/*

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

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 "OgreShaderPrecompiledHeaders.h"

#ifdef RTSHADER_SYSTEM_BUILD_EXT_SHADERS

#define SGX_LIB_DUAL_QUATERNION                 "SGXLib_DualQuaternion"

#define SGX_FUNC_CALCULATE_BLEND_POSITION       "SGX_CalculateBlendPosition"

#define SGX_FUNC_CALCULATE_BLEND_NORMAL         "SGX_CalculateBlendNormal"

#define SGX_FUNC_ADJOINT_TRANSPOSE_MATRIX       "SGX_AdjointTransposeMatrix"

namespace Ogre {

namespace RTShader {

/************************************************************************/

/*                                                                      */

/************************************************************************/

bool DualQuaternionSkinning::resolveParameters(Program* vsProgram)

{

    Function* vsMain = vsProgram->getEntryPointFunction();

    mParamInWorldMatrices = vsProgram->resolveParameter(GpuProgramParameters::ACT_WORLD_DUALQUATERNION_ARRAY_2x4, mBoneCount);

    mParamBlendDQ = vsMain->resolveLocalParameter(GCT_MATRIX_2X4, "blendDQ");

    if(mScalingShearingSupport)

    {

        mParamInScaleShearMatrices = vsProgram->resolveParameter(GpuProgramParameters::ACT_WORLD_SCALE_SHEAR_MATRIX_ARRAY_3x4, mBoneCount);

        mParamBlendS = vsMain->resolveLocalParameter(GCT_MATRIX_3X4, "blendS");

        mParamTempFloat3x3 = vsMain->resolveLocalParameter(GCT_MATRIX_3X3, "TempVal3x3");

    }

    return true;

}

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

void DualQuaternionSkinning::addPositionCalculations(const FunctionStageRef& stage)

{

    if (mScalingShearingSupport)

    {

        // Construct a scaling and shearing matrix based on the blend weights

        stage.callFunction("blendBonesMat3x4", {In(mParamInScaleShearMatrices), In(mParamInIndices),

                                                In(mParamInWeights), Out(mParamBlendS)});

        // Transform the position based by the scaling and shearing matrix

        stage.callFunction(FFP_FUNC_TRANSFORM, mParamBlendS, mParamInPosition, Out(mParamInPosition).xyz());

    }

    // Calculate the resultant dual quaternion based on the weights given

    stage.callFunction("blendBonesDQ",

                       {In(mParamInWorldMatrices), In(mParamInIndices), In(mParamInWeights), Out(mParamBlendDQ)});

    // Calculate the blend position

    stage.callFunction(SGX_FUNC_CALCULATE_BLEND_POSITION, In(mParamInPosition).xyz(), mParamBlendDQ, mParamInPosition);

}

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

void DualQuaternionSkinning::addNormalRelatedCalculations(const FunctionStageRef& stage)

{

    if (mScalingShearingSupport)

    {

        // Calculate the adjoint transpose of the blended scaling and shearing matrix

        stage.callFunction(SGX_FUNC_ADJOINT_TRANSPOSE_MATRIX, mParamBlendS, mParamTempFloat3x3);

        // Transform the normal by the adjoint transpose of the blended scaling and shearing matrix

        stage.callBuiltin("mul", mParamTempFloat3x3, mParamInNormal, mParamInNormal);

        // Need to normalize again after transforming the normal

        stage.callBuiltin("normalize", mParamInNormal, mParamInNormal);

    }

    // Transform the normal according to the dual quaternion

    stage.callFunction(SGX_FUNC_CALCULATE_BLEND_NORMAL, mParamInNormal, mParamBlendDQ, mParamInNormal);

}

}

}

#endif