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Diffstat (limited to 'src/chips/ymf262_lle/nopl3.c')
-rw-r--r--src/chips/ymf262_lle/nopl3.c261
1 files changed, 261 insertions, 0 deletions
diff --git a/src/chips/ymf262_lle/nopl3.c b/src/chips/ymf262_lle/nopl3.c
new file mode 100644
index 0000000..6deb005
--- /dev/null
+++ b/src/chips/ymf262_lle/nopl3.c
@@ -0,0 +1,261 @@
+/*
+ * Copyright (C) 2023 nukeykt
+ *
+ * This file is part of YMF262-LLE.
+ *
+ * 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.
+ *
+ * YMF262 emulator
+ * Thanks:
+ * John McMaster (siliconpr0n.org):
+ * YMF262 decap and die shot
+ *
+ */
+
+#include "nuked_fmopl3.h"
+#include <stdint.h>
+#include <stdlib.h>
+#include "nopl3.h"
+
+#define OPL_WRITEBUF_SIZE 2048
+#define OPL_WRITEBUF_DELAY 1
+#define RSM_FRAC 10
+
+typedef struct _opl3_writebuf {
+ uint64_t time;
+ uint8_t reg;
+ uint8_t data;
+} opl3_writebuf;
+
+typedef struct {
+ fmopl3_t chip;
+
+ int sample_a;
+ int sample_b;
+ int o_sy;
+ int o_smpbd;
+ int o_smpac;
+ int shifter_ab;
+
+ int32_t rateratio;
+ int32_t samplecnt;
+ int oldsample[2];
+
+ uint64_t writebuf_samplecnt;
+ uint32_t writebuf_cur;
+ uint32_t writebuf_last;
+ uint64_t writebuf_lasttime;
+ opl3_writebuf writebuf[OPL_WRITEBUF_SIZE];
+} nopl3_t;
+
+void nopl3_cycle(nopl3_t *chip)
+{
+ int i;
+ for (i = 0; i < 576/4; i++)
+ {
+ chip->chip.input.mclk = i & 1;
+ FMOPL3_Clock(&chip->chip);
+
+ if (chip->o_sy && !chip->chip.o_sy)
+ {
+
+ if (chip->o_smpac && !chip->chip.o_smpac)
+ {
+ chip->sample_a = chip->shifter_ab & 0xffff;
+ if (chip->sample_a & 0x8000)
+ {
+ chip->sample_a &= 0x7fff;
+ }
+ else
+ {
+ chip->sample_a |= ~0x7fff;
+ }
+ }
+ if (chip->o_smpbd && !chip->chip.o_smpbd)
+ {
+ chip->sample_b = chip->shifter_ab & 0xffff;
+ if (chip->sample_b & 0x8000)
+ {
+ chip->sample_b &= 0x7fff;
+ }
+ else
+ {
+ chip->sample_b |= ~0x7fff;
+ }
+ }
+ chip->shifter_ab = (chip->shifter_ab >> 1) | (chip->chip.o_doab << 15);
+
+ chip->o_smpac = chip->chip.o_smpac;
+ chip->o_smpbd = chip->chip.o_smpbd;
+ }
+
+ chip->o_sy = chip->chip.o_sy;
+ }
+}
+
+void *nopl3_init(int clock, int samplerate)
+{
+ nopl3_t *chip = calloc(1, sizeof(nopl3_t));
+ nopl3_set_rate(chip, clock, samplerate);
+ return chip;
+}
+
+void nopl3_set_rate(void* chip_p, int clock, int samplerate)
+{
+ nopl3_t *chip = (nopl3_t*)chip_p;
+
+ chip->chip.input.cs = 0;
+ chip->chip.input.ic = 1;
+ chip->chip.input.rd = 1;
+ chip->chip.input.wr = 1;
+
+ samplerate *= 1;
+
+ chip->rateratio = ((samplerate << RSM_FRAC) * (int64_t)288) / clock;
+
+ /* printf("%i %i\n", clock, samplerate); */
+
+ nopl3_reset(chip);
+}
+
+void nopl3_shutdown(void *chip)
+{
+ free(chip);
+}
+
+void nopl3_reset(void *chip)
+{
+ nopl3_t* chip2 = chip;
+ int i = 0;
+
+ chip2->chip.input.ic = 0;
+ for (i = 0; i < 100; i++)
+ {
+ nopl3_cycle(chip2);
+ }
+ chip2->chip.input.ic = 1;
+ for (i = 0; i < 100; i++)
+ {
+ nopl3_cycle(chip2);
+ }
+
+}
+
+void nopl3_write2(nopl3_t *chip, int port, int val)
+{
+ chip->chip.input.address = port;
+ chip->chip.input.data_i = val;
+ chip->chip.input.wr = 0;
+ FMOPL3_Clock(&chip->chip); /* propagate */
+ chip->chip.input.wr = 1;
+ FMOPL3_Clock(&chip->chip); /* propagate */
+}
+
+void nopl3_getsample(void *chip, short *sndptr, int numsamples)
+{
+ nopl3_t* chip2 = chip;
+ int i, buf0, buf1;
+ short *p = sndptr;
+ opl3_writebuf* writebuf;
+
+ for (i = 0; i < numsamples; i++)
+ {
+ while (chip2->samplecnt >= chip2->rateratio)
+ {
+ chip2->oldsample[0] = chip2->sample_a;
+ chip2->oldsample[1] = chip2->sample_b;
+ nopl3_cycle(chip2);
+
+ while ((writebuf = &chip2->writebuf[chip2->writebuf_cur]), writebuf->time <= chip2->writebuf_samplecnt)
+ {
+ if (!(writebuf->reg & 4))
+ {
+ break;
+ }
+ writebuf->reg &= 3;
+ nopl3_write2(chip2, writebuf->reg, writebuf->data);
+ chip2->writebuf_cur = (chip2->writebuf_cur + 1) % OPL_WRITEBUF_SIZE;
+ }
+ chip2->writebuf_samplecnt++;
+ chip2->samplecnt -= chip2->rateratio;
+ }
+
+ buf0 = (chip2->oldsample[0] * (chip2->rateratio - chip2->samplecnt)
+ + chip2->sample_a * chip2->samplecnt) / chip2->rateratio;
+ buf1 = (chip2->oldsample[1] * (chip2->rateratio - chip2->samplecnt)
+ + chip2->sample_b * chip2->samplecnt) / chip2->rateratio;
+ chip2->samplecnt += 1 << RSM_FRAC;
+ *p++ = buf0;
+ *p++ = buf1;
+ }
+}
+
+void nopl3_getsample_one_native(void *chip, short *sndptr)
+{
+ nopl3_t* chip2 = chip;
+ short *p = sndptr;
+ opl3_writebuf* writebuf;
+
+ chip2->oldsample[0] = chip2->sample_a;
+ chip2->oldsample[1] = chip2->sample_b;
+ nopl3_cycle(chip2);
+
+ while ((writebuf = &chip2->writebuf[chip2->writebuf_cur]), writebuf->time <= chip2->writebuf_samplecnt)
+ {
+ if (!(writebuf->reg & 4))
+ break;
+
+ writebuf->reg &= 3;
+ nopl3_write2(chip2, writebuf->reg, writebuf->data);
+ chip2->writebuf_cur = (chip2->writebuf_cur + 1) % OPL_WRITEBUF_SIZE;
+ }
+
+ chip2->writebuf_samplecnt++;
+ chip2->samplecnt -= chip2->rateratio;
+ chip2->samplecnt += 1 << RSM_FRAC;
+
+ *p++ = chip2->sample_a;
+ *p++ = chip2->sample_b;
+}
+
+void nopl3_write(void *chip, int port, int val)
+{
+ nopl3_t* chip2 = chip;
+ uint64_t time1, time2;
+ opl3_writebuf *writebuf;
+ uint32_t writebuf_last;
+
+ writebuf_last = chip2->writebuf_last;
+ writebuf = &chip2->writebuf[writebuf_last];
+
+ if (writebuf->reg & 4)
+ {
+ nopl3_write2(chip2, writebuf->reg & 1, writebuf->data);
+ nopl3_cycle(chip2);
+
+ chip2->writebuf_cur = (writebuf_last + 1) % OPL_WRITEBUF_SIZE;
+ chip2->writebuf_samplecnt = writebuf->time;
+ }
+
+ writebuf->reg = port | 4;
+ writebuf->data = val;
+ time1 = chip2->writebuf_lasttime + OPL_WRITEBUF_DELAY;
+ time2 = chip2->writebuf_samplecnt;
+
+ if (time1 < time2)
+ {
+ time1 = time2;
+ }
+
+ writebuf->time = time1;
+ chip2->writebuf_lasttime = time1;
+ chip2->writebuf_last = (writebuf_last + 1) % OPL_WRITEBUF_SIZE;
+}
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