allback.</p>
</td></tr>
<tr valign=top><td><b>black_spans</b></td><td>
<p>The black span drawing callback. UNIMPLEMENTED!</p>
</td></tr>
<tr valign=top><td><b>bit_test</b></td><td>
<p>The bit test callback. UNIMPLEMENTED!</p>
</td></tr>
<tr valign=top><td><b>bit_set</b></td><td>
<p>The bit set callback. UNIMPLEMENTED!</p>
</td></tr>
<tr valign=top><td><b>user</b></td><td>
<p>User-supplied data that is passed to each drawing callback.</p>
</td></tr>
<tr valign=top><td><b>clip_box</b></td><td>
<p>An optional 