/*-------------------------------------------------------------------------

This source file is a 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

You may alternatively use this source under the terms of a specific version of

the OGRE Unrestricted License provided you have obtained such a license from

Torus Knot Software Ltd.

-------------------------------------------------------------------------*/

#include "OgreStableHeaders.h"

#include "OgreHardwarePixelBuffer.h"

namespace Ogre

{

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

    bool operator== ( const ShadowTextureConfig& lhs, const ShadowTextureConfig& rhs )

    {

        if ( lhs.width != rhs.width ||

            lhs.height != rhs.height ||

            lhs.format != rhs.format )

        {

            return false;

        }

        return true;

    }

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

    bool operator!= ( const ShadowTextureConfig& lhs, const ShadowTextureConfig& rhs )

    {

        return !( lhs == rhs );

    }

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

    template<> ShadowTextureManager* Singleton<ShadowTextureManager>::msSingleton = 0;

    ShadowTextureManager* ShadowTextureManager::getSingletonPtr(void)

    {

        return msSingleton;

    }

    ShadowTextureManager& ShadowTextureManager::getSingleton(void)

    {

        assert( msSingleton );  return ( *msSingleton );

    }

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

    ShadowTextureManager::ShadowTextureManager()

        : mCount(0)

    {

    }

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

    ShadowTextureManager::~ShadowTextureManager()

    {

        clear();

    }

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

    void ShadowTextureManager::getShadowTextures(ShadowTextureConfigList& configList,

        ShadowTextureList& listToPopulate)

    {

        listToPopulate.clear();

        std::set<Texture*> usedTextures;

        for (ShadowTextureConfig& config : configList)

        {

            bool found = false;

            for (auto & tex : mTextureList)

            {

                // Skip if already used this one

                if (usedTextures.find(tex.get()) != usedTextures.end())

                    continue;

                if (config.width == tex->getWidth() && config.height == tex->getHeight() &&

                    config.depth == tex->getDepth() && config.type == tex->getTextureType() &&

                    config.format == tex->getFormat() && config.fsaa == tex->getFSAA())

                {

                    // Ok, a match

                    listToPopulate.push_back(tex);

                    usedTextures.insert(tex.get());

                    found = true;

                    break;

                }

            }

            if (!found)

            {

                // Create a new texture

                String targName = StringUtil::format("Ogre/ShadowTexture%zu", mCount++);

                TexturePtr shadowTex = TextureManager::getSingleton().createManual(

                    targName, RGN_INTERNAL, config.type, config.width, config.height, config.depth, 0, config.format,

                    TU_RENDERTARGET | config.extraFlags, NULL, false, config.fsaa);

                OgreAssert(shadowTex, "Unsupported shadow texture configuration");

                // Ensure texture loaded

                shadowTex->load();

                // update with actual format, if the requested format is not supported

                config.format = shadowTex->getFormat();

                listToPopulate.push_back(shadowTex);

                usedTextures.insert(shadowTex.get());

                mTextureList.push_back(shadowTex);

            }

        }

    }

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

    TexturePtr ShadowTextureManager::getNoShadowTexture(PixelFormat format)

    {

        for (auto & tex : mNullTextureList)

        {

            if (format == tex->getFormat())

            {

                // Ok, a match

                return tex;

            }

        }

        // not found, create a new one

        // A 1x1 texture of the correct format, not a render target

        static const String baseName = "Ogre/ShadowTextureNull";

        String targName = baseName + StringConverter::toString(mCount++);

        TexturePtr shadowTex = TextureManager::getSingleton().createManual(

            targName, 

            ResourceGroupManager::INTERNAL_RESOURCE_GROUP_NAME, 

            TEX_TYPE_2D, 1, 1, 0, format, TU_STATIC_WRITE_ONLY);

        mNullTextureList.push_back(shadowTex);

        // lock & populate the texture based on format

        if(PixelUtil::isDepth(format))

            return shadowTex;

        HardwareBufferLockGuard shadowTexLock(shadowTex->getBuffer(), HardwareBuffer::HBL_DISCARD);

        const PixelBox& box = shadowTex->getBuffer()->getCurrentLock();

        // set high-values across all bytes of the format 

        PixelUtil::packColour( 1.0f, 1.0f, 1.0f, 1.0f, shadowTex->getFormat(), box.data );

        return shadowTex;

    }

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

    void ShadowTextureManager::clearUnused()

    {

        for (ShadowTextureList::iterator i = mTextureList.begin(); i != mTextureList.end(); )

        {

            // Unreferenced if only this reference and the resource system

            // Any cached shadow textures should be re-bound each frame dropping

            // any old references

            if ((*i).use_count() == ResourceGroupManager::RESOURCE_SYSTEM_NUM_REFERENCE_COUNTS + 1)

            {

                TextureManager::getSingleton().remove((*i)->getHandle());

                i = mTextureList.erase(i);

            }

            else

            {

                ++i;

            }

        }

        for (ShadowTextureList::iterator i = mNullTextureList.begin(); i != mNullTextureList.end(); )

        {

            // Unreferenced if only this reference and the resource system

            // Any cached shadow textures should be re-bound each frame dropping

            // any old references

            if ((*i).use_count() == ResourceGroupManager::RESOURCE_SYSTEM_NUM_REFERENCE_COUNTS + 1)

            {

                TextureManager::getSingleton().remove((*i)->getHandle());

                i = mNullTextureList.erase(i);

            }

            else

            {

                ++i;

            }

        }

    }

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

    void ShadowTextureManager::clear()

    {

        for (auto & i : mTextureList)

        {

            TextureManager::getSingleton().remove(i->getHandle());

        }

        mTextureList.clear();

    }

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

}