Add an HRTF example

Doubles as a psuedo-test to play a sound with HRTF.

3 files changed, 254 insertions, 0 deletions

diff --git a/CMakeLists.txt b/CMakeLists.txt
index db918de0..bd73876c 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -1233,6 +1233,11 @@ IF(ALSOFT_EXAMPLES)
         SET_PROPERTY(TARGET alloopback APPEND PROPERTY INCLUDE_DIRECTORIES ${SDL2_INCLUDE_DIR}
                                                                            ${SDL_SOUND_INCLUDE_DIR})
 
+        ADD_EXECUTABLE(alhrtf examples/alhrtf.c)
+        TARGET_LINK_LIBRARIES(alhrtf ex-common ${SDL_SOUND_LIBRARIES} ${SDL2_LIBRARY} ${LIBNAME})
+        SET_PROPERTY(TARGET alhrtf APPEND PROPERTY INCLUDE_DIRECTORIES ${SDL2_INCLUDE_DIR}
+                                                                       ${SDL_SOUND_INCLUDE_DIR})
+
         IF(ALSOFT_INSTALL)
             INSTALL(TARGETS alstream alreverb allatency alloopback
                     RUNTIME DESTINATION bin
diff --git a/ChangeLog b/ChangeLog
index f5d04c75..40ff34ed 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -47,6 +47,8 @@ openal-soft-1.17.0:
 
     Improved support for building as a sub-project.
 
+    Added an HRTF playback example.
+
     Added a tone generator output test.
 
     Added a toolchain to help with cross-compiling to Android.
diff --git a/examples/alhrtf.c b/examples/alhrtf.c
new file mode 100644
index 00000000..e787f5dd
--- /dev/null
+++ b/examples/alhrtf.c
@@ -0,0 +1,247 @@
+/*
+ * OpenAL HRTF Example
+ *
+ * Copyright (c) 2015 by Chris Robinson <[email protected]>
+ *
+ * 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 "AL/al.h"
+#include "AL/alc.h"
+#include "AL/alext.h"
+
+#include "common/alhelpers.h"
+#include "common/sdl_sound.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)
+{
+    ALenum err, format, type, channels;
+    ALuint rate, buffer;
+    size_t datalen;
+    void *data;
+    FilePtr sound;
+
+    /* Open the audio file */
+    sound = openAudioFile(filename, 1000);
+    if(!sound)
+    {
+        fprintf(stderr, "Could not open audio in %s\n", filename);
+        closeAudioFile(sound);
+        return 0;
+    }
+
+    /* Get the sound format, and figure out the OpenAL format */
+    if(getAudioInfo(sound, &rate, &channels, &type) != 0)
+    {
+        fprintf(stderr, "Error getting audio info for %s\n", filename);
+        closeAudioFile(sound);
+        return 0;
+    }
+
+    format = GetFormat(channels, type, NULL);
+    if(format == AL_NONE)
+    {
+        fprintf(stderr, "Unsupported format (%s, %s) for %s\n",
+                ChannelsName(channels), TypeName(type), filename);
+        closeAudioFile(sound);
+        return 0;
+    }
+
+    /* Decode the whole audio stream to a buffer. */
+    data = decodeAudioStream(sound, &datalen);
+    if(!data)
+    {
+        fprintf(stderr, "Failed to read audio from %s\n", filename);
+        closeAudioFile(sound);
+        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, data, datalen, rate);
+    free(data);
+    closeAudioFile(sound);
+
+    /* 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;
+    ALuint source, buffer;
+    const char *soundname;
+    const char *hrtfname;
+    ALCint hrtf_state;
+    ALCint num_hrtf;
+    ALdouble angle;
+    ALenum state;
+
+    /* Print out usage if no file was specified */
+    if(argc < 2 || (strcmp(argv[1], "-hrtf") == 0 && argc < 4))
+    {
+        fprintf(stderr, "Usage: %s [-hrtf <name>] <soundfile>\n", argv[0]);
+        return 1;
+    }
+
+    /* Initialize OpenAL with the default device, and check for HRTF support. */
+    if(InitAL() != 0)
+        return 1;
+
+    if(strcmp(argv[1], "-hrtf") == 0)
+    {
+        hrtfname = argv[2];
+        soundname = argv[3];
+    }
+    else
+    {
+        hrtfname = NULL;
+        soundname = argv[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
+
+    /* 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;
+        }
+
+        if(index == -1)
+        {
+            if(hrtfname)
+                printf("HRTF \"%s\" not found\n", hrtfname);
+            index = 0;
+        }
+        printf("Selecting HRTF %d...\n", index);
+
+        attr[0] = ALC_HRTF_SOFT;
+        attr[1] = ALC_TRUE;
+        attr[2] = ALC_HRTF_ID_SOFT;
+        attr[3] = index;
+        attr[4] = 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);
+
+    /* Load the sound into a buffer. */
+    buffer = LoadSound(soundname);
+    if(!buffer)
+    {
+        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 {
+        Sleep(10);
+
+        /* Rotate the source around the listener by about 1/4 cycle per second.
+         * Only affects mono sounds.
+         */
+        angle += 0.01 * M_PI * 0.5;
+        alSource3f(source, AL_POSITION, (ALfloat)sin(angle), 0.0f, -(ALfloat)cos(angle));
+
+        alGetSourcei(source, AL_SOURCE_STATE, &state);
+    } while(alGetError() == AL_NO_ERROR && state == AL_PLAYING);
+
+    /* All done. Delete resources, and close OpenAL. */
+    alDeleteSources(1, &source);
+    alDeleteBuffers(1, &buffer);
+
+    CloseAL();
+
+    return 0;
+}