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Port von [1]

procedure CreateSphere(c: TVector3f; r: Single; n: Integer);
const
  TWOPI = PI*2;
  PID2 = PI/2;
var
  i,j: Integer;
  theta1,theta2,theta3: Single;
  e,p:TVector3f;
begin
  if (r < 0) then r := -r;
  if (n < 0) then n := -n;
  if (n < 4) or (r <= 0) then
  begin
    glBegin(GL_POINTS);
      glVertex3f(c[0],c[1],c[2]);
    glEnd;
    exit;
  end;

  for j:=0 to n div 2 do
  begin
    theta1 := j * TWOPI / n - PID2;
    theta2 := (j + 1) * TWOPI / n - PID2;

    glBegin(GL_QUAD_STRIP);
    for i:=0 to n do
    begin
      theta3 := i * TWOPI / n;

      e[0] := cos(theta2) * cos(theta3);
      e[1] := sin(theta2);
      e[2] := cos(theta2) * sin(theta3);
      p[0] := c[0] + r * e[0];
      p[1] := c[1] + r * e[1];
      p[2] := c[2] + r * e[2];

      glNormal3f(e[0],e[1],e[2]);
      glTexCoord2f(i/n,2*(j+1)/n);
      glVertex3f(p[0],p[1],p[2]);

      e[0] := cos(theta1) * cos(theta3);
      e[1] := sin(theta1);
      e[2] := cos(theta1) * sin(theta3);
      p[0] := c[0] + r * e[0];
      p[1] := c[1] + r * e[1];
      p[2] := c[2] + r * e[2];

      glNormal3f(e[0],e[1],e[2]);
      glTexCoord2f(i/n,2*j/n);
      glVertex3f(p[0],p[1],p[2]);
    end;
   glEnd;
  end;
end;