Genesis-Plus-GX/core/sound/sound.c

565 lines
14 KiB
C

/***************************************************************************************
* Genesis Plus
* Sound Hardware
*
* Copyright (C) 1998-2003 Charles Mac Donald (original code)
* Copyright (C) 2007-2020 Eke-Eke (Genesis Plus GX)
*
* Redistribution and use of this code or any derivative works are permitted
* provided that the following conditions are met:
*
* - Redistributions may not be sold, nor may they be used in a commercial
* product or activity.
*
* - Redistributions that are modified from the original source must include the
* complete source code, including the source code for all components used by a
* binary built from the modified sources. However, as a special exception, the
* source code distributed need not include anything that is normally distributed
* (in either source or binary form) with the major components (compiler, kernel,
* and so on) of the operating system on which the executable runs, unless that
* component itself accompanies the executable.
*
* - Redistributions must reproduce the above copyright notice, this list of
* conditions and the following disclaimer in the documentation and/or other
* materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
* LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*
****************************************************************************************/
#include "shared.h"
#include "blip_buf.h"
/* YM2612 internal clock = input clock / 6 = (master clock / 7) / 6 */
#define YM2612_CLOCK_RATIO (7*6)
/* FM output buffer (large enough to hold a whole frame at original chips rate) */
#if defined(HAVE_YM3438_CORE) || defined(HAVE_OPLL_CORE)
static int fm_buffer[1080 * 2 * 24];
#else
static int fm_buffer[1080 * 2];
#endif
static int fm_last[2];
static int *fm_ptr;
/* Cycle-accurate FM samples */
static int fm_cycles_ratio;
static int fm_cycles_start;
static int fm_cycles_count;
static int fm_cycles_busy;
/* YM chip function pointers */
static void (*YM_Update)(int *buffer, int length);
void (*fm_reset)(unsigned int cycles);
void (*fm_write)(unsigned int cycles, unsigned int address, unsigned int data);
unsigned int (*fm_read)(unsigned int cycles, unsigned int address);
#ifdef HAVE_YM3438_CORE
static ym3438_t ym3438;
static short ym3438_accm[24][2];
static int ym3438_sample[2];
static int ym3438_cycles;
#endif
#ifdef HAVE_OPLL_CORE
static opll_t opll;
static int opll_accm[18][2];
static int opll_sample;
static int opll_cycles;
static int opll_status;
#endif
/* Run FM chip until required M-cycles */
INLINE void fm_update(int cycles)
{
if (cycles > fm_cycles_count)
{
/* number of samples to run */
int samples = (cycles - fm_cycles_count + fm_cycles_ratio - 1) / fm_cycles_ratio;
/* run FM chip to sample buffer */
YM_Update(fm_ptr, samples);
/* update FM buffer pointer */
fm_ptr += (samples * 2);
/* update FM cycle counter */
fm_cycles_count += (samples * fm_cycles_ratio);
}
}
static void YM2612_Reset(unsigned int cycles)
{
/* synchronize FM chip with CPU */
fm_update(cycles);
/* reset FM chip */
YM2612ResetChip();
fm_cycles_busy = 0;
}
static void YM2612_Write(unsigned int cycles, unsigned int a, unsigned int v)
{
/* detect DATA port write */
if (a & 1)
{
/* synchronize FM chip with CPU */
fm_update(cycles);
/* set FM BUSY end cycle (discrete or ASIC-integrated YM2612 chip only) */
if (config.ym2612 < YM2612_ENHANCED)
{
fm_cycles_busy = (((cycles + YM2612_CLOCK_RATIO - 1) / YM2612_CLOCK_RATIO) + 32) * YM2612_CLOCK_RATIO;
}
}
/* write FM register */
YM2612Write(a, v);
}
static unsigned int YM2612_Read(unsigned int cycles, unsigned int a)
{
/* FM status can only be read from (A0,A1)=(0,0) on discrete YM2612 */
if ((a == 0) || (config.ym2612 > YM2612_DISCRETE))
{
/* synchronize FM chip with CPU */
fm_update(cycles);
/* read FM status */
if (cycles >= fm_cycles_busy)
{
/* BUSY flag cleared */
return YM2612Read();
}
else
{
/* BUSY flag set */
return YM2612Read() | 0x80;
}
}
/* invalid FM status address */
return 0x00;
}
static void YM2413_Reset(unsigned int cycles)
{
/* synchronize FM chip with CPU */
fm_update(cycles);
/* reset FM chip */
YM2413ResetChip();
}
static void YM2413_Write(unsigned int cycles, unsigned int a, unsigned int v)
{
/* detect DATA port write */
if (a & 1)
{
/* synchronize FM chip with CPU */
fm_update(cycles);
}
/* write FM register */
YM2413Write(a, v);
}
static unsigned int YM2413_Read(unsigned int cycles, unsigned int a)
{
return YM2413Read();
}
#ifdef HAVE_YM3438_CORE
static void YM3438_Update(int *buffer, int length)
{
int i, j;
for (i = 0; i < length; i++)
{
OPN2_Clock(&ym3438, ym3438_accm[ym3438_cycles]);
ym3438_cycles = (ym3438_cycles + 1) % 24;
if (ym3438_cycles == 0)
{
ym3438_sample[0] = 0;
ym3438_sample[1] = 0;
for (j = 0; j < 24; j++)
{
ym3438_sample[0] += ym3438_accm[j][0];
ym3438_sample[1] += ym3438_accm[j][1];
}
}
*buffer++ = ym3438_sample[0] * 11;
*buffer++ = ym3438_sample[1] * 11;
}
}
static void YM3438_Reset(unsigned int cycles)
{
/* synchronize FM chip with CPU */
fm_update(cycles);
/* reset FM chip */
OPN2_Reset(&ym3438);
}
static void YM3438_Write(unsigned int cycles, unsigned int a, unsigned int v)
{
/* synchronize FM chip with CPU */
fm_update(cycles);
/* write FM register */
OPN2_Write(&ym3438, a, v);
}
static unsigned int YM3438_Read(unsigned int cycles, unsigned int a)
{
/* synchronize FM chip with CPU */
fm_update(cycles);
/* read FM status */
return OPN2_Read(&ym3438, a);
}
#endif
#ifdef HAVE_OPLL_CORE
static void OPLL2413_Update(int* buffer, int length)
{
int i, j;
for (i = 0; i < length; i++)
{
OPLL_Clock(&opll, opll_accm[opll_cycles]);
opll_cycles = (opll_cycles + 1) % 18;
if (opll_cycles == 0)
{
opll_sample = 0;
for (j = 0; j < 18; j++)
{
opll_sample += opll_accm[j][0] + opll_accm[j][1];
}
}
*buffer++ = opll_sample * 16 * opll_status;
*buffer++ = opll_sample * 16 * opll_status;
}
}
static void OPLL2413_Reset(unsigned int cycles)
{
/* synchronize FM chip with CPU */
fm_update(cycles);
/* reset FM chip */
OPLL_Reset(&opll, opll_type_ym2413);
}
static void OPLL2413_Write(unsigned int cycles, unsigned int a, unsigned int v)
{
if (!(a&2))
{
/* synchronize FM chip with CPU */
fm_update(cycles);
/* write FM register */
OPLL_Write(&opll, a, v);
}
else
{
opll_status = v&1;
}
}
static unsigned int OPLL2413_Read(unsigned int cycles, unsigned int a)
{
return 0xf8 | opll_status;
}
#endif
void sound_init( void )
{
/* Initialize FM chip */
if ((system_hw & SYSTEM_PBC) == SYSTEM_MD)
{
/* YM2612 */
#ifdef HAVE_YM3438_CORE
if (config.ym3438)
{
/* Nuked OPN2 */
memset(&ym3438, 0, sizeof(ym3438));
memset(&ym3438_sample, 0, sizeof(ym3438_sample));
memset(&ym3438_accm, 0, sizeof(ym3438_accm));
YM_Update = YM3438_Update;
fm_reset = YM3438_Reset;
fm_write = YM3438_Write;
fm_read = YM3438_Read;
/* chip is running at internal clock */
fm_cycles_ratio = YM2612_CLOCK_RATIO;
}
else
#endif
{
/* MAME OPN2*/
YM2612Init();
YM2612Config(config.ym2612);
YM_Update = YM2612Update;
fm_reset = YM2612_Reset;
fm_write = YM2612_Write;
fm_read = YM2612_Read;
/* chip is running at sample clock */
fm_cycles_ratio = YM2612_CLOCK_RATIO * 24;
}
}
else
{
/* YM2413 */
#ifdef HAVE_OPLL_CORE
if (config.opll)
{
/* Nuked OPLL */
memset(&opll, 0, sizeof(opll));
memset(&opll_accm, 0, sizeof(opll_accm));
opll_sample = 0;
opll_status = 0;
YM_Update = (config.ym2413 & 1) ? OPLL2413_Update : NULL;
fm_reset = OPLL2413_Reset;
fm_write = OPLL2413_Write;
fm_read = OPLL2413_Read;
/* chip is running at internal clock */
fm_cycles_ratio = 4 * 15;
}
else
#endif
{
YM2413Init();
YM_Update = (config.ym2413 & 1) ? YM2413Update : NULL;
fm_reset = YM2413_Reset;
fm_write = YM2413_Write;
fm_read = YM2413_Read;
/* chip is running at ZCLK / 72 = MCLK / 15 / 72 */
fm_cycles_ratio = 72 * 15;
}
}
/* Initialize PSG chip */
psg_init((system_hw == SYSTEM_SG) ? PSG_DISCRETE : PSG_INTEGRATED);
}
void sound_reset(void)
{
/* reset sound chips */
fm_reset(0);
psg_reset();
psg_config(0, config.psg_preamp, 0xff);
/* reset FM buffer ouput */
fm_last[0] = fm_last[1] = 0;
/* reset FM buffer pointer */
fm_ptr = fm_buffer;
/* reset FM cycle counters */
fm_cycles_start = fm_cycles_count = 0;
}
int sound_update(unsigned int cycles)
{
/* Run PSG chip until end of frame */
psg_end_frame(cycles);
/* FM chip is enabled ? */
if (YM_Update)
{
int prev_l, prev_r, preamp, time, l, r, *ptr;
/* Run FM chip until end of frame */
fm_update(cycles);
/* FM output pre-amplification */
preamp = config.fm_preamp;
/* FM frame initial timestamp */
time = fm_cycles_start;
/* Restore last FM outputs from previous frame */
prev_l = fm_last[0];
prev_r = fm_last[1];
/* FM buffer start pointer */
ptr = fm_buffer;
/* flush FM samples */
if (config.hq_fm)
{
/* high-quality Band-Limited synthesis */
do
{
/* left & right channels */
l = ((*ptr++ * preamp) / 100);
r = ((*ptr++ * preamp) / 100);
blip_add_delta(snd.blips[0], time, l-prev_l, r-prev_r);
prev_l = l;
prev_r = r;
/* increment time counter */
time += fm_cycles_ratio;
}
while (time < cycles);
}
else
{
/* faster Linear Interpolation */
do
{
/* left & right channels */
l = ((*ptr++ * preamp) / 100);
r = ((*ptr++ * preamp) / 100);
blip_add_delta_fast(snd.blips[0], time, l-prev_l, r-prev_r);
prev_l = l;
prev_r = r;
/* increment time counter */
time += fm_cycles_ratio;
}
while (time < cycles);
}
/* reset FM buffer pointer */
fm_ptr = fm_buffer;
/* save last FM output for next frame */
fm_last[0] = prev_l;
fm_last[1] = prev_r;
/* adjust FM cycle counters for next frame */
fm_cycles_count = fm_cycles_start = time - cycles;
if (fm_cycles_busy > cycles)
{
fm_cycles_busy -= cycles;
}
else
{
fm_cycles_busy = 0;
}
}
/* end of blip buffer time frame */
blip_end_frame(snd.blips[0], cycles);
/* return number of available samples */
return blip_samples_avail(snd.blips[0]);
}
int sound_context_save(uint8 *state)
{
int bufferptr = 0;
if ((system_hw & SYSTEM_PBC) == SYSTEM_MD)
{
#ifdef HAVE_YM3438_CORE
save_param(&config.ym3438, sizeof(config.ym3438));
if (config.ym3438)
{
save_param(&ym3438, sizeof(ym3438));
save_param(&ym3438_accm, sizeof(ym3438_accm));
save_param(&ym3438_sample, sizeof(ym3438_sample));
save_param(&ym3438_cycles, sizeof(ym3438_cycles));
}
else
{
bufferptr += YM2612SaveContext(state + sizeof(config.ym3438));
}
#else
bufferptr = YM2612SaveContext(state);
#endif
}
else
{
#ifdef HAVE_OPLL_CORE
save_param(&config.opll, sizeof(config.opll));
if (config.opll)
{
save_param(&opll, sizeof(opll));
save_param(&opll_accm, sizeof(opll_accm));
save_param(&opll_sample, sizeof(opll_sample));
save_param(&opll_cycles, sizeof(opll_cycles));
save_param(&opll_status, sizeof(opll_status));
}
else
#endif
{
save_param(YM2413GetContextPtr(),YM2413GetContextSize());
}
}
bufferptr += psg_context_save(&state[bufferptr]);
save_param(&fm_cycles_start,sizeof(fm_cycles_start));
return bufferptr;
}
int sound_context_load(uint8 *state)
{
int bufferptr = 0;
if ((system_hw & SYSTEM_PBC) == SYSTEM_MD)
{
#ifdef HAVE_YM3438_CORE
uint8 config_ym3438;
load_param(&config_ym3438, sizeof(config_ym3438));
if (config_ym3438)
{
load_param(&ym3438, sizeof(ym3438));
load_param(&ym3438_accm, sizeof(ym3438_accm));
load_param(&ym3438_sample, sizeof(ym3438_sample));
load_param(&ym3438_cycles, sizeof(ym3438_cycles));
}
else
{
bufferptr += YM2612LoadContext(state + sizeof(config_ym3438));
}
#else
bufferptr = YM2612LoadContext(state);
#endif
}
else
{
#ifdef HAVE_OPLL_CORE
uint8 config_opll;
load_param(&config_opll, sizeof(config_opll));
if (config_opll)
{
load_param(&opll, sizeof(opll));
load_param(&opll_accm, sizeof(opll_accm));
load_param(&opll_sample, sizeof(opll_sample));
load_param(&opll_cycles, sizeof(opll_cycles));
load_param(&opll_status, sizeof(opll_status));
}
else
#endif
{
load_param(YM2413GetContextPtr(),YM2413GetContextSize());
}
}
bufferptr += psg_context_load(&state[bufferptr]);
load_param(&fm_cycles_start,sizeof(fm_cycles_start));
fm_cycles_count = fm_cycles_start;
return bufferptr;
}