minor update poking around why the texturing code is broken

README.md

@@ -1,10 +1,13 @@
-# ParadisSO - a minimal 2D rendering engine for 
+# 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. 
 
 ## Educational
 
-* plenty of mix and match of concepts and paradigms to write expressive but concise code 
-* math code is eager evaluation but constexpr to compensate overheads
-* it hides old-style APIs behind a renovated facade
+Some arguments for its educational side:
+
+* mix and match of various concepts and paradigms to write expressive but concise code 
+* 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 

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
 

src/lib/src/renderer.cpp

@@ -53,12 +53,6 @@ struct Renderer::impl {
                GL_TRUE == glIsVertexArray(vertex_array_obj);
     }
 
-    void bind_texture() {
-        glActiveTexture(GL_TEXTURE0);
-        glBindTexture(GL_TEXTURE_2D, texture_id);
-    }
-
-    void unbind_texture() { glBindTexture(GL_TEXTURE_2D, 0); }
 
     bool build(const Sprite& sprite) {
         // reset if the Renderer already in use
@@ -120,7 +114,15 @@ struct Renderer::impl {
         return ready();
     }
 
-    void update_texture(const Bitmap& image) {
+
+    void texture_bind() {
+        glActiveTexture(GL_TEXTURE0);
+        glBindTexture(GL_TEXTURE_2D, texture_id);
+    }
+
+    void texture_unbind() { glBindTexture(GL_TEXTURE_2D, 0); }
+
+    void texture_update(const Bitmap& image) {
         if (GL_FALSE == glIsTexture(texture_id)) {
             glGenTextures(1, &texture_id);
 
@@ -170,7 +172,12 @@ struct Renderer::impl {
                             image.data.data()); // pointer
         }
 
-        glBindTexture(GL_TEXTURE_2D, 0);
+        // glBindTexture(GL_TEXTURE_2D, 0);
+    }
+
+    void texture_release()
+    {
+        glDeleteTextures(1, &texture_id);
     }
 
     void release() {
@@ -181,7 +188,8 @@ struct Renderer::impl {
 
         glDeleteVertexArrays(1, &vertex_array_obj);
 
-        // glDeleteTextures(1, &texture_id);
+        texture_release();
+
     }
 
     void just_draw(const Sprite& sprite) {
@@ -215,6 +223,7 @@ bool Renderer::draw(const Sprite& sprite, const Shader& shader) {
     // if interna are not ready or sprite has been altered - rebuild
     if (!impl_->ready() || sprite.change_count != impl_->change_count) {
         impl_->build(sprite);
+        impl_->texture_update(sprite.bitmap);
     }
 
     // render the sprite with the shader
@@ -222,8 +231,16 @@ bool Renderer::draw(const Sprite& sprite, const Shader& shader) {
 
         shader.use();
 
+        shader.set_uniform("tex_color", 0u); // texture unit 0
+
+        impl_->texture_bind();
+
         impl_->just_draw(sprite);
 
+        //Renderer::impl::fetch_errors(__PRETTY_FUNCTION__);
+
+        // impl_->texture_unbind();
+
         return true;
     }
 

src/lib/src/shader.cpp

@@ -177,11 +177,11 @@ struct Shader::impl {
     // 	glUniform4fv(location,1,v.ptr());
     // }
 
-    void bind(int location, const float& v) { glUniform1f(location, v); }
+    void bind(int location, const float& v) const { glUniform1f(location, v); }
 
-    void bind(int location, const uint32_t& i) { glUniform1ui(location, i); }
+    void bind(int location, const uint32_t& i) const { glUniform1ui(location, i); }
 
-    void bind(int location, const int32_t& i) { glUniform1i(location, i); }
+    void bind(int location, const int32_t& i) const { glUniform1i(location, i); }
 
     // void bind(int location,const texture& v)
     // {
@@ -206,7 +206,7 @@ Shader& Shader::set_uniform_at_location(int location, uint32_t v) {
     return *this;
 }
 
-Shader& Shader::set_uniform_at_location(int location, int32_t v) {
+const Shader& Shader::set_uniform_at_location(int location, int32_t v) const {
     impl_->bind(location, v);
     return *this;
 }

src/main.cpp

@@ -77,7 +77,7 @@ auto main() -> int {
     auto ctx = paradiso::Context{};
 
     auto sprite = paradiso::Sprite{
-        //
+        .bitmap = checker_board_2
     };
 
     auto renderer = paradiso::Renderer{};
@@ -102,9 +102,9 @@ auto main() -> int {
     while (window.update([&](auto& w) -> bool {
 
         ctx.set_clearcolor(paradiso::RGBA::from_rgb(0xFF, green_slider, 0x00));
-        ctx.set_viewport(paradiso::Rectangle{
-            .size = w.client_size()
-        });
+        // ctx.set_viewport(paradiso::Rectangle{
+        //     .size = w.client_size()
+        // });
         ctx.clear();
 
         renderer.draw(sprite, shader);