/*

-----------------------------------------------------------------------------

This source file is part of OGRE

    (Object-oriented Graphics Rendering Engine)

For the latest info, see http://www.ogre3d.org/

Copyright (c) 2000-2014 Torus Knot Software Ltd

Permission is hereby granted, free of charge, to any person obtaining a copy

of this software and associated documentation files (the "Software"), to deal

in the Software without restriction, including without limitation the rights

to use, copy, modify, merge, publish, distribute, sublicense, and/or sell

copies of the Software, and to permit persons to whom the Software is

furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in

all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR

IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,

FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE

AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER

LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,

OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN

THE SOFTWARE.

-----------------------------------------------------------------------------

*/

#ifndef __RenderQueue_H__

#define __RenderQueue_H__

#include "OgrePrerequisites.h"

#include "OgreHeaderPrefix.h"

namespace Ogre {

    class Camera;

    class MovableObject;

    struct VisibleObjectsBoundsInfo;

    /** \addtogroup Core

    *  @{

    */

    /** \addtogroup RenderSystem

    *  @{

    */

    /** Enumeration of queue groups, by which the application may group queued renderables

        so that they are rendered together with events in between

        When passed into methods these are actually passed as a uint8 to allow you

        to use values in between if you want to.

    */

    enum RenderQueueGroupID

    {

        /// Use this queue for objects which must be rendered first e.g. backgrounds

        RENDER_QUEUE_BACKGROUND = 0,

        /// First queue (after backgrounds), used for skyboxes if rendered first

        RENDER_QUEUE_SKIES_EARLY = 5,

        RENDER_QUEUE_1 = 10,

        RENDER_QUEUE_2 = 20,

        RENDER_QUEUE_WORLD_GEOMETRY_1 = 25,

        RENDER_QUEUE_3 = 30,

        RENDER_QUEUE_4 = 40,

        /// The default render queue

        RENDER_QUEUE_MAIN = 50,

        RENDER_QUEUE_6 = 60,

        RENDER_QUEUE_7 = 70,

        RENDER_QUEUE_WORLD_GEOMETRY_2 = 75,

        RENDER_QUEUE_8 = 80,

        /// Used for skyboxes if rendered last

        RENDER_QUEUE_SKIES_LATE = 90,

        /// Penultimate queue(before overlays)

        RENDER_QUEUE_TRANSPARENTS = 95,

        /// Use this queue for objects which must be rendered last e.g. overlays

        RENDER_QUEUE_OVERLAY = 100, 

        /// Final possible render queue, don't exceed this

        RENDER_QUEUE_MAX = 105,

        RENDER_QUEUE_COUNT

    };

    /// @deprecated

    #define OGRE_RENDERABLE_DEFAULT_PRIORITY  Ogre::Renderable::DEFAULT_PRIORITY

    /** Class to manage the scene object rendering queue.

        Objects are grouped by material to minimise rendering state changes. The map from

        material to renderable object is wrapped in a class for ease of use.

        @par

            This class now includes the concept of 'queue groups' which allows the application

            adding the renderable to specifically schedule it so that it is included in 

            a discrete group. Good for separating renderables into the main scene,

            backgrounds and overlays, and also could be used in the future for more

            complex multipass routines like stenciling.

    */

    class _OgreExport RenderQueue : public RenderQueueAlloc

    {

    public:

        typedef std::unique_ptr<RenderQueueGroup> RenderQueueGroupMap[RENDER_QUEUE_COUNT];

        /** Class to listen in on items being added to the render queue. 

            Use RenderQueue::setRenderableListener to get callbacks when an item

            is added to the render queue.

        */

        class _OgreExport RenderableListener

        {

        public:

            RenderableListener() {}

            virtual ~RenderableListener() {}

            /** Method called when a Renderable is added to the queue.

                You can use this event hook to alter the Technique used to

                render a Renderable as the item is added to the queue. This is

                a low-level way to override the material settings for a given

                Renderable on the fly.

            @param rend The Renderable being added to the queue

            @param groupID The render queue group this Renderable is being added to

            @param priority The priority the Renderable has been given

            @param ppTech A pointer to the pointer to the Technique that is 

                intended to be used; you can alter this to an alternate Technique

                if you so wish (the Technique doesn't have to be from the same

                Material either).

            @param pQueue Pointer to the render queue that this object is being

                added to. You can for example call this back to duplicate the 

                object with a different technique

            @return true to allow the Renderable to be added to the queue, 

                false if you want to prevent it being added

            */

            virtual bool renderableQueued(Renderable* rend, uint8 groupID, 

                ushort priority, Technique** ppTech, RenderQueue* pQueue) = 0;

        };

    private:

        RenderQueueGroupMap mGroups;

        /// The current default queue group

        uint8 mDefaultQueueGroup;

        /// The default priority

        ushort mDefaultRenderablePriority;

        bool mSplitPassesByLightingType;

        bool mSplitNoShadowPasses;

        bool mShadowCastersCannotBeReceivers;

        RenderableListener* mRenderableListener;

    public:

        RenderQueue();

        virtual ~RenderQueue();

        /** Empty the queue - should only be called by SceneManagers.

        @param destroyPassMaps Set to true to destroy all pass maps so that

            the queue is completely clean (useful when switching scene managers)

        */

        void clear(bool destroyPassMaps = false);

        /** Get a render queue group.

            OGRE registers new queue groups as they are requested, 

            therefore this method will always return a valid group.

        */

        RenderQueueGroup* getQueueGroup(uint8 qid);

        /** Add a renderable object to the queue.

            This methods adds a Renderable to the queue, which will be rendered later by 

            the SceneManager. This is the advanced version of the call which allows the renderable

            to be added to any queue.

        @note

            Called by implementation of MovableObject::_updateRenderQueue.

        @param

            pRend Pointer to the Renderable to be added to the queue

        @param

            groupID The group the renderable is to be added to. This

            can be used to schedule renderable objects in separate groups such that the SceneManager

            respects the divisions between the groupings and does not reorder them outside these

            boundaries. This can be handy for overlays where no matter what you want the overlay to 

            be rendered last.

        @param

            priority Controls the priority of the renderable within the queue group. If this number

            is raised, the renderable will be rendered later in the group compared to it's peers.

            Don't use this unless you really need to, manually ordering renderables prevents OGRE

            from sorting them for best efficiency. However this could be useful for ordering 2D

            elements manually for example.

        */

        void addRenderable(Renderable* pRend, uint8 groupID, ushort priority);

        /** Add a renderable object to the queue.

            This methods adds a Renderable to the queue, which will be rendered later by 

            the SceneManager. This is the simplified version of the call which does not 

            require a priority to be specified. The queue priority is take from the

            current default (see setDefaultRenderablePriority).

        @note

            Called by implementation of MovableObject::_updateRenderQueue.

        @param pRend

            Pointer to the Renderable to be added to the queue

        @param groupId

            The group the renderable is to be added to. This

            can be used to schedule renderable objects in separate groups such that the SceneManager

            respects the divisions between the groupings and does not reorder them outside these

            boundaries. This can be handy for overlays where no matter what you want the overlay to 

            be rendered last.

        */

        void addRenderable(Renderable* pRend, uint8 groupId);

        /** Add a renderable object to the queue.

            This methods adds a Renderable to the queue, which will be rendered later by 

            the SceneManager. This is the simplified version of the call which does not 

            require a queue or priority to be specified. The queue group is taken from the

            current default (see setDefaultQueueGroup).  The queue priority is take from the

            current default (see setDefaultRenderablePriority).

        @note

            Called by implementation of MovableObject::_updateRenderQueue.

        @param

            pRend Pointer to the Renderable to be added to the queue

        */

        void addRenderable(Renderable* pRend);

        /** Gets the current default queue group, which will be used for all renderable which do not

            specify which group they wish to be on.

        */

        uint8 getDefaultQueueGroup(void) const;

        /** Sets the current default renderable priority, 

            which will be used for all renderables which do not

            specify which priority they wish to use.

        */

        void setDefaultRenderablePriority(ushort priority);

        /** Gets the current default renderable priority, which will be used for all renderables which do not

            specify which priority they wish to use.

        */

        ushort getDefaultRenderablePriority(void) const;

        /** Sets the current default queue group, which will be used for all renderable which do not

            specify which group they wish to be on. See the enum RenderQueueGroupID for what kind of

            values can be used here.

        */

        void setDefaultQueueGroup(uint8 grp);

        /** Internal method, returns the queue groups. */

        const RenderQueueGroupMap& _getQueueGroups() const {

            return mGroups;

        }

        /** Sets whether or not the queue will split passes by their lighting type,

            ie ambient, per-light and decal. 

        */

        void setSplitPassesByLightingType(bool split);

        /** Gets whether or not the queue will split passes by their lighting type,

            ie ambient, per-light and decal. 

        */

        bool getSplitPassesByLightingType(void) const;

        /** Sets whether or not the queue will split passes which have shadow receive

        turned off (in their parent material), which is needed when certain shadow

        techniques are used.

        */

        void setSplitNoShadowPasses(bool split);

        /** Gets whether or not the queue will split passes which have shadow receive

        turned off (in their parent material), which is needed when certain shadow

        techniques are used.

        */

        bool getSplitNoShadowPasses(void) const;

        /** Sets whether or not objects which cast shadows should be treated as

        never receiving shadows. 

        */

        void setShadowCastersCannotBeReceivers(bool ind);

        /** Gets whether or not objects which cast shadows should be treated as

        never receiving shadows. 

        */

        bool getShadowCastersCannotBeReceivers(void) const;

        /** Set a renderable listener on the queue.

            There can only be a single renderable listener on the queue, since

            that listener has complete control over the techniques in use.

        */

        void setRenderableListener(RenderableListener* listener)

        { mRenderableListener = listener; }

        RenderableListener* getRenderableListener(void) const

        { return mRenderableListener; }

        /** Merge render queue.

        */

        void merge( const RenderQueue* rhs );

        /** Utility method to perform the standard actions associated with 

            getting a visible object to add itself to the queue. This is 

            a replacement for SceneManager implementations of the associated

            tasks related to calling MovableObject::_updateRenderQueue.

        */

        void processVisibleObject(MovableObject* mo, 

            Camera* cam, 

            bool onlyShadowCasters, 

            VisibleObjectsBoundsInfo* visibleBounds);

    };

    /** @} */

    /** @} */

}

#include "OgreHeaderSuffix.h"

#endif