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Open Asset Import Library (assimp)
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*/
#include "UnitTestPCH.h"

#include "Common/ScenePreprocessor.h"
#include <assimp/mesh.h>
#include <assimp/scene.h>
#include <assimp/Importer.hpp>

using namespace std;
using namespace Assimp;

class ScenePreprocessorTest : public ::testing::Test {
public:
    ScenePreprocessorTest() :
            Test(), mScenePreprocessor(nullptr), mScene(nullptr) {
        // empty
    }

protected:
    virtual void SetUp();
    virtual void TearDown();

protected:
    void CheckIfOnly(aiMesh *p, unsigned int num, unsigned flag);
    void ProcessAnimation(aiAnimation *anim) { mScenePreprocessor->ProcessAnimation(anim); }
    void ProcessMesh(aiMesh *mesh) { mScenePreprocessor->ProcessMesh(mesh); }

private:
    ScenePreprocessor *mScenePreprocessor;
    aiScene *mScene;
};

// ------------------------------------------------------------------------------------------------
void ScenePreprocessorTest::SetUp() {
    // setup a dummy scene with a single node
    mScene = new aiScene();
    mScene->mRootNode = new aiNode();
    mScene->mRootNode->mName.Set("<test>");

    // add some translation
    mScene->mRootNode->mTransformation.a4 = 1.f;
    mScene->mRootNode->mTransformation.b4 = 2.f;
    mScene->mRootNode->mTransformation.c4 = 3.f;

    // and allocate a ScenePreprocessor to operate on the scene
    mScenePreprocessor = new ScenePreprocessor(mScene);
}

// ------------------------------------------------------------------------------------------------
void ScenePreprocessorTest::TearDown() {
    delete mScenePreprocessor;
    delete mScene;
}

// ------------------------------------------------------------------------------------------------
// Check whether ProcessMesh() returns flag for a mesh that consist of primitives with num indices
void ScenePreprocessorTest::CheckIfOnly(aiMesh *p, unsigned int num, unsigned int flag) {
    // Triangles only
    for (unsigned i = 0; i < p->mNumFaces; ++i) {
        p->mFaces[i].mNumIndices = num;
    }
    mScenePreprocessor->ProcessMesh(p);
    EXPECT_EQ(flag, p->mPrimitiveTypes);
    p->mPrimitiveTypes = 0;
}

// ------------------------------------------------------------------------------------------------
// Check whether a mesh is preprocessed correctly. Case 1: The mesh needs preprocessing
TEST_F(ScenePreprocessorTest, testMeshPreprocessingPos) {
    aiMesh *p = new aiMesh;
    p->mNumFaces = 100;
    p->mFaces = new aiFace[p->mNumFaces];

    p->mTextureCoords[0] = new aiVector3D[10];
    p->mNumUVComponents[0] = 0;
    p->mNumUVComponents[1] = 0;

    CheckIfOnly(p, 1, aiPrimitiveType_POINT);
    CheckIfOnly(p, 2, aiPrimitiveType_LINE);
    CheckIfOnly(p, 3, aiPrimitiveType_TRIANGLE);
    CheckIfOnly(p, 4, aiPrimitiveType_POLYGON);
    CheckIfOnly(p, 1249, aiPrimitiveType_POLYGON);

    // Polygons and triangles mixed
    unsigned i;
    for (i = 0; i < p->mNumFaces / 2; ++i) {
        p->mFaces[i].mNumIndices = 3;
    }
    for (; i < p->mNumFaces - p->mNumFaces / 4; ++i) {
        p->mFaces[i].mNumIndices = 4;
    }
    for (; i < p->mNumFaces; ++i) {
        p->mFaces[i].mNumIndices = 10;
    }
    ProcessMesh(p);
    EXPECT_EQ(static_cast<unsigned int>(aiPrimitiveType_TRIANGLE | aiPrimitiveType_POLYGON),
            p->mPrimitiveTypes);
    EXPECT_EQ(2U, p->mNumUVComponents[0]);
    EXPECT_EQ(0U, p->mNumUVComponents[1]);
    delete p;
}

// ------------------------------------------------------------------------------------------------
// Check whether a mesh is preprocessed correctly. Case 1: The mesh doesn't need preprocessing
TEST_F(ScenePreprocessorTest, testMeshPreprocessingNeg) {
    aiMesh *p = new aiMesh;
    p->mPrimitiveTypes = aiPrimitiveType_TRIANGLE | aiPrimitiveType_POLYGON;
    ProcessMesh(p);

    // should be unmodified
    EXPECT_EQ(static_cast<unsigned int>(aiPrimitiveType_TRIANGLE | aiPrimitiveType_POLYGON),
            p->mPrimitiveTypes);

    delete p;
}

// ------------------------------------------------------------------------------------------------
// Make a dummy animation with a single channel, '<test>'
aiAnimation *MakeDummyAnimation() {
    aiAnimation *p = new aiAnimation();
    p->mNumChannels = 1;
    p->mChannels = new aiNodeAnim *[1];
    aiNodeAnim *anim = p->mChannels[0] = new aiNodeAnim();
    anim->mNodeName.Set("<test>");
    return p;
}

// ------------------------------------------------------------------------------------------------
// Check whether an anim is preprocessed correctly. Case 1: The anim needs preprocessing
TEST_F(ScenePreprocessorTest, testAnimationPreprocessingPos) {
    aiAnimation *p = MakeDummyAnimation();
    aiNodeAnim *anim = p->mChannels[0];

    // we don't set the animation duration, but generate scaling channels
    anim->mNumScalingKeys = 10;
    anim->mScalingKeys = new aiVectorKey[10];

    for (unsigned int i = 0; i < 10; ++i) {
        anim->mScalingKeys[i].mTime = i;
        anim->mScalingKeys[i].mValue = aiVector3D((float)i);
    }
    ProcessAnimation(p);

    // we should now have a proper duration
    EXPECT_NEAR(p->mDuration, 9., 0.005);

    // ... one scaling key
    EXPECT_TRUE(anim->mNumPositionKeys == 1 &&
                anim->mPositionKeys &&
                anim->mPositionKeys[0].mTime == 0.0 &&
                anim->mPositionKeys[0].mValue == aiVector3D(1.f, 2.f, 3.f));

    // ... and one rotation key
    EXPECT_TRUE(anim->mNumRotationKeys == 1 && anim->mRotationKeys &&
                anim->mRotationKeys[0].mTime == 0.0);

    delete p;
}
