SceneGraph rework, part 6: base for grouped features.

src/SceneGraph/AbstractGroupedFeature.h

@@ -0,0 +1,239 @@
+#ifndef Magnum_SceneGraph_AbstractGroupedFeature_h
+#define Magnum_SceneGraph_AbstractGroupedFeature_h
+/*
+    Copyright © 2010, 2011, 2012 Vladimír Vondruš <mosra@centrum.cz>
+
+    This file is part of Magnum.
+
+    Magnum is free software: you can redistribute it and/or modify
+    it under the terms of the GNU Lesser General Public License version 3
+    only, as published by the Free Software Foundation.
+
+    Magnum is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+    GNU Lesser General Public License version 3 for more details.
+*/
+
+/** @file
+ * @brief Class Magnum::SceneGraph::AbstractGroupedFeature, Magnum::SceneGraph::FeatureGroup, alias Magnum::SceneGraph::AbstractGroupedFeature2D, Magnum::SceneGraph::AbstractGroupedFeature3D, Magnum::SceneGraph::FeatureGroup2D, Magnum::SceneGraph::FeatureGroup3D
+ */
+
+#include <algorithm>
+#include <vector>
+
+#include "AbstractFeature.h"
+
+namespace Magnum { namespace SceneGraph {
+
+template<std::uint8_t, class, class> class FeatureGroup;
+
+/**
+@brief Base for grouped features
+
+Used together with FeatureGroup.
+
+@section AbstractGroupedFeature-usage Usage
+
+Usage is via subclassing the feature using [CRTP](http://en.wikipedia.org/wiki/Curiously_recurring_template_pattern)
+and typedef'ing FeatureGroup to accept only given type, e.g.:
+@code
+class Drawable: public SceneGraph::AbstractGroupedFeature3D<Drawable> {
+    // ...
+};
+
+typedef SceneGraph::FeatureGroup3D<Drawable> DrawableGroup;
+@endcode
+
+@see AbstractGroupedFeature2D, AbstractGroupedFeature3D, FeatureGroup,
+    FeatureGroup2D, FeatureGroup3D
+*/
+template<std::uint8_t dimensions, class Derived, class T = GLfloat> class AbstractGroupedFeature: public AbstractFeature<dimensions, T> {
+    friend class FeatureGroup<dimensions, Derived, T>;
+
+    public:
+        /**
+         * @brief Constructor
+         * @param object    %Object this feature belongs to
+         * @param group     Group this feature belongs to
+         *
+         * Adds the feature to the object and to group, if specified.
+         * @see FeatureGroup::add(), FeatureGroup::remove()
+         */
+        inline AbstractGroupedFeature(AbstractObject<dimensions, T>* object, FeatureGroup<dimensions, Derived, T>* group = nullptr): AbstractFeature<dimensions, T>(object), _group(nullptr) {
+            if(group) group->add(static_cast<Derived*>(this));
+        }
+
+        /**
+         * @brief Destructor
+         *
+         * Removes the feature from object and from group, if it belongs to
+         * any.
+         */
+        inline ~AbstractGroupedFeature() {
+            if(_group) _group->remove(static_cast<Derived*>(this));
+        }
+
+        /** @brief Group this feature belongs to */
+        inline FeatureGroup<dimensions, Derived, T>* group() {
+            return _group;
+        }
+
+        /** @overload */
+        inline const FeatureGroup<dimensions, Derived, T>* group() const {
+            return _group;
+        }
+
+    private:
+        FeatureGroup<dimensions, Derived, T>* _group;
+};
+
+/**
+@brief Base for two-dimensional grouped features
+
+Convenience alternative to <tt>%AbstractGroupedFeature<2, Derived, T></tt>. See
+AbstractGroupedFeature for more information.
+@see AbstractGroupedFeature3D
+@note Not available on GCC < 4.7. Use <tt>%AbstractGroupedFeature<2, Derived, T></tt>
+    instead.
+@todoc Remove workaround when Doxygen supports alias template
+*/
+#ifndef DOXYGEN_GENERATING_OUTPUT
+#ifndef MAGNUM_GCC46_COMPATIBILITY
+template<class Derived, class T = GLfloat> using AbstractGroupedFeature2D = AbstractGroupedFeature<2, Derived, T>;
+#endif
+#else
+typedef AbstractGroupedFeature<2, Derived, T = GLfloat> AbstractGroupedFeature2D;
+#endif
+
+/**
+@brief Base for three-dimensional grouped features
+
+Convenience alternative to <tt>%AbstractGroupedFeature<3, Derived, T></tt>. See
+AbstractGroupedFeature for more information.
+@see AbstractGroupedFeature2D
+@note Not available on GCC < 4.7. Use <tt>%AbstractGroupedFeature<3, Derived, T></tt>
+    instead.
+@todoc Remove workaround when Doxygen supports alias template
+*/
+#ifndef DOXYGEN_GENERATING_OUTPUT
+#ifndef MAGNUM_GCC46_COMPATIBILITY
+template<class Derived, class T = GLfloat> using AbstractGroupedFeature3D = AbstractGroupedFeature<3, Derived, T>;
+#endif
+#else
+typedef AbstractGroupedFeature<3, Derived, T = GLfloat> AbstractGroupedFeature3D;
+#endif
+
+/**
+@brief Group of features
+
+See AbstractGroupedFeature for more information.
+@see FeatureGroup2D, FeatureGroup3D
+*/
+template<std::uint8_t dimensions, class Feature, class T = GLfloat> class FeatureGroup {
+    friend class AbstractGroupedFeature<dimensions, Feature, T>;
+
+    public:
+        /**
+         * @brief Destructor
+         *
+         * Deletes all features belogning to this group.
+         */
+        inline virtual ~FeatureGroup() {
+            for(auto i: features) {
+                i->_group = nullptr;
+                delete i;
+            }
+        }
+
+        /** @brief Whether the group is empty */
+        inline bool isEmpty() const { return features.empty(); }
+
+        /** @brief Count of features in the group */
+        inline std::size_t size() const { return features.size(); }
+
+        /** @brief Feature at given index */
+        inline Feature* operator[](std::size_t index) {
+            return features[index];
+        }
+
+        /** @overload */
+        inline const Feature* operator[](std::size_t index) const {
+            return features[index];
+        }
+
+        /**
+         * @brief Add feature to the group
+         *
+         * If the features is part of another group, it is removed from it.
+         */
+        void add(Feature* feature) {
+            /** @todo Assert the same scene for all items? -- can't easily
+                watch when feature object is removed from hierarchy */
+
+            /* Remove from previous group */
+            if(feature->_group)
+                feature->_group->remove(feature);
+
+            /* Crossreference the feature and group together */
+            features.push_back(feature);
+            feature->_group = this;
+        }
+
+        /**
+         * @brief Remove feature from the group
+         *
+         * The feature must be part of the group.
+         */
+        void remove(Feature* feature) {
+            CORRADE_ASSERT(feature->_group == this,
+                "SceneGraph::AbstractFeatureGroup::remove(): feature is not part of this group", );
+
+            /* Remove the feature and reset group pointer */
+            features.erase(std::find(features.begin(), features.end(), feature));
+            feature->_group = nullptr;
+        }
+
+    private:
+        std::vector<Feature*> features;
+};
+
+/**
+@brief Base for two-dimensional object features
+
+Convenience alternative to <tt>%FeatureGroup<2, Feature, T></tt>. See
+AbstractGroupedFeature for more information.
+@note Not available on GCC < 4.7. Use <tt>%FeatureGroup<2, Feature, T></tt>
+    instead.
+@see FeatureGroup3D
+@todoc Remove workaround when Doxygen supports alias template
+*/
+#ifndef DOXYGEN_GENERATING_OUTPUT
+#ifndef MAGNUM_GCC46_COMPATIBILITY
+template<class Feature, class T = GLfloat> using FeatureGroup2D = FeatureGroup<2, Feature, T>;
+#endif
+#else
+typedef FeatureGroup<2, Feature, T = GLfloat> FeatureGroup2D;
+#endif
+
+/**
+@brief Base for three-dimensional object features
+
+Convenience alternative to <tt>%FeatureGroup<3, Feature, T></tt>. See
+AbstractGroupedFeature for more information.
+@note Not available on GCC < 4.7. Use <tt>%FeatureGroup<3, Feature, T></tt>
+    instead.
+@see FeatureGroup2D
+@todoc Remove workaround when Doxygen supports alias template
+*/
+#ifndef DOXYGEN_GENERATING_OUTPUT
+#ifndef MAGNUM_GCC46_COMPATIBILITY
+template<class Feature, class T = GLfloat> using FeatureGroup3D = FeatureGroup<3, Feature, T>;
+#endif
+#else
+typedef FeatureGroup<3, Feature, T = GLfloat> FeatureGroup3D;
+#endif
+
+}}
+
+#endif

src/SceneGraph/CMakeLists.txt

@@ -1,6 +1,7 @@
 set(MagnumSceneGraph_SRCS )
 set(MagnumSceneGraph_HEADERS
     AbstractFeature.h
+    AbstractGroupedFeature.h
     AbstractObject.h
     AbstractTransformation.h
     AbstractTranslationRotation2D.h