/*

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

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.

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

*/

#include "OgreStableHeaders.h"

#include "OgreRenderQueue.h"

#include <memory>

#include "OgreMaterial.h"

#include "OgreRenderQueueSortingGrouping.h"

#include "OgreSceneManagerEnumerator.h"

namespace Ogre {

    //---------------------------------------------------------------------

    RenderQueue::RenderQueue()

        : mSplitPassesByLightingType(false)

        , mSplitNoShadowPasses(false)

        , mShadowCastersCannotBeReceivers(false)

        , mRenderableListener(0)

    {

        // Create the 'main' queue up-front since we'll always need that

        mGroups[RENDER_QUEUE_MAIN] = std::make_unique<RenderQueueGroup>(

            mSplitPassesByLightingType, mSplitNoShadowPasses, mShadowCastersCannotBeReceivers);

        // set default queue

        mDefaultQueueGroup = RENDER_QUEUE_MAIN;

        mDefaultRenderablePriority = Renderable::DEFAULT_PRIORITY;

    }

    //---------------------------------------------------------------------

    RenderQueue::~RenderQueue()

    {

        // trigger the pending pass updates, otherwise we could leak

        Pass::processPendingPassUpdates();

    }

    static bool onTransparentQueue(Technique* pTech)

    {

        // Transparent and depth/colour settings mean depth sorting is required?

        // Note: colour write disabled with depth check/write enabled means

        //       setup depth buffer for other passes use.

        if (pTech->isTransparentSortingForced() ||

            (pTech->isTransparent() &&

             (!pTech->isDepthWriteEnabled() || !pTech->isDepthCheckEnabled() || pTech->hasColourWriteDisabled())))

        {

            return true;

        }

        return false;

    }

    //-----------------------------------------------------------------------

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

    {

        Technique* pTech;

        // tell material it's been used

        if (pRend->getMaterial())

            pRend->getMaterial()->touch();

        // Check material & technique supplied (the former since the default implementation

        // of getTechnique is based on it for backwards compatibility

        if(!pRend->getMaterial() || !pRend->getTechnique())

        {

            // Use default base white, with lighting only if vertices has normals

            RenderOperation op;

            pRend->getRenderOperation(op);

            bool useLighting = (NULL != op.vertexData->vertexDeclaration->findElementBySemantic(VES_NORMAL));

            MaterialPtr defaultMat = MaterialManager::getSingleton().getDefaultMaterial(useLighting);

            defaultMat->load();

            pTech = defaultMat->getBestTechnique();

        }

        else

            pTech = pRend->getTechnique();

        if (mRenderableListener)

        {

            // Allow listener to override technique and to abort

            if (!mRenderableListener->renderableQueued(pRend, groupID, priority, 

                &pTech, this))

                return; // rejected

            // tell material it's been used (incase changed)

            pTech->getParent()->touch();

        }

        if(groupID == mDefaultQueueGroup && onTransparentQueue(pTech))

            groupID = RENDER_QUEUE_TRANSPARENTS;

        // Find group

        RenderQueueGroup* pGroup = getQueueGroup(groupID);

        pGroup->addRenderable(pRend, pTech, priority);

    }

    //-----------------------------------------------------------------------

    void RenderQueue::clear(bool destroyPassMaps)

    {

        // Note: We clear dirty passes from all RenderQueues in all 

        // SceneManagers, because the following recalculation of pass hashes

        // also considers all RenderQueues and could become inconsistent, otherwise.

        for (auto p : SceneManagerEnumerator::getSingleton().getSceneManagers())

        {

            RenderQueue* queue = p.second->getRenderQueue();

            for (auto & g : queue->mGroups)

            {

                if(g)

                    g->clear(destroyPassMaps);

            }

        }

        // Now trigger the pending pass updates

        Pass::processPendingPassUpdates();

        // NB this leaves the items present (but empty)

        // We're assuming that frame-by-frame, the same groups are likely to 

        //  be used, so no point destroying the vectors and incurring the overhead

        //  that would cause, let them be destroyed in the destructor.

    }

    //-----------------------------------------------------------------------

    void RenderQueue::addRenderable(Renderable* pRend, uint8 groupID)

    {

        addRenderable(pRend, groupID, mDefaultRenderablePriority);

    }

    //-----------------------------------------------------------------------

    void RenderQueue::addRenderable(Renderable* pRend)

    {

        addRenderable(pRend, mDefaultQueueGroup, mDefaultRenderablePriority);

    }

    //-----------------------------------------------------------------------

    uint8 RenderQueue::getDefaultQueueGroup(void) const

    {

        return mDefaultQueueGroup;

    }

    //-----------------------------------------------------------------------

    void RenderQueue::setDefaultQueueGroup(uint8 grp)

    {

        mDefaultQueueGroup = grp;

    }

    //-----------------------------------------------------------------------

    ushort RenderQueue::getDefaultRenderablePriority(void) const

    {

        return mDefaultRenderablePriority;

    }

    //-----------------------------------------------------------------------

    void RenderQueue::setDefaultRenderablePriority(ushort priority)

    {

        mDefaultRenderablePriority = priority;

    }

    //-----------------------------------------------------------------------

    RenderQueueGroup* RenderQueue::getQueueGroup(uint8 groupID)

    {

        if (!mGroups[groupID])

        {

            // Insert new

            mGroups[groupID] = std::make_unique<RenderQueueGroup>(mSplitPassesByLightingType, mSplitNoShadowPasses,

                                                        mShadowCastersCannotBeReceivers);

        }

        return mGroups[groupID].get();

    }

    //-----------------------------------------------------------------------

    void RenderQueue::setSplitPassesByLightingType(bool split)

    {

        mSplitPassesByLightingType = split;

        for (auto & g : mGroups)

        {

            if(g)

                g->setSplitPassesByLightingType(split);

        }

    }

    //-----------------------------------------------------------------------

    bool RenderQueue::getSplitPassesByLightingType(void) const

    {

        return mSplitPassesByLightingType;

    }

    //-----------------------------------------------------------------------

    void RenderQueue::setSplitNoShadowPasses(bool split)

    {

        mSplitNoShadowPasses = split;

        for (auto & g : mGroups)

        {

            if(g)

                g->setSplitNoShadowPasses(split);

        }

    }

    //-----------------------------------------------------------------------

    bool RenderQueue::getSplitNoShadowPasses(void) const

    {

        return mSplitNoShadowPasses;

    }

    //-----------------------------------------------------------------------

    void RenderQueue::setShadowCastersCannotBeReceivers(bool ind)

    {

        mShadowCastersCannotBeReceivers = ind;

        for (auto & g : mGroups)

        {

            if(g)

                g->setShadowCastersCannotBeReceivers(ind);

        }

    }

    //-----------------------------------------------------------------------

    bool RenderQueue::getShadowCastersCannotBeReceivers(void) const

    {

        return mShadowCastersCannotBeReceivers;

    }

    //-----------------------------------------------------------------------

    void RenderQueue::merge( const RenderQueue* rhs )

    {

        for (size_t i = 0; i < RENDER_QUEUE_COUNT; ++i)

        {

            if(!rhs->mGroups[i])

                continue;

            RenderQueueGroup* pDstGroup = getQueueGroup( i );

            pDstGroup->merge( rhs->mGroups[i].get() );

        }

    }

    //---------------------------------------------------------------------

    void RenderQueue::processVisibleObject(MovableObject* mo, 

        Camera* cam, 

        bool onlyShadowCasters, 

        VisibleObjectsBoundsInfo* visibleBounds)

    {

        // receiveShadows is a material property, so we can query it before LOD

        bool receiveShadows = getQueueGroup(mo->getRenderQueueGroup())->getShadowsEnabled() && mo->getReceivesShadows();

        if(onlyShadowCasters && !mo->getCastShadows() && !receiveShadows)

            return;

        mo->_notifyCurrentCamera(cam);

        if (!mo->isVisible())

            return;

        const auto& bbox = mo->getWorldBoundingBox(true);

        const auto& bsphere = mo->getWorldBoundingSphere(true);

        if (!onlyShadowCasters || mo->getCastShadows())

        {

            mo->_updateRenderQueue(this);

            if (visibleBounds)

            {

                visibleBounds->merge(bbox, bsphere, cam, receiveShadows);

            }

        }

        // not shadow caster, receiver only?

        else if (receiveShadows)

        {

            visibleBounds->mergeNonRenderedButInFrustum(bbox, bsphere, cam);

        }

    }

}