i trying to draw ellipse in MFC C++ just use OPENGL. it ran for the resulting ellipse but it is not correct mouse coordinates. My code:

in class Ellispe.cpp

void VeEllispe::putPixel(int x,int y,int xc, int yc)
{

    glBegin(GL_POINTS);// bat dau bang ve diem
    glVertex2i(xc+x,yc+y);
    glVertex2i(xc-x,yc-y);
    glVertex2i(xc+x,yc-y);
    glVertex2i(xc-x,yc+y);
    glEnd();
} 
void VeEllispe::Draw(int a, int b,int xc,int yc)
{
    int x = 0;
    int y = b;
    float a2 = (a*a);
    float b2 = (b*b);
    float p = b2 - a2*b + 0.25*a2;
    while(2*b2*x <= 2*y*a2)
    {
        putPixel(x,y,xc,yc);
        if (p < 0) p+= 2*b2*x + 3*b2;
        else
        {
            p+= 2*b2*x + 3*b2 - 2*a2*y + 2*a2;
            y--;
        }
        x++;
    }
    x = a;
    y = 0;
    p = a2 - b2*a + 0.25*b2;
    while(2*a2*y <= 2*x*b2)
    {
        putPixel(x,y,xc, yc);
        if (p < 0) p+= 2*a2*y + 3*a2;
        else
        {
            p+= 2*a2*y + 3*a2 - 2*b2*x + 2*b2;
            x--;
        }
        y++;
    }
}

in class XYZView.cpp

.
.
VeEllispe e;
void Cbaitap1View::OnDraw(CDC* /*pDC*/)
{
    Cbaitap1Doc* pDoc = GetDocument();
    ASSERT_VALID(pDoc);
    if (!pDoc)
        return;
    wglMakeCurrent(m_hDC,m_hRC);
    glClear(GL_COLOR_BUFFER_BIT);
    glClearColor(1.0,1.0,1.0,0.0);
    glColor3f(0.0,0.0,1.0);
    glPointSize(2);
    if (state==4)
        e.Draw(X2,Y2,X1,Y1);
    glFlush();

    SwapBuffers(::GetDC(GetSafeHwnd()));
    wglMakeCurrent(NULL,NULL);
}

And if possible, can you teach me the document to drawing triangles or parapol use OPENGL?