some clean up

README.md

@@ -1,6 +1,6 @@
 # ParadisSO - a minimal 2D graphics engine
 
-**ParadiSO** was conceived as a heavily stripped down version of my pixwerx engine. It is a minimalistic 2D graphics engine for educational purposes. It uses modern C++ and a datadriven design, but no ECS. 
+**ParadiSO** was conceived as a heavily stripped down 2D version of my `pixwerx` engine. *ParadiSO* mimics a minimalistic approach to 2D graphics for educational purposes. It uses modern C++ and a data-driven design, but no ECS. 
 
 ## Educational
 
@@ -10,4 +10,16 @@ Some arguments for its educational side:
 * heavily inspired by Rust code
 * math code is eager evaluation but `constexpr` to compensate overheads
 * hides old-style `C` APIs behind a renovated facade
-* it leans heavily on the STL and its algorithms 
+* it leans heavily on the STL and its algorithms 
+
+## Minimal
+
+Because this engine should show some patterns and design concepts it tries to avoid adding unnecessary bloat. 
+
+## Dependencies
+
+ParadiSO comes with batteries included. However, it should be mentioned here:
+
+* [GLFW 3.3.8](https://github.com/glfw/glfw)
+* [GLAD](https://github.com/Dav1dde/glad)
+

src/lib/src/shader.cpp

@@ -148,14 +148,17 @@ struct Shader::impl {
         // potentially the GL driver hasn't been loaded
         if (is_valid()) {
 
-            // deleting and detaching should happen much earlier
+            // detach first
+            for (auto s : _shader_stages) {
+                glDetachShader(_shader_program, s);
+            }
 
+            // deleting
             for (auto s : _shader_stages) {
                 glDeleteShader(s);
             }
 
             // only program needs to be deleted
-
             glDeleteProgram(_shader_program);
         }
     }