Quaternions go over value about opengl4tutorials HOT 9 CLOSED

class testObject
{
    private Vector3 position;
    private Quaternion rotation;
    private ShaderProgram shader;
    private Texture texture;

    private VBO<Vector3> vertices;
    private VBO<Vector3> normals;
    private VBO<Vector2> uvs;
    private VBO<int> indices;

    public TestObject(ShaderProgram shader, Texture texture)
    {
        this.position = Vector3.Zero;
        this.rotation = Quaternion.identity;

        this.shader = shader;
        this.texture = texture;

        Vector3[] verts = new Vector3[] {
                new Vector3(1, 1, -1), new Vector3(-1, 1, -1), new Vector3(-1, 1, 1), new Vector3(1, 1, 1),
                new Vector3(1, -1, 1), new Vector3(-1, -1, 1), new Vector3(-1, -1, -1), new Vector3(1, -1, -1),
                new Vector3(1, 1, 1), new Vector3(-1, 1, 1), new Vector3(-1, -1, 1), new Vector3(1, -1, 1),
                new Vector3(1, -1, -1), new Vector3(-1, -1, -1), new Vector3(-1, 1, -1), new Vector3(1, 1, -1),
                new Vector3(-1, 1, 1), new Vector3(-1, 1, -1), new Vector3(-1, -1, -1), new Vector3(-1, -1, 1),
                new Vector3(1, 1, -1), new Vector3(1, 1, 1), new Vector3(1, -1, 1), new Vector3(1, -1, -1) 
            };
            Vector2[] uvs = new Vector2[] {
                new Vector2(0.55, 0.55), new Vector2(0.95, 0.55), new Vector2(0.95, 0.95), new Vector2(0.55, 0.95), 
                new Vector2(0.55, 0.55), new Vector2(0.95, 0.55), new Vector2(0.95, 0.95), new Vector2(0.55, 0.95),
                new Vector2(0.55, 0.55), new Vector2(0.95, 0.55), new Vector2(0.95, 0.95), new Vector2(0.55, 0.95),
                new Vector2(0.55, 0.55), new Vector2(0.95, 0.55), new Vector2(0.95, 0.95), new Vector2(0.55, 0.95),
                new Vector2(0.55, 0.55), new Vector2(0.95, 0.55), new Vector2(0.95, 0.95), new Vector2(0.55, 0.95),
                new Vector2(0.55, 0.55), new Vector2(0.95, 0.55), new Vector2(0.95, 0.95), new Vector2(0.55, 0.95)
            };
            Vector3[] normals = new Vector3[] {
                new Vector3(0, 1, 0), new Vector3(0, 1, 0), new Vector3(0, 1, 0), new Vector3(0, 1, 0), 
                new Vector3(0, -1, 0), new Vector3(0, -1, 0), new Vector3(0, -1, 0), new Vector3(0, -1, 0), 
                new Vector3(0, 0, 1), new Vector3(0, 0, 1), new Vector3(0, 0, 1), new Vector3(0, 0, 1), 
                new Vector3(0, 0, -1), new Vector3(0, 0, -1), new Vector3(0, 0, -1), new Vector3(0, 0, -1), 
                new Vector3(-1, 0, 0), new Vector3(-1, 0, 0), new Vector3(-1, 0, 0), new Vector3(-1, 0, 0), 
                new Vector3(1, 0, 0), new Vector3(1, 0, 0), new Vector3(1, 0, 0), new Vector3(1, 0, 0)
            };
            int[] indices = new int[] { 
                0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23 
            };

        this.vertices = new VBO<Vector3>(verts);
        this.normals = new VBO<Vector3>(normals);
        this.uvs = new VBO<Vector2>(uvs);
        this.indices = new VBO<int>(indices);
    }

    public void Rotate(Quaternion )
    {
        // make rotation quaternion
        Quaternion rotate = new Quaternion(rotateAmount.x / 360.0f, rotateAmount.y / 360.0f, rotateAmount.z / 360.0f, 1);
        rotation = rotate * rotation;
    }

    public void Render()
    {
         Gl.UseProgram(shader.ProgramID);
         Gl.BindTexture(texture);

         shader["model_matrix"].SetValue(GetModelMatrix());
         shader["Color"].SetValue(new Vector3(1,1,1));
         shader["enable_lighting"].SetValue(true);

         Gl.BindBufferToShaderAttribute(vertices, shader, "vPosition"); // sets vertex position in "vPosition in shader input (vertexPosition in tutorial shader)"
         Gl.BindBufferToShaderAttribute(normals, shader, "vNormal"); // sets Normals in "vNormal" in shader input
         Gl.BindBufferToShaderAttribute(uvs, shader, "UV"); // sets uvs in "UV" in shader input
         Gl.BindBuffer(BufferTarget.ElementArrayBuffer, indices.vboID);

         Gl.DrawElements(BeginMode.Quads, indices.Count, DrawElementsType.UnsignedInt, IntPtr.Zero);

         Gl.UseProgram(0);
    }

    private Matrix4 GetModelMatrix()
    {
         Matrix4 transform = new Matrix4();
         // make rotation matrix
         Vector3[] mat3 = new Vector3[3] ={
             rotation * Vector3.Right,
             rotation * Vector3.Up,
             rotation * Vector3.Backward
         };

         transform[0] = new Vector4(mat3[0].x * scale.x, mat3[0].y * scale.y, mat3[0].z * scale.z, 0.0f);
         transform[1] = new Vector4(mat3[1].x * scale.x, mat3[1].y * scale.y, mat3[1].z * scale.z, 0.0f);
         transform[2] = new Vector4(mat3[2].x * scale.x, mat3[2].y * scale.y, mat3[2].z * scale.z, 0.0f);
         transform[3] = new Vector4(position.x, position.y, position.z, 1.0f);            

         return transform;
    }
}

        /// <summary>
        /// Creates an orientation Quaternion using an angle and arbitrary axis.
        /// </summary>
        public static Quaternion FromAngleAxis(float Angle, Vector3 Axis)
        {
            if (Axis.SquaredLength == 0.0f)
                return Identity;

            return new Quaternion(new Vector4(Axis.Normalize() * (float)Math.Sin(Angle * 0.5f), (float)Math.Cos(Angle * 0.5f)));
        }

        public void Rotate(float dt)
        {
            angle += 1f * dt;
            rotation = Quaternion.FromAngleAxis(angle, new Vector3(0.5, 0.2, 0.8).Normalize());
        }

        private Matrix4 GetModelMatrix()
        {
            Matrix4 transform = rotation.Matrix4;
            transform[0] = transform[0] * new Vector4(scale, 0);
            transform[1] = transform[1] * new Vector4(scale, 0);
            transform[2] = transform[2] * new Vector4(scale, 0);
            transform[3] = new Vector4(position.x, position.y, position.z, 1.0f);

            return transform;
        }