/*
* OpenAL HRTF Example
*
* Copyright (c) 2015 by Chris Robinson <chris.kcat@gmail.com>
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
* in the Software without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
* THE SOFTWARE.
*/
/* This file contains an example for selecting an HRTF. */
#include <stdio.h>
#include <assert.h>
#include <math.h>
#include <SDL_sound.h>
#include "AL/al.h"
#include "AL/alc.h"
#include "AL/alext.h"
#include "common/alhelpers.h"
#ifndef M_PI
#define M_PI (3.14159265358979323846)
#endif
static LPALCGETSTRINGISOFT alcGetStringiSOFT;
static LPALCRESETDEVICESOFT alcResetDeviceSOFT;
/* LoadBuffer loads the named audio file into an OpenAL buffer object, and
* returns the new buffer ID.
*/
static ALuint LoadSound(const char *filename)
{
Sound_Sample *sample;
ALenum err, format;
ALuint buffer;
Uint32 slen;
/* Open the audio file */
sample = Sound_NewSampleFromFile(filename, NULL, 65536);
if(!sample)
{
fprintf(stderr, "Could not open audio in %s\n", filename);
return 0;
}
/* Get the sound format, and figure out the OpenAL format */
if(sample->actual.channels == 1)
{
if(sample->actual.format == AUDIO_U8)
format = AL_FORMAT_MONO8;
else if(sample->actual.format == AUDIO_S16SYS)
format = AL_FORMAT_MONO16;
else
{
fprintf(stderr, "Unsupported sample format: 0x%04x\n", sample->actual.format);
Sound_FreeSample(sample);
return 0;
}
}
else if(sample->actual.channels == 2)
{
if(sample->actual.format == AUDIO_U8)
format = AL_FORMAT_STEREO8;
else if(sample->actual.format == AUDIO_S16SYS)
format = AL_FORMAT_STEREO16;
else
{
fprintf(stderr, "Unsupported sample format: 0x%04x\n", sample->actual.format);
Sound_FreeSample(sample);
return 0;
}
}
else
{
fprintf(stderr, "Unsupported channel count: %d\n", sample->actual.channels);
Sound_FreeSample(sample);
return 0;
}
/* Decode the whole audio stream to a buffer. */
slen = Sound_DecodeAll(sample);
if(!sample->buffer || slen == 0)
{
fprintf(stderr, "Failed to read audio from %s\n", filename);
Sound_FreeSample(sample);
return 0;
}
/* Buffer the audio data into a new buffer object, then free the data and
* close the file. */
buffer = 0;
alGenBuffers(1, &buffer);
alBufferData(buffer, format, sample->buffer, slen, sample->actual.rate);
Sound_FreeSample(sample);
/* Check if an error occured, and clean up if so. */
err = alGetError();
if(err != AL_NO_ERROR)
{
fprintf(stderr, "OpenAL Error: %s\n", alGetString(err));
if(buffer && alIsBuffer(buffer))
alDeleteBuffers(1, &buffer);
return 0;
}
return buffer;
}
int main(int argc, char **argv)
{
ALCdevice *device;
ALboolean has_angle_ext;
ALuint source, buffer;
const char *soundname;
const char *hrtfname;
ALCint hrtf_state;
ALCint num_hrtf;
ALdouble angle;
ALenum state;
/* Print out usage if no arguments were specified */
if(argc < 2)
{
fprintf(stderr, "Usage: %s [-device <name>] [-hrtf <name>] <soundfile>\n", argv[0]);
return 1;
}
/* Initialize OpenAL, and check for HRTF support. */
argv++; argc--;
if(InitAL(&argv, &argc) != 0)
return 1;
device = alcGetContextsDevice(alcGetCurrentContext());
if(!alcIsExtensionPresent(device, "ALC_SOFT_HRTF"))
{
fprintf(stderr, "Error: ALC_SOFT_HRTF not supported\n");
CloseAL();
return 1;
}
/* Define a macro to help load the function pointers. */
#define LOAD_PROC(d, x) ((x) = alcGetProcAddress((d), #x))
LOAD_PROC(device, alcGetStringiSOFT);
LOAD_PROC(device, alcResetDeviceSOFT);
#undef LOAD_PROC
/* Check for the AL_EXT_STEREO_ANGLES extension to be able to also rotate
* stereo sources.
*/
has_angle_ext = alIsExtensionPresent("AL_EXT_STEREO_ANGLES");
printf("AL_EXT_STEREO_ANGLES%s found\n", has_angle_ext?"":" not");
/* Check for user-preferred HRTF */
if(strcmp(argv[0], "-hrtf") == 0)
{
hrtfname = argv[1];
soundname = argv[2];
}
else
{
hrtfname = NULL;
soundname = argv[0];
}
/* Enumerate available HRTFs, and reset the device using one. */
alcGetIntegerv(device, ALC_NUM_HRTF_SPECIFIERS_SOFT, 1, &num_hrtf);
if(!num_hrtf)
printf("No HRTFs found\n");
else
{
ALCint attr[5];
ALCint index = -1;
ALCint i;
printf("Available HRTFs:\n");
for(i = 0;i < num_hrtf;i++)
{
const ALCchar *name = alcGetStringiSOFT(device, ALC_HRTF_SPECIFIER_SOFT, i);
printf(" %d: %s\n", i, name);
/* Check if this is the HRTF the user requested. */
if(hrtfname && strcmp(name, hrtfname) == 0)
index = i;
}
i = 0;
attr[i++] = ALC_HRTF_SOFT;
attr[i++] = ALC_TRUE;
if(index == -1)
{
if(hrtfname)
printf("HRTF \"%s\" not found\n", hrtfname);
printf("Using default HRTF...\n");
}
else
{
printf("Selecting HRTF %d...\n", index);
attr[i++] = ALC_HRTF_ID_SOFT;
attr[i++] = index;
}
attr[i] = 0;
if(!alcResetDeviceSOFT(device, attr))
printf("Failed to reset device: %s\n", alcGetString(device, alcGetError(device)));
}
/* Check if HRTF is enabled, and show which is being used. */
alcGetIntegerv(device, ALC_HRTF_SOFT, 1, &hrtf_state);
if(!hrtf_state)
printf("HRTF not enabled!\n");
else
{
const ALchar *name = alcGetString(device, ALC_HRTF_SPECIFIER_SOFT);
printf("HRTF enabled, using %s\n", name);
}
fflush(stdout);
/* Initialize SDL_sound. */
Sound_Init();
/* Load the sound into a buffer. */
buffer = LoadSound(soundname);
if(!buffer)
{
Sound_Quit();
CloseAL();
return 1;
}
/* Create the source to play the sound with. */
source = 0;
alGenSources(1, &source);
alSourcei(source, AL_SOURCE_RELATIVE, AL_TRUE);
alSource3f(source, AL_POSITION, 0.0f, 0.0f, -1.0f);
alSourcei(source, AL_BUFFER, buffer);
assert(alGetError()==AL_NO_ERROR && "Failed to setup sound source");
/* Play the sound until it finishes. */
angle = 0.0;
alSourcePlay(source);
do {
al_nssleep(10000000);
/* Rotate the source around the listener by about 1/4 cycle per second,
* and keep it within -pi...+pi.
*/
angle += 0.01 * M_PI * 0.5;
if(angle > M_PI)
angle -= M_PI*2.0;
/* This only rotates mono sounds. */
alSource3f(source, AL_POSITION, (ALfloat)sin(angle), 0.0f, -(ALfloat)cos(angle));
if(has_angle_ext)
{
/* This rotates stereo sounds with the AL_EXT_STEREO_ANGLES
* extension. Angles are specified counter-clockwise in radians.
*/
ALfloat angles[2] = { (ALfloat)(M_PI/6.0 - angle), (ALfloat)(-M_PI/6.0 - angle) };
alSourcefv(source, AL_STEREO_ANGLES, angles);
}
alGetSourcei(source, AL_SOURCE_STATE, &state);
} while(alGetError() == AL_NO_ERROR && state == AL_PLAYING);
/* All done. Delete resources, and close down SDL_sound and OpenAL. */
alDeleteSources(1, &source);
alDeleteBuffers(1, &buffer);
Sound_Quit();
CloseAL();
return 0;
}