cone _cy

void Viewer::init_cone()
{
    float alpha;
    int div=25;
    float step=2*M_PI/div;
    m_cone=Mesh(GL_TRIANGLE_STRIP);
    for(int i=0;i<div+1;i++)
    {
        alpha=i*step;
        m_cone.normal(Vector (cos(alpha)/sqrt(2),1/sqrt(2),sin(alpha)/sqrt(2)));
        m_cone.vertex(Point(cos(alpha),0,sin(alpha)));
        m_cone.vertex(Point(0,1,0));
    }
}

void Viewer::init_sphere()
{
    int divbeta=25;
    int divalpha=divbeta/2;
    float alpha, alpha2, beta;
    m_sphere=Mesh(GL_TRIANGLE_STRIP);
    for(int i=0;i<divalpha;i++)
    {
        alpha=0.5*2*M_PI+float(i)*2*M_PI/divalpha;
        alpha2=0.5*2*M_PI+float(i+1)*2*M_PI/divalpha;
        for(float j= 0 ;j<divbeta;j++)
        {
            beta= j*2*M_PI/divbeta;
            m_sphere.normal(Vector(cos(alpha)*cos(beta),sin(alpha),cos(alpha)*sin(beta)));
            m_sphere.vertex(Point(cos(alpha)*cos(beta),sin(alpha),cos(alpha)*sin(beta)));
            m_sphere.normal(Vector(cos(alpha2)*cos(beta),sin(alpha),cos(alpha2)*sin(beta)));
            m_sphere.vertex(Point(cos(alpha2)*cos(beta),sin(alpha),cos(alpha2)*sin(beta)));
        }
    }
}