<?xml version="1.0"?>
<rss version="2.0">
	<channel>
		<title>Point A to Point B</title>
		<link>http://www.allegro.cc/forums/view/590006</link>
		<description>Allegro.cc Forum Thread</description>
		<webMaster>matthew@allegro.cc (Matthew Leverton)</webMaster>
		<lastBuildDate>Mon, 12 Feb 2007 12:20:43 +0000</lastBuildDate>
	</channel>
	<item>
		<description><![CDATA[<div class="mockup v2"><p>Just trying to get a dot moving smoothly from predecided point A to moving, player-controlled point B.  Because of the way I&#39;m doing it, the dots stop just short  of point B.  I&#39;d just like to know about any better ways of doing this.</p><div class="source-code snippet"><div class="inner"><pre>                <span class="k1">for</span><span class="k2">(</span> iRe2 <span class="k3">=</span> <span class="n">0</span> <span class="k2">;</span> iRe2 <span class="k3">&lt;</span> n<span class="k2">;</span> <span class="k3">+</span><span class="k3">+</span>iRe2<span class="k2">)</span>
                <span class="k2">{</span>
                    iLX <span class="k3">=</span> <span class="k2">(</span>mouse_x-iEnemyX<span class="k2">[</span>iRe2<span class="k2">]</span><span class="k2">)</span><span class="k3">*</span><span class="n">0</span>.<span class="n">1</span><span class="k2">;</span>
                    iLY <span class="k3">=</span> <span class="k2">(</span>mouse_y-iEnemyY<span class="k2">[</span>iRe2<span class="k2">]</span><span class="k2">)</span><span class="k3">*</span><span class="n">0</span>.<span class="n">1</span><span class="k2">;</span>
                    iEnemyX<span class="k2">[</span>iRe2<span class="k2">]</span> <span class="k3">+</span><span class="k3">=</span> iLX<span class="k2">;</span>
                    iEnemyY<span class="k2">[</span>iRe2<span class="k2">]</span> <span class="k3">+</span><span class="k3">=</span> iLY<span class="k2">;</span>

                    <a href="http://www.allegro.cc/manual/circlefill" target="_blank"><span class="a">circlefill</span></a><span class="k2">(</span> buffer, iEnemyX<span class="k2">[</span>iRe2<span class="k2">]</span>, iEnemyY<span class="k2">[</span>iRe2<span class="k2">]</span>, <span class="n">2</span>, <a href="http://www.allegro.cc/manual/makecol" target="_blank"><span class="a">makecol</span></a><span class="k2">(</span> <span class="n">255</span>, <span class="n">0</span>, <span class="n">0</span> <span class="k2">)</span><span class="k2">)</span><span class="k2">;</span>

                    <span class="k1">if</span><span class="k2">(</span> iEnemyX<span class="k2">[</span>iRe2<span class="k2">]</span> <span class="k3">=</span><span class="k3">=</span> <a href="http://www.allegro.cc/manual/mouse_x" target="_blank"><span class="a">mouse_x</span></a> <span class="k3">&amp;</span><span class="k3">&amp;</span> iEnemyY<span class="k2">[</span>iRe2<span class="k2">]</span> <span class="k3">=</span><span class="k3">=</span> <a href="http://www.allegro.cc/manual/mouse_y" target="_blank"><span class="a">mouse_y</span></a> <span class="k2">)</span> <span class="k1">return</span><span class="k2">(</span><span class="n">0</span><span class="k2">)</span><span class="k2">;</span>
                <span class="k2">}</span>
</pre></div></div><p>

Relevant code and exe attatched.</p><p>I know it&#39;s because of the 0.1&#39;s at the end of the iLX and iLY lines.
</p></div>]]>
		</description>
		<author>no-reply@allegro.cc (Cerpin Taxt)</author>
		<pubDate>Sun, 11 Feb 2007 01:31:53 +0000</pubDate>
	</item>
	<item>
		<description><![CDATA[<div class="mockup v2"><div class="source-code snippet"><div class="inner"><pre><span class="k1">float</span> Angle <span class="k3">=</span> atan2f<span class="k2">(</span>B.Y-Dot.Y, B.X-Dot.X<span class="k2">)</span><span class="k2">;</span>

Dot.X <span class="k3">+</span><span class="k3">=</span> <a href="http://www.delorie.com/djgpp/doc/libc/libc_113.html" target="_blank">cos</a><span class="k2">(</span>Angle<span class="k2">)</span><span class="k3">*</span>Speed<span class="k2">;</span>
Dot.Y <span class="k3">+</span><span class="k3">=</span> <a href="http://www.delorie.com/djgpp/doc/libc/libc_728.html" target="_blank">sin</a><span class="k2">(</span>Angle<span class="k2">)</span><span class="k3">*</span>Speed<span class="k2">;</span>
</pre></div></div><p>
I&#39;m not sure if that&#39;s what you want tough...
</p></div>]]>
		</description>
		<author>no-reply@allegro.cc (CursedTyrant)</author>
		<pubDate>Sun, 11 Feb 2007 03:34:44 +0000</pubDate>
	</item>
	<item>
		<description><![CDATA[<div class="mockup v2"><p>This seems to give me the same result as when I had the super-simple movement.  Enemies moving in either straight lines or fourty-five degree angles.</p><p>I&#39;m looking for lines directly toward the target, but the way I was doing it earlier kept the enemies from reaching the target.</p><p>Any more help would be fantastic.
</p></div>]]>
		</description>
		<author>no-reply@allegro.cc (Cerpin Taxt)</author>
		<pubDate>Sun, 11 Feb 2007 03:55:05 +0000</pubDate>
	</item>
	<item>
		<description><![CDATA[<div class="mockup v2"><p>Get x/y distances, use Pythagorean Theorem to find total distance, divide the total distance by the speed, divide x and y distances total distance, you got x and y speeds. Only slow part is the <tt>sqrt()</tt> in the total distance. <img src="http://www.allegro.cc/forums/smileys/smiley.gif" alt=":)" />
</p></div>]]>
		</description>
		<author>no-reply@allegro.cc (Kikaru)</author>
		<pubDate>Sun, 11 Feb 2007 04:13:02 +0000</pubDate>
	</item>
	<item>
		<description><![CDATA[<div class="mockup v2"><p>Okay, I&#39;m sure I&#39;m doing that wrong, but it&#39;s not going well.  It seems way more complicated than what I was doing.  Is there any way to just fix what I did before, so that it doesn&#39;t fail at the end?
</p></div>]]>
		</description>
		<author>no-reply@allegro.cc (Cerpin Taxt)</author>
		<pubDate>Sun, 11 Feb 2007 06:34:53 +0000</pubDate>
	</item>
	<item>
		<description><![CDATA[<div class="mockup v2"><p>Some example code:
</p><div class="source-code snippet"><div class="inner"><pre>point get_speeds<span class="k2">(</span>point A, point B, <span class="k1">int</span> speed<span class="k2">)</span>
<span class="k2">{</span>
    <span class="k1">int</span> xd <span class="k3">=</span> <a href="http://www.delorie.com/djgpp/doc/libc/libc_38.html" target="_blank">abs</a><span class="k2">(</span>a.x-b.x<span class="k2">)</span><span class="k2">;</span>
    <span class="k1">int</span> yd <span class="k3">=</span> <a href="http://www.delorie.com/djgpp/doc/libc/libc_38.html" target="_blank">abs</a><span class="k2">(</span>a.y-b.y<span class="k2">)</span><span class="k2">;</span>
    <span class="k1">int</span> td <span class="k3">=</span> <span class="k1">int</span><span class="k2">(</span><a href="http://www.delorie.com/djgpp/doc/libc/libc_738.html" target="_blank">sqrt</a><span class="k2">(</span><span class="k2">(</span>xd<span class="k3">*</span>xd<span class="k2">)</span><span class="k3">+</span><span class="k2">(</span>yd<span class="k3">*</span>yd<span class="k2">)</span><span class="k2">)</span><span class="k2">)</span><span class="k2">;</span>
    td <span class="k3">/</span><span class="k3">=</span> speed<span class="k2">;</span>
    yd <span class="k3">/</span><span class="k3">=</span> td<span class="k2">;</span>
    xd <span class="k3">/</span><span class="k3">=</span> td<span class="k2">;</span>
    point speeds<span class="k2">(</span>xd, yd<span class="k2">)</span><span class="k2">;</span>
    <span class="k1">return</span> speeds<span class="k2">;</span>
<span class="k2">}</span>
</pre></div></div><p>

This assumes you declared a struct/class called point, with member <tt>x</tt> and <tt>y</tt>. It also assumes you set up a proper constructor for that class.</p><p>(P.S. sorry of it&#39;s really messy)
</p></div>]]>
		</description>
		<author>no-reply@allegro.cc (Kikaru)</author>
		<pubDate>Sun, 11 Feb 2007 07:22:50 +0000</pubDate>
	</item>
	<item>
		<description><![CDATA[<div class="mockup v2"><p>Your game ends abruptly when I intentionally &quot;touch&quot; a red dot.<br />CursedTyrant&#39;s algo is what you need, I am using something like that in my game and it works fine.
</p></div>]]>
		</description>
		<author>no-reply@allegro.cc (Paul whoknows)</author>
		<pubDate>Sun, 11 Feb 2007 09:45:36 +0000</pubDate>
	</item>
	<item>
		<description><![CDATA[<div class="mockup v2"><p>Sorry about that. It&#39;s not really much of a game yet, huh?</p><p>I must have been doing something wrong with that, but I was able to adapt Kikaru&#39;s code to something that sems to work for me.</p><p>Thank you very much.
</p></div>]]>
		</description>
		<author>no-reply@allegro.cc (Cerpin Taxt)</author>
		<pubDate>Mon, 12 Feb 2007 12:20:43 +0000</pubDate>
	</item>
</rss>
