/*

SDL_mixer: An audio mixer library based on the SDL library

Copyright (C) 1997-2009 Sam Lantinga

This library is free software; you can redistribute it and/or

modify it under the terms of the GNU Library General Public

License as published by the Free Software Foundation; either

version 2 of the License, or (at your option) any later version.

This library is distributed in the hope that it will be useful,

but WITHOUT ANY WARRANTY; without even the implied warranty of

MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU

Library General Public License for more details.

You should have received a copy of the GNU Library General Public

License along with this library; if not, write to the Free

Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA

Sam Lantinga

slouken@libsdl.org

*/

/* $Id: music_mod.c 4211 2008-12-08 00:27:32Z slouken $ */

#ifdef MOD_MUSIC

/* This file supports MOD tracker music streams */

#include "SDL_mixer.h"

#include "dynamic_mod.h"

#include "music_mod.h"

#include "mikmod.h"

#define SDL_SURROUND

#ifdef SDL_SURROUND

#define MAX_OUTPUT_CHANNELS 6

#else

#define MAX_OUTPUT_CHANNELS 2

#endif

/* Reference for converting mikmod output to 4/6 channels */

static int current_output_channels;

static Uint16 current_output_format;

static int music_swap8;

static int music_swap16;

/* Initialize the MOD player, with the given mixer settings

This function returns 0, or -1 if there was an error.

*/

int MOD_init(SDL_AudioSpec *mixerfmt)

{

CHAR *list;

if ( Mix_InitMOD() < 0 ) {

return NULL;

}

/* Set the MikMod music format */

music_swap8 = 0;

music_swap16 = 0;

switch (mixerfmt->format) {

case AUDIO_U8:

case AUDIO_S8: {

if ( mixerfmt->format == AUDIO_S8 ) {

music_swap8 = 1;

}

*mikmod.md_mode = 0;

}

break;

case AUDIO_S16LSB:

case AUDIO_S16MSB: {

/* See if we need to correct MikMod mixing */

#if SDL_BYTEORDER == SDL_LIL_ENDIAN

if ( mixerfmt->format == AUDIO_S16MSB ) {

#else

if ( mixerfmt->format == AUDIO_S16LSB ) {

#endif

music_swap16 = 1;

}

*mikmod.md_mode = DMODE_16BITS;

}

break;

default: {

Mix_SetError("Unknown hardware audio format");

return -1;

}

}

current_output_channels = mixerfmt->channels;

current_output_format = mixerfmt->format;

if ( mixerfmt->channels > 1 ) {

if ( mixerfmt->channels > MAX_OUTPUT_CHANNELS ) {

Mix_SetError("Hardware uses more channels than mixerfmt");

return -1;

}

*mikmod.md_mode |= DMODE_STEREO;

}

*mikmod.md_mixfreq = mixerfmt->freq;

*mikmod.md_device = 0;

*mikmod.md_volume = 96;

*mikmod.md_musicvolume = 128;

*mikmod.md_sndfxvolume = 128;

*mikmod.md_pansep = 128;

*mikmod.md_reverb = 0;

*mikmod.md_mode |= DMODE_HQMIXER|DMODE_SOFT_MUSIC|DMODE_SURROUND;

list = mikmod.MikMod_InfoDriver();

if ( list )

free(list);

else

mikmod.MikMod_RegisterDriver(mikmod.drv_nos);

list = mikmod.MikMod_InfoLoader();

if ( list )

free(list);

else

mikmod.MikMod_RegisterAllLoaders();

if ( mikmod.MikMod_Init(NULL) ) {

Mix_SetError("%s", mikmod.MikMod_strerror(*mikmod.MikMod_errno));

return -1;

}

return 0;

}

/* Uninitialize the music players */

void MOD_exit(void)

{

mikmod.MikMod_Exit();

Mix_QuitMOD();

}

/* Set the volume for a MOD stream */

void MOD_setvolume(MODULE *music, int volume)

{

mikmod.Player_SetVolume((SWORD)volume);

}

/* Load a MOD stream from the given file */

MODULE *MOD_new(const char *file)

{

SDL_RWops *rw;

rw = SDL_RWFromFile(file, "rb");

if ( rw == NULL ) {

/* FIXME: Free rw, need to free on delete */

SDL_SetError("Couldn't open %s", file);

return NULL;

}

return MOD_new_RW(rw);

}

typedef struct

{

MREADER mr;

int offset;

int eof;

SDL_RWops *rw;

} LMM_MREADER;

BOOL LMM_Seek(struct MREADER *mr,long to,int dir)

{

LMM_MREADER* lmmmr = (LMM_MREADER*)mr;

if ( dir == SEEK_SET ) {

to += lmmmr->offset;

}

return (SDL_RWseek(lmmmr->rw, to, dir) < lmmmr->offset);

}

long LMM_Tell(struct MREADER *mr)

{

LMM_MREADER* lmmmr = (LMM_MREADER*)mr;

return SDL_RWtell(lmmmr->rw) - lmmmr->offset;

}

BOOL LMM_Read(struct MREADER *mr,void *buf,size_t sz)

{

LMM_MREADER* lmmmr = (LMM_MREADER*)mr;

return SDL_RWread(lmmmr->rw, buf, sz, 1);

}

int LMM_Get(struct MREADER *mr)

{

unsigned char c;

LMM_MREADER* lmmmr = (LMM_MREADER*)mr;

if ( SDL_RWread(lmmmr->rw, &c, 1, 1) ) {

return c;

}

return EOF;

}

BOOL LMM_Eof(struct MREADER *mr)

{

int offset;

LMM_MREADER* lmmmr = (LMM_MREADER*)mr;

offset = LMM_Tell(mr);

return offset >= lmmmr->eof;

}

MODULE *MikMod_LoadSongRW(SDL_RWops *rw, int maxchan)

{

LMM_MREADER lmmmr = {

{ LMM_Seek, LMM_Tell, LMM_Read, LMM_Get, LMM_Eof },

0,

0,

0

};

lmmmr.offset = SDL_RWtell(rw);

SDL_RWseek(rw, 0, SEEK_END);

lmmmr.eof = SDL_RWtell(rw);

SDL_RWseek(rw, lmmmr.offset, SEEK_SET);

lmmmr.rw = rw;

return mikmod.Player_LoadGeneric((MREADER*)&lmmmr, maxchan, 0);

}

/* Load a MOD stream from an SDL_RWops object */

MODULE *MOD_new_RW(SDL_RWops *rw)

{

MODULE *module;

module = MikMod_LoadSongRW(rw,64);

if (!module) {

Mix_SetError("%s", mikmod.MikMod_strerror(*mikmod.MikMod_errno));

return NULL;

}

/* Stop implicit looping, fade out and other flags. */

module->extspd = 1;

module->panflag = 1;

module->wrap = 0;

module->loop = 0;

#if 0 /* Don't set fade out by default - unfortunately there's no real way

to query the status of the song or set trigger actions. Hum. */

module->fadeout = 1;

#endif

return module;

}

/* Start playback of a given MOD stream */

void MOD_play(MODULE *music)

{

mikmod.Player_Start(music);

}

/* Return non-zero if a stream is currently playing */

int MOD_playing(MODULE *music)

{

return mikmod.Player_Active();

}

/* Play some of a stream previously started with MOD_play() */

int MOD_playAudio(MODULE *music, Uint8 *stream, int len)

{

if (current_output_channels > 2) {

int small_len = 2 * len / current_output_channels;

int i;

Uint8 *src, *dst;

mikmod.VC_WriteBytes((SBYTE *)stream, small_len);

/* and extend to len by copying channels */

src = stream + small_len;

dst = stream + len;

switch (current_output_format & 0xFF) {

case 8:

for ( i=small_len/2; i; --i ) {

src -= 2;

dst -= current_output_channels;

dst[0] = src[0];

dst[1] = src[1];

dst[2] = src[0];

dst[3] = src[1];

if (current_output_channels == 6) {

dst[4] = src[0];

dst[5] = src[1];

}

}

break;

case 16:

for ( i=small_len/4; i; --i ) {

src -= 4;

dst -= 2 * current_output_channels;

dst[0] = src[0];

dst[1] = src[1];

dst[2] = src[2];

dst[3] = src[3];

dst[4] = src[0];

dst[5] = src[1];

dst[6] = src[2];

dst[7] = src[3];

if (current_output_channels == 6) {

dst[8] = src[0];

dst[9] = src[1];

dst[10] = src[2];

dst[11] = src[3];

}

}

break;

}

} else {

mikmod.VC_WriteBytes((SBYTE *)stream, len);

}

if ( music_swap8 ) {

Uint8 *dst;

int i;

dst = stream;

for ( i=len; i; --i ) {

*dst++ ^= 0x80;

}

} else

if ( music_swap16 ) {

Uint8 *dst, tmp;

int i;

dst = stream;

for ( i=(len/2); i; --i ) {

tmp = dst[0];

dst[0] = dst[1];

dst[1] = tmp;

dst += 2;

}

}

return 0;

}

/* Stop playback of a stream previously started with MOD_play() */

void MOD_stop(MODULE *music)

{

mikmod.Player_Stop();

}

/* Close the given MOD stream */

void MOD_delete(MODULE *music)

{

mikmod.Player_Free(music);

}

/* Jump (seek) to a given position (time is in seconds) */

void MOD_jump_to_time(MODULE *music, double time)

{

mikmod.Player_SetPosition((UWORD)time);

}

#endif /* MOD_MUSIC */