Small changes to C API unit tests.

- (1) Changed randomized math structure values to predefined values to prevent cases that could potentially lead to division by zero.
- (2) Removed unused variable(s) due to (1).
- (3) Renamed variable(s) for better clarity.

test/unit/AssimpAPITest_aiMatrix3x3.cpp

@@ -143,7 +143,8 @@ TEST_F(AssimpAPITest_aiMatrix3x3, aiMatrix3TranslationTest) {
 }
 
 TEST_F(AssimpAPITest_aiMatrix3x3, aiMatrix3FromToTest) {
-    const auto from = random_vec3(), to = random_vec3();
+    // Use predetermined vectors to prevent running into division by zero.
+    const auto from = aiVector3D(1,2,1).Normalize(), to = aiVector3D(-1,1,1).Normalize();
     aiMatrix3x3::FromToMatrix(from, to, result_cpp);
     aiMatrix3FromTo(&result_c, &from, &to);
     EXPECT_EQ(result_cpp, result_c);

test/unit/AssimpAPITest_aiMatrix4x4.cpp

@@ -51,6 +51,16 @@ protected:
         result_c = result_cpp = aiMatrix4x4();
     }
 
+    /* Generates a predetermined transformation matrix to use
+       for the aiDecompose functions to prevent running into
+       division by zero. */
+    aiMatrix4x4 get_predetermined_transformation_matrix_for_decomposition() const {
+        aiMatrix4x4 t, r;
+        aiMatrix4x4::Translation(aiVector3D(14,-25,-8), t);
+        aiMatrix4x4::Rotation(Math::PI<float>() / 4.0f, aiVector3D(1).Normalize(), r);
+        return t * r;
+    }
+
     aiMatrix4x4 result_c, result_cpp;
 };
 
@@ -142,7 +152,7 @@ TEST_F(AssimpAPITest_aiMatrix4x4, aiDecomposeMatrixTest) {
         position_c, position_cpp;
     aiQuaternion rotation_c, rotation_cpp;
 
-    result_c = result_cpp = random_mat4();
+    result_c = result_cpp = get_predetermined_transformation_matrix_for_decomposition();
     result_cpp.Decompose(scaling_cpp, rotation_cpp, position_cpp);
     aiDecomposeMatrix(&result_c, &scaling_c, &rotation_c, &position_c);
     EXPECT_EQ(scaling_cpp, scaling_c);
@@ -155,7 +165,7 @@ TEST_F(AssimpAPITest_aiMatrix4x4, aiMatrix4DecomposeIntoScalingEulerAnglesPositi
         rotation_c, rotation_cpp,
         position_c, position_cpp;
 
-    result_c = result_cpp = random_mat4();
+    result_c = result_cpp = get_predetermined_transformation_matrix_for_decomposition();
     result_cpp.Decompose(scaling_cpp, rotation_cpp, position_cpp);
     aiMatrix4DecomposeIntoScalingEulerAnglesPosition(&result_c, &scaling_c, &rotation_c, &position_c);
     EXPECT_EQ(scaling_cpp, scaling_c);
@@ -169,7 +179,7 @@ TEST_F(AssimpAPITest_aiMatrix4x4, aiMatrix4DecomposeIntoScalingAxisAnglePosition
         position_c, position_cpp;
     float angle_c, angle_cpp;
 
-    result_c = result_cpp = random_mat4();
+    result_c = result_cpp = get_predetermined_transformation_matrix_for_decomposition();
     result_cpp.Decompose(scaling_cpp, axis_cpp, angle_cpp, position_cpp);
     aiMatrix4DecomposeIntoScalingAxisAnglePosition(&result_c, &scaling_c, &axis_c, &angle_c, &position_c);
     EXPECT_EQ(scaling_cpp, scaling_c);
@@ -182,7 +192,7 @@ TEST_F(AssimpAPITest_aiMatrix4x4, aiMatrix4DecomposeNoScalingTest) {
     aiVector3D position_c, position_cpp;
     aiQuaternion rotation_c, rotation_cpp;
 
-    result_c = result_cpp = random_mat4();
+    result_c = result_cpp = get_predetermined_transformation_matrix_for_decomposition();
     result_cpp.DecomposeNoScaling(rotation_cpp, position_cpp);
     aiMatrix4DecomposeNoScaling(&result_c, &rotation_c, &position_c);
     EXPECT_EQ(position_cpp, position_c);
@@ -242,7 +252,8 @@ TEST_F(AssimpAPITest_aiMatrix4x4, aiMatrix4ScalingTest) {
 }
 
 TEST_F(AssimpAPITest_aiMatrix4x4, aiMatrix4FromToTest) {
-    const auto from = random_vec3(), to = random_vec3();
+    // Use predetermined vectors to prevent running into division by zero.
+    const auto from = aiVector3D(1,2,1).Normalize(), to = aiVector3D(-1,1,1).Normalize();
     aiMatrix4x4::FromToMatrix(from, to, result_cpp);
     aiMatrix4FromTo(&result_c, &from, &to);
     EXPECT_EQ(result_cpp, result_c);

test/unit/AssimpAPITest_aiQuaternion.cpp

@@ -55,7 +55,13 @@ protected:
 };
 
 TEST_F(AssimpAPITest_aiQuaternion, aiCreateQuaternionFromMatrixTest) {
-    const auto m = random_mat3();
+    // Use a predetermined transformation matrix
+    // to prevent running into division by zero.
+    aiMatrix3x3 m, r;
+    aiMatrix3x3::Translation(aiVector2D(14,-25), m);
+    aiMatrix3x3::RotationZ(Math::PI<float>() / 4.0f, r);
+    m = m * r;
+
     result_cpp = aiQuaternion(m);
     aiCreateQuaternionFromMatrix(&result_c, &m);
     EXPECT_EQ(result_cpp, result_c);
@@ -118,9 +124,11 @@ TEST_F(AssimpAPITest_aiQuaternion, aiQuaternionMultiplyTest) {
 }
 
 TEST_F(AssimpAPITest_aiQuaternion, aiQuaternionInterpolateTest) {
-    const float INTERPOLATION(RandUnit.next());
-    const auto q1 = random_quat();
-    const auto q2 = random_quat();
+    // Use predetermined quaternions to prevent division by zero
+    // during slerp calculations.
+    const float INTERPOLATION(0.5f);
+    const auto q1 = aiQuaternion(aiVector3D(-1,1,1).Normalize(), Math::PI<float>() / 4.0f);
+    const auto q2 = aiQuaternion(aiVector3D(1,2,1).Normalize(), Math::PI<float>() / 2.0f);
     aiQuaternion::Interpolate(result_cpp, q1, q2, INTERPOLATION);
     aiQuaternionInterpolate(&result_c, &q1, &q2, INTERPOLATION);
     EXPECT_EQ(result_cpp, result_c);

test/unit/AssimpAPITest_aiVector2D.cpp

@@ -49,7 +49,7 @@ class AssimpAPITest_aiVector2D : public AssimpMathTest {
 protected:
     virtual void SetUp() {
         result_c = result_cpp = aiVector2D();
-        temp = random_vec2();
+        temp = random_vec2(); // Generates a random 2D vector != null vector.
     }
 
     aiVector2D result_c, result_cpp, temp;
@@ -82,7 +82,7 @@ TEST_F(AssimpAPITest_aiVector2D, aiVector2SubtractTest) {
 }
 
 TEST_F(AssimpAPITest_aiVector2D, aiVector2ScaleTest) {
-    const float FACTOR = Rand.next();
+    const float FACTOR = RandNonZero.next();
     result_c = result_cpp = random_vec2();
     result_cpp *= FACTOR;
     aiVector2Scale(&result_c, FACTOR);
@@ -97,7 +97,7 @@ TEST_F(AssimpAPITest_aiVector2D, aiVector2SymMulTest) {
 }
 
 TEST_F(AssimpAPITest_aiVector2D, aiVector2DivideByScalarTest) {
-    const float DIVISOR = Rand.next();
+    const float DIVISOR = RandNonZero.next();
     result_c = result_cpp = random_vec2();
     result_cpp /= DIVISOR;
     aiVector2DivideByScalar(&result_c, DIVISOR);

test/unit/AssimpAPITest_aiVector3D.cpp

@@ -49,7 +49,7 @@ class AssimpAPITest_aiVector3D : public AssimpMathTest {
 protected:
     virtual void SetUp() {
         result_c = result_cpp = aiVector3D();
-        temp = random_vec3();
+        temp = random_vec3(); // Generates a random 3D vector != null vector.
     }
 
     aiVector3D result_c, result_cpp, temp;
@@ -88,7 +88,7 @@ TEST_F(AssimpAPITest_aiVector3D, aiVector3SubtractTest) {
 }
 
 TEST_F(AssimpAPITest_aiVector3D, aiVector3ScaleTest) {
-    const float FACTOR = Rand.next();
+    const float FACTOR = RandNonZero.next();
     result_c = result_cpp = random_vec3();
     result_cpp *= FACTOR;
     aiVector3Scale(&result_c, FACTOR);
@@ -103,7 +103,7 @@ TEST_F(AssimpAPITest_aiVector3D, aiVector3SymMulTest) {
 }
 
 TEST_F(AssimpAPITest_aiVector3D, aiVector3DivideByScalarTest) {
-    const float DIVISOR = Rand.next();
+    const float DIVISOR = RandNonZero.next();
     result_c = result_cpp = random_vec3();
     result_cpp /= DIVISOR;
     aiVector3DivideByScalar(&result_c, DIVISOR);

test/unit/MathTest.cpp

@@ -47,13 +47,10 @@ namespace Assimp {
 // Initialize epsilon value.
 const float AssimpMathTest::Epsilon = Math::getEpsilon<float>();
 
-// Initialize with an interval of [1,100] to avoid null values.
-RandomUniformFloatGenerator AssimpMathTest::Rand(1.0f, 100.0f);
+// Initialize with an interval of [1,100].
+RandomUniformFloatGenerator AssimpMathTest::RandNonZero(1.0f, 100.0f);
 
 // Initialize with an interval of [-PI,PI] inclusively.
 RandomUniformFloatGenerator AssimpMathTest::RandPI(-Math::PI<float>(), Math::PI<float>());
 
-// Initialize with an interval of [0,1] inclusively.
-RandomUniformFloatGenerator AssimpMathTest::RandUnit(0.0f, 1.0f);
-
 }

test/unit/MathTest.h

@@ -53,14 +53,14 @@ namespace Assimp {
 /** Custom test class providing several math related utilities. */
 class AssimpMathTest : public ::testing::Test {
 public:
-    /** Return a random 2D vector. */
+    /** Return a random non-null 2D vector. */
     inline static aiVector2D random_vec2() {
-        return aiVector2D(Rand.next(), Rand.next());
+        return aiVector2D(RandNonZero.next(), RandNonZero.next());
     }
 
-    /** Return a random 3D vector. */
+    /** Return a random non-null 3D vector. */
     inline static aiVector3D random_vec3() {
-        return aiVector3D(Rand.next(), Rand.next(),Rand.next());
+        return aiVector3D(RandNonZero.next(), RandNonZero.next(),RandNonZero.next());
     }
 
     /** Return a random unit 3D vector. */
@@ -74,28 +74,28 @@ public:
         return aiQuaternion(random_unit_vec3(), RandPI.next());
     }
 
-    /** Return a random 3x3 matrix. */
+    /** Return a random non-null 3x3 matrix. */
     inline static aiMatrix3x3 random_mat3() {
         return aiMatrix3x3(
-            Rand.next(), Rand.next(),Rand.next(),
-            Rand.next(), Rand.next(),Rand.next(),
-            Rand.next(), Rand.next(),Rand.next());
+            RandNonZero.next(), RandNonZero.next(),RandNonZero.next(),
+            RandNonZero.next(), RandNonZero.next(),RandNonZero.next(),
+            RandNonZero.next(), RandNonZero.next(),RandNonZero.next());
     }
 
-    /** Return a random 4x4 matrix. */
+    /** Return a random non-null 4x4 matrix. */
     inline static aiMatrix4x4 random_mat4() {
         return aiMatrix4x4(
-            Rand.next(), Rand.next(),Rand.next(), Rand.next(),
-            Rand.next(), Rand.next(),Rand.next(), Rand.next(),
-            Rand.next(), Rand.next(),Rand.next(), Rand.next(),
-            Rand.next(), Rand.next(),Rand.next(), Rand.next());
+            RandNonZero.next(), RandNonZero.next(),RandNonZero.next(), RandNonZero.next(),
+            RandNonZero.next(), RandNonZero.next(),RandNonZero.next(), RandNonZero.next(),
+            RandNonZero.next(), RandNonZero.next(),RandNonZero.next(), RandNonZero.next(),
+            RandNonZero.next(), RandNonZero.next(),RandNonZero.next(), RandNonZero.next());
     }
 
     /** Epsilon value to use in tests. */
     static const float Epsilon;
 
     /** Random number generators. */
-    static RandomUniformFloatGenerator Rand, RandPI, RandUnit;
+    static RandomUniformFloatGenerator RandNonZero, RandPI;
 };
 
 }