/*
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Open Asset Import Library (assimp)
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Copyright (c) 2006-2019, assimp team



All rights reserved.

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* Redistributions in binary form must reproduce the above
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* Neither the name of the assimp team, nor the names of its
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THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
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A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
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*/
#include "UnitTestPCH.h"

#include "assimp/types.h"
#include "assimp/mesh.h"

#include <VertexTriangleAdjacency.h>


using namespace std;
using namespace Assimp;

class VTAdjacencyTest : public ::testing::Test
{
protected:

    void checkMesh(const aiMesh& mesh);
};

// ------------------------------------------------------------------------------------------------
TEST_F(VTAdjacencyTest, largeRandomDataSet)
{
    // build a test mesh with randomized input data
    // *******************************************************************************
    aiMesh mesh;

    mesh.mNumVertices = 500;
    mesh.mNumFaces = 600;

    mesh.mFaces = new aiFace[600];
    unsigned int iCurrent = 0;
    for (unsigned int i = 0; i < 600;++i)
    {
        aiFace& face = mesh.mFaces[i];
        face.mNumIndices = 3;
        face.mIndices = new unsigned int[3];

        if (499 == iCurrent)iCurrent = 0;
        face.mIndices[0] = iCurrent++;


        while(face.mIndices[0] == ( face.mIndices[1] = (unsigned int)(((float)rand()/RAND_MAX)*499)));
        while(face.mIndices[0] == ( face.mIndices[2] = (unsigned int)(((float)rand()/RAND_MAX)*499)) ||
            face.mIndices[1] == face.mIndices[2]);
    }

    checkMesh(mesh);
}

// ------------------------------------------------------------------------------------------------
TEST_F(VTAdjacencyTest, smallDataSet)
{

    // build a test mesh - this one is extremely small
    // *******************************************************************************
    aiMesh mesh;

    mesh.mNumVertices = 5;
    mesh.mNumFaces = 3;

    mesh.mFaces = new aiFace[3];
    mesh.mFaces[0].mIndices = new unsigned int[3];
    mesh.mFaces[0].mNumIndices = 3;
    mesh.mFaces[1].mIndices = new unsigned int[3];
    mesh.mFaces[1].mNumIndices = 3;
    mesh.mFaces[2].mIndices = new unsigned int[3];
    mesh.mFaces[2].mNumIndices = 3;

    mesh.mFaces[0].mIndices[0] = 1;
    mesh.mFaces[0].mIndices[1] = 3;
    mesh.mFaces[0].mIndices[2] = 2;

    mesh.mFaces[1].mIndices[0] = 0;
    mesh.mFaces[1].mIndices[1] = 2;
    mesh.mFaces[1].mIndices[2] = 3;

    mesh.mFaces[2].mIndices[0] = 3;
    mesh.mFaces[2].mIndices[1] = 0;
    mesh.mFaces[2].mIndices[2] = 4;

    checkMesh(mesh);
}

// ------------------------------------------------------------------------------------------------
TEST_F(VTAdjacencyTest, unreferencedVerticesSet)
{
    // build a test mesh which does not reference all vertices
    // *******************************************************************************
    aiMesh mesh;

    mesh.mNumVertices = 500;
    mesh.mNumFaces = 600;

    mesh.mFaces = new aiFace[600];
    unsigned int iCurrent = 0;
    for (unsigned int i = 0; i < 600;++i)
    {
        aiFace& face = mesh.mFaces[i];
        face.mNumIndices = 3;
        face.mIndices = new unsigned int[3];

        if (499 == iCurrent)iCurrent = 0;
        face.mIndices[0] = iCurrent++;

        if (499 == iCurrent)iCurrent = 0;
        face.mIndices[1] = iCurrent++;

        if (499 == iCurrent)iCurrent = 0;
        face.mIndices[2] = iCurrent++;

        if (rand() > RAND_MAX/2 && face.mIndices[0])
        {
            face.mIndices[0]--;
        }
        else if (face.mIndices[1]) face.mIndices[1]--;
    }

    checkMesh(mesh);
}

// ------------------------------------------------------------------------------------------------
void VTAdjacencyTest::checkMesh(const aiMesh& mesh)
{
    VertexTriangleAdjacency adj(mesh.mFaces,mesh.mNumFaces,mesh.mNumVertices,true);

    unsigned int* const piNum = adj.mLiveTriangles;

    // check the primary adjacency table and check whether all faces
    // are contained in the list
    unsigned int maxOfs = 0;
    for (unsigned int i = 0; i < mesh.mNumFaces;++i)
    {
        aiFace& face = mesh.mFaces[i];
        for (unsigned int qq = 0; qq < 3 ;++qq)
        {
            const unsigned int idx = face.mIndices[qq];
            const unsigned int num = piNum[idx];

            // go to this offset
            const unsigned int ofs = adj.mOffsetTable[idx];
            maxOfs = std::max(ofs+num,maxOfs);
            unsigned int* pi = &adj.mAdjacencyTable[ofs];

            // and search for us ...
            unsigned int tt = 0;
            for (; tt < num;++tt,++pi)
            {
                if (i == *pi)
                {
                    // mask our entry in the table. Finally all entries should be masked
                    *pi = 0xffffffff;

                    // there shouldn't be two entries for the same face
                    break;
                }
            }
            // assert if *this* vertex has not been found in the table
            EXPECT_LT(tt, num);
        }
    }

    // now check whether there are invalid faces
    const unsigned int* pi = adj.mAdjacencyTable;
    for (unsigned int i = 0; i < maxOfs;++i,++pi)
    {
        EXPECT_EQ(0xffffffff, *pi);
    }

    // check the numTrianglesPerVertex table
    for (unsigned int i = 0; i < mesh.mNumFaces;++i)
    {
        aiFace& face = mesh.mFaces[i];
        for (unsigned int qq = 0; qq < 3 ;++qq)
        {
            const unsigned int idx = face.mIndices[qq];

            // we should not reach 0 here ...
            EXPECT_NE(0U, piNum[idx]);
            piNum[idx]--;
        }
    }

    // check whether we reached 0 in all entries
    for (unsigned int i = 0; i < mesh.mNumVertices;++i)
    {
        EXPECT_FALSE(piNum[i]);
    }
}
