minor update poking around why the texturing code is broken

src/lib/include/paradiso/shader.hpp

@@ -56,9 +56,9 @@ struct Shader final {
     Shader&
     set_uniform_at_location(int location,
                             uint32_t v); //!< sets a 32bit unsigned in a shader
-    Shader&
+    const Shader&
     set_uniform_at_location(int location,
-                            int32_t v); //!< sets a 32bit signed in a shader
+                            int32_t v) const; //!< sets a 32bit signed in a shader
 
     /**
      * @brief retrieves the position of a uniform
@@ -80,7 +80,7 @@ struct Shader final {
      * sets data of the
      */
     template <typename T>
-    Shader& set_uniform(std::string const& name, T&& value) {
+    const Shader& set_uniform(std::string const& name, T&& value) const {
         return set_uniform_at_location(uniform_location(name),
                                        std::forward<T>(value));
     }

src/lib/include/paradiso/sprite.hpp

@@ -35,6 +35,8 @@ struct Sprite final {
 
     static constexpr Sprite create() noexcept { return {}; }
 
+    Bitmap bitmap{};
+
     Vector2<float> pivot{Vector2<float>::zero()};
 
     std::array<std::uint32_t, 6> indices{0, 3, 2, 2, 1, 0};
@@ -57,6 +59,7 @@ struct Sprite final {
     };
 
     ChangeCountType change_count{};
+
 };
 } // namespace paradiso