Unit test Quaternion::Quaternion(Matrix3x3).

tests/LinearAlgebra/QuaternionTests.hpp

@@ -95,6 +95,20 @@ namespace QuaternionTests {
             jtest::check(Math::EqualAbs(expected_result.w, from_axis.w, 1e-6f));
         });
 
+        QuaternionUnit += Test("To&FromMatrix3x3", [] {
+            // TODO: Test multiple rotation values.
+            // https://www.andre-gaschler.com/rotationconverter/
+            Matrix3x3 matrix_rep = {
+                0.9902160,  0.0000000,  0.1395431,
+                0.1273699,  0.4084874, -0.9038334,
+                -0.0570016,  0.9127640,  0.4044908};
+            Quaternion quat_rep = {0.5425029, 0.0586955, 0.0380374, 0.8371371};
+
+            Quaternion from_mat = Quaternion(matrix_rep);
+
+            jtest::check(quat_rep.Equals(from_mat));
+        });
+
         QuaternionUnit += Test("Mat4x4Conversion", [] { throw("Not Implemented"); });
         QuaternionUnit += Test("MulOpQuat", [] { throw("Not Implemented"); });
         QuaternionUnit += Test("DivOpQuat", [] { throw("Not Implemented"); });