/*
 * OpenAL Helpers
 *
 * Copyright (c) 2011 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 routines to help with some menial OpenAL-related tasks,
 * such as opening a device and setting up a context, closing the device and
 * destroying its context, converting between frame counts and byte lengths,
 * finding an appropriate buffer format, and getting readable strings for
 * channel configs and sample types. */

#include "common.h"
#include "audio/alhelpers.h"


/* InitAL opens the default device and sets up a context using default
 * attributes, making the program ready to call OpenAL functions. */
ALCcontext* InitAL(void)
{
    ALCdevice *device;
    ALCcontext *ctx;

    /* Open and initialize a device with default settings */
    device = alcOpenDevice(NULL);
    if(!device)
    {
        ERRLOG("Could not open a device!");
        return NULL;
    }

    ctx = alcCreateContext(device, NULL);
    if(ctx == NULL || alcMakeContextCurrent(ctx) == ALC_FALSE)
    {
        if(ctx != NULL)
        {
            alcDestroyContext(ctx);
        }
        alcCloseDevice(device);
        ERRLOG("Could not set a context!");
        return NULL;
    }

    LOG("Opened \"%s\"", alcGetString(device, ALC_DEVICE_SPECIFIER));
    return ctx;
}

/* CloseAL closes the device belonging to the current context, and destroys the
 * context. */
void CloseAL(void)
{
    ALCdevice *device;
    ALCcontext *ctx;

    ctx = alcGetCurrentContext();
    if(ctx == NULL)
    {
        return;
    }

    device = alcGetContextsDevice(ctx);

    alcMakeContextCurrent(NULL);
    alcDestroyContext(ctx);
    alcCloseDevice(device);
}