<?xml version="1.0"?>
<rss version="2.0">
	<channel>
		<title>Adjust camera depending on mouse location</title>
		<link>http://www.allegro.cc/forums/view/614956</link>
		<description>Allegro.cc Forum Thread</description>
		<webMaster>matthew@allegro.cc (Matthew Leverton)</webMaster>
		<lastBuildDate>Sun, 04 Jan 2015 09:52:51 +0000</lastBuildDate>
	</channel>
	<item>
		<description><![CDATA[<div class="mockup v2"><p>I&#39;m making a multiplayer shooter game and added a sniper to the game. I want the camera to move away from the player depending on how far the mouse is from the player whenever they get the sniper. For some reason I can&#39;t get it right. Whenever I did get it sorta working, it would only work whenever the player was in a certain place on the map. I want it to be sorta like the one in terraria in this video <a href="https://www.youtube.com/watch?v=GqmLiupdhzw&amp;feature=player_detailpage#t=38">https://www.youtube.com/watch?v=GqmLiupdhzw&amp;feature=player_detailpage#t=38</a> . I am using ALLEGRO_TRANSFORM for the camera. Nevermind... I got it with this code:</p><div class="source-code"><div class="toolbar"><span class="button numbers"><b>#</b></span><span class="button select">Select</span><span class="button expand">Expand</span></div><div class="inner"><span class="number">  1</span><span class="k1">void</span> UpdateCamera<span class="k2">(</span><span class="k1">float</span> <span class="k3">*</span>cameraPos, Player player<span class="k2">)</span> <span class="k2">{</span>
<span class="number">  2</span>  <span class="k1">if</span> <span class="k2">(</span>player.weapon <span class="k3">!</span><span class="k3">=</span> SNIPER<span class="k2">)</span> <span class="k2">{</span>
<span class="number">  3</span>    cameraPos<span class="k2">[</span><span class="n">0</span><span class="k2">]</span> <span class="k3">=</span> <span class="k3">-</span><span class="k2">(</span>screenWidth <span class="k3">/</span> <span class="n">2</span><span class="k2">)</span> <span class="k3">+</span> <span class="k2">(</span><span class="k1">int</span><span class="k2">)</span>player.x<span class="k2">;</span>
<span class="number">  4</span>    cameraPos<span class="k2">[</span><span class="n">1</span><span class="k2">]</span> <span class="k3">=</span> <span class="k3">-</span><span class="k2">(</span>screenHeight <span class="k3">/</span> <span class="n">2</span><span class="k2">)</span> <span class="k3">+</span> <span class="k2">(</span><span class="k1">int</span><span class="k2">)</span>player.y<span class="k2">;</span>
<span class="number">  5</span>  <span class="k2">}</span>
<span class="number">  6</span>  <span class="k1">else</span> <span class="k1">if</span> <span class="k2">(</span>player.weapon <span class="k3">=</span><span class="k3">=</span> SNIPER<span class="k2">)</span> <span class="k2">{</span>
<span class="number">  7</span>    <span class="k1">float</span> cameraPos2<span class="k2">[</span><span class="n">2</span><span class="k2">]</span><span class="k2">;</span>
<span class="number">  8</span>    cameraPos2<span class="k2">[</span><span class="n">0</span><span class="k2">]</span> <span class="k3">=</span> <span class="k3">-</span><span class="k2">(</span>screenWidth <span class="k3">/</span> <span class="n">2</span><span class="k2">)</span> <span class="k3">+</span> <span class="k2">(</span><span class="k1">int</span><span class="k2">)</span>player.x<span class="k2">;</span>
<span class="number">  9</span>    cameraPos2<span class="k2">[</span><span class="n">1</span><span class="k2">]</span> <span class="k3">=</span> <span class="k3">-</span><span class="k2">(</span>screenHeight <span class="k3">/</span> <span class="n">2</span><span class="k2">)</span> <span class="k3">+</span> <span class="k2">(</span><span class="k1">int</span><span class="k2">)</span>player.y<span class="k2">;</span>
<span class="number"> 10</span>
<span class="number"> 11</span>    <a href="http://www.allegro.cc/manual/ALLEGRO_MOUSE_STATE"><span class="a">ALLEGRO_MOUSE_STATE</span></a> mouse<span class="k2">;</span>
<span class="number"> 12</span>    <a href="http://www.allegro.cc/manual/al_get_mouse_state"><span class="a">al_get_mouse_state</span></a><span class="k2">(</span><span class="k3">&amp;</span>mouse<span class="k2">)</span><span class="k2">;</span>
<span class="number"> 13</span>
<span class="number"> 14</span>    cameraPos<span class="k2">[</span><span class="n">0</span><span class="k2">]</span> <span class="k3">=</span> cameraPos2<span class="k2">[</span><span class="n">0</span><span class="k2">]</span> <span class="k3">+</span> <span class="k2">(</span><span class="k2">(</span>screenWidth <span class="k3">/</span> <span class="n">2</span> <span class="k3">+</span> mouse.x<span class="k2">)</span> <span class="k3">/</span> <span class="n">2</span><span class="k2">)</span> <span class="k3">-</span> screenWidth <span class="k3">/</span> <span class="n">2</span><span class="k2">;</span>
<span class="number"> 15</span>    cameraPos<span class="k2">[</span><span class="n">1</span><span class="k2">]</span> <span class="k3">=</span> cameraPos2<span class="k2">[</span><span class="n">1</span><span class="k2">]</span> <span class="k3">+</span> <span class="k2">(</span><span class="k2">(</span>screenHeight <span class="k3">/</span> <span class="n">2</span> <span class="k3">+</span> mouse.y<span class="k2">)</span> <span class="k3">/</span> <span class="n">2</span><span class="k2">)</span> <span class="k3">-</span> screenWidth <span class="k3">/</span> <span class="n">2</span><span class="k2">;</span>
<span class="number"> 16</span>  <span class="k2">}</span>
<span class="number"> 17</span>
<span class="number"> 18</span>  <span class="k1">if</span> <span class="k2">(</span>cameraPos<span class="k2">[</span><span class="n">0</span><span class="k2">]</span> <span class="k3">&lt;</span> <span class="n">0</span><span class="k2">)</span>
<span class="number"> 19</span>    cameraPos<span class="k2">[</span><span class="n">0</span><span class="k2">]</span> <span class="k3">=</span> <span class="n">0</span><span class="k2">;</span>
<span class="number"> 20</span>  <span class="k1">if</span> <span class="k2">(</span>cameraPos<span class="k2">[</span><span class="n">1</span><span class="k2">]</span> <span class="k3">&lt;</span> <span class="n">0</span><span class="k2">)</span>
<span class="number"> 21</span>    cameraPos<span class="k2">[</span><span class="n">1</span><span class="k2">]</span> <span class="k3">=</span> <span class="n">0</span><span class="k2">;</span>
<span class="number"> 22</span>
<span class="number"> 23</span>  <span class="k1">if</span> <span class="k2">(</span>cameraPos<span class="k2">[</span><span class="n">0</span><span class="k2">]</span> <span class="k3">&gt;</span> levelWidth <span class="k3">-</span> screenWidth<span class="k2">)</span>
<span class="number"> 24</span>    cameraPos<span class="k2">[</span><span class="n">0</span><span class="k2">]</span> <span class="k3">=</span> levelWidth <span class="k3">-</span> screenWidth<span class="k2">;</span>
<span class="number"> 25</span>  <span class="k1">if</span> <span class="k2">(</span>cameraPos<span class="k2">[</span><span class="n">1</span><span class="k2">]</span> <span class="k3">&gt;</span> levelHeight <span class="k3">-</span> screenHeight<span class="k2">)</span>
<span class="number"> 26</span>    cameraPos<span class="k2">[</span><span class="n">1</span><span class="k2">]</span> <span class="k3">=</span> levelHeight <span class="k3">-</span> screenHeight<span class="k2">;</span>
<span class="number"> 27</span><span class="k2">}</span>
</div></div><p>
</p></div>]]>
		</description>
		<author>no-reply@allegro.cc (Bingocat)</author>
		<pubDate>Sun, 04 Jan 2015 09:52:51 +0000</pubDate>
	</item>
</rss>
