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snes9x/apu/apu.cpp

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/*****************************************************************************\
Snes9x - Portable Super Nintendo Entertainment System (TM) emulator.
This file is licensed under the Snes9x License.
For further information, consult the LICENSE file in the root directory.
\*****************************************************************************/
#include <cmath>
#include <vector>
#include "../snes9x.h"
#include "apu.h"
#include "../msu1.h"
#include "../snapshot.h"
#include "../display.h"
#include "resampler.h"
#include "bapu/snes/snes.hpp"
static const int APU_DEFAULT_INPUT_RATE = 31950; // ~59.94Hz
static const int APU_SAMPLE_BLOCK = 48;
static const int APU_NUMERATOR_NTSC = 15664;
static const int APU_DENOMINATOR_NTSC = 328125;
static const int APU_NUMERATOR_PAL = 34176;
static const int APU_DENOMINATOR_PAL = 709379;
// Max number of samples we'll ever generate before call to port API and
// moving the samples to the resampler.
// This is 535 sample frames, which corresponds to 1 video frame + some leeway
// for use with SoundSync, multiplied by 2, for left and right samples.
static const int MINIMUM_BUFFER_SIZE = 550 * 2;
namespace SNES {
#include "bapu/dsp/blargg_endian.h"
CPU cpu;
} // namespace SNES
namespace spc {
static apu_callback callback = NULL;
static void *callback_data = NULL;
static bool8 sound_in_sync = true;
static bool8 sound_enabled = false;
static Resampler resampler;
static int32 reference_time;
static uint32 remainder;
static const int timing_hack_numerator = 256;
static int timing_hack_denominator = 256;
/* Set these to NTSC for now. Will change to PAL in S9xAPUTimingSetSpeedup
if necessary on game load. */
static uint32 ratio_numerator = APU_NUMERATOR_NTSC;
static uint32 ratio_denominator = APU_DENOMINATOR_NTSC;
static double dynamic_rate_multiplier = 1.0;
} // namespace spc
namespace msu {
// Always 16-bit, Stereo; 1.5x dsp buffer to never overflow
static Resampler resampler;
static std::vector<int16_t> resampler_buffer;
} // namespace msu
static void UpdatePlaybackRate(void);
static void SPCSnapshotCallback(void);
static inline int S9xAPUGetClock(int32);
static inline int S9xAPUGetClockRemainder(int32);
bool8 S9xMixSamples(uint8 *dest, int sample_count)
{
int16 *out = (int16 *)dest;
if (Settings.Mute)
{
memset(out, 0, sample_count << 1);
S9xClearSamples();
spc::sound_in_sync = true;
return true;
}
if (spc::resampler.avail() < sample_count)
{
memset(out, 0, sample_count << 1);
return false;
}
spc::resampler.read((short *)out, sample_count);
if (Settings.MSU1)
{
if ((int)msu::resampler_buffer.size() < sample_count)
msu::resampler_buffer.resize(sample_count);
msu::resampler.read(msu::resampler_buffer.data(), sample_count);
for (int i = 0; i < sample_count; ++i)
{
int32 mixed = (int32)out[i] + msu::resampler_buffer[i];
out[i] = ((int16)mixed != mixed) ? (mixed >> 31) ^ 0x7fff : mixed;
}
}
if (spc::resampler.space_empty() >= 535 * 2 || !Settings.SoundSync ||
Settings.TurboMode || Settings.Mute)
spc::sound_in_sync = true;
else
spc::sound_in_sync = false;
return true;
}
int S9xGetSampleCount(void)
{
int avail = spc::resampler.avail();
if (Settings.MSU1) // return minimum available samples, otherwise we can run into the assert above due to partial sample generation in msu1
avail = Resampler::min(avail, msu::resampler.avail());
return avail;
}
void S9xLandSamples(void)
{
if (spc::callback != NULL)
spc::callback(spc::callback_data);
if (spc::resampler.space_empty() >= 535 * 2 || !Settings.SoundSync ||
Settings.TurboMode || Settings.Mute)
spc::sound_in_sync = true;
else
spc::sound_in_sync = false;
}
void S9xClearSamples(void)
{
spc::resampler.clear();
if (Settings.MSU1)
msu::resampler.clear();
}
bool8 S9xSyncSound(void)
{
if (!Settings.SoundSync || spc::sound_in_sync)
return true;
S9xLandSamples();
return (spc::sound_in_sync);
}
void S9xSetSamplesAvailableCallback(apu_callback callback, void *data)
{
spc::callback = callback;
spc::callback_data = data;
}
void S9xUpdateDynamicRate(int avail, int buffer_size)
{
spc::dynamic_rate_multiplier = 1.0 + (Settings.DynamicRateLimit * (buffer_size - 2 * avail)) /
(double)(1000 * buffer_size);
UpdatePlaybackRate();
}
static void UpdatePlaybackRate(void)
{
if (Settings.SoundInputRate == 0)
Settings.SoundInputRate = APU_DEFAULT_INPUT_RATE;
double time_ratio = (double)Settings.SoundInputRate * spc::timing_hack_numerator / (Settings.SoundPlaybackRate * spc::timing_hack_denominator);
if (Settings.DynamicRateControl)
{
time_ratio *= spc::dynamic_rate_multiplier;
}
spc::resampler.time_ratio(time_ratio);
if (Settings.MSU1)
{
time_ratio = time_ratio * 44100 / 32040;
msu::resampler.time_ratio(time_ratio);
}
}
bool8 S9xInitSound(int buffer_ms)
{
// The resampler and spc unit use samples (16-bit short) as arguments.
int buffer_size_samples = MINIMUM_BUFFER_SIZE;
int requested_buffer_size_samples = Settings.SoundPlaybackRate * buffer_ms * 2 / 1000;
if (requested_buffer_size_samples > buffer_size_samples)
buffer_size_samples = requested_buffer_size_samples;
spc::resampler.resize(buffer_size_samples);
msu::resampler.resize(buffer_size_samples * 3 / 2);
SNES::dsp.spc_dsp.set_output(&spc::resampler);
S9xMSU1SetOutput(&msu::resampler);
UpdatePlaybackRate();
spc::sound_enabled = S9xOpenSoundDevice();
return (spc::sound_enabled);
}
void S9xSetSoundControl(uint8 voice_switch)
{
SNES::dsp.spc_dsp.set_stereo_switch(voice_switch << 8 | voice_switch);
}
void S9xSetSoundMute(bool8 mute)
{
Settings.Mute = mute;
if (!spc::sound_enabled)
Settings.Mute = true;
}
void S9xDumpSPCSnapshot(void)
{
SNES::dsp.spc_dsp.dump_spc_snapshot();
}
static void SPCSnapshotCallback(void)
{
S9xSPCDump(S9xGetFilenameInc((".spc"), SPC_DIR).c_str());
printf("Dumped key-on triggered spc snapshot.\n");
}
bool8 S9xInitAPU(void)
{
spc::resampler.clear();
msu::resampler.clear();
return true;
}
void S9xDeinitAPU(void)
{
S9xMSU1DeInit();
msu::resampler_buffer.clear();
}
static inline int S9xAPUGetClock(int32 cpucycles)
{
return (spc::ratio_numerator * (cpucycles - spc::reference_time) + spc::remainder) /
spc::ratio_denominator;
}
static inline int S9xAPUGetClockRemainder(int32 cpucycles)
{
return (spc::ratio_numerator * (cpucycles - spc::reference_time) + spc::remainder) %
spc::ratio_denominator;
}
uint8 S9xAPUReadPort(int port)
{
S9xAPUExecute();
return ((uint8)SNES::smp.port_read(port & 3));
}
void S9xAPUWritePort(int port, uint8 byte)
{
S9xAPUExecute();
SNES::cpu.port_write(port & 3, byte);
}
void S9xAPUSetReferenceTime(int32 cpucycles)
{
spc::reference_time = cpucycles;
}
void S9xAPUExecute(void)
{
int cycles = S9xAPUGetClock(CPU.Cycles);
spc::remainder = S9xAPUGetClockRemainder(CPU.Cycles);
SNES::smp.clock -= cycles;
SNES::smp.enter();
S9xAPUSetReferenceTime(CPU.Cycles);
}
void S9xAPUEndScanline(void)
{
S9xAPUExecute();
SNES::dsp.synchronize();
if (spc::resampler.space_filled() >= APU_SAMPLE_BLOCK)
S9xLandSamples();
}
void S9xAPUTimingSetSpeedup(int ticks)
{
if (ticks != 0)
printf("APU speedup hack: %d\n", ticks);
spc::timing_hack_denominator = 256 - ticks;
spc::ratio_numerator = Settings.PAL ? APU_NUMERATOR_PAL : APU_NUMERATOR_NTSC;
spc::ratio_denominator = Settings.PAL ? APU_DENOMINATOR_PAL : APU_DENOMINATOR_NTSC;
spc::ratio_denominator = spc::ratio_denominator * spc::timing_hack_denominator / spc::timing_hack_numerator;
UpdatePlaybackRate();
}
void S9xResetAPU(void)
{
spc::reference_time = 0;
spc::remainder = 0;
SNES::cpu.reset();
SNES::smp.power();
SNES::dsp.power();
SNES::dsp.spc_dsp.set_spc_snapshot_callback(SPCSnapshotCallback);
S9xClearSamples();
}
void S9xSoftResetAPU(void)
{
spc::reference_time = 0;
spc::remainder = 0;
SNES::cpu.reset();
SNES::smp.reset();
SNES::dsp.reset();
S9xClearSamples();
}
void S9xAPUSaveState(uint8 *block)
{
uint8 *ptr = block;
SNES::smp.save_state(&ptr);
SNES::dsp.save_state(&ptr);
SNES::set_le32(ptr, spc::reference_time);
ptr += sizeof(int32);
SNES::set_le32(ptr, spc::remainder);
ptr += sizeof(int32);
SNES::set_le32(ptr, SNES::dsp.clock);
ptr += sizeof(int32);
memcpy(ptr, SNES::cpu.registers, 4);
ptr += sizeof(int32);
memset(ptr, 0, SPC_SAVE_STATE_BLOCK_SIZE - (ptr - block));
}
void S9xAPULoadState(uint8 *block)
{
uint8 *ptr = block;
SNES::smp.load_state(&ptr);
SNES::dsp.load_state(&ptr);
spc::reference_time = SNES::get_le32(ptr);
ptr += sizeof(int32);
spc::remainder = SNES::get_le32(ptr);
ptr += sizeof(int32);
SNES::dsp.clock = SNES::get_le32(ptr);
ptr += sizeof(int32);
memcpy(SNES::cpu.registers, ptr, 4);
}
static void to_var_from_buf(uint8 **buf, void *var, size_t size)
{
memcpy(var, *buf, size);
*buf += size;
}
#undef IF_0_THEN_256
#define IF_0_THEN_256(n) ((uint8)((n)-1) + 1)
void S9xAPULoadBlarggState(uint8 *oldblock)
{
uint8 *ptr = oldblock;
SNES::SPC_State_Copier copier(&ptr, to_var_from_buf);
copier.copy(SNES::smp.apuram, 0x10000); // RAM
uint8 regs_in[0x10];
uint8 regs[0x10];
uint16 pc, spc_time, dsp_time;
uint8 a, x, y, psw, sp;
copier.copy(regs, 0x10); // REGS
copier.copy(regs_in, 0x10); // REGS_IN
// CPU Regs
pc = copier.copy_int(0, sizeof(uint16));
a = copier.copy_int(0, sizeof(uint8));
x = copier.copy_int(0, sizeof(uint8));
y = copier.copy_int(0, sizeof(uint8));
psw = copier.copy_int(0, sizeof(uint8));
sp = copier.copy_int(0, sizeof(uint8));
copier.extra();
// times
spc_time = copier.copy_int(0, sizeof(uint16));
dsp_time = copier.copy_int(0, sizeof(uint16));
int cur_time = S9xAPUGetClock(CPU.Cycles);
// spc_time is absolute, dsp_time is relative
// smp.clock is relative, dsp.clock relative but counting upwards
SNES::smp.clock = spc_time - cur_time;
SNES::dsp.clock = -1 * dsp_time;
// DSP
SNES::dsp.load_state(&ptr);
// Timers
uint16 next_time[3];
uint8 divider[3], counter[3];
for (int i = 0; i < 3; i++)
{
next_time[i] = copier.copy_int(0, sizeof(uint16));
divider[i] = copier.copy_int(0, sizeof(uint8));
counter[i] = copier.copy_int(0, sizeof(uint8));
copier.extra();
}
// construct timers out of available parts from blargg smp
SNES::smp.timer0.enable = regs[1] >> 0 & 1; // regs[1] = CONTROL
SNES::smp.timer0.target = IF_0_THEN_256(regs[10]); // regs[10+i] = TiTARGET
// blargg counts time, get ticks through timer frequency
// (assume tempo = 256)
SNES::smp.timer0.stage1_ticks = 128 - (next_time[0] - cur_time) / 128;
SNES::smp.timer0.stage2_ticks = divider[0];
SNES::smp.timer0.stage3_ticks = counter[0];
SNES::smp.timer1.enable = regs[1] >> 1 & 1;
SNES::smp.timer1.target = IF_0_THEN_256(regs[11]);
SNES::smp.timer1.stage1_ticks = 128 - (next_time[1] - cur_time) / 128;
SNES::smp.timer1.stage2_ticks = divider[0];
SNES::smp.timer1.stage3_ticks = counter[0];
SNES::smp.timer2.enable = regs[1] >> 2 & 1;
SNES::smp.timer2.target = IF_0_THEN_256(regs[12]);
SNES::smp.timer2.stage1_ticks = 16 - (next_time[2] - cur_time) / 16;
SNES::smp.timer2.stage2_ticks = divider[0];
SNES::smp.timer2.stage3_ticks = counter[0];
copier.extra();
SNES::smp.opcode_number = 0;
SNES::smp.opcode_cycle = 0;
SNES::smp.regs.pc = pc;
SNES::smp.regs.sp = sp;
SNES::smp.regs.B.a = a;
SNES::smp.regs.x = x;
SNES::smp.regs.B.y = y;
// blargg's psw has same layout as byuu's flags
SNES::smp.regs.p = psw;
// blargg doesn't explicitly store iplrom_enable
SNES::smp.status.iplrom_enable = regs[1] & 0x80;
SNES::smp.status.dsp_addr = regs[2];
SNES::smp.status.ram00f8 = regs_in[8];
SNES::smp.status.ram00f9 = regs_in[9];
// default to 0 - we are on an opcode boundary, shouldn't matter
SNES::smp.rd = SNES::smp.wr = SNES::smp.dp = SNES::smp.sp = SNES::smp.ya = SNES::smp.bit = 0;
spc::reference_time = SNES::get_le32(ptr);
ptr += sizeof(int32);
spc::remainder = SNES::get_le32(ptr);
// blargg stores CPUIx in regs_in
memcpy(SNES::cpu.registers, regs_in + 4, 4);
}
bool8 S9xSPCDump(const char *filename)
{
FILE *fs;
uint8 buf[SPC_FILE_SIZE];
size_t ignore;
fs = fopen(filename, "wb");
if (!fs)
return false;
S9xSetSoundMute(true);
SNES::smp.save_spc(buf);
ignore = fwrite(buf, SPC_FILE_SIZE, 1, fs);
if (ignore == 0)
{
fprintf(stderr, "Couldn't write file %s.\n", filename);
}
fclose(fs);
S9xSetSoundMute(false);
return true;
}
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