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<h1 class="title">Tank Wars - 10-Minute Complete Step-by-Step Tutorial</h1>


<div id="table-of-contents">
<h2>Table of Contents</h2>
<div id="text-table-of-contents">
<ul>
<li><a href="#sec-1">Prerequisites : </a></li>
<li><a href="#sec-2">Introduction : </a></li>
<li><a href="#sec-3">Aim of the Game: </a></li>
<li><a href="#sec-4">Instructions for running the game </a></li>
<li><a href="#sec-5">Your Score and Number of Moves left </a></li>
<li><a href="#sec-6">Step 0 - The co-ordinate axes </a></li>
<li><a href="#sec-7">Step 1 - A simple proof-of-concept Tank: </a></li>
<li><a href="#sec-8">Step 2 - Each of the 8 moves possible </a></li>
<li><a href="#sec-9">Code Example - Attack enemy falcon </a></li>
<li><a href="#sec-10">Step 3 - Carries out each of the four actions </a></li>
<li><a href="#sec-11">Code Example - Attack enemy bunkers </a></li>
<li><a href="#sec-12">Step 4 - Introduce calculate_best_action_plan </a></li>
<li><a href="#sec-13">Code Example - Dodge bullets </a></li>
<li><a href="#sec-14">Step 5 - Creating some local functions for calculations of your own </a></li>
<li><a href="#sec-15">Step 6 - Changing Decision Table weightage </a></li>
<li><a href="#sec-16">Introducing Info </a></li>
<li><a href="#sec-17">Introducing the Map </a></li>
<li><a href="#sec-18">Direction </a></li>
<li><a href="#sec-19">Move </a></li>
<li><a href="#sec-20">Position </a></li>
<li><a href="#sec-21">Object Info </a></li>
<li><a href="#sec-22">Bullet Info </a></li>
<li><a href="#sec-23">Scoring Key </a></li>
<li><a href="#sec-24">Testing </a></li>
<li><a href="#sec-25">Creating maps </a></li>
<li><a href="#sec-26">Hints and Cautions about various advanced strategies </a></li>
</ul>
</div>
</div>

<div id="outline-container-1" class="outline-2">
<h2 id="sec-1">Prerequisites : </h2>
<div class="outline-text-2" id="text-1">

<ul>
<li id="sec-1.1">The TankWars.zip file - Unzip it in any folder of your choice <br/>
</li>
<li id="sec-1.2">10 minutes <br/>
</li>
</ul>
</div>

</div>

<div id="outline-container-2" class="outline-2">
<h2 id="sec-2">Introduction : </h2>
<div class="outline-text-2" id="text-2">

<ul>
<li id="sec-2.1">All you need to do to control your Tank is fill in the get_player_move () function in DecisionMaker1.cpp. <br/>
</li>
<li id="sec-2.2">This tutorial will take you through a series of increasingly complex definitions for that function. <br/>
</li>
<li id="sec-2.3">That will also familiarize you with the general information and structure of the code available to you to make your ultimate, indestructible Tank <br/>
</li>
<li id="sec-2.4">If you're really, REALLY impatient, you can simply check out the code bits under each step and copy-paste them into your DecisionMaker file and run them. You'd probably figure the rest out as you go along. <br/>
</li>
</ul>
</div>

</div>

<div id="outline-container-3" class="outline-2">
<h2 id="sec-3">Aim of the Game: </h2>
<div class="outline-text-2" id="text-3">

<ul>
<li id="sec-3.1">To end the game with maximum points <br/>
</li>
<li id="sec-3.2">The game ends when either your Falcon (military base) is killed or if your Tank dies or if the same happens to the opponent or if the Maximum number of moves are exceeded <br/>
</li>
</ul>
</div>

</div>

<div id="outline-container-4" class="outline-2">
<h2 id="sec-4">Instructions for running the game </h2>
<div class="outline-text-2" id="text-4">

<ul>
<li id="sec-4.1">Simply open a terminal and type <br/>

<p><br/>
<pre class="src src-bash">make play
</pre>


</p></li>
<li id="sec-4.2">To display the game in your browser, just type <br/>

<p><br/>
<pre class="src src-bash">make display
</pre>


</p></li>
</ul>
</div>

</div>

<div id="outline-container-5" class="outline-2">
<h2 id="sec-5">Your Score and Number of Moves left </h2>
<div class="outline-text-2" id="text-5">

<ul>
<li id="sec-5.1">The get_player_move () function receives <br/>
<ul>
<li id="sec-5.1.1">Your score [my_score] and <br/>
</li>
<li id="sec-5.1.2">Your enemy's score [enemy_score]. <br/>
</li>
</ul>
</li>
<li id="sec-5.2">It also receives the [total_moves_done] so far <br/>
</li>
<li id="sec-5.3">MAX_NUMBER_OF_MOVES tells you how many moves you can make <br/>
</li>
<li id="sec-5.4"><a href="#sec-23">Scoring Key</a> <br/>
</li>
</ul>
</div>

</div>

<div id="outline-container-6" class="outline-2">
<h2 id="sec-6">Step 0 - The co-ordinate axes </h2>
<div class="outline-text-2" id="text-6">


<p><br/>
(0, 0)<br/>
+&mdash;&mdash;&mdash;&mdash;&mdash;&mdash;&mdash;&mdash;&gt; (y-axis)<br/>
v<br/>
(x-axis)<br/>
</p>
<p><br/>
^ UP     <br/>
LEFT    |   RIGHT<br/>
&lt;&ndash;&mdash;&mdash;|&ndash;&mdash;&mdash;&gt;<br/>
v DOWN<br/>
</p>
<p><br/>
</p></div>

</div>

<div id="outline-container-7" class="outline-2">
<h2 id="sec-7">Step 1 - A simple proof-of-concept Tank: </h2>
<div class="outline-text-2" id="text-7">

<ul>
<li id="sec-7.1">Just type : <br/>

<p><br/>
<pre class="src src-c++"><span style="color: #a020f0;">return</span> Move (GO_RIGHT);
</pre>


</p></li>
<li id="sec-7.2">Not surprisingly, this makes your Tank move right each time <br/>
</li>
<li id="sec-7.3">However, that would have either led to it being shot by one of the Machine Guns out there or inevitably dashing into a wall and dying. <br/>
</li>
<li id="sec-7.4">Note : If your Tank dies, the opponent gains 400 points, so that is another incentive to stay alive <br/>
</li>
</ul>
</div>

</div>

<div id="outline-container-8" class="outline-2">
<h2 id="sec-8">Step 2 - Each of the 8 moves possible </h2>
<div class="outline-text-2" id="text-8">

<ul>
<li id="sec-8.1">Choose any one of the following 8 moves <br/>

<p><br/>
<pre class="src src-c++"><span style="color: #99968b; font-style: italic;">// </span><span style="color: #b22222;">Go in one of the four directions
</span><span style="color: #a020f0;">return</span> Move (GO_UP);
<span style="color: #a020f0;">return</span> Move (GO_DOWN);
<span style="color: #a020f0;">return</span> Move (GO_LEFT);
<span style="color: #a020f0;">return</span> Move (GO_RIGHT);
 
<span style="color: #99968b; font-style: italic;">// </span><span style="color: #b22222;">Shoot in one of the four directions
</span><span style="color: #a020f0;">return</span> Move (SHOOT_UP);
<span style="color: #a020f0;">return</span> Move (SHOOT_DOWN);
<span style="color: #a020f0;">return</span> Move (SHOOT_LEFT);
<span style="color: #a020f0;">return</span> Move (SHOOT_RIGHT);
</pre>


</p></li>
<li id="sec-8.2">Documentation - <a href="#sec-19">Move</a> <br/>
</li>
</ul>
</div>

</div>

<div id="outline-container-9" class="outline-2">
<h2 id="sec-9">Code Example - Attack enemy falcon </h2>
<div class="outline-text-2" id="text-9">

<ul>
<li id="sec-9.1">Let's dive into the actual coding process by skipping all the boring documentation bit <br/>
</li>
<li id="sec-9.2">How would you attack the Enemy Falcon? <br/>
</li>
<li id="sec-9.3">For that you need 3 things <br/>
<ul>
<li id="sec-9.3.1">The position of the falcon <br/>
</li>
<li id="sec-9.3.2">The next move you have to make in order to get closer to it <br/>
</li>
<li id="sec-9.3.3">And the direction to shoot in so that you hit the Falcon <br/>
</li>
</ul>
</li>
<li id="sec-9.4">The answers are in the variable my_info in the DecisionMaker class <br/>
</li>
<li id="sec-9.5">It contains <br/>

<p><br/>
<pre class="src src-c++"><span style="color: #228b22;">object_info</span> <span style="color: #b8860b;">opp_falcon</span>;
</pre>


</p></li>
<li id="sec-9.6">Also, my_info contains a boolean - can_shoot_at_enemy_falcon - which is true whenever the Falcon is in your sights <br/>
</li>
<li id="sec-9.7">The resulting code is simple enough <br/>

<p><br/>
<pre class="src src-c++"><span style="color: #99968b; font-style: italic;">// </span><span style="color: #b22222;">If you can shoot at the Enemy Falcon from the current position, do so
</span><span style="color: #228b22;">Move</span> <span style="color: #b8860b;">my_next_move</span>;
<span style="color: #a020f0;">if</span> (my_info.can_shoot_at_enemy_falcon){
     <span style="color: #99968b; font-style: italic;">// </span><span style="color: #b22222;">This is the move to go closer
</span>     my_next_move = my_info.my_falcon.initial_move;
     <span style="color: #99968b; font-style: italic;">// </span><span style="color: #b22222;">However, we don't want to go closer
</span>     <span style="color: #99968b; font-style: italic;">// </span><span style="color: #b22222;">We want to shoot in that direction!
</span>     my_next_move.shoot = <span style="color: #5f9ea0;">true</span>;
     <span style="color: #a020f0;">return</span> my_next_move;
}
<span style="color: #a020f0;">else</span>{
     <span style="color: #99968b; font-style: italic;">// </span><span style="color: #b22222;">Just go closer
</span>     my_next_move = my_info.my_falcon.initial_move;
     <span style="color: #a020f0;">return</span> my_next_move;
}
</pre>


</p></li>
<li id="sec-9.8">Documentation - <a href="#sec-20">Position</a> <br/>
</li>
</ul>
</div>

</div>

<div id="outline-container-10" class="outline-2">
<h2 id="sec-10">Step 3 - Carries out each of the four actions </h2>
<div class="outline-text-2" id="text-10">

<ul>
<li id="sec-10.1">Let's try making some more complex moves <br/>
</li>
<li id="sec-10.2">Say you want to pick up the gold piece nearest to you <br/>
</li>
<li id="sec-10.3">It's simple. All you need to do is <br/>

<p><br/>
<pre class="src src-c++"><span style="color: #228b22;">int</span> <span style="color: #b8860b;">my_action_plan</span> = GO_TO_NEAREST_GOLD
get_best_move_for (my_action_plan)
</pre>


</p></li>
<li id="sec-10.4">You can pass any of the following default Action Plans as parameters <br/>
<table border="2" cellspacing="0" cellpadding="6" rules="groups" frame="hsides">
<caption></caption>
<colgroup><col align="left" /><col align="left" />
</colgroup>
<tbody>
<tr><td>GO_TO_NEAREST_GOLD</td><td>Each time, your Tank will move in the direction of the nearest gold piece. Neat, huh?</td></tr>
<tr><td>ATTACK_ENEMY_FALCON</td><td>That will take your Tank closer to the Enemy Falcon and shoot if it is in your sights.</td></tr>
<tr><td>ATTACK_ENEMY_TANK</td><td>This will take your Tank closer to the Enemy Tank and shoot if it is in your sights</td></tr>
<tr><td>DEFEND_MY_FALCON</td><td>Just go back towards your Falcon so that you can defend it from any attack</td></tr>
</tbody>
</table>

</li>
<li id="sec-10.5">get_best_move_for, as the name suggests, gets you the best move you could make for a particular Action Plan. <br/>
</li>
</ul>
</div>

</div>

<div id="outline-container-11" class="outline-2">
<h2 id="sec-11">Code Example - Attack enemy bunkers </h2>
<div class="outline-text-2" id="text-11">

<ul>
<li id="sec-11.1">Again, my_info comes to the rescue. You have a vector of object_infos which tell you about each bunker's position, distance from you, initial_move, etc. <br/>
</li>
<li id="sec-11.2">Code is pretty much the same as for attack enemy falcon <br/>
</li>
<li id="sec-11.3">And, you can do the same to attack the Enemy Tank itself! <br/>
</li>
</ul>
</div>

</div>

<div id="outline-container-12" class="outline-2">
<h2 id="sec-12">Step 4 - Introduce calculate_best_action_plan </h2>
<div class="outline-text-2" id="text-12">

<ul>
<li id="sec-12.1">However, it can get pretty monotonous doing the same action again and again. <br/>
</li>
<li id="sec-12.2">To aid in making your Tank dynamic and more adaptive, we have come up with a rudimentary Decision Making model <br/>
You can use it to calculate the best moves for your Tank based on the situation and your preferences.<br/>
</li>
<li id="sec-12.3">We provide four different strategies that you can choose by default. <br/>
</li>
<li id="sec-12.4">They are <br/>
<ul>
<li id="sec-12.4.1">AGGRESSIVE <br/>
</li>
<li id="sec-12.4.2">DEFENSIVE <br/>
</li>
<li id="sec-12.4.3">GREEDY <br/>
</li>
<li id="sec-12.4.4">CUSTOMIZED <br/>
</li>
</ul>
</li>
<li id="sec-12.5">To put it in action, just say <br/>

<p><br/>
<pre class="src src-c++"><span style="color: #228b22;">int</span> <span style="color: #b8860b;">my_strategy</span> = AGGRESSIVE;
<span style="color: #228b22;">int</span> <span style="color: #b8860b;">my_action_plan</span> = calculate_best_action_plan_for (my_strategy);
<span style="color: #99968b; font-style: italic;">// </span><span style="color: #b22222;">Now, my_action_plan will contain one of the four basic action plans mentioned above
</span><span style="color: #a020f0;">return</span> get_best_move_for (my_action_plan);
</pre>


</p></li>
<li id="sec-12.6">Explanation <br/>
<ul>
<li id="sec-12.6.1">What calculate_best_action_plan_for does is it looks for the utility or expected benefits of each of the four default Action Plans. <br/>
</li>
<li id="sec-12.6.2">This is done based on the weightage given for each plan and the difficulty of carrying each plan out as defined in your DecisionMaker object. <br/>
</li>
<li id="sec-12.6.3">It then returns the Action Plan which has maximum expected benefit <br/>
</li>
<li id="sec-12.6.4">To see what the default weightages are, go to DECISION_MAKER::DMinitializer function in DecisionMaker1.cpp <br/>
</li>
<li id="sec-12.6.5">To see how the default difficulty values are determined, go to DECISION_MAKER::fill_difficulty_table function in DecisionMaker1.cpp <br/>
</li>
<li id="sec-12.6.6">By default, the difficulty of carrying out an action plan is the shortest distance to the goal object. ie. for GO_TO_NEAREST_GOLD, the difficulty is the distance to the nearest gold <br/>
</li>
<li id="sec-12.6.7">In short, if a particular Action Plan, say ATTACK_ENEMY_TANK, is given higher weightage than the others then it will be recommended as the best plan when the distance from the enemy tank is not too high <br/>
</li>
</ul>
</li>
</ul>
</div>

</div>

<div id="outline-container-13" class="outline-2">
<h2 id="sec-13">Code Example - Dodge bullets </h2>
<div class="outline-text-2" id="text-13">

<ul>
<li id="sec-13.1">If you play the game for long enough, you'll find that most of the time, your Tank dies because it was hit by some bullet <br/>
</li>
<li id="sec-13.2">Let's try to dodge those pesky bullets <br/>
</li>
<li id="sec-13.3">A naive method <br/>

<p><br/>
<pre class="src src-c++"><span style="color: #228b22;">bullet_info</span> <span style="color: #b8860b;">curr_bullet</span>;
<span style="color: #99968b; font-style: italic;">// </span><span style="color: #b22222;">Tank's current position
</span>posn = my_info.curr_posn;

<span style="color: #99968b; font-style: italic;">// </span><span style="color: #b22222;">Go this many steps to the RIGHT and see if any bullet there is
</span><span style="color: #99968b; font-style: italic;">// </span><span style="color: #b22222;">coming towards you
</span><span style="color: #a020f0;">for</span> (i = 1; i &lt;= BULLET_SPEED; i++){

     <span style="color: #99968b; font-style: italic;">// </span><span style="color: #b22222;">Make posn become the position to its right
</span>     posn.go_in_direction (Direction (RIGHT));
     safe_dirn = UP;            <span style="color: #99968b; font-style: italic;">// </span><span style="color: #b22222;">Direction in which to dodge
</span>     opposite_dirn = LEFT;      <span style="color: #99968b; font-style: italic;">// </span><span style="color: #b22222;">Direction in which bullets will come
</span>
     <span style="color: #99968b; font-style: italic;">// </span><span style="color: #b22222;">For each bullet out there
</span>     <span style="color: #a020f0;">for</span> (j = 0; j &lt; my_info.machine_gun_bullets.size (); j++){
          curr_bullet = my_info.machine_gun_bullets[j];

          <span style="color: #99968b; font-style: italic;">// </span><span style="color: #b22222;">If you are within its range and if it is coming towards you
</span>          <span style="color: #a020f0;">if</span> (curr_bullet.posn == posn &amp;&amp; curr_bullet.dirn == Direction (opposite_dirn)){
               <span style="color: #a020f0;">return</span> Move (safe_dirn); <span style="color: #99968b; font-style: italic;">// </span><span style="color: #b22222;">Dodge
</span>          }
     }
}
</pre>


</p></li>
<li id="sec-13.4">This example introduces <br/>
<ul>
<li id="sec-13.4.1">Position curr_posn <br/>
</li>
<li id="sec-13.4.2">BULLET_SPEED <br/>
Each bullet travels BULLET_SPEED steps in one move<br/>
</li>
<li id="sec-13.4.3">Direction <br/>
Documentation - <a href="#sec-18">Direction</a><br/>
</li>
<li id="sec-13.4.4">Bullet Lists in my_info <br/>
Documentation - <a href="#sec-22">Bullet Info</a><br/>
<ul>
<li id="sec-13.4.4.1">The info object contains 3 Bullet Lists <br/>
<table border="2" cellspacing="0" cellpadding="6" rules="groups" frame="hsides">
<caption></caption>
<colgroup><col align="left" /><col align="left" />
</colgroup>
<tbody>
<tr><td>my_bullets</td><td>List of info about all my bullets</td></tr>
<tr><td>enemy_bullets</td><td>List of info about all enemy bullets</td></tr>
<tr><td>machine_gun_bullets</td><td>List of info about all MG bullets</td></tr>
</tbody>
</table>

</li>
</ul>
</li>
</ul>
</li>
<li id="sec-13.5">Of course, it is just a toy example. :-) <br/>
</li>
<li id="sec-13.6">Your actual function should take care of a lot of factors and check for various corner cases. Good Luck! :-) <br/>
</li>
</ul>
</div>

</div>

<div id="outline-container-14" class="outline-2">
<h2 id="sec-14">Step 5 - Creating some local functions for calculations of your own </h2>
<div class="outline-text-2" id="text-14">

<ul>
<li id="sec-14.1">Simple. You can just create new functions in the DecisionMaker1.cpp file and call them. <br/>
</li>
<li id="sec-14.2">Just remember not to change anything anywhere else. <br/>
</li>
</ul>
</div>

</div>

<div id="outline-container-15" class="outline-2">
<h2 id="sec-15">Step 6 - Changing Decision Table weightage </h2>
<div class="outline-text-2" id="text-15">

<ul>
<li id="sec-15.1">Of course, you don't have to put up with the default weightages or the default ways of calculating difficulties. Try experimenting. <br/>
</li>
<li id="sec-15.2">Go to [ DMinitializer function ] <br/>
</li>
<li id="sec-15.3">For example, if you feel DEFENSIVE plan should never even consider ATTACK_ENEMY_TANK or ATTACK_ENEMY_FALCON, then put weightages for them as 0. <br/>
</li>
<li id="sec-15.4">Maybe set GREEDY's weightage for GO_TO_NEAREST_GOLD as 100 and everything else as 0. That's really greedy! :-). Be careful, though, chances of getting shot by Machine Guns and the Enemy tank are very high. <br/>
</li>
<li id="sec-15.5">You can set the values for each Strategy in the Weightage Table on the fly by calling <br/>

<p><br/>
<pre class="src src-c++">set_weightage_table (AGGRESSIVE, 20, 80, 80, 0);
</pre>


</p></li>
<li id="sec-15.6"><a name="Info" id="Info"></a>This can be useful when you want to tweaks based on the current situation <br/>
</li>
</ul>
</div>

</div>

<div id="outline-container-16" class="outline-2">
<h2 id="sec-16">Introducing Info </h2>
<div class="outline-text-2" id="text-16">

<ul>
<li id="sec-16.1">Info object contains pretty much all the basic game information you're going to need <br/>
</li>
<li id="sec-16.2">This way you don't even have to know what Breadth-First Search means or deal with things like 'What is the next move to make in order to shoot the Enemy Falcon?'. Phew! <br/>
</li>
<li id="sec-16.3">DecisionMaker contains two objects <br/>

<p><br/>
<pre class="src src-c++"><span style="color: #228b22;">Info</span> <span style="color: #b8860b;">my_info</span>;
<span style="color: #228b22;">Info</span> <span style="color: #b8860b;">opp_info</span>;
</pre>


</p></li>
<li id="sec-16.4">my_info pertains to information about your Tank <br/>
</li>
<li id="sec-16.5">opp_info pertains to information about the Enemy Tank <br/>
</li>
<li id="sec-16.6">Contents <br/>
<table border="2" cellspacing="0" cellpadding="6" rules="groups" frame="hsides">
<caption></caption>
<colgroup><col align="left" /><col align="left" /><col align="left" />
</colgroup>
<thead>
<tr><th scope="col">Type</th><th scope="col">Variable</th><th scope="col">Value</th></tr>
</thead>
<tbody>
<tr><td>Position</td><td>curr_posn</td><td>Your current Position</td></tr>
<tr><td>ID</td><td>my_ID</td><td>Your ID</td></tr>
<tr><td>ID</td><td>enemy_ID</td><td>Enemy ID</td></tr>
<tr><td>bool</td><td>can_shoot_at_enemy_tank</td><td>Whether the enemy tank is in your sights</td></tr>
<tr><td>bool</td><td>can_shoot_at_enemy_falcon</td><td>Whether the enemy Falcon is in your sights</td></tr>
<tr><td>Direction</td><td>shoot_falcon_dirn</td><td>Direction in which Enemy Falcon lies</td></tr>
<tr><td>Direction</td><td>shoot_enemy_tank_dirn</td><td>Direction in which Enemy Tank lies</td></tr>
<tr><td>Vector of Bullet Info</td><td>my_bullets</td><td>Information about all bullets you shot</td></tr>
<tr><td>Vector of Bullet Info</td><td>enemy_bullets</td><td>Information about all bullets the Enemy shot</td></tr>
<tr><td>Vector of Bullet Info</td><td>machine_gun_bullets</td><td>Information about all bullets the MGs shot</td></tr>
<tr><td>Vector of object_infos</td><td>gold</td><td>Information about all gold pieces</td></tr>
<tr><td>Object_info</td><td>my_falcon</td><td>Information about your falcon</td></tr>
<tr><td>Object_info</td><td>opp_falcon</td><td>Information about Enemy falcon</td></tr>
<tr><td>Object_info</td><td>opp_tank</td><td>Information about Enemy Tank</td></tr>
<tr><td>Object_info</td><td>nearest_gold</td><td>Information about the nearest gold piece</td></tr>
<tr><td>bool</td><td>gold_available</td><td>Do any more gold pieces exist on Map?</td></tr>
</tbody>
</table>

<ul>
<li id="sec-16.6.1"><a name="Map" id="Map"></a>That's all <br/>
</li>
</ul>
</li>
</ul>
</div>

</div>

<div id="outline-container-17" class="outline-2">
<h2 id="sec-17">Introducing the Map </h2>
<div class="outline-text-2" id="text-17">

<ul>
<li id="sec-17.1">OK! So, now you have an all-new, shiny, mean and destructive Tank at your command. <br/>
</li>
<li id="sec-17.2">But, how exactly do you analyze the game? <br/>
</li>
<li id="sec-17.3">How do you know what to do? Should you be GREEDY? Should you switch to an AGGRESSIVE strategy? Should you do something else altogether? <br/>
</li>
<li id="sec-17.4">For that you need to look at the "Map" <br/>
</li>
<li id="sec-17.5">It is nothing but the 2-D array of cells in which all the Tanks, Bunkers, Falcons, Walls, etc. are stored. <br/>
</li>
<li id="sec-17.6">Each object occupies one cell. <br/>
</li>
<li id="sec-17.7">Your DecisionMaker class will have an object called <br/>

<p><br/>
<pre class="src src-c++"><span style="color: #228b22;">MapClass</span> <span style="color: #b8860b;">my_map</span>;
</pre>


</p></li>
<li id="sec-17.8">This contains a 2-D array - <br/>

<p><br/>
<pre class="src src-c++"><span style="color: #228b22;">char</span> <span style="color: #b8860b;">map</span>[MAP_SIZE][MAP_SIZE];
</pre>


</p></li>
<li id="sec-17.9">This is what will get updated each time as your Tank and your Enemy's tank move around and shoot bullets <br/>
</li>
<li id="sec-17.10"><a name="Symbols" id="Symbols"></a>This is what is shown in your browser when you call 'make display' <br/>
</li>
<li id="sec-17.11">The character symbols represent various objects <br/>
<table border="2" cellspacing="0" cellpadding="6" rules="groups" frame="hsides">
<caption></caption>
<colgroup><col align="left" /><col align="left" /><col align="left" />
</colgroup>
<thead>
<tr><th scope="col">Object</th><th scope="col">Constant defined</th><th scope="col">Actual character</th></tr>
</thead>
<tbody>
<tr><td>Gold piece</td><td>GOLD</td><td>G</td></tr>
<tr><td>Wall</td><td>WALL</td><td>#</td></tr>
<tr><td>Empty cell</td><td>EMPTY</td><td>.</td></tr>
<tr><td>Dead Tank / MG</td><td>DEAD</td><td>D</td></tr>
<tr><td>Tank 1</td><td>TANK1</td><td>1</td></tr>
<tr><td>Bunker of Tank 1</td><td>BUNKER1</td><td>X</td></tr>
<tr><td>Falcon of Tank 1</td><td>FALCON1</td><td>F</td></tr>
<tr><td>Bullet of Tank 1</td><td>BULLET1</td><td>A</td></tr>
<tr><td>Tank 2</td><td>TANK2</td><td>2</td></tr>
<tr><td>Bunker of Tank 2</td><td>BUNKER2</td><td>Y</td></tr>
<tr><td>Falcon of Tank 2</td><td>FALCON2</td><td>E</td></tr>
<tr><td>Bullet of Tank 2</td><td>BULLET2</td><td>B</td></tr>
<tr><td>Machine Gun</td><td>MACHINE_GUN</td><td>M</td></tr>
<tr><td>Bullet of MG</td><td>MACHINE_GUN_BULLET</td><td>K</td></tr>
</tbody>
</table>

</li>
<li id="sec-17.12">You can access the elements of the map[][] array directly. Like so <br/>

<p><br/>
<pre class="src src-c++"><span style="color: #a020f0;">if</span> (my_map.map[i][j] == WALL){
     <span style="color: #99968b; font-style: italic;">// </span><span style="color: #b22222;">Then do something
</span>}
<span style="color: #a020f0;">else</span> <span style="color: #a020f0;">if</span> (my_map.map[i][j] == GOLD){
     <span style="color: #99968b; font-style: italic;">// </span><span style="color: #b22222;">Go for it!
</span>}
</pre>


</p></li>
<li id="sec-17.13">Or, more simply, you can simply use Positions <br/>

<p><br/>
<pre class="src src-c++"><span style="color: #228b22;">Direction</span> <span style="color: #b8860b;">d</span> = Direction (RIGHT);                <span style="color: #99968b; font-style: italic;">// </span><span style="color: #b22222;">or (LEFT) or (0), (1), etc.
</span>my_neighbour = curr_posn.get_neighbour (d);
<span style="color: #a020f0;">if</span> (my_map.get_element (my_neighbour) == WALL){
     <span style="color: #99968b; font-style: italic;">// </span><span style="color: #b22222;">Then do something
</span>}
<span style="color: #a020f0;">else</span> <span style="color: #a020f0;">if</span> (my_map.get_element (my_neighbour) == GOLD){
     <span style="color: #99968b; font-style: italic;">// </span><span style="color: #b22222;">Go for it!
</span>}
</pre>


</p></li>
</ul>
</div>

</div>

<div id="outline-container-18" class="outline-2">
<h2 id="sec-18"><a name="Direction" id="Direction"></a>Direction </h2>
<div class="outline-text-2" id="text-18">

<ul>
<li id="sec-18.1">Basically just a pair - xdir and ydir <br/>
</li>
<li id="sec-18.2">You can use it in different ways <br/>

<p><br/>
<pre class="src src-c++"><span style="color: #228b22;">Direction</span> <span style="color: #b8860b;">dirn</span> = Direction (LEFT); <span style="color: #99968b; font-style: italic;">// </span><span style="color: #b22222;">RIGHT, etc
</span><span style="color: #228b22;">Direction</span> <span style="color: #b8860b;">dirn2</span> = dirn;
<span style="color: #a020f0;">if</span> (dirn == Direction (1)){      <span style="color: #99968b; font-style: italic;">// </span><span style="color: #b22222;">1 : DOWN
</span>     <span style="color: #99968b; font-style: italic;">// </span><span style="color: #b22222;">Something or the other
</span>}
</pre>


</p></li>
</ul>
</div>

</div>

<div id="outline-container-19" class="outline-2">
<h2 id="sec-19"><a name="Move" id="Move"></a>Move </h2>
<div class="outline-text-2" id="text-19">

<ul>
<li id="sec-19.1">It has two variables <br/>
<table border="2" cellspacing="0" cellpadding="6" rules="groups" frame="hsides">
<caption></caption>
<colgroup><col align="left" /><col align="left" />
</colgroup>
<tbody>
<tr><td>bool</td><td>shoot</td></tr>
<tr><td>Direction</td><td>dirn</td></tr>
</tbody>
</table>

</li>
<li id="sec-19.2">Usage <br/>

<p><br/>
<pre class="src src-c++"><span style="color: #228b22;">Move</span> <span style="color: #b8860b;">my_move</span> = Move (SHOOT_LEFT);
<span style="color: #99968b; font-style: italic;">// </span><span style="color: #b22222;">or
</span><span style="color: #228b22;">Move</span> <span style="color: #b8860b;">move1</span>;
move1.shoot = <span style="color: #5f9ea0;">true</span>;
move1.dirn = Direction (LEFT);
<span style="color: #228b22;">Move</span> <span style="color: #b8860b;">move2</span> = move1;
</pre>


</p></li>
</ul>
</div>

</div>

<div id="outline-container-20" class="outline-2">
<h2 id="sec-20"><a name="Position" id="Position"></a>Position </h2>
<div class="outline-text-2" id="text-20">

<ul>
<li id="sec-20.1">Again just a pair - x, y <br/>
</li>
<li id="sec-20.2">Main usage <br/>

<p><br/>
<pre class="src src-c++"><span style="color: #228b22;">Position</span> <span style="color: #b8860b;">posn</span> = my_info.curr_posn;
my_left_neighbour = posn.get_neighbour (Direction (LEFT));
posn.go_in_direction (Direction (RIGHT));
<span style="color: #99968b; font-style: italic;">// </span><span style="color: #b22222;">Now, posn is the cell to the right
</span></pre>


</p></li>
</ul>
</div>

</div>

<div id="outline-container-21" class="outline-2">
<h2 id="sec-21"><a name="Object==Info" id="Object==Info"></a>Object Info </h2>
<div class="outline-text-2" id="text-21">

<table border="2" cellspacing="0" cellpadding="6" rules="groups" frame="hsides">
<caption></caption>
<colgroup><col align="left" /><col align="left" />
</colgroup>
<thead>
<tr><th scope="col">Variable</th><th scope="col">Value</th></tr>
</thead>
<tbody>
<tr><td>shortest_distance</td><td>Shortest Distance to the Object</td></tr>
<tr><td>posn</td><td>The Position of the Object</td></tr>
<tr><td>initial_move</td><td>The Move you need to make now to get closer to the Object</td></tr>
</tbody>
</table>

</div>

</div>

<div id="outline-container-22" class="outline-2">
<h2 id="sec-22"><a name="Bullet==Info" id="Bullet==Info"></a>Bullet Info </h2>
<div class="outline-text-2" id="text-22">

<table border="2" cellspacing="0" cellpadding="6" rules="groups" frame="hsides">
<caption></caption>
<colgroup><col align="left" /><col align="left" />
</colgroup>
<tbody>
<tr><td>posn</td><td>Current position of the Bullet</td></tr>
<tr><td>dirn</td><td>Direction in which it is travelling</td></tr>
</tbody>
</table>

</div>

</div>

<div id="outline-container-23" class="outline-2">
<h2 id="sec-23"><a name="Scoring==Key" id="Scoring==Key"></a>Scoring Key </h2>
<div class="outline-text-2" id="text-23">

<table border="2" cellspacing="0" cellpadding="6" rules="groups" frame="hsides">
<caption></caption>
<colgroup><col align="left" /><col align="right" />
</colgroup>
<thead>
<tr><th scope="col">Event</th><th scope="col">Points</th></tr>
</thead>
<tbody>
<tr><td>ENEMY_FALCON_KILLED</td><td>1000</td></tr>
<tr><td>ENEMY_KILLED</td><td>500</td></tr>
<tr><td>ALIVE_AT_THE_END</td><td>400</td></tr>
<tr><td>DESTROYED_ENEMY_BUNKER</td><td>65</td></tr>
<tr><td>PICKED_UP_GOLD</td><td>40</td></tr>
<tr><td>TIME_LIMIT_EXCEEDED</td><td>-300</td></tr>
<tr><td>INVALID_MOVE</td><td>-100</td></tr>
</tbody>
</table>

</div>

</div>

<div id="outline-container-24" class="outline-2">
<h2 id="sec-24">Testing </h2>
<div class="outline-text-2" id="text-24">

<ul>
<li id="sec-24.1">You can test your bots on your own computer by changing the code for DecisionMaker2 as well. <br/>
</li>
<li id="sec-24.2">You can even run your bot against another bot just like itself and seet what the result is! :-) <br/>
</li>
</ul>
</div>

</div>

<div id="outline-container-25" class="outline-2">
<h2 id="sec-25">Creating maps </h2>
<div class="outline-text-2" id="text-25">

<ul>
<li id="sec-25.1">To test your bot's functionality, you can try creating your own maps <br/>
</li>
<li id="sec-25.2">Simply edit 'map.txt' in your Tank-Wars folder <br/>
</li>
<li id="sec-25.3">The symbols representing each object are described in <a href="#sec-17.10">Symbols</a> <br/>
</li>
<li id="sec-25.4">The only conditions on the Map are that it should have <br/>
<ul>
<li id="sec-25.4.1">TANK1 <br/>
</li>
<li id="sec-25.4.2">TANK2 <br/>
</li>
<li id="sec-25.4.3">FALCON1 <br/>
</li>
<li id="sec-25.4.4">FALCON2 <br/>
</li>
</ul>
</li>
<li id="sec-25.5">That's all <br/>
</li>
<li id="sec-25.6">Some sample maps are present in maps/ directory. <br/>
</li>
</ul>
</div>

</div>

<div id="outline-container-26" class="outline-2">
<h2 id="sec-26">Hints and Cautions about various advanced strategies </h2>
<div class="outline-text-2" id="text-26">

<ul>
<li id="sec-26.1">Make sure you can handle Bunkers (both yours and the enemy's). Maps in the tournament will be more and more complex <br/>
</li>
<li id="sec-26.2">Make sure that your bot doesn't get stuck shooting continuously in the same direction <br/>
That can happen when both you and the enemy tank are facing each other and want to kill each other. The game might go on and on with you both shooting at each other<br/>
</li>
<li id="sec-26.3">Make sure you prioritize according to the situations and the point allocation. <br/>
</li>
</ul>
</div>
</div>
<div id="postamble">
<p class="author"> Author: Tank Wars Team
<a href="mailto:tankwars@exebit.org">&lt;tankwars@exebit.org&gt;</a>
</p>
<p class="date"> Date: 2011-03-13 Sun</p>
<p class="creator">HTML generated by org-mode 6.33x in emacs 23</p>
</div>
</div>
</body>
</html>