void meshDraw(){

Vec3d VP= Vec3d();

//set 

for( int x=0; x<meshW; x++ )

{

for( int y=0; y<meshH; y++ )

{

    VP.x = x;

VP.y = y;

VP.z = -(float(y)/5);

mesh[x][y] = VP ;

    }

}

//draw  grid

glColor3f( 0,1,1 );

glPointSize(3.0);

    // draw y

   for( int x=0; x<meshW; x++ )

{glBegin(GL_LINE_STRIP);

for( int y=0; y<meshH; y++ )

{

VP = mesh[x][y]; 

glVertex3f( VP.x, VP.y, VP.z);

    }

glEnd(); 

}

//draw xs

    for( int x=0; x<meshW; x++ )

{glBegin(GL_LINE_STRIP);

for( int y=0; y<meshH; y++ )

{

VP = mesh[y][x]; 

glVertex3f( VP.x, VP.y, VP.z);

    }

glEnd(); 

}

}