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[Java-game-lib-cvs] CVS: LWJGL/website/documents/tutorials/openal openal_basics.html,1.2,1.3
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From: Brian M. <ma...@us...> - 2003-04-27 18:38:05
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Update of /cvsroot/java-game-lib/LWJGL/website/documents/tutorials/openal In directory sc8-pr-cvs1:/tmp/cvs-serv22143/documents/tutorials/openal Modified Files: openal_basics.html Log Message: New OpenAL programming model: no context/device fiddling easier initialization Index: openal_basics.html CVS Browser: http://cvs.sourceforge.net/cgi-bin/viewcvs.cgi/java-game-lib/LWJGL/website/documents/tutorials/openal/openal_basics.html =================================================================== RCS file: /cvsroot/java-game-lib/LWJGL/website/documents/tutorials/openal/openal_basics.html,v retrieving revision 1.2 retrieving revision 1.3 diff -u -d -r1.2 -r1.3 --- openal_basics.html 21 Dec 2002 12:10:51 -0000 1.2 +++ openal_basics.html 27 Apr 2003 18:38:00 -0000 1.3 @@ -29,99 +29,57 @@ <br> <b>1.2 Basic setup</b><br> Lets start out by creating a skeleton class for some very basic sound. We'll -start of by creating the required OpenAL objects<br> +start of by creating the required OpenAL object<br> <p style="border-style: solid; border-width: 1px; padding: 3px; background-color: rgb(255,255,204);"><tt>import org.lwjgl.openal.AL;<br> -import org.lwjgl.openal.ALC;<br> -import org.lwjgl.openal.ALCcontext;<br> -import org.lwjgl.openal.ALCdevice;<br> -<br> <br> public class PlayTest {<br> <br> /** OpenAL instance */<br> protected AL al;<br> - <br> - /** OpenAL Context instance */<br> - protected ALC alc;<br> - <br> - /** OpenAL context */<br> - protected ALCcontext context;<br> - <br> - /** OpenAL device */<br> - protected ALCdevice device; <br> - <br> + <br> + /**<br> * Creates an instance of PlayTest<br> */<br> public PlayTest() {<br> try {<br> </tt> -<tt> al = new AL();<br> - alc = new ALC();<br> -<br> +<tt> al = new AL(null, 44100, 15, false);<br> al.create();<br> - alc.create();<br> } catch (Exception e) {<br> e.printStackTrace();<br> }</tt><tt><br> }<br> -}</tt><code></code></p> -We need instances of the following classes:<br> +}</tt></p> +The arguments passed to AL, are as follows:<br> <ul> - <li><tt>AL </tt>- basic source, buffer and listener interaction</li> - <li><tt>ALC </tt>- context and device creatiuon</li> + <li><i>null</i> - Device argument, depends on OpenAL native implementation. We just pass Null to get default device.</li> + <li><i>44100</i> - Frequency for mixing output buffer, in units of Hz.</li> + <li><i>15</i> - Refresh intervalls, in units of Hz.</li> + <li><i>false</i> - Flag, indicating a synchronous context (Whether or not you're not going to synchronice sound to framerate).</li> </ul> -<b>1.3 OpenAL initialization</b><br> -Now that we have created a basic class containing instances of the relevant -OpenAL classes, lets start of by initializing OpenAL - that is create a device -and a context:<br> -<p - style="border-style: solid; border-width: 1px; padding: 3px; background-color: rgb(255,255,204);"> <tt> -/**<br> - * Initializes OpenAL<br> - */<br> - protected void alInitialize() { <br> - //get default device<br> - device = alc.openDevice(null);<br> - <br> - //create context (no attributes specified)<br> - context = alc.createContext(device, 0);<br> - <br> - //make context current<br> - alc.makeContextCurrent(context);<br> - }</tt><code><br> -</code></p> -Start of by opening a device using the <tt>openDevice </tt>method. <tt>openDevice -</tt>takes a <tt>String </tt>as argument, containing the name of the device -to open. If no name is supplied, the default device will be used (OpenAL -currently doesn't support enumeration of devices available).<br> -<br> -Having opened a device, create a context to that device using <tt>createContext</tt>. -<tt>createContext</tt> takes two arguments: device to use and a list of attributes -(see specification for list of attributes). Since we're going by default context, -we just specify <tt>0</tt> for attributes.<br> -<br> -Finish of by making the created context current. Do this by calling <tt>makeContextCurrent</tt>, -supplying just created context as argument.<br> -<p><b>1.4 Buffer and Source creation</b><br> -Now that we have opened a device and gotten a context, we need to create +<p><b>1.3 Buffer and Source creation</b><br> +Now that we have created the AL instance, we need to create two things to actually get some sound. We need to create a buffer to hold -sounddata, and a source that is to play the sounddata.<br> +sound data, and a source that is to play the sound data.<br> Lets start of by creating one source, and one buffer:</p> -<p - style="border-style: solid; border-width: 1px; padding: 3px; background-color: rgb(255,255,204);"><tt> -//create one IntBuffer as buffer and one as source<br> +<p style="border-style: solid; border-width: 1px; padding: 3px; background-color: rgb(255,255,204);"> +<tt> + //create one IntBuffer as buffer and one as source<br> + //createIntBuffer is a utility method which allocates a direct ByteBuffer in native order<br> IntBuffer buffers = createIntBuffer(1);<br> IntBuffer sources = createIntBuffer(1);<br> <br> //generate buffers and sources<br> al.genBuffers(1, Sys.getDirectBufferAddress(buffers));<br> - al.genSources(1, Sys.getDirectBufferAddress(sources));</tt></p> -<p>There, all set for actually loading some sounddata into the buffer.<br> + al.genSources(1, Sys.getDirectBufferAddress(sources)); +</tt> </p> -<b>1.5 Loading sounddata and setting up a buffer</b><br> +<p>There, all set for actually loading some sound data into the buffer.<br> +</p> +<b>1.4 Loading sound data and setting up a buffer</b><br> Now that we have a buffer, we need to load some sound data into this buffer. This is done using the <tt>al.bufferData</tt> method. In our example we will "cheat" a bit, by using the <tt>WaveData</tt> class to load @@ -138,11 +96,11 @@ wavefile.dispose(); <br> </tt></p> Having loaded the data, we pass it to <tt>bufferData</tt>. Once the buffer -has been filled with sounddata, we unload it from the system using <tt>wavefile.dispose()</tt>. -Don't worry about deleting it this soon - the sounddata has been <b>copied</b> +has been filled with sound data, we unload it from the system using <tt>wavefile.dispose()</tt>. +Don't worry about deleting it this soon - the sound data has been <b>copied</b> to the buffer.<br> <br> -<b>1.6 Associating sources and buffers</b><br> +<b>1.5 Associating sources and buffers</b><br> To associate a source to a buffer we set the integer BUFFER attribute on the source, and assign it a value of the buffer to play:<br> <p @@ -150,7 +108,7 @@ //set up source input<br> al.sourcei(sources.get(0), AL.BUFFER, buffers.get(0));</tt><tt><br> </tt></p> -<b>1.7 Setting source properties</b><br> +<b>1.6 Setting source properties</b><br> Having set up the source, it is time to set some attributes on the source - there are many that can be set, but in this example we only set the looping attribute to true by doing the following:<br> @@ -159,7 +117,7 @@ //loop source<br> al.sourcei(sources.get(0), AL.LOOPING, AL.TRUE);</tt><tt><br> </tt></p> -<b>1.8 Sound...<br> +<b>1.7 Sound...<br> </b>There, ready to play the sound, do this using the <tt>sourcePlay </tt>method of the <tt>AL </tt>class. to stop and pause use <tt>sourcePause </tt>and <tt>sourceStop </tt>respectively, and supply the source to affect:<br> @@ -177,12 +135,11 @@ <br> //stop source 0<br> al.sourceStop(sources.get(0));</tt></p> -<b>1.9 Cleaning up<br> +<b>1.8 Cleaning up<br> </b>Having had loads of fun playing a sound (!), it is now time to do some house chores. We need to clean up what we have created, this amounts to:<br> - deleting source and buffer<br> - - deleting context<br> - - closing devce<br> + - destroying AL<br> as is shown here:<b><br> </b> <p @@ -192,9 +149,9 @@ al.deleteBuffers(1, Sys.getDirectBufferAddress(buffers));<br> <br> //shutdown<br> - alc.makeContextCurrent(null);<br> - alc.destroyContext(context);<br> - alc.closeDevice(device);</tt></p> + al.destroy();<br> +</tt> +</p> There, all set. Now you should be able to play some basic sound!<br> This tutorial is rather short, and the above examples feature no error checking. For the complete source code, look at the classes in the <br> |
