working ECS base

README.md

@@ -1,6 +1,34 @@
-pixwerx 
--------
+# pixwerx 
+
+pixwerx is an opinionated, academic approach to a 3D engine. It tries to mix 
+modern andproven methods to build a fast and portable engine beyond pure 3D. 
+
+## Design Principles
+
+Dogdooding: pixwerx is built on the principle of dogfooding. The engine is a 
+full-stack system that tries to implement all necessary functions. The engine 
+editor is just a UI build with the engine.
+
+Reasonable dependencies: like many engines pixwerx tries to include as much 3rd-
+party code as possible and implements some of the core systems itself.
+
+No premature optimization: pixwerx implements only very few systems with machine
+code. It tries to utilize the power of the compiler as much as possible.
+
+Computer graphics 101: pixwerx does implement graphics components and systems in 
+a  way that makes code portable and not over-parameterized. Usability is 
+achieved through layers on top of the core components. 
+
+
+## License
+
+pixwerx is licenced under the terms of the MIT License. Please consult the 
+LICENSE file.
+
+## Authors
+
+© 1999-2020 Hartmut Seichter
+
 
-an academic approach to a 3D engine
 
 

src/binding/src/script_core.cpp

@@ -121,6 +121,8 @@ void register_core_function(sol::state& lua,sol::table& ns)
     //                , "line_strip", geometry::topology_type::line_strip
     //                );
 
+
+
     ns.new_usertype<image>("image"
                            , sol::constructors<image()>()
                            ,"create",&image::create

src/binding/src/script_scene.cpp

@@ -26,6 +26,7 @@ void register_scene_function(sol::state&,sol::table &ns)
     ns.new_usertype<entity>("entity"
                             ,sol::constructors<entity(),entity(const entity&),entity(scene&)>()
                             ,"add_child",&entity::add_child
+                            ,"remove_child",&entity::remove_child
                             ,"child_count",sol::readonly_property(&entity::child_count)
                             );
 

src/scene/include/pw/scene/entity.hpp

@@ -32,8 +32,6 @@
 #include <vector>
 #include <memory>
 
-#include <entt/entt.hpp>
-
 namespace pw {
 
 class entity {
@@ -43,46 +41,85 @@ public:
     entity(scene& s);
     ~entity();
 
+    /**
+     * adds a component
+     */
     template <typename T,typename... Args>
     [[nodiscard]] T& add_component(Args&&... args) {
         return _registry->emplace<T>(this->_entity,std::forward<Args>(args)...);
     }
 
+    /**
+     * removes a component
+     */
     template <typename T>
     void remove_component() {
         _registry->remove<T>(_entity);
     }
 
+
+    /**
+     * returns a component
+     */
     template<typename T>
     [[nodiscard]] T& get_component() const {
         return _registry->get<T>(this->_entity);
     }
 
+    /**
+     * gets or creates a component
+     */
     template <typename T,typename... Args>
-    T& get_or_create_component(Args&&... args) {
+    [[nodiscard]] T& get_or_create_component(Args&&... args) {
         return _registry->get_or_emplace<T>(this->_entity,std::forward<Args>(args)...);
     }
 
+    /**
+     * checks if this entity contains a component
+     */
     template<typename T>
     bool has_component() const { return _registry->has<T>(_entity);}
 
+    /**
+     * @brief destroy
+     */
     void destroy();
 
-    operator bool() const { return _registry && _entity != entt::null; }
 
+    /**
+     * @brief conversion to an entt entity
+     */
     operator std::uint32_t() const { return static_cast<std::uint32_t>(_entity); }
 
+    /**
+     * @brief checks if this entity is valid
+     * @return true of it belongs to a scene already
+     */
     bool valid() const { return _registry && _registry->valid(_entity); }
 
 
+
+    operator bool() const { return _registry && _entity != entt::null; }
+
+
     /**
      * @brief adds another child entity to this entity -> establishing a
      * @param child
+     * @return true if the given child could be added to the hierarchy
      */
     bool add_child(entity &child);
 
-    void remove_child(entity &child);
+    /**
+     * @brief remove child entity from this parent
+     * @param child
+     * @return true if the given child could be remove from the hierarchy
+     */
+    bool remove_child(entity &child);
 
+    /**
+     * @brief returns the number of children on this entity
+     * @return number of children
+     */
     size_t child_count() const;
 
 private:

src/scene/include/pw/scene/projection.hpp

@@ -39,7 +39,10 @@ public:
     projection(node &host);
 
     void set_matrix(const matrix4x4 &projection);
-    const matrix4x4& matrix() const;
+    const matrix4x4& matrix() const
+    {
+        return _m;
+    }
 
     void set_frustum(real_t left,
                      real_t right,

src/scene/src/entity.cpp

@@ -7,7 +7,6 @@ namespace pw {
 
 namespace detail {
 
-
 // entity relationsships are hidden
 struct relationship {
     relationship() = default;
@@ -25,7 +24,7 @@ entity::entity(scene &s)
 {
 }
 
-bool entity::add_child(entity& child)
+bool entity::add_child(entity &child)
 {
     // not mixing scenes (yet)
     if (child._registry != this->_registry) {
@@ -46,12 +45,12 @@ bool entity::add_child(entity& child)
     return true;
 }
 
-void entity::remove_child(entity& child)
+bool entity::remove_child(entity& child)
 {
     // not mixing scenes (yet)
     if (child._registry != this->_registry) {
         debug::e() << "Cannot mix entities from different scenes";
-        return;
+        return false;
     }
 
     // both need to have a relationship component
@@ -62,13 +61,18 @@ void entity::remove_child(entity& child)
         auto r_p = child.get_component<detail::relationship>();
         if (r_p.parent == _entity)
         {
-            // now go ahead
+            // now go ahead delete parent
             r_p.parent = entt::null;
 
-            auto r = get_component<detail::relationship>();
-            std::remove(r.children.begin(),r.children.end(),child._entity);
+            // now remove all children
+            auto& r = this->get_component<detail::relationship>();
+            r.children.erase(std::remove(r.children.begin(),r.children.end(),child._entity));
+
+            // flag success
+            return true;
         }
     }
+    return false;
 }
 
 size_t entity::child_count() const

src/scene/src/projection.cpp

@@ -31,10 +31,7 @@ void projection::set_matrix(const matrix4x4 &projection)
 //	real_t fov_raw = float( atan (top / near_)) *  * 2.0f;
 }
 
-const matrix4x4 &projection::matrix() const
-{
-    return _m;
-}
+
 
 void projection::set_frustum(real_t left, real_t right, real_t top, real_t bottom)
 {

src/scripts/demos/simple_001.lua

@@ -11,17 +11,26 @@ local s = pw.scene.new()
 print(s)
 
 local e = pw.entity.new(s)
-c = pw.entity.new(s)
+local c = pw.entity.new(s)
 
 print(e)
+print(c)
 print(e.child_count)
 
 -- add child
-e.add_child(c)
-
+e:add_child(c)
 
 print(e.child_count)
 
+if e:remove_child(c) then
+    print("remove_child success")
+else
+    print("remove_child fail")
+end
+
+print(e.child_count)
+
+
 print("bye, bye pixwerx!")
 
 return 1