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*/
/** @file Implementation of the post processing step to remove
 *        any parts of the mesh structure from the imported data.
*/

#include "RemoveVCProcess.h"
#include <assimp/postprocess.h>
#include <assimp/scene.h>
#include <assimp/DefaultLogger.hpp>

using namespace Assimp;

// ------------------------------------------------------------------------------------------------
// Constructor to be privately used by Importer
RemoveVCProcess::RemoveVCProcess() :
        configDeleteFlags(), mScene() {}

// ------------------------------------------------------------------------------------------------
// Destructor, private as well
RemoveVCProcess::~RemoveVCProcess() {}

// ------------------------------------------------------------------------------------------------
// Returns whether the processing step is present in the given flag field.
bool RemoveVCProcess::IsActive(unsigned int pFlags) const {
    return (pFlags & aiProcess_RemoveComponent) != 0;
}

// ------------------------------------------------------------------------------------------------
// Small helper function to delete all elements in a T** aray using delete
template <typename T>
inline void ArrayDelete(T **&in, unsigned int &num) {
    for (unsigned int i = 0; i < num; ++i)
        delete in[i];

    delete[] in;
    in = nullptr;
    num = 0;
}

#if 0
// ------------------------------------------------------------------------------------------------
// Updates the node graph - removes all nodes which have the "remove" flag set and the
// "don't remove" flag not set. Nodes with meshes are never deleted.
bool UpdateNodeGraph(aiNode* node,std::list<aiNode*>& childsOfParent,bool root)
{
    bool b = false;

    std::list<aiNode*> mine;
    for (unsigned int i = 0; i < node->mNumChildren;++i)
    {
        if(UpdateNodeGraph(node->mChildren[i],mine,false))
            b = true;
    }

    // somewhat tricky ... mNumMeshes must be originally 0 and MSB2 may not be set,
    // so we can do a simple comparison against MSB here
    if (!root && AI_RC_UINT_MSB == node->mNumMeshes )
    {
        // this node needs to be removed
        if(node->mNumChildren)
        {
            childsOfParent.insert(childsOfParent.end(),mine.begin(),mine.end());

            // set all children to nullptr to make sure they are not deleted when we delete ourself
            for (unsigned int i = 0; i < node->mNumChildren;++i)
                node->mChildren[i] = nullptr;
        }
        b = true;
        delete node;
    }
    else
    {
        AI_RC_UNMASK(node->mNumMeshes);
        childsOfParent.push_back(node);

        if (b)
        {
            // reallocate the array of our children here
            node->mNumChildren = (unsigned int)mine.size();
            aiNode** const children = new aiNode*[mine.size()];
            aiNode** ptr = children;

            for (std::list<aiNode*>::iterator it = mine.begin(), end = mine.end();
                 it != end; ++it)
            {
                *ptr++ = *it;
            }
            delete[] node->mChildren;
            node->mChildren = children;
            return false;
        }
    }
    return b;
}
#endif

// ------------------------------------------------------------------------------------------------
// Executes the post processing step on the given imported data.
void RemoveVCProcess::Execute(aiScene *pScene) {
    ASSIMP_LOG_DEBUG("RemoveVCProcess begin");
    bool bHas = false; //,bMasked = false;

    mScene = pScene;

    // handle animations
    if (configDeleteFlags & aiComponent_ANIMATIONS) {

        bHas = true;
        ArrayDelete(pScene->mAnimations, pScene->mNumAnimations);
    }

    // handle textures
    if (configDeleteFlags & aiComponent_TEXTURES) {
        bHas = true;
        ArrayDelete(pScene->mTextures, pScene->mNumTextures);
    }

    // handle materials
    if (configDeleteFlags & aiComponent_MATERIALS && pScene->mNumMaterials) {
        bHas = true;
        for (unsigned int i = 1; i < pScene->mNumMaterials; ++i)
            delete pScene->mMaterials[i];

        pScene->mNumMaterials = 1;
        aiMaterial *helper = (aiMaterial *)pScene->mMaterials[0];
        ai_assert(nullptr != helper);
        helper->Clear();

        // gray
        aiColor3D clr(0.6f, 0.6f, 0.6f);
        helper->AddProperty(&clr, 1, AI_MATKEY_COLOR_DIFFUSE);

        // add a small ambient color value
        clr = aiColor3D(0.05f, 0.05f, 0.05f);
        helper->AddProperty(&clr, 1, AI_MATKEY_COLOR_AMBIENT);

        aiString s;
        s.Set("Dummy_MaterialsRemoved");
        helper->AddProperty(&s, AI_MATKEY_NAME);
    }

    // handle light sources
    if (configDeleteFlags & aiComponent_LIGHTS) {
        bHas = true;
        ArrayDelete(pScene->mLights, pScene->mNumLights);
    }

    // handle camneras
    if (configDeleteFlags & aiComponent_CAMERAS) {
        bHas = true;
        ArrayDelete(pScene->mCameras, pScene->mNumCameras);
    }

    // handle meshes
    if (configDeleteFlags & aiComponent_MESHES) {
        bHas = true;
        ArrayDelete(pScene->mMeshes, pScene->mNumMeshes);
    } else {
        for (unsigned int a = 0; a < pScene->mNumMeshes; a++) {
            if (ProcessMesh(pScene->mMeshes[a]))
                bHas = true;
        }
    }

    // now check whether the result is still a full scene
    if (!pScene->mNumMeshes || !pScene->mNumMaterials) {
        pScene->mFlags |= AI_SCENE_FLAGS_INCOMPLETE;
        ASSIMP_LOG_DEBUG("Setting AI_SCENE_FLAGS_INCOMPLETE flag");

        // If we have no meshes anymore we should also clear another flag ...
        if (!pScene->mNumMeshes)
            pScene->mFlags &= ~AI_SCENE_FLAGS_NON_VERBOSE_FORMAT;
    }

    if (bHas) {
        ASSIMP_LOG_INFO("RemoveVCProcess finished. Data structure cleanup has been done.");
    } else {
        ASSIMP_LOG_DEBUG("RemoveVCProcess finished. Nothing to be done ...");
    }
}

// ------------------------------------------------------------------------------------------------
// Setup configuration properties for the step
void RemoveVCProcess::SetupProperties(const Importer *pImp) {
    configDeleteFlags = pImp->GetPropertyInteger(AI_CONFIG_PP_RVC_FLAGS, 0x0);
    if (!configDeleteFlags) {
        ASSIMP_LOG_WARN("RemoveVCProcess: AI_CONFIG_PP_RVC_FLAGS is zero.");
    }
}

// ------------------------------------------------------------------------------------------------
// Executes the post processing step on the given imported data.
bool RemoveVCProcess::ProcessMesh(aiMesh *pMesh) {
    bool ret = false;

    // if all materials have been deleted let the material
    // index of the mesh point to the created default material
    if (configDeleteFlags & aiComponent_MATERIALS)
        pMesh->mMaterialIndex = 0;

    // handle normals
    if (configDeleteFlags & aiComponent_NORMALS && pMesh->mNormals) {
        delete[] pMesh->mNormals;
        pMesh->mNormals = nullptr;
        ret = true;
    }

    // handle tangents and bitangents
    if (configDeleteFlags & aiComponent_TANGENTS_AND_BITANGENTS && pMesh->mTangents) {
        delete[] pMesh->mTangents;
        pMesh->mTangents = nullptr;

        delete[] pMesh->mBitangents;
        pMesh->mBitangents = nullptr;
        ret = true;
    }

    // handle texture coordinates
    bool b = (0 != (configDeleteFlags & aiComponent_TEXCOORDS));
    for (unsigned int i = 0, real = 0; real < AI_MAX_NUMBER_OF_TEXTURECOORDS; ++real) {
        if (!pMesh->mTextureCoords[i]) break;
        if (configDeleteFlags & aiComponent_TEXCOORDSn(real) || b) {
            delete[] pMesh->mTextureCoords[i];
            pMesh->mTextureCoords[i] = nullptr;
            ret = true;

            if (!b) {
                // collapse the rest of the array
                for (unsigned int a = i + 1; a < AI_MAX_NUMBER_OF_TEXTURECOORDS; ++a)
                    pMesh->mTextureCoords[a - 1] = pMesh->mTextureCoords[a];

                pMesh->mTextureCoords[AI_MAX_NUMBER_OF_TEXTURECOORDS - 1] = nullptr;
                continue;
            }
        }
        ++i;
    }

    // handle vertex colors
    b = (0 != (configDeleteFlags & aiComponent_COLORS));
    for (unsigned int i = 0, real = 0; real < AI_MAX_NUMBER_OF_COLOR_SETS; ++real) {
        if (!pMesh->mColors[i]) break;
        if (configDeleteFlags & aiComponent_COLORSn(i) || b) {
            delete[] pMesh->mColors[i];
            pMesh->mColors[i] = nullptr;
            ret = true;

            if (!b) {
                // collapse the rest of the array
                for (unsigned int a = i + 1; a < AI_MAX_NUMBER_OF_COLOR_SETS; ++a)
                    pMesh->mColors[a - 1] = pMesh->mColors[a];

                pMesh->mColors[AI_MAX_NUMBER_OF_COLOR_SETS - 1] = nullptr;
                continue;
            }
        }
        ++i;
    }

    // handle bones
    if (configDeleteFlags & aiComponent_BONEWEIGHTS && pMesh->mBones) {
        ArrayDelete(pMesh->mBones, pMesh->mNumBones);
        ret = true;
    }
    return ret;
}
