CRenderizableDisplayList.h

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/* +---------------------------------------------------------------------------+
   |                     Mobile Robot Programming Toolkit (MRPT)               |
   |                          http://www.mrpt.org/                             |
   |                                                                           |
   | Copyright (c) 2005-2017, Individual contributors, see AUTHORS file        |
   | See: http://www.mrpt.org/Authors - All rights reserved.                   |
   | Released under BSD License. See details in http://www.mrpt.org/License    |
   +---------------------------------------------------------------------------+ */
#ifndef opengl_CRenderizableDisplayList_H
#define opengl_CRenderizableDisplayList_H

#include <mrpt/opengl/CRenderizable.h>

namespace mrpt
{
        namespace opengl
        {
                #define INVALID_DISPLAY_LIST_ID  static_cast<unsigned int>(-1)

                // This must be added to any CSerializable derived class:
                DEFINE_SERIALIZABLE_PRE_CUSTOM_BASE_LINKAGE( CRenderizableDisplayList, CRenderizable, OPENGL_IMPEXP )

                /** A renderizable object suitable for rendering with OpenGL's display lists.
                  *   The idea is to use the derived classes' ::render() method to save all the primitives
                  *   into one display list, then in subsequent rendering events, just execute the list.
                  *   This method is normally faster since it avoids the bottleneck between CPU-GPU. On the 
                  *   other hand, it demands more memory on the graphic card.
                  *
                  *  Instructions for implementing derived classes:
                  *             - Each time the object is modified is some way that modifies its appearance, you must call notifyChange()
                  *             - Implement the rendering method: render_dl(), calling to OpenGL primitives as usual. They'll be saved in a display list transparently.
                  *
                  *  \sa mrpt::opengl::CRenderizable
                  * \ingroup mrpt_opengl_grp
                  */
                class OPENGL_IMPEXP CRenderizableDisplayList : public mrpt::opengl::CRenderizable
                {
                        DEFINE_VIRTUAL_SERIALIZABLE( CRenderizableDisplayList  )

                private:
                        mutable unsigned int    m_dl; //!< Display list ID, for derived classes that want to use it (it's automatically deleted and freed on destruction of this base class).
                        mutable bool                    m_dl_recreate; //!< If using display lists, this is true when the list must be updated (the object changes, it's the first rendering, etc...).

                protected:
                        /** @name Methods accesible or implemented by derived classes 
                            @{ */

                        /** Must be called to notify that the object has changed (so, the display list must be updated) */
                        EIGEN_STRONG_INLINE void notifyChange() const { m_dl_recreate=true;}

                        /** Derived classes must implement this method to the render the object. */
                        virtual void render_dl() const = 0;

                        /** Optional: If the object has some state in which creating a display list is NOT preferred over direct rendering, 
                          *  implement this method and return "true" in those cases. */
                        virtual bool should_skip_display_list_cache() const { return false; }

                        inline void  readFromStreamRender(mrpt::utils::CStream &in)
                        { 
                                CRenderizable::readFromStreamRender(in);
                                notifyChange();
                        }

                        /** @} */

                public:
                        CRenderizableDisplayList();
                        virtual ~CRenderizableDisplayList();

                        /** Interface for the stlplus smart pointer class. */
                        inline CRenderizableDisplayList * clone() const
                        {
                                return static_cast<CRenderizableDisplayList*>( this->duplicate() );
                        }

                        /** Render the object, regenerating the display list if needed, otherwise just calling it. */
                        void render() const MRPT_OVERRIDE;


                        /** @name Changes the appearance of the object to render (methods from CRenderizable that need to be redefined)
                            @{ */
                        CRenderizable&  setColorR_u8(const uint8_t r) MRPT_OVERRIDE     {m_color.R=r; notifyChange(); return *this;}    //!<Color components in the range [0,255] \return a ref to this
                        CRenderizable&  setColorG_u8(const uint8_t g) MRPT_OVERRIDE     {m_color.G=g; notifyChange(); return *this;}    //!<Color components in the range [0,255] \return a ref to this
                        CRenderizable&  setColorB_u8(const uint8_t b) MRPT_OVERRIDE     {m_color.B=b; notifyChange(); return *this;}    //!<Color components in the range [0,255] \return a ref to this
                        CRenderizable&  setColorA_u8(const uint8_t a) MRPT_OVERRIDE     {m_color.A=a; notifyChange(); return *this;}    //!<Color components in the range [0,255] \return a ref to this
                        CRenderizable& setColor_u8( const mrpt::utils::TColor &c) MRPT_OVERRIDE { CRenderizable::setColor_u8(c); notifyChange(); return *this; } //!< Changes the default object color \return a ref to this
                        inline CRenderizable& setColor_u8( uint8_t R, uint8_t G, uint8_t B, uint8_t A=255) { CRenderizable::setColor_u8(R,G,B,A);  notifyChange(); return *this; }      //!<Color components in the range [0,255] \return a ref to this
                        /** @} */

                };
                DEFINE_SERIALIZABLE_POST_CUSTOM_BASE_LINKAGE( CRenderizableDisplayList, CRenderizable, OPENGL_IMPEXP )

        } // end namespace

} // End of namespace


#endif