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/*
MACLIB: A companion library to SDL for working with Macintosh (tm) data
Copyright (C) 1997 Sam Lantinga
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2 of the License, or
(at your option) any later version.
This program 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 General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
Sam Lantinga
5635-34 Springhouse Dr.
Pleasanton, CA 94588 (USA)
slouken@devolution.com
*/
/* This is a general mixer that takes Macintosh sound resource files
and mixes various sounds on command.
*/
#include <stdio.h>
#include <stdarg.h>
#include <string.h>
#include "SDL_types.h"
#include "SDL_mutex.h"
#include "SDL_thread.h"
#include "SDL_audio.h"
#include "Mac_Wave.h"
#define MAX_VOLUME 8 /* Software volume ranges from 0 - 8 */
#define NUM_CHANNELS 4 /* 4 sound mixing channels, limit 128 */
#define DSP_FREQUENCY 11025 /* Convert the SNDs to this frequency */
class Sound {
public:
Sound(const char *soundfile, Uint8 vol = 4);
~Sound();
/* Set volume in the range 0-8 */
Uint8 Volume(Uint8 vol);
Uint8 Volume(void) {
return(volume);
}
/* Play the requested sound */
int PlaySound(Uint16 sndID, Uint8 priority = 0,
void (*callback)(Uint8 channel) = NULL) {
int i;
for ( i=0; i<NUM_CHANNELS; ++i ) {
if ( channels[i].len <= 0 )
return(PlaySound(sndID, priority, i, callback));
}
for ( i=0; i<NUM_CHANNELS; ++i ) {
if ( priority > Priority(i) )
return(PlaySound(sndID, priority, i, callback));
}
return(-1);
}
int PlaySound(Uint16 sndID, Uint8 priority, Uint8 channel,
void (*callback)(Uint8 channel) = NULL);
/* Stop mixing on the requested channels */
void HaltSound(void) {
Uint8 i;
for ( i=0; i<NUM_CHANNELS; ++i )
HaltSound(i);
}
void HaltSound(Uint8 channel) {
channels[channel].len = 0;
}
/* Find out if a sound is playing on a channel */
int Playing(Sint16 sndID = 0, Sint8 *channel = NULL) {
Uint8 i;
for ( i=0; i<NUM_CHANNELS; ++i ) {
if ( channels[i].len <= 0 )
continue;
if ( (sndID == 0) || (sndID == channels[i].ID) ) {
if ( channel )
*channel = i;
return(1);
}
}
return(0);
}
Sint16 Priority(Uint8 channel) {
if ( channels[channel].len > 0 )
return(channels[channel].priority);
return(-1);
}
int ChannelFree(Sint8 channel = -1) {
Uint8 i;
/* Checking a particular channel? */
if ( channel >= 0 )
return((channels[channel].len > 0) ? 1 : 0);
/* Checking any channel */
for ( i=0; i<NUM_CHANNELS; ++i ) {
if ( channels[i].len > 0 )
return(1);
}
return(0);
}
char *Error(void) {
return(errstr);
}
/* These functions really do all the work */
static void FillAudioU8(Sound *sound, Uint8 *stream, int len);
private:
Uint8 playing;
struct channel {
Uint16 ID;
Sint16 priority;
int len; /* Signed, so race conditions can make it < 0 */
Uint8 *src;
void (*callback)(Uint8 channel);
} channels[NUM_CHANNELS];
SDL_AudioSpec *spec;
Uint8 volume;
/* Fake audio handler, in case we can't open the real thing */
SDL_Thread *bogus_audio;
/* Functions for getting and setting a hash indexed by Uint16 */
/* We use a sparse tiered pointer page scheme :-)
It's probably not unique, but I made this version up. :-)
*/
Wave ***hashpage;
void InitHash(void) {
hashpage = new Wave **[256];
memset(hashpage, 0, 256*sizeof(Wave **));
}
void Hash(Uint16 index, Wave *value) {
Uint8 upper, lower;
upper = index>>8;
lower = index&0xFF;
if ( hashpage[upper] == NULL ) {
hashpage[upper] = new Wave *[256];
memset(hashpage[upper], 0, 256*sizeof(Wave *));
}
if ( hashpage[upper][lower] ) {
#ifdef DEBUG_HASH
printf("Warning: Hash page %d/%d already used!\n", upper, lower);
#endif
delete hashpage[upper][lower];
}
#ifdef DEBUG_HASH
printf("Saving Wave id %hu to hash page %d/%d\n", index, upper, lower);
#endif
hashpage[upper][lower] = value;
}
Wave *Hash(Uint16 index) {
Uint8 upper, lower;
upper = index>>8;
lower = index&0xFF;
if ( hashpage[upper] == NULL )
return(NULL);
return(hashpage[upper][lower]);
}
void FreeHash(void) {
Uint16 upper, lower;
for ( upper = 0; upper < 256; ++upper ) {
if ( hashpage[upper] ) {
for ( lower = 0; lower < 256; ++lower ) {
if ( hashpage[upper][lower] ) {
#ifdef DEBUG_HASH
printf("Freeing Wave id %hu at hash page %d/%d\n",(upper<<8)|lower,upper,lower);
#endif
delete hashpage[upper][lower];
}
}
delete[] hashpage[upper];
}
}
delete[] hashpage;
}
/* Useful for getting error feedback */
void error(char *fmt, ...) {
va_list ap;
va_start(ap, fmt);
vsnprintf(errbuf, sizeof(errbuf), fmt, ap);
va_end(ap);
errstr = errbuf;
}
char *errstr;
char errbuf[BUFSIZ];
};
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