/***************************************************************************
Flower sound driver (quick hack of the Wiping sound driver)
***************************************************************************/
#include "driver.h"
#include "streams.h"
#include "sound/custom.h"
/* 8 voices max */
#define MAX_VOICES 8
static const int samplerate = 48000;
static const int defgain = 48;
/* this structure defines the parameters for a channel */
typedef struct
{
int frequency;
int counter;
int volume;
const UINT8 *wave;
int oneshot;
int oneshotplaying;
} sound_channel;
/* globals available to everyone */
UINT8 *flower_soundregs1,*flower_soundregs2;
/* data about the sound system */
static sound_channel channel_list[MAX_VOICES];
static sound_channel *last_channel;
/* global sound parameters */
static const UINT8 *sound_rom1,*sound_rom2;
static int num_voices;
static int sound_enable;
static sound_stream * stream;
/* mixer tables and internal buffers */
static INT16 *mixer_table;
static INT16 *mixer_lookup;
static short *mixer_buffer;
static short *mixer_buffer_2;
/* build a table to divide by the number of voices; gain is specified as gain*16 */
static int make_mixer_table(int voices, int gain)
{
int count = voices * 128;
int i;
/* allocate memory */
mixer_table = auto_malloc(256 * voices * sizeof(INT16));
/* find the middle of the table */
mixer_lookup = mixer_table + (128 * voices);
/* fill in the table - 16 bit case */
for (i = 0; i < count; i++)
{
int val = i * gain * 16 / voices;
if (val > 32767) val = 32767;
mixer_lookup[ i] = val;
mixer_lookup[-i] = -val;
}
return 0;
}
/* generate sound to the mix buffer in mono */
static void flower_update_mono(void *param, stream_sample_t **inputs, stream_sample_t **outputs, int length)
{
stream_sample_t *buffer = outputs[0];
sound_channel *voice;
short *mix;
int i;
/* if no sound, we're done */
if (sound_enable == 0)
{
memset(buffer, 0, length * sizeof(*buffer));
return;
}
/* zap the contents of the mixer buffer */
memset(mixer_buffer, 0, length * sizeof(short));
/* loop over each voice and add its contribution */
for (voice = channel_list; voice < last_channel; voice++)
{
int f = 256*voice->frequency;
int v = voice->volume;
/* only update if we have non-zero volume and frequency */
if (v && f)
{
const UINT8 *w = voice->wave;
int c = voice->counter;
mix = mixer_buffer;
/* add our contribution */
for (i = 0; i < length; i++)
{
int offs;
c += f;
if (voice->oneshot)
{
if (voice->oneshotplaying)
{
offs = (c >> 15);
if (w[offs] == 0xff)
{
voice->oneshotplaying = 0;
}
if (voice->oneshotplaying)
{
// *mix++ += ((w[offs] - 0x80) * v) / 16;
*mix++ += sound_rom2[v*256 + w[offs]] - 0x80;
}
}
}
else
{
offs = (c >> 15) & 0x1ff;
// *mix++ += ((w[offs] - 0x80) * v) / 16;
*mix++ += sound_rom2[v*256 + w[offs]] - 0x80;
}
}
/* update the counter for this voice */
voice->counter = c;
}
}
/* mix it down */
mix = mixer_buffer;
for (i = 0; i < length; i++)
*buffer++ = mixer_lookup[*mix++];
}
void * flower_sh_start(int clock, const struct CustomSound_interface *config)
{
sound_channel *voice;
/* get stream channels */
stream = stream_create(0, 1, samplerate, 0, flower_update_mono);
/* allocate a pair of buffers to mix into - 1 second's worth should be more than enough */
mixer_buffer = auto_malloc(2 * sizeof(short) * samplerate);
mixer_buffer_2 = mixer_buffer + samplerate;
/* build the mixer table */
if (make_mixer_table(8, defgain))
return NULL;
/* extract globals from the interface */
num_voices = 8;
last_channel = channel_list + num_voices;
sound_rom1 = memory_region(REGION_SOUND1);
sound_rom2 = memory_region(REGION_SOUND2);
/* start with sound enabled, many games don't have a sound enable register */
sound_enable = 1;
/* reset all the voices */
for (voice = channel_list; voice < last_channel; voice++)
{
voice->frequency = 0;
voice->volume = 0;
voice->wave = &sound_rom1[0];
voice->counter = 0;
}
return auto_malloc(1);
}
/********************************************************************************/
WRITE8_HANDLER( flower_sound1_w )
{
sound_channel *voice;
int base;
/* update the streams */
stream_update(stream);
/* set the register */
flower_soundregs1[offset] = data;
/* recompute all the voice parameters */
for (base = 0, voice = channel_list; voice < last_channel; voice++, base += 8)
{
voice->frequency = flower_soundregs1[2 + base] & 0x0f;
voice->frequency = voice->frequency * 16 + ((flower_soundregs1[3 + base]) & 0x0f);
voice->frequency = voice->frequency * 16 + ((flower_soundregs1[0 + base]) & 0x0f);
voice->frequency = voice->frequency * 16 + ((flower_soundregs1[1 + base]) & 0x0f);
voice->volume = (flower_soundregs1[7 + base] >> 4) | ((flower_soundregs2[7 + base] & 0x03) << 4);
// the following would fix the hanging notes...
//if ((flower_soundregs2[7 + base] & 0x01) == 0)
// voice->volume = 0;
if (flower_soundregs1[4 + base] & 0x10)
{
voice->oneshot = 0;
voice->oneshotplaying = 0;
}
else
{
voice->oneshot = 1;
}
}
}
WRITE8_HANDLER( flower_sound2_w )
{
sound_channel *voice;
int base = offset & 0xf8;
/*
popmessage("%02x%02x %02x%02x %02x%02x %02x%02x %02x%02x %02x%02x %02x%02x %02x%02x",
flower_soundregs2[7 + 8*0],flower_soundregs1[7 + 8*0],
flower_soundregs2[7 + 8*1],flower_soundregs1[7 + 8*1],
flower_soundregs2[7 + 8*2],flower_soundregs1[7 + 8*2],
flower_soundregs2[7 + 8*3],flower_soundregs1[7 + 8*3],
flower_soundregs2[7 + 8*4],flower_soundregs1[7 + 8*4],
flower_soundregs2[7 + 8*5],flower_soundregs1[7 + 8*5],
flower_soundregs2[7 + 8*6],flower_soundregs1[7 + 8*6],
flower_soundregs2[7 + 8*7],flower_soundregs1[7 + 8*7]
);
*/
/* update the streams */
stream_update(stream);
/* set the register */
flower_soundregs2[offset] = data;
/* recompute all the voice parameters */
voice = &channel_list[offset/8];
if (voice->oneshot)
{
int start;
start = flower_soundregs2[5 + base] & 0x0f;
start = start * 16 + ((flower_soundregs2[4 + base]) & 0x0f);
start = start * 16 + ((flower_soundregs2[3 + base]) & 0x0f);
start = start * 16 + ((flower_soundregs2[2 + base]) & 0x0f);
start = start * 16 + ((flower_soundregs2[1 + base]) & 0x0f);
start = start * 16 + ((flower_soundregs2[0 + base]) & 0x0f);
voice->wave = &sound_rom1[(start >> 7) & 0x7fff];
voice->counter = 0;
voice->oneshotplaying = 1;
}
else
{
int start;
start = flower_soundregs2[5 + base] & 0x0f;
start = start * 16 + ((flower_soundregs2[4 + base]) & 0x0f);
voice->wave = &sound_rom1[(start << 9) & 0x7fff]; // ???
voice->oneshot = 0;
voice->oneshotplaying = 0;
}
}