
 
-        // Sprite for testing
-        std::unique_ptr<Sprite> sprite_{nullptr};
+        // Sprites for testing
+        Sprite player_sprite_;
+        std::vector<Sprite> sprites_;
 
         // Private constructor
         explicit Game(core::Engine& engine)
-            : engine_(engine)
-        {
-            // TODO: Texture should be a reference/pointer to an object managed by a ResourceManager or similar.
-            auto texture = sdl_image::LoadTexture(
-                engine_.get_renderer().get_sdl_renderer(),
-                "assets/neocat.png"
-            );
-
-            sprite_ = std::make_unique<Sprite>(std::move(texture), 100, 100);
+            : engine_(engine),
+              player_sprite_{
+                  engine_.get_render_server().load_texture("assets/neocat.png"),
+                  sdl::FRect{0, 0, 100, 100}
               }
+        {}
 
         public:
             Game() = delete;
@@ -62,15 +60,28 @@ export namespace game
             }
 
             // Handles an SDL event. Returns true if the event has been handled.
-            bool handle_event(const sdl::Event* event) const
+            bool handle_event(const sdl::Event* event)
             {
-                if (event->type == SDL_EVENT_MOUSE_MOTION) {
-                    sprite_->move(
+                if (event->type == sdl::EventType::MouseMotion) {
+                    player_sprite_.move(
                         event->motion.x - 50,
                         event->motion.y - 50
                     );
                     return true;
                 }
+
+                if (event->type == sdl::EventType::MouseButtonUp) {
+                    sprites_.emplace_back(
+                        engine_.get_render_server().load_texture("assets/neofox.png"),
+                        sdl::FRect{
+                            event->motion.x - 50,
+                            event->motion.y - 50,
+                            100, 100
+                        }
+                    );
+                    return true;
+                }
+
                 return false;
             }
 
@@ -80,10 +91,15 @@ export namespace game
 
             void render() const
             {
-                const auto& renderer = engine_.get_renderer();
-                renderer.start_frame();
-                sprite_->draw(renderer);
-                renderer.finish_frame();
+                const auto& render_server = engine_.get_render_server();
+                render_server.start_frame();
+
+                for (const Sprite& sprite : sprites_) {
+                    sprite.draw(render_server);
+                }
+                player_sprite_.draw(render_server);
+
+                render_server.finish_frame();
             }
 
             void shutdown()

src/game/sprite.cppm

@@ -1,11 +1,10 @@
 module;
 
-#include <utility>
 #include <SDL3/SDL.h>
 
 export module game.sprite;
 
-import core.renderer;
+import core.render_server;
 import wrappers.sdl;
 
 // TODO: Move this to a different namespace (core, drawing, ...?)
@@ -13,21 +12,14 @@ export namespace game
 {
     class Sprite
     {
-        // TODO: Texture should be a reference/pointer to an object managed by a ResourceManager or similar.
-        sdl::Texture texture_;
+        core::TextureID texture_id_;
         sdl::FRect dest_rect_{0, 0, 0, 0};
 
         public:
-            explicit Sprite(
-                sdl::Texture&& texture,
-                const int width,
-                const int height
-            )
-                : texture_{std::move(texture)}
-            {
-                dest_rect_.w = static_cast<float>(width);
-                dest_rect_.h = static_cast<float>(height);
-            }
+            explicit Sprite(const core::TextureID texture_id, const sdl::FRect dest_rect)
+                : texture_id_{texture_id},
+                  dest_rect_{dest_rect}
+            {}
 
             void move(const float x, const float y)
             {
@@ -35,9 +27,9 @@ export namespace game
                 dest_rect_.y = y;
             }
 
-            void draw(const core::Renderer& renderer) const
+            void draw(const core::RenderServer& render_server) const
             {
-                renderer.render_texture(texture_, nullptr, &dest_rect_);
+                render_server.render_texture(texture_id_, nullptr, &dest_rect_);
             }
     };
 }

src/wrappers/sdl/events.cppm

@@ -8,4 +8,23 @@ export namespace sdl
 {
     // Simple alias for SDL_Event union
     using Event = SDL_Event;
+
+    // Alias for EventType enum
+    using EventType_t = SDL_EventType;
+
+    /**
+     * Wrapper for the SDL_EventType enum.
+     *
+     * We're using a namespace here to emulate an enum-like interface, without having to copy the entire enum.
+     * More constants can be added on demand.
+     */
+    namespace EventType
+    {
+        constexpr EventType_t Quit = SDL_EVENT_QUIT;
+        constexpr EventType_t KeyDown = SDL_EVENT_KEY_DOWN;
+        constexpr EventType_t KeyUp = SDL_EVENT_KEY_UP;
+        constexpr EventType_t MouseMotion = SDL_EVENT_MOUSE_MOTION;
+        constexpr EventType_t MouseButtonUp = SDL_EVENT_MOUSE_BUTTON_UP;
+        constexpr EventType_t MouseButtonDown = SDL_EVENT_MOUSE_BUTTON_DOWN;
+    }
 }