/*
-----------------------------------------------------------------------------
This source file is part of OGRE
    (Object-oriented Graphics Rendering Engine)
For the latest info, see http://www.ogre3d.org/

Copyright (c) 2000-2006 Torus Knot Software Ltd
Also see acknowledgements in Readme.html

This program is free software; you can redistribute it and/or modify it under
the terms of the GNU Lesser General Public License as published by the Free Software
Foundation; either version 2 of the License, or (at your option) any later
version.

This program 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 for more details.

You should have received a copy of the GNU Lesser General Public License along with
this program; if not, write to the Free Software Foundation, Inc., 59 Temple
Place - Suite 330, Boston, MA 02111-1307, USA, or go to
http://www.gnu.org/copyleft/lesser.txt.

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 "OgreOptimisedUtil.h"

#include "OgrePlatformInformation.h"

//#define __DO_PROFILE__
#ifdef __DO_PROFILE__
#include "OgreRoot.h"
#endif

namespace Ogre {

    //---------------------------------------------------------------------
    // External functions
    extern OptimisedUtil* _getOptimisedUtilGeneral(void);
#if __OGRE_HAVE_SSE
    extern OptimisedUtil* _getOptimisedUtilSSE(void);
#endif

#ifdef __DO_PROFILE__
    //---------------------------------------------------------------------
#if OGRE_COMPILER == OGRE_COMPILER_MSVC
    typedef unsigned __int64 uint64;
#pragma warning(push)
#pragma warning(disable: 4035)  // no return value
    static FORCEINLINE uint64 getCpuTimestamp(void)
    {
        __asm rdtsc
        // Return values in edx:eax, No return statment requirement here for VC.
    }
#pragma warning(pop)

#elif OGRE_COMPILER == OGRE_COMPILER_GNUC
    typedef unsigned long long uint64;
    static FORCEINLINE uint64 getCpuTimestamp(void)
    {
        uint64 result;
        __asm__ __volatile__ ( "rdtsc" : "=A" (result) );
        return result;
    }

#endif  // OGRE_COMPILER

    //---------------------------------------------------------------------
    class OptimisedUtilProfiler : public OptimisedUtil
    {
    protected:

        enum
        {
            IMPL_DEFAULT,
#if __OGRE_HAVE_SSE
            IMPL_SSE,
#endif
            IMPL_COUNT
        };

        struct ProfileItem
        {
            uint mAvgTicks;
            uint mCount;
            uint64 mTotalTicks;
            uint64 mStartTick;

            ProfileItem(void)
                : mAvgTicks()
                , mCount()
                , mTotalTicks()
            {
            }

            void begin(void)
            {
                mStartTick = getCpuTimestamp();
            }

            void end(void)
            {
                uint64 ticks = getCpuTimestamp() - mStartTick;
                mTotalTicks += ticks;
                ++mCount;
                mAvgTicks = mTotalTicks / mCount;
            }
        };

        typedef ProfileItem ProfileItems[IMPL_COUNT];

        typedef std::vector<OptimisedUtil*> OptimisedUtilList;
        OptimisedUtilList mOptimisedUtils;

    public:
        OptimisedUtilProfiler(void)
        {
            mOptimisedUtils.push_back(_getOptimisedUtilGeneral());
#if __OGRE_HAVE_SSE
            if (PlatformInformation::getCpuFeatures() & PlatformInformation::CPU_FEATURE_SSE)
            {
                mOptimisedUtils.push_back(_getOptimisedUtilSSE());
            }
#endif
        }

        virtual void softwareVertexSkinning(
            const float *srcPosPtr, float *destPosPtr,
            const float *srcNormPtr, float *destNormPtr,
            const float *blendWeightPtr, const unsigned char* blendIndexPtr,
            const Matrix4* const* blendMatrices,
            size_t srcPosStride, size_t destPosStride,
            size_t srcNormStride, size_t destNormStride,
            size_t blendWeightStride, size_t blendIndexStride,
            size_t numWeightsPerVertex,
            size_t numVertices)
        {
            static ProfileItems results;
            static size_t index;
            index = Root::getSingleton().getNextFrameNumber() % mOptimisedUtils.size();
            OptimisedUtil* impl = mOptimisedUtils[index];
            ProfileItem& profile = results[index];

            profile.begin();
            impl->softwareVertexSkinning(
                srcPosPtr, destPosPtr,
                srcNormPtr, destNormPtr,
                blendWeightPtr, blendIndexPtr,
                blendMatrices,
                srcPosStride, destPosStride,
                srcNormStride, destNormStride,
                blendWeightStride, blendIndexStride,
                numWeightsPerVertex,
                numVertices);
            profile.end();

            // You can put break point here while running test application, to
            // watch profile results.
            ++index;    // So we can put break point here even if in release build
        }

        virtual void softwareVertexMorph(
            Real t,
            const float *srcPos1, const float *srcPos2,
            float *dstPos,
            size_t numVertices)
        {
            static ProfileItems results;
            static size_t index;
            index = Root::getSingleton().getNextFrameNumber() % mOptimisedUtils.size();
            OptimisedUtil* impl = mOptimisedUtils[index];
            ProfileItem& profile = results[index];

            profile.begin();
            impl->softwareVertexMorph(
                t,
                srcPos1, srcPos2,
                dstPos,
                numVertices);
            profile.end();

            // You can put break point here while running test application, to
            // watch profile results.
            ++index;    // So we can put break point here even if in release build
        }

        virtual void concatenateAffineMatrices(
            const Matrix4& baseMatrix,
            const Matrix4* srcMatrices,
            Matrix4* dstMatrices,
            size_t numMatrices)
        {
            static ProfileItems results;
            static size_t index;
            index = Root::getSingleton().getNextFrameNumber() % mOptimisedUtils.size();
            OptimisedUtil* impl = mOptimisedUtils[index];
            ProfileItem& profile = results[index];

            profile.begin();
            impl->concatenateAffineMatrices(
                baseMatrix,
                srcMatrices,
                dstMatrices,
                numMatrices);
            profile.end();

            // You can put break point here while running test application, to
            // watch profile results.
            ++index;    // So we can put break point here even if in release build
        }

        /// @copydoc OptimisedUtil::calculateFaceNormals
        virtual void calculateFaceNormals(
            const float *positions,
            const EdgeData::Triangle *triangles,
            Vector4 *faceNormals,
            size_t numTriangles)
        {
            static ProfileItems results;
            static size_t index;
            index = Root::getSingleton().getNextFrameNumber() % mOptimisedUtils.size();
            OptimisedUtil* impl = mOptimisedUtils[index];
            ProfileItem& profile = results[index];

            profile.begin();
            impl->calculateFaceNormals(
                positions,
                triangles,
                faceNormals,
                numTriangles);
            profile.end();

            //
            //   Dagon SkeletonAnimation sample test results (CPU timestamp per-function call):
            //
            //                  Pentium 4 3.0G HT       Athlon XP 2500+
            //
            //      General     657080                  486494
            //      SSE         223559                  399495
            //

            // You can put break point here while running test application, to
            // watch profile results.
            ++index;    // So we can put break point here even if in release build
        }

        /// @copydoc OptimisedUtil::calculateLightFacing
        virtual void calculateLightFacing(
            const Vector4& lightPos,
            const Vector4* faceNormals,
            char* lightFacings,
            size_t numFaces)
        {
            static ProfileItems results;
            static size_t index;
            index = Root::getSingleton().getNextFrameNumber() % mOptimisedUtils.size();
            OptimisedUtil* impl = mOptimisedUtils[index];
            ProfileItem& profile = results[index];

            profile.begin();
            impl->calculateLightFacing(
                lightPos,
                faceNormals,
                lightFacings,
                numFaces);
            profile.end();

            //
            //   Dagon SkeletonAnimation sample test results (CPU timestamp per-function call):
            //
            //                  Pentium 4 3.0G HT       Athlon XP 2500+
            //
            //      General     171875                  86998
            //      SSE          47934                  63995
            //

            // You can put break point here while running test application, to
            // watch profile results.
            ++index;    // So we can put break point here even if in release build
        }

        virtual void extrudeVertices(
            const Vector4& lightPos,
            Real extrudeDist,
            const float* srcPositions,
            float* destPositions,
            size_t numVertices)
        {
            static ProfileItems results;
            static size_t index;
            index = Root::getSingleton().getNextFrameNumber() % mOptimisedUtils.size();
            OptimisedUtil* impl = mOptimisedUtils[index];
            ProfileItem& profile = results[index];

            profile.begin();
            impl->extrudeVertices(
                lightPos,
                extrudeDist,
                srcPositions,
                destPositions,
                numVertices);
            profile.end();

            //
            //   Dagon SkeletonAnimation sample test results (CPU timestamp per-function call):
            //
            //                                  Pentium 4 3.0G HT   Athlon XP 2500+
            //
            //      Directional Light, General   38106               92306
            //      Directional Light, SSE       27292               67055
            //
            //      Point Light, General        224209              155483
            //      Point Light, SSE             56817              106663
            //

            // You can put break point here while running test application, to
            // watch profile results.
            ++index;    // So we can put break point here even if in release build
        }

    };
#endif // __DO_PROFILE__

    //---------------------------------------------------------------------
    OptimisedUtil* OptimisedUtil::msImplementation = OptimisedUtil::_detectImplementation();

    //---------------------------------------------------------------------
    OptimisedUtil* OptimisedUtil::_detectImplementation(void)
    {
        //
        // Some speed test results (averaged number of CPU timestamp (RDTSC) per-function call):
        //
        //   Dagon SkeletonAnimation sample - softwareVertexSkinning:
        //
        //                                      Pentium 4 3.0G HT       Athlon XP 2500+     Athlon 64 X2 Dual Core 3800+
        //
        //      Shared Buffers, General C       763677                  462903              473038
        //      Shared Buffers, Unrolled SSE    210030 *best*           369762              228328 *best*
        //      Shared Buffers, General SSE     286202                  352412 *best*       302796
        //
        //      Separated Buffers, General C    762640                  464840              478740
        //      Separated Buffers, Unrolled SSE 219222 *best*           287992 *best*       238770 *best*
        //      Separated Buffers, General SSE  290129                  341614              307262
        //
        //      PosOnly, General C              388663                  257350              262831
        //      PosOnly, Unrolled SSE           139814 *best*           200323 *best*       168995 *best*
        //      PosOnly, General SSE            172693                  213704              175447
        //
        //   Another my own test scene - softwareVertexSkinning:
        //
        //                                      Pentium P4 3.0G HT      Athlon XP 2500+
        //
        //      Shared Buffers, General C       74527                   -
        //      Shared Buffers, Unrolled SSE    22743 *best*            -
        //      Shared Buffers, General SSE     28527                   -
        //
        //
        // Note that speed test appears unaligned load/store instruction version
        // loss performance 5%-10% than aligned load/store version, even if both
        // of them access to aligned data. Thus, we should use aligned load/store
        // as soon as possible.
        //
        //
        // We are pick up the implementation based on test results above.
        //
#ifdef __DO_PROFILE__
        {
            static OptimisedUtilProfiler msOptimisedUtilProfiler;
            return &msOptimisedUtilProfiler;
        }

#else   // !__DO_PROFILE__

#if __OGRE_HAVE_SSE
        if (PlatformInformation::getCpuFeatures() & PlatformInformation::CPU_FEATURE_SSE)
        {
            return _getOptimisedUtilSSE();
        }
        else
#endif  // __OGRE_HAVE_SSE
        {
            return _getOptimisedUtilGeneral();
        }

#endif  // __DO_PROFILE__
    }

}
