Add a simple example that prints out some OpenAL info

CMakeLists.txt

@@ -24,6 +24,8 @@ OPTION(DLOPEN  "Check for the dlopen API for loading optional libs"  ON)
 
 OPTION(WERROR  "Treat compile warnings as errors"      OFF)
 
+OPTION(EXAMPLES  "Build example programs"              ON)
+
 
 SET(LIB_MAJOR_VERSION "1")
 SET(LIB_MINOR_VERSION "3")
@@ -316,6 +318,11 @@ INSTALL(FILES include/AL/al.h
         DESTINATION include/AL
 )
 
+IF(EXAMPLES)
+    ADD_EXECUTABLE(openal-info examples/openal-info.c)
+    TARGET_LINK_LIBRARIES(openal-info ${LIBNAME})
+ENDIF()
+
 MESSAGE(STATUS "")
 MESSAGE(STATUS "Building OpenAL with support for the following backends:")
 MESSAGE(STATUS "    ${BACKENDS}")

examples/openal-info.c

@@ -0,0 +1,170 @@
+/*
+ * openal-info: Display information about ALC and AL.
+ *
+ * Idea based on glxinfo for OpenGL.
+ * Initial OpenAL version by Erik Hofman <erik@ehofman.com>.
+ * Further hacked by Sven Panne <sven.panne@aedion.de>.
+ *
+ */
+
+#if HAVE_CONFIG_H
+#include "config.h"
+#endif
+
+#include <stdio.h>
+#include <stdlib.h>
+
+#include "AL/alc.h"
+#include "AL/al.h"
+#include "AL/alext.h"
+
+
+static const int indentation = 4;
+static const int maxmimumWidth = 79;
+
+static void printChar(int c, int *width)
+{
+    putchar(c);
+    *width = ((c == '\n') ? 0 : ((*width) + 1));
+}
+
+static void indent(int *width)
+{
+    int i;
+    for(i = 0; i < indentation; i++)
+        printChar(' ', width);
+}
+
+static void printExtensions(const char *header, char separator, const char *extensions)
+{
+    int width = 0, start = 0, end = 0;
+
+    printf("%s:\n", header);
+    if(extensions == NULL || extensions[0] == '\0')
+        return;
+
+    indent(&width);
+    while (1)
+    {
+        if(extensions[end] == separator || extensions[end] == '\0')
+        {
+            if(width + end - start + 2 > maxmimumWidth)
+            {
+                printChar('\n', &width);
+                indent(&width);
+            }
+            while(start < end)
+            {
+                printChar(extensions[start], &width);
+                start++;
+            }
+            if(extensions[end] == '\0')
+                break;
+            start++;
+            end++;
+            if(extensions[end] == '\0')
+                break;
+            printChar(',', &width);
+            printChar(' ', &width);
+        }
+        end++;
+    }
+    printChar('\n', &width);
+}
+
+static void die(const char *kind, const char *description)
+{
+    fprintf(stderr, "%s error %s occured\n", kind, description);
+    exit(EXIT_FAILURE);
+}
+
+static void checkForErrors(void)
+{
+    {
+        ALCdevice *device = alcGetContextsDevice(alcGetCurrentContext());
+        ALCenum error = alcGetError(device);
+        if(error != ALC_NO_ERROR)
+            die("ALC", (const char*)alcGetString(device, error));
+    }
+    {
+        ALenum error = alGetError();
+        if(error != AL_NO_ERROR)
+            die("AL", (const char*)alGetString(error));
+    }
+}
+
+static void printDevices(ALCenum which, const char *kind)
+{
+    const char *s = alcGetString(NULL, which);
+    checkForErrors();
+
+    printf("Available %sdevices:\n", kind);
+    while(*s != '\0')
+    {
+        printf("    %s\n", s);
+        while(*s++ != '\0')
+            ;
+    }
+}
+
+static void printALCInfo (void)
+{
+    ALCint major, minor;
+    ALCdevice *device;
+
+    if(alcIsExtensionPresent(NULL, (const ALCchar*)"ALC_ENUMERATION_EXT") == AL_TRUE)
+    {
+        if(alcIsExtensionPresent(NULL, (const ALCchar*)"ALC_ENUMERATE_ALL_EXT") == AL_TRUE)
+            printDevices(ALC_ALL_DEVICES_SPECIFIER, "playback ");
+        else
+            printDevices(ALC_DEVICE_SPECIFIER, "playback ");
+        printDevices(ALC_CAPTURE_DEVICE_SPECIFIER, "capture ");
+    }
+    else
+        printf("No device enumeration available\n");
+
+    device = alcGetContextsDevice(alcGetCurrentContext());
+    checkForErrors();
+
+    printf("Default device: %s\n",
+           alcGetString(device, ALC_DEFAULT_DEVICE_SPECIFIER));
+
+    printf("Default capture device: %s\n",
+           alcGetString(device, ALC_CAPTURE_DEFAULT_DEVICE_SPECIFIER));
+
+    alcGetIntegerv(device, ALC_MAJOR_VERSION, 1, &major);
+    alcGetIntegerv(device, ALC_MAJOR_VERSION, 1, &minor);
+    checkForErrors();
+    printf("ALC version: %d.%d\n", (int)major, (int)minor);
+
+    printExtensions("ALC extensions", ' ',
+                    alcGetString(device, ALC_EXTENSIONS));
+    checkForErrors();
+}
+
+static void printALInfo(void)
+{
+    printf("OpenAL vendor string: %s\n", alGetString(AL_VENDOR));
+    printf("OpenAL renderer string: %s\n", alGetString(AL_RENDERER));
+    printf("OpenAL version string: %s\n", alGetString(AL_VERSION));
+    printExtensions("OpenAL extensions", ' ', alGetString(AL_EXTENSIONS));
+    checkForErrors();
+}
+
+int main()
+{
+    ALCdevice *device = alcOpenDevice(NULL);
+    ALCcontext *context = alcCreateContext(device, NULL);
+    alcMakeContextCurrent(context);
+    checkForErrors();
+
+    printALCInfo();
+    printALInfo();
+    checkForErrors();
+
+    alcMakeContextCurrent(NULL);
+    alcDestroyContext(context);
+    alcCloseDevice(device);
+
+    return EXIT_SUCCESS;
+}