(Sorry ! my english not very good)Does opengl smooth need some prerequisite

Recently I draw the earth on the computer but I find that my code can’t realize antialias.And I am sure that there must someting wrong in blow codes,but I do not know where the error.

this is my code :

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void DrawEarth(float radius,int h_slip,int l_slip)

{

//

float alpha_step = 2*PI/h_slip;

float beta_step = PI/l_slip;

float alpha = 0.0f;

float beta = PI;

//

float x = 0;

float y = 0;

float x_step = 1.0f/h_slip;

float y_step = 1.0f/l_slip;

int i;

int j;

for(i=0;i<l_slip;i++){

glBegin(GL_TRIANGLE_STRIP);

for(j=0;j<h_slip;j++)

{

```
}
glEnd();
```

}

```
glBegin(GL_QUADS);
```

for(i=0;i<l_slip;i++){

for(j=0;j<h_slip;j++)

{

glNormal3f(sin(beta)*cos(alpha),sin(beta)*sin(alpha),cos(beta));
glTexCoord2f(x,y);
glVertex3f(radius*sin(beta)

*cos(alpha),radius*sin(beta)

*sin(alpha),radius*cos(beta));

```
alpha += alpha_step;
glTexCoord2f(x+x_step,y);
glVertex3f(radius*sin(beta)*cos(alpha),radius*sin(beta)*sin(alpha),radius*cos(beta));
beta -= beta_step;
glTexCoord2f(x+x_step,y+y_step);
glVertex3f(radius*sin(beta)*cos(alpha),radius*sin(beta)*sin(alpha),radius*cos(beta));
alpha -=alpha_step;
glTexCoord2f(x,y+y_step);
glVertex3f(radius*sin(beta)*cos(alpha),radius*sin(beta)*sin(alpha),radius*cos(beta));
beta += beta_step;
x += x_step;
alpha +=alpha_step;
}
x =0.0f;
y += y_step;
```

alpha = 0.0f;

beta -= beta_step;

}

glEnd();

}//endfunc

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