not a good idea yet

examples/simple/main.cpp

@@ -24,13 +24,15 @@ layout (location = 0) in vec3 vertices;
 layout (location = 1) in vec3 normals;
 layout (location = 2) in vec2 texture_coords;
 
-uniform vec4 pivot = vec4( 0.5, 0.5, 0.0, 1.0 );
+uniform vec2 pivot = vec2( 0.0, 0.0 );
+
+vec4 pivot_3d = vec4( pivot , 0.0, 1.0 );
 
 out vec2 tex_c;
 
 void main() {
     tex_c = texture_coords;
-    gl_Position = vec4(vertices, 1.0) + pivot;
+    gl_Position = vec4(vertices, 1.0) + pivot_3d;
 }
 )";
 
@@ -94,13 +96,21 @@ auto main() -> int {
 
     // eine sehr rudimentäre Eingabebehandlung. Bei vorhandenen
     // Eingaben landen diese hier. Wer sich am Design beteiligen
-    // möchte, kann hier einen eleganteren Vorschlag machen
+    // möchte: hier gibt es viel Potential zur Verbesserung ;)
     window.set_keyboardcallback(
         [&](auto& w, int key, int scancode, int action, int mods) {
-            if (key == 'Q' || key == 256)
+            if (key == 'Q' || key == 256) // Q oder ESC beenden das Programm
                 want_close = true;
-            else if (key == 'A') {
+            else if (key == 'B') { // kleine Spielerei
                 slider_value += 10;
+            } else if (key == 'W') {
+                sprite.pivot.y() += 0.1f;
+            } else if (key == 'S') {
+                sprite.pivot.y() -= 0.1f;
+            } else if (key == 'A') {
+                sprite.pivot.x() -= 0.1f;
+            } else if (key == 'D') {
+                sprite.pivot.x() += 0.1f;
             }
         });
 
@@ -119,13 +129,16 @@ auto main() -> int {
         // werden
         ctx.set_viewport(paradiso::Rectangle{
             .size =
-                w.client_size().minimal_extent() // wir wollen das
+                w.client_size().maximal_extent() // wir wollen das
                                                  // Seitenverhältnis beibehalten
         });
 
         // hier wird das eigentliche löschen des vorherigen Inhalts ausgelöst
         ctx.clear();
 
+        // wir setzen den pivot der sprite über den shader
+        shader.set_uniform("pivot", sprite.pivot);
+
         // Ein `renderer` kann nur mit einer Sprite verwendet werden!
         // Aber ein Shader kann man für mehrere Sprite-Renderer Kombis verwenden
         renderer.draw(sprite, shader);

src/lib/include/paradiso/geometry.hpp

@@ -27,11 +27,18 @@
 
 namespace paradiso {
 
+/**
+ * @brief position with integral type
+ */
+
 struct Point final {
     using value_type = int32_t;
     value_type x{0}, y{0};
 };
 
+/**
+ * @brief size with integral type
+ */
 struct Size final {
     using value_type = uint32_t;
     value_type width{0}, height{0};
@@ -42,11 +49,20 @@ struct Size final {
         return {.width = std::min(width, height),
                 .height = std::min(width, height)};
     }
+
+    constexpr Size maximal_extent() const noexcept {
+        return {.width = std::max(width, height),
+                .height = std::max(width, height)};
+    }
 };
 
-struct Rectangle {
-    Point position;
-    Size size;
+/**
+ * @brief position and size with integral type
+ */
+
+struct Rectangle final {
+    Point position{.x = 0, .y = 0};
+    Size size{};
 
     constexpr bool contains(const Point& p) const noexcept {
         return p.x >= position.x && p.x <= position.x + size.width &&

src/lib/include/paradiso/shader.hpp

@@ -24,6 +24,8 @@
 #define PARADISO_SHADER_HPP
 
 #include <paradiso/globals.hpp>
+#include <paradiso/matrix.hpp>
+#include <paradiso/vector.hpp>
 
 #include <memory>
 #include <unordered_map>
@@ -60,6 +62,9 @@ struct Shader final {
     set_uniform_at_location(int location,
                             int32_t v) const; //!< sets a 32bit signed in a shader
 
+    const Shader&
+    set_uniform_at_location(int location,
+                            const Vector2<float>& v) const; //!< sets a 2D float vector
     /**
      * @brief retrieves the position of a uniform
      * @param name of the uniform
@@ -77,7 +82,7 @@ struct Shader final {
     }
 
     /**
-     * sets data of the
+     * sets data of the uniform inside a shader program
      */
     template <typename T>
     const Shader& set_uniform(std::string const& name, T&& value) const {
@@ -87,7 +92,7 @@ struct Shader final {
 
     using uniform_t =
         std::variant<bool, int, float,
-                     double /*,vector2f,vector3f,vector4f,matrix4x4f*/>;
+                     double ,Vector2<float>/*vector3f,vector4f,matrix4x4f*/>;
     using uniform_entry_t = std::tuple<std::string, uniform_t, int>;
 
     using uniform_cache_t = std::vector<uniform_entry_t>;

src/lib/src/shader.cpp

@@ -172,16 +172,19 @@ struct Shader::impl {
     // 	glUniformMatrix4fv(location,1,GL_FALSE,m.ptr());
     // }
 
-    // void bind(int location,const vector4f& v)
-    // {
-    // 	glUniform4fv(location,1,v.ptr());
-    // }
+    void bind(int location, const Vector2<float>& v) const {
+        glUniform2fv(location, 1, v.ptr());
+    }
 
     void bind(int location, const float& v) const { glUniform1f(location, v); }
 
-    void bind(int location, const uint32_t& i) const { glUniform1ui(location, i); }
+    void bind(int location, const uint32_t& i) const {
+        glUniform1ui(location, i);
+    }
 
-    void bind(int location, const int32_t& i) const { glUniform1i(location, i); }
+    void bind(int location, const int32_t& i) const {
+        glUniform1i(location, i);
+    }
 
     // void bind(int location,const texture& v)
     // {
@@ -211,11 +214,11 @@ const Shader& Shader::set_uniform_at_location(int location, int32_t v) const {
     return *this;
 }
 
-// Shader &Shader::set_uniform_at_location(int location, vector4f const &v)
-// {
-//     impl_->bind(location, v);
-//     return *this;
-// }
+const Shader &Shader::set_uniform_at_location(int location, Vector2<float> const &v) const
+{
+    impl_->bind(location, v);
+    return *this;
+}
 
 // Shader &Shader::set_uniform_at_location(int location, matrix4x4f const &v)
 // {