color keying for sprite sheets and properly keyed texture map params

src/engine/rendering/sdl/sdlrenderer.hpp

@@ -11,6 +11,10 @@
 #include <SDL_ttf.h>
 #include <SDL_image.h>
 
+struct SDL_WindowDeleter {
+    void operator()(SDL_Window* window) { SDL_DestroyWindow(window);}
+};
+
 class SdlRenderer : public Renderer {
 public:
     ~SdlRenderer();
@@ -23,8 +27,8 @@ public:
 
 private:
     RendererParams renderer_params;
-    SDL_Window* window = nullptr;
-    SDL_Renderer* renderer = nullptr;
+    std::unique_ptr<SDL_Window, SDL_WindowDeleter> window;
+    std::shared_ptr<SDL_Renderer> renderer = nullptr;
     std::unique_ptr<SdlTextureManager> texture_manager = nullptr;
     std::unique_ptr<SdlFontManager> font_manager = nullptr;