magnum/src/SceneGraph/Object.h

#ifndef Magnum_SceneGraph_Object_h
#define Magnum_SceneGraph_Object_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::Object
 */

#include <Containers/EnumSet.h>

#include "AbstractFeature.h"
#include "AbstractObject.h"

#include "magnumSceneGraphVisibility.h"

namespace Magnum { namespace SceneGraph {

#ifndef DOXYGEN_GENERATING_OUTPUT
namespace Implementation {
    enum class ObjectFlag: UnsignedByte {
        Dirty = 1 << 0,
        Visited = 1 << 1,
        Joint = 1 << 2
    };

    typedef Corrade::Containers::EnumSet<ObjectFlag, UnsignedByte> ObjectFlags;

    CORRADE_ENUMSET_OPERATORS(ObjectFlags)
}
#endif

/**
@brief %Object

Base of scene graph. Contains specific transformation implementation, takes
care of parent/children relationship and contains features. See @ref scenegraph
for introduction.

Common usage is to typedef Object with desired transformation type to save
unnecessary typing later, along with Scene and possibly other types, e.g.:
@code
typedef SceneGraph::Scene<SceneGraph::MatrixTransformation3D<>> Scene3D;
typedef SceneGraph::Object<SceneGraph::MatrixTransformation3D<>> Object3D;
@endcode

Uses Corrade::Containers::LinkedList for parent/children relationship.
Traversing through the list is done like in the following code. It is also
possible to go in reverse order using lastChild() and previousSibling().
@code
for(Object* child = o->firstChild(); child; child = child->nextSibling()) {
    // ...
}
@endcode

@section Object-explicit-specializations Explicit template specializations

The following specialization are explicitly compiled into SceneGraph library.
For other specializations (e.g. using Double type or special transformation
class) you have to use Object.hpp implementation file to avoid linker errors.
See @ref compilation-speedup-hpp for more information.

 - @ref MatrixTransformation2D "Object<MatrixTransformation2D<Float>>"
 - @ref MatrixTransformation3D "Object<MatrixTransformation3D<Float>>"
 - @ref EuclideanMatrixTransformation2D "Object<EuclideanMatrixTransformation2D<Float>>"
 - @ref EuclideanMatrixTransformation3D "Object<EuclideanMatrixTransformation3D<Float>>"

@see Scene, AbstractFeature, AbstractTransformation, DebugTools::ObjectRenderer
*/
template<class Transformation> class MAGNUM_SCENEGRAPH_EXPORT Object: public AbstractObject<Transformation::Dimensions, typename Transformation::Type>, public Transformation
    #ifndef DOXYGEN_GENERATING_OUTPUT
    , private Corrade::Containers::LinkedList<Object<Transformation>>, private Corrade::Containers::LinkedListItem<Object<Transformation>, Object<Transformation>>
    #endif
{
    friend class Corrade::Containers::LinkedList<Object<Transformation>>;
    friend class Corrade::Containers::LinkedListItem<Object<Transformation>, Object<Transformation>>;

    #ifndef DOXYGEN_GENERATING_OUTPUT
    Object(const Object<Transformation>& other) = delete;
    Object(Object<Transformation>&& other) = delete;
    Object<Transformation>& operator=(const Object<Transformation>& other) = delete;
    Object<Transformation>& operator=(Object<Transformation>&& other) = delete;
    #endif

    public:
        /**
         * @brief Clean absolute transformations of given set of objects
         *
         * Only dirty objects in the list are cleaned.
         * @see setClean(), AbstractObject::setClean()
         */
        /* `objects` passed by copy intentionally (to avoid copy internally) */
        static void setClean(std::vector<Object<Transformation>*> objects);

        /**
         * @brief Constructor
         * @param parent    Parent object
         */
        inline explicit Object(Object<Transformation>* parent = nullptr): counter(0xFFFFu), flags(Flag::Dirty) {
            setParent(parent);
        }

        /**
         * @brief Destructor
         *
         * Removes itself from parent's children list and destroys all own
         * children.
         */
        inline virtual ~Object() {}

        /**
         * @{ @name Scene hierarchy
         *
         * See @ref scenegraph-hierarchy for more information.
         */

        /** @brief Whether this object is scene */
        virtual inline bool isScene() const { return false; }

        /**
         * @brief %Scene
         * @return %Scene or `nullptr`, if the object is not part of any scene.
         */
        Scene<Transformation>* scene();

        /** @overload */
        const Scene<Transformation>* scene() const;

        /** @brief Parent object or `nullptr`, if this is root object */
        inline Object<Transformation>* parent() {
            return Corrade::Containers::LinkedListItem<Object<Transformation>, Object<Transformation>>::list();
        }

        /** @overload */
        inline const Object<Transformation>* parent() const {
            return Corrade::Containers::LinkedListItem<Object<Transformation>, Object<Transformation>>::list();
        }

        /** @brief Previous sibling object or `nullptr`, if this is first object */
        inline Object<Transformation>* previousSibling() {
            return Corrade::Containers::LinkedListItem<Object<Transformation>, Object<Transformation>>::previous();
        }

        /** @overload */
        inline const Object<Transformation>* previousSibling() const {
            return Corrade::Containers::LinkedListItem<Object<Transformation>, Object<Transformation>>::previous();
        }

        /** @brief Next sibling object or `nullptr`, if this is last object */
        inline Object<Transformation>* nextSibling() {
            return Corrade::Containers::LinkedListItem<Object<Transformation>, Object<Transformation>>::next();
        }

        /** @overload */
        inline const Object<Transformation>* nextSibling() const {
            return Corrade::Containers::LinkedListItem<Object<Transformation>, Object<Transformation>>::next();
        }

        /** @brief Whether this object has children */
        inline bool hasChildren() const {
            return !Corrade::Containers::LinkedList<Object<Transformation>>::isEmpty();
        }

        /** @brief First child object or `nullptr`, if this object has no children */
        inline Object<Transformation>* firstChild() {
            return Corrade::Containers::LinkedList<Object<Transformation>>::first();
        }

        /** @overload */
        inline const Object<Transformation>* firstChild() const {
            return Corrade::Containers::LinkedList<Object<Transformation>>::first();
        }

        /** @brief Last child object or `nullptr`, if this object has no children */
        inline Object<Transformation>* lastChild() {
            return Corrade::Containers::LinkedList<Object<Transformation>>::last();
        }

        /** @overload */
        inline const Object<Transformation>* lastChild() const {
            return Corrade::Containers::LinkedList<Object<Transformation>>::last();
        }

        /**
         * @brief Set parent object
         * @return Pointer to self (for method chaining)
         */
        Object<Transformation>* setParent(Object<Transformation>* parent);

        /*@}*/

        /** @{ @name Object transformation */

        inline typename DimensionTraits<Transformation::Dimensions, typename Transformation::Type>::MatrixType transformationMatrix() const override {
            return Transformation::toMatrix(Transformation::transformation());
        }

        inline typename DimensionTraits<Transformation::Dimensions, typename Transformation::Type>::MatrixType absoluteTransformationMatrix() const override {
            return Transformation::toMatrix(absoluteTransformation());
        }

        /**
         * @brief Transformation relative to root object
         *
         * @see absoluteTransformationMatrix()
         */
        typename Transformation::DataType absoluteTransformation() const;

        /**
         * @brief Transformations of given group of objects relative to this object
         *
         * All transformations can be premultiplied with @p initialTransformation,
         * if specified.
         * @see AbstractObject::transformationMatrices()
         */
        /* `objects` passed by copy intentionally (to allow move from
           transformationMatrices() and avoid copy in the function itself) */
        std::vector<typename Transformation::DataType> transformations(std::vector<Object<Transformation>*> objects, const typename Transformation::DataType& initialTransformation = typename Transformation::DataType()) const;

        /*@}*/

        inline bool isDirty() const override { return !!(flags & Flag::Dirty); }
        void setDirty() override;
        void setClean() override;

    private:
        Object<Transformation>* sceneObject() override;
        const Object<Transformation>* sceneObject() const override;

        std::vector<typename DimensionTraits<Transformation::Dimensions, typename Transformation::Type>::MatrixType> transformationMatrices(const std::vector<AbstractObject<Transformation::Dimensions, typename Transformation::Type>*>& objects, const typename DimensionTraits<Transformation::Dimensions, typename Transformation::Type>::MatrixType& initialTransformationMatrix = (typename DimensionTraits<Transformation::Dimensions, typename Transformation::Type>::MatrixType())) const override;

        typename Transformation::DataType MAGNUM_SCENEGRAPH_LOCAL computeJointTransformation(const std::vector<Object<Transformation>*>& jointObjects, std::vector<typename Transformation::DataType>& jointTransformations, const std::size_t joint, const typename Transformation::DataType& initialTransformation) const;

        void setClean(const std::vector<AbstractObject<Transformation::Dimensions, typename Transformation::Type>*>& objects) const override;

        void MAGNUM_SCENEGRAPH_LOCAL setClean(const typename Transformation::DataType& absoluteTransformation);

        typedef Implementation::ObjectFlag Flag;
        typedef Implementation::ObjectFlags Flags;
        UnsignedShort counter;
        Flags flags;
};

}}

#endif