From a6abfd2da66bb04739dcddf13d9dc382c1d1b831 Mon Sep 17 00:00:00 2001 From: athomas Date: Sun, 29 Jun 2003 02:42:53 +0000 Subject: set paragraph alignment to "justify" git-svn-id: file:///home/mbien/NetBeansProjects/JOGAMP/joal-sync/svn-server-sync-demos/joal-demos/trunk@23 235fdd13-0e8c-4fed-b5ee-0a390d04b286 --- www/devmaster/lesson1.html | 172 +++++++++++++++++++++++---------------------- www/devmaster/lesson2.html | 29 ++++---- 2 files changed, 104 insertions(+), 97 deletions(-) (limited to 'www') diff --git a/www/devmaster/lesson1.html b/www/devmaster/lesson1.html index d01c159..69cab92 100644 --- a/www/devmaster/lesson1.html +++ b/www/devmaster/lesson1.html @@ -36,38 +36,39 @@ Source
Maurais
Adapted for Java by: Athomas Goldberg

-

Welcome to the exciting world of OpenAL! OpenAL -is still in a stage of growth, and even though there is an ever larger following -to the API it still hasn't reached it's full potential. One of the big reasons -for this is that there is still not yet hardware acceleration built in for -specific cards. However, Creative Labs is a major contributor to the OpenAL -project and also happens to be one of the largest soundcard manufacturers. So -there is a promise of hardware accelerated features in the near future. OpenAL's -only other major contributor, Loki, has gone the way of the dinosaur. So the -future of OpenAL on Linux platforms is uncertain. You can still obtain the Linux -binaries on some more obscure websites.

-

OpenAL has also not been seen in many major -commercial products, which may have also hurt it's growth. As far as I know the -only pc game to use OpenAL has been Metal Gear 2 (although recently I've -discovered that Unreal 2 does as well). The popular modeling program, Blender3D, -was also known to use OpenAL for all it's audio playback. Aside from these -however the only other OpenAL uses have been in the sdk examples and a few -obscure tutorials on the internet.

-

But lets face it, OpenAL has a lot of -potential. There are many other audio libraries that claim to work with the -hardware on a lower level (and this may be true), but the designers of OpenAL -did several things in it's design which make it a superior API. First of all -they emulated the OpenGL API which is one of the best ever designed. The API -style is flexible, so different coding methods and hardware implementations will -take advantage of this. People who have had a lot of experience with OpenGL will -be able to pick up OpenAL quite fast. OpenAL also has the advantage of creating -3D surround sound which a lot of other API's cannot boast. On top of all of that -it also has the ability to extend itself into EAX and AC3 flawlessly. To my -knowledge no other audio library has that capability.

-

If you still haven't found a reason here to use -OpenAL then here's another. It's just cool. It's a nice looking API and will -integrate well into your code. You will be able to do many cool sound effects -with it. But before we do that we have to learn the basics.

+ +

Welcome to the exciting world of OpenAL! OpenAL is still in + a stage of growth, and even though there is an ever larger following to the + API it still hasn't reached it's full potential. One of the big reasons for + this is that there is still not yet hardware acceleration built in for specific + cards. However, Creative Labs is a major contributor to the OpenAL project and + also happens to be one of the largest soundcard manufacturers. So there is a + promise of hardware accelerated features in the near future. OpenAL's only other + major contributor, Loki, has gone the way of the dinosaur. So the future of + OpenAL on Linux platforms is uncertain. You can still obtain the Linux binaries + on some more obscure websites.

+

OpenAL has also not been seen in many major commercial products, + which may have also hurt it's growth. As far as I know the only pc game to use + OpenAL has been Metal Gear 2 (although recently I've discovered that Unreal + 2 does as well). The popular modeling program, Blender3D, was also known to + use OpenAL for all it's audio playback. Aside from these however the only other + OpenAL uses have been in the sdk examples and a few obscure tutorials on the + internet.

+

But lets face it, OpenAL has a lot of potential. There are + many other audio libraries that claim to work with the hardware on a lower level + (and this may be true), but the designers of OpenAL did several things in it's + design which make it a superior API. First of all they emulated the OpenGL API + which is one of the best ever designed. The API style is flexible, so different + coding methods and hardware implementations will take advantage of this. People + who have had a lot of experience with OpenGL will be able to pick up OpenAL + quite fast. OpenAL also has the advantage of creating 3D surround sound which + a lot of other API's cannot boast. On top of all of that it also has the ability + to extend itself into EAX and AC3 flawlessly. To my knowledge no other audio + library has that capability.

+

If you still haven't found a reason here to use OpenAL then + here's another. It's just cool. It's a nice looking API and will integrate well + into your code. You will be able to do many cool sound effects with it. But + before we do that we have to learn the basics.

So let's get coding!

import net.java.games.joal.*;
@@ -84,19 +85,20 @@ with it. But before we do that we have to learn the basics.

     // Sources are points emitting sound.
     static int[] source = new int[1];
-

Those familiar with OpenGL know that it uses "texture objects" (or "texture -names") to handle textures used by a program. OpenAL does a similar thing with -audio samples. There are essentially 3 kinds of objects in OpenAL. A buffer -which stores all the information about how a sound should be played and the -sound data itself, and a source which is a point in space that emits a sound. -It's important to understand that a source is not itself an audio sample. A -source only plays back sound data from a buffer bound to it. The source is also -given special properties like position and velocity.

-

The third object which I have not mentioned yet is the listener. There is -only one listener which represents where 'you' are, the user. The listener -properties along with the source properties determine how the audio sample will -be heard. For example their relative positions will determine the intensity of -the sound.

+

Those familiar with OpenGL know that it uses "texture + objects" (or "texture names") to handle textures used by a program. + OpenAL does a similar thing with audio samples. There are essentially 3 kinds + of objects in OpenAL. A buffer which stores all the information about how a + sound should be played and the sound data itself, and a source which is a point + in space that emits a sound. It's important to understand that a source is not + itself an audio sample. A source only plays back sound data from a buffer bound + to it. The source is also given special properties like position and velocity. +

+

The third object which I have not mentioned yet is the listener. + There is only one listener which represents where 'you' are, the user. The listener + properties along with the source properties determine how the audio sample will + be heard. For example their relative positions will determine the intensity + of the sound.

	
     // Position of the source sound.
@@ -115,10 +117,10 @@ the sound.

     static float[] listenerOri = { 0.0f, 0.0f, -1.0f,  0.0f, 1.0f, 0.0f };
-

In the above code we specify the position and velocity of the source and listener - objects. These arrays are vector based Cartesian coordinates. You could easily - build a structure or class to do the same thing. In this example I used arrays - for simplicity.

+

In the above code we specify the position and velocity of the + source and listener objects. These arrays are vector based Cartesian coordinates. + You could easily build a structure or class to do the same thing. In this example + I used arrays for simplicity.

Here we will create a function that loads all of our sound data from a file. 

    static int LoadALData() {
@@ -136,15 +138,15 @@ the sound.

         al.alBufferData(buffer[0], format[0], data[0], size[0], freq[0]);
         ALut.alutUnloadWAV(format[0],data[0],size[0],freq[0]);
-

The function 'alGenBuffers' will create the buffer objects and store them in -the variable we passed it. It's important to do an error check to make sure -everything went smoothly. There may be a case in which OpenAL could not generate -a buffer object due to a lack of memory. In this case it would set the error -bit.

-

The ALut is very helpful here. It opens up the file for us and gives us all - the information we need to create the buffer. And after we have attached all - this data to the buffer it will help use dispose of the data. It all works in - a clean and efficient manner.

+

The function 'alGenBuffers' will create the buffer objects + and store them in the variable we passed it. It's important to do an error check + to make sure everything went smoothly. There may be a case in which OpenAL could + not generate a buffer object due to a lack of memory. In this case it would + set the error bit.

+

The ALut is very helpful here. It opens up the file for us + and gives us all the information we need to create the buffer. And after we + have attached all this data to the buffer it will help use dispose of the data. + It all works in a clean and efficient manner.

 
         // Bind buffer with a source.
@@ -159,17 +161,18 @@ bit.

         al.alSourcefv(source[0], AL.AL_POSITION, sourcePos);
         al.alSourcefv(source[0], AL.AL_VELOCITY, sourceVel);
         al.alSourcei (source[0], AL.AL_LOOPING,  loop[0]     );
-

We generate a source object in the same manner we generated the buffer object. -Then we define the source properties that it will use when it's in playback. The -most important of these properties is the buffer it should use. This tells the -source which audio sample to playback. In this case we only have one so we bind -it. We also tell the source it's position and velocity which we defined earlier.

-

One more thing on 'alGenBuffers' and 'alGenSources'. In some example code I -have seen these functions will return an integer value for the number of -buffers/sources created. I suppose this was meant as an error checking feature -that was left out in a later version. If you see this done in other code don't -use it yourself. If you want to do this check, use 'alGetError' instead (like we -have done above).

+

We generate a source object in the same manner we generated + the buffer object. Then we define the source properties that it will use when + it's in playback. The most important of these properties is the buffer it should + use. This tells the source which audio sample to playback. In this case we only + have one so we bind it. We also tell the source it's position and velocity which + we defined earlier.

+

One more thing on 'alGenBuffers' and 'alGenSources'. In some + example code I have seen these functions will return an integer value for the + number of buffers/sources created. I suppose this was meant as an error checking + feature that was left out in a later version. If you see this done in other + code don't use it yourself. If you want to do this check, use 'alGetError' instead + (like we have done above).

 
         // Do another error check and return.
@@ -203,11 +206,11 @@ all the memory and audio devices that our program may be using.

         al.alGetError();
-

The function 'alutInit' will setup everything that the Alc needs to do for -us. Basically Alut creates a single OpenAL context through Alc and sets it to -current. On the Windows platform it initializes DirectSound. We also do an -initial call to the error function to clear it. Every time we call 'glGetError' -it will reset itself to 'AL_NO_ERROR'.

+

The function 'alutInit' will setup everything that the Alc + needs to do for us. Basically Alut creates a single OpenAL context through Alc + and sets it to current. On the Windows platform it initializes DirectSound. + We also do an initial call to the error function to clear it. Every time we + call 'glGetError' it will reset itself to 'AL_NO_ERROR'.

 
         // Load the wav data.
@@ -229,9 +232,9 @@ it will reset itself to 'AL_NO_ERROR'.

             )
         );
-

We will check to see if the wav files loaded correctly. If not we must exit -the program. Then we update the listener values, and finally we set our exit -procedure.

+

We will check to see if the wav files loaded correctly. If + not we must exit the program. Then we update the listener values, and finally + we set our exit procedure.

        char[] c = new char[1];
         while(c[0] != 'q') {	
         try {
@@ -261,13 +264,14 @@ procedure.

 }
-

This is the interesting part of the tutorial. It's a very basic loop that -lets us control the playback of the audio sample. Pressing 'p' will replay the -sample, pressing 's' will stop the sample, and pressing 'h' will pause the -sample. Pressing 'q' will exit the program.

-

Well there it is. Your first delve into OpenAL. I hope it was made simple -enough for you. It may have been a little too simple for the 1337 h4X0r, but we -all got to start somewhere. Things will get more advanced as we go along.

+

This is the interesting part of the tutorial. It's a very basic + loop that lets us control the playback of the audio sample. Pressing 'p' will + replay the sample, pressing 's' will stop the sample, and pressing 'h' will + pause the sample. Pressing 'q' will exit the program.

+

Well there it is. Your first delve into OpenAL. I hope it was + made simple enough for you. It may have been a little too simple for the 1337 + h4X0r, but we all got to start somewhere. Things will get more advanced as we + go along.

Download the Java Source and Ant Build File

diff --git a/www/devmaster/lesson2.html b/www/devmaster/lesson2.html index a70ef71..68c05e1 100644 --- a/www/devmaster/lesson2.html +++ b/www/devmaster/lesson2.html @@ -37,7 +37,7 @@ Fade-away
Maurais
Adapted for Java By: Athomas Goldberg

-

Hope you found the last tutorial of some use. I know I did. This will be a +

Hope you found the last tutorial of some use. I know I did. This will be a real quick and easy tutorial. It won't get too much more complicated at this point.

@@ -58,8 +58,9 @@ point.

   	static float[] listenerOri = { 0.0f, 0.0f, -1.0f, 0.0f, 1.0f, 0.0f };
   	static AL al;
   	static ALC alc;
-

There is only one change in the code since the last tutorial in this fist -section. It is that we altered the sources velocity. It's 'z' field is now 0.1.

+

There is only one change in the code since the last tutorial + in this fist section. It is that we altered the sources velocity. It's 'z' field + is now 0.1.

     static int loadALData() {
         if (al.alGetError() != AL.AL_NO_ERROR) {
@@ -99,10 +100,11 @@ section. It is that we altered the sources velocity. It's 'z' field is now 0.1.<
         }
         return AL.AL_TRUE;
     }
-

Two changes in this section. First we are loading the file "Footsteps.wav". - We are also explicitly setting the sources 'AL_LOOPING' value to 'AL_TRUE'. - What this means is that when the source is prompted to play it will continue - to play until stopped. It will play over again after the sound clip has ended.

+

Two changes in this section. First we are loading the file + "Footsteps.wav". We are also explicitly setting the sources 'AL_LOOPING' + value to 'AL_TRUE'. What this means is that when the source is prompted to play + it will continue to play until stopped. It will play over again after the sound + clip has ended.

     static void setListenerValues() {
         al.alListenerfv(AL.AL_POSITION,	listenerPos);
@@ -149,12 +151,13 @@ section. It is that we altered the sources velocity. It's 'z' field is now 0.1.<
         ALut.alutExit();
     }
 }
-

The only thing that has changed in this code is the loop. Instead of playing -and stopping the audio sample it will slowly get quieter as the sources position -grows more distant. We do this by slowly incrementing the position by it's -velocity over time. The time is sampled by checking the system clock which gives -us a tick count. It shouldn't be necessary to change this, but if the audio clip -fades too fast you might want to change 100 to some higher number.

+

The only thing that has changed in this code is the loop. Instead + of playing and stopping the audio sample it will slowly get quieter as the sources + position grows more distant. We do this by slowly incrementing the position + by it's velocity over time. The time is sampled by checking the system clock + which gives us a tick count. It shouldn't be necessary to change this, but if + the audio clip fades too fast you might want to change 100 to some higher number. +

Download the Java Source and Ant Build file.

-- cgit v1.2.3