(svn r2065) -Fix: reverted revision 2044, because it had more negative effects than positive
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<meta name="Description" content="Structure of OpenTTD (OTTD) landscape arrays #2">
<title>OpenTTD Landscape Internals - #2</title>
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<h3 style="font-weight: bold;">Landscape</h3>
<span style="font-weight: bold;"></span>Five arrays are used to encode the information of the contents of the tile.
This can be seen in the <a href="landscape.html">Landscape</a> document. This page tries to give an overview of used and free bits of
the array so you can quickly see what is used and what is not.
<ul>
<li><span style="font-weight: bold;"><span class="freebits">O</span></span> - bit is free</li>
<li><span style="font-weight: bold;">X</span> - bit is used</li>
<li><span style="font-weight: bold;"><span class="abuse"> </span></span> - bit of _map_* is abused for different purposes</li>
</ul>
<p>
<ul>
<li><span style="font-weight: bold;">_map_owner[]</span> - 8 bits in size, used to identify the owner of that tile (eg piece of rail, bridge, etc.).</li>
<li><span style="font-weight: bold;">_map2[]</span> - 16 bits in size, used to identify the index of the given tile (object) in the (object-)array.</li>
<li><span style="font-weight: bold;">_map3[]</span> - 16 bits in size, which is split up into _map3lo[] and _map3hi[] is used for general storage.</li>
<li><span style="font-weight: bold;">_map_type_and_height[]</span> - 8 bits in size, stores tile height (lower 4 bits) and tile class (upper 4 bits).</li>
<li><span style="font-weight: bold;">_map5[]</span> - 8 bits in size, is used for general storage.</li>
</ul>
<table style="text-align: left;" border="1" cellpadding="2"
cellspacing="2" width="100%">
<tbody>
<tr>
<th style="white-space: nowrap; text-align: left;">class</th>
<th style="white-space: nowrap; text-align: center;">_map_owner[L1] (8)</th>
<th style="white-space: nowrap; text-align: center;">_map2[L2] (16)</th>
<th style="white-space: nowrap; text-align: center;">_map3[lo& hi,L3] (16)</th>
<th style="white-space: nowrap; text-align: center;">_map_type_and_height[L4] (8)</th>
<th style="white-space: nowrap; text-align: center;">_map5[L5] (8)</th>
</tr>
<tr>
<td style="white-space: nowrap; text-align: left;">(0) ground</td>
<td style="white-space: nowrap; text-align: center;">XXXX XXXX</td>
<td style="white-space: nowrap; text-align: center;"><span class="freebits">OOOO OOOO OOOO OOOO</span></td>
<td style="white-space: nowrap; text-align: center;">XXXX <span class="freebits">OOOO OO</span>XX XXXX</td>
<td style="white-space: nowrap; text-align: center;">XXXX XXXX</td>
<td style="white-space: nowrap; text-align: center;">XXXX X<span class="freebits">O</span>XX</td>
</tr>
<tr>
<td style="white-space: nowrap; text-align: left;">(1) rail</td>
<td style="white-space: nowrap; text-align: center;"><span class="abuse">XXXX XXXX</span></td>
<td style="white-space: nowrap; text-align: center;">XXXX XXXX <span class="freebits">OOOO OOOO</span><br>
</td>
<td style="white-space: nowrap; text-align: center;">XXXX XXXX XXX<span class="freebits">O OOOO</span><br>
</td>
<td style="white-space: nowrap; text-align: center;">XXXX XXXX</td>
<td style="white-space: nowrap; text-align: center;">XXXX XXXX<br>
</td>
</tr>
<tr>
<td>
<ul>
<li style="white-space: nowrap; text-align: left;">depot/checkpoint</li>
</ul>
</td>
<td style="text-align: center;">-inherit-</td>
<td style="text-align: center;"><span class="freebits">OOOO OOOO OOOO OOOO</span></td>
<td style="text-align: center;">XXXX X<span class="freebits">OOO</span> XXXX XXXX</td>
<td style="text-align: center;">-inherit-</td>
<td style="white-space: nowrap; text-align: center;">XXX<span class="freebits">O OO</span>XX</td>
</tr>
<tr>
<td style="white-space: nowrap; text-align: left;">(2) road</td>
<td style="text-align: center;">XXXX XXXX</td>
<td style="text-align: center;"><span class="abuse">XXXX XXXX XXXX XXXX</span></td>
<td style="text-align: center;"><span class="freebits">OOOO OOOO</span> XXXX XXXX</td>
<td style="text-align: center;">XXXX XXXX</td>
<td style="text-align: center;">XXXX XXXX</td>
</tr>
<tr>
<td>
<ul>
<li style="white-space: nowrap; text-align: left;">level crossing</li>
</ul>
</td>
<td style="text-align: center;">-inherit-</td>
<td style="text-align: center;"><span class="abuse">XXXX XXXX XXXX XXXX</span></td>
<td style="text-align: center;">XXXX XXXX XXXX XXXX</td>
<td style="text-align: center;">-inherit-</td>
<td style="text-align: center;"><span class="freebits">OO</span>XX XXXX</td>
</tr>
<tr>
<td>
<ul>
<li style="white-space: nowrap; text-align: left;">road depot</li>
</ul>
</td>
<td style="text-align: center;">-inherit-</td>
<td style="text-align: center;"><span class="freebits">OOOO OOOO OOOO OOOO</span></td>
<td style="text-align: center;"><span class="freebits">OOOO OOOO OOOO OOO</span>X</td>
<td style="text-align: center;">-inherit-</td>
<td style="text-align: center;">XXXX XXXX</td>
</tr>
<tr>
<td style="white-space: nowrap; text-align: left;">(3) town</td>
<td style="white-space: nowrap; text-align: center;"><span class="abuse">XXXX XXXX</span></td>
<td style="white-space: nowrap; text-align: center;">XXXX XXXX XXXX XXXX<br>
</td>
<td style="white-space: nowrap; text-align: center;">XXXX XXXX XXXX XXXX<br>
</td>
<td style="white-space: nowrap; text-align: center;">XXXX XXXX</td>
<td style="white-space: nowrap; text-align: center;">XXXX XX<span class="freebits">O</span>X</td>
</tr>
<tr>
<td style="white-space: nowrap; text-align: left;">(4) trees</td>
<td style="white-space: nowrap; text-align: center;"><span class="abuse">XXXX XXXX</span></td>
<td style="white-space: nowrap; text-align: center;">XXXX XX<span class="freebits">OO OOOO OOOO</span></td>
<td style="white-space: nowrap; text-align: center;">XXXX XXXX <span class="freebits">OO</span>XX XXXX</td>
<td style="white-space: nowrap; text-align: center;">XXXX XXXX</td>
<td style="white-space: nowrap; text-align: center;">XXX<span class="freebits">O OO</span>XX</td>
</tr>
<tr>
<td style="white-space: nowrap; text-align: left;">(5) station</td>
<td style="white-space: nowrap; text-align: center;">XXXX XXXX</td>
<td style="white-space: nowrap; text-align: center;">XXXX XXXX XXXX XXXX</td>
<td style="white-space: nowrap; text-align: center;">XXXX X<span class="freebits">OOO</span> XXXX XXXX</td>
<td style="white-space: nowrap; text-align: center;">XXXX XXXX</td>
<td style="white-space: nowrap; text-align: center;">XXXX XXXX</td>
</tr>
<tr>
<td style="white-space: nowrap; text-align: left;">(6) water</td>
<td style="white-space: nowrap; text-align: center;">XXXX XXXX</td>
<td style="white-space: nowrap; text-align: center;"><span class="freebits">OOOO OOOO OOOO OOOO</span></td>
<td style="white-space: nowrap; text-align: center;"><span class="freebits">OOOO OOOO OOOO OOOO</span></td>
<td style="white-space: nowrap; text-align: center;">XXXX XXXX</td>
<td style="white-space: nowrap; text-align: center;">XXXX XXXX</td>
</tr>
<tr>
<td style="white-space: nowrap; text-align: left;">(8) industry</td>
<td style="white-space: nowrap; text-align: center;"><span class="abuse">XXXX X</span><span class="freebits">OO</span><span class="abuse">X</span></td>
<td style="white-space: nowrap; text-align: center;">XXXX XXXX XXXX XXXX</td>
<td style="white-space: nowrap; text-align: center;"><span class="freebits">OOOO OOOO OOOO OOOO</span></td>
<td style="white-space: nowrap; text-align: center;">XXXX XXXX</td>
<td style="white-space: nowrap; text-align: center;">XXXX XXXX</td>
</tr>
<tr>
<td>
<ul>
<li style="white-space: nowrap; text-align: left;">bubble/sugar/toffee</li>
</ul>
</td>
<td style="text-align: center;">-inherit-</td>
<td style="text-align: center;">-inherit-</td>
<td style="text-align: center;">XXXX XXXX <span class="freebits">OOOO OOOO</span></td>
<td style="text-align: center;">-inherit-</td>
<td style="text-align: center;">-inherit-</td>
</tr>
<tr>
<td>
<ul>
<li style="white-space: nowrap; text-align: left;">toy factory</li>
</ul>
</td>
<td style="text-align: center;">-inherit-</td>
<td style="text-align: center;">-inherit-</td>
<td style="text-align: center;">XXXX XXXX XXXX XXXX</td>
<td style="text-align: center;">-inherit-</td>
<td style="text-align: center;">-inherit-</td>
</tr>
<tr>
<td>
<ul>
<li style="white-space: nowrap; text-align: left;">gold/copper/coal</li>
</ul>
</td>
<td style="text-align: center;">XXXX XXXX</td>
<td style="text-align: center;">-inherit-</td>
<td style="text-align: center;">-inherit-</td>
<td style="text-align: center;">-inherit-</td>
<td style="text-align: center;">-inherit-</td>
</tr>
<tr>
<td>
<ul>
<li style="white-space: nowrap; text-align: left;">oil wells</li>
</ul>
</td>
<td style="text-align: center;">-inherit-</td>
<td style="text-align: center;">-inherit-</td>
<td style="text-align: center;">-inherit-</td>
<td style="text-align: center;">-inherit-</td>
<td style="text-align: center;">-inherit-</td>
</tr>
<tr>
<td>
<ul>
<li style="white-space: nowrap; text-align: left;">power station</li>
</ul>
</td>
<td style="text-align: center;">XXXX XX<span class="freebits">O</span>X</td>
<td style="text-align: center;">-inherit-</td>
<td style="text-align: center;">-inherit-</td>
<td style="text-align: center;">-inherit-</td>
<td style="text-align: center;">-inherit-</td>
</tr>
<tr>
<td style="white-space: nowrap; text-align: left;">(9) tunnel</td>
<td style="white-space: nowrap; text-align: center;">XXXX XXXX</td>
<td style="white-space: nowrap; text-align: center;"><span class="freebits">OOOO OOOO OOOO OOOO</span></td>
<td style="white-space: nowrap; text-align: center;">XXXX <span class="freebits">OOOO OOOO OOO</span>X</td>
<td style="white-space: nowrap; text-align: center;">XXXX XXXX</td>
<td style="white-space: nowrap; text-align: center;">XXXX XXXX</td>
</tr>
<tr>
<td>
<ul>
<li style="white-space: nowrap; text-align: left;">bridge</li>
</ul>
</td>
<td style="text-align: center;">XXXX XXXX</td>
<td style="text-align: center;"><span class="abuse">XXXX XXXX</span> <span class="freebits">OOOO OOOO</span></td>
<td style="text-align: center;">XXXX XXXX <span class="freebits">OOOO OOO</span>X</td>
<td style="text-align: center;">XXXX XXXX</td>
<td style="text-align: center;">XXXX XXXX</td>
</tr>
<tr>
<td style="white-space: nowrap; text-align: left;">(10) various (HQ)</td>
<td style="white-space: nowrap; text-align: center;">XXXX XXXX</td>
<td style="white-space: nowrap; text-align: center;"><span class="freebits">OOOO OOOO OOOO OOOO</span></td>
<td style="white-space: nowrap; text-align: center;"><span class="freebits">OOOO OOOO OOOO OOOO</span></td>
<td style="white-space: nowrap; text-align: center;">XXXX XXXX</td>
<td style="white-space: nowrap; text-align: center;">XXXX XXXX</td>
</tr>
</tbody>
</table>
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