From 499d7dcf4912ba9b224a68439520407c25f8c9ae Mon Sep 17 00:00:00 2001 From: Takamichi Horikawa Date: Wed, 23 Aug 2017 21:15:14 +0900 Subject: LIBOPNA: ssg: added YMF288 mode --- libopna/opnassg.c | 158 +++++++++++++++++++++++++++++++++--------------------- libopna/opnassg.h | 18 +++++++ 2 files changed, 115 insertions(+), 61 deletions(-) (limited to 'libopna') diff --git a/libopna/opnassg.c b/libopna/opnassg.c index d92a8b8..a40e6c8 100644 --- a/libopna/opnassg.c +++ b/libopna/opnassg.c @@ -1,22 +1,9 @@ #include "opnassg.h" #include "oscillo/oscillo.h" -#include -/* -static const float voltable[32] = { - 0.0f, 0.0f, 0x1.ae89f9p-8f, 0x1.000000p-7f, - 0x1.306fe0p-7f, 0x1.6a09e6p-7f, 0x1.ae89f9p-7f, 0x1.000000p-6f, - 0x1.306fe0p-6f, 0x1.6a09e6p-6f, 0x1.ae89f9p-6f, 0x1.000000p-5f, - 0x1.306fe0p-5f, 0x1.6a09e6p-5f, 0x1.ae89f9p-5f, 0x1.000000p-4f, - 0x1.306fe0p-4f, 0x1.6a09e6p-4f, 0x1.ae89f9p-4f, 0x1.000000p-3f, - 0x1.306fe0p-3f, 0x1.6a09e6p-3f, 0x1.ae89f9p-3f, 0x1.000000p-2f, - 0x1.306fe0p-2f, 0x1.6a09e6p-2f, 0x1.ae89f9p-2f, 0x1.000000p-1f, - 0x1.306fe0p-1f, 0x1.6a09e6p-1f, 0x1.ae89f9p-1f, 0x1.000000p-0f -}; -*/ // if (i < 2) voltable[i] = 0; // else voltable[i] = round((0x7fff / 3.0) * pow(2.0, (i - 31)/4.0)); - +/* static const int16_t voltable[32] = { 0, 0, 72, 85, 101, 121, 144, 171, @@ -27,6 +14,50 @@ static const int16_t voltable[32] = { 3247, 3862, 4592, 5461, 6494, 7723, 9185, 10922 }; +*/ + +// captured from YMF288 +static const uint16_t voltable[32] = { + 0, 0, 0, 0, + 4, 8, 12, 16, + 20, 24, 28, 32, + 36, 44, 52, 64, + 76, 92, 108, 128, + 152, 180, 216, 256, + 304, 360, 428, 512, + 608, 720, 856, 1020, +}; + +/* + * on YMF288: + * when TP >= 8: + * + * | + * +voltab + ----- ----- -- + * | + * 0 +--------------------------- + * | + * -voltab + ----- ----- + * | + * + * when TP < 8: + * | + * +voltab + ---------------------- + * | + * 0 +--------------------------- + * | + * -voltab + + * | + * + * when /TONE=1 && /NOISE=1 (both diabled) + * | + * +2voltab + ---------------------- + * | + * + + * | + * 0 +--------------------------- + * | + */ // GNU Octave // Fc = 7987200 @@ -111,22 +142,10 @@ const int16_t opna_ssg_sinctable[OPNA_SSG_SINCTABLELEN*2] = { opna_ssg_sinc_calc_func_type opna_ssg_sinc_calc_func = opna_ssg_sinc_calc_c; void opna_ssg_reset(struct opna_ssg *ssg) { - for (int i = 0; i < 3; i++) { - ssg->ch[i].tone_counter = 0; - ssg->ch[i].out = false; - } - for (int i = 0; i < 0x10; i++) { - ssg->regs[i] = 0; - } - ssg->noise_counter = 0; - ssg->lfsr = 0; - ssg->env_counter = 0; - ssg->env_level = 0; - ssg->env_att = false; - ssg->env_alt = false; - ssg->env_hld = false; - ssg->env_holding = false; - ssg->mask = 0; + *ssg = (struct opna_ssg) { + .mix = 0x10000, + .ymf288 = true, + }; } void opna_ssg_resampler_reset(struct opna_ssg_resampler *resampler) { @@ -182,12 +201,17 @@ static bool opna_ssg_tone_out(const struct opna_ssg *ssg, int chan) { return (ssg->ch[chan].out || (reg & 0x1)) && ((ssg->lfsr & 1) || (reg & 0x8)); } -#if 0 +static bool opna_ssg_tone_out_ymf288(const struct opna_ssg *ssg, int chan) { + unsigned reg = ssg->regs[0x7] >> chan; + bool toneout = + opna_ssg_tone_period(ssg, chan) < 8 ? true : ssg->ch[chan].out; + return (toneout || (reg & 0x1)) && ((ssg->lfsr & 1) || (reg & 0x8)); +} + static bool opna_ssg_tone_silent(const struct opna_ssg *ssg, int chan) { unsigned reg = ssg->regs[0x7] >> chan; return (reg & 0x1) && (reg & 0x8); } -#endif static int opna_ssg_noise_period(const struct opna_ssg *ssg) { return ssg->regs[0x6] & 0x1f; @@ -243,28 +267,26 @@ void opna_ssg_generate_raw(struct opna_ssg *ssg, int16_t *buf, int samples) { ssg->ch[ch].tone_counter = 0; ssg->ch[ch].out = !ssg->ch[ch].out; } -#if 1 - // YMF288 seems to disable output when 0 <= Tp < 8 - int32_t previntmp = 0; - if (opna_ssg_tone_out(ssg, ch)) { - int level = opna_ssg_chan_env(ssg, ch) - ? opna_ssg_env_level(ssg) - : (opna_ssg_tone_volume(ssg, ch) << 1) + 1; - //out += voltable[level]; - previntmp = voltable[level]/2; - } - previntmp *= COEFF; - ssg->prevout[ch] = previntmp - ssg->previn[ch] + ((((int64_t)COEFF)*ssg->prevout[ch]) >> COEFFSH); - ssg->previn[ch] = previntmp; - buf[i*4+ch] = ssg->prevout[ch] >> COEFFSH; - //buf[i*4+ch] = voltable[level]/2; -#else - if (!opna_ssg_tone_silent(ssg, ch)) { + if (!ssg->ymf288) { + // OPNA output level + HPF + int32_t previntmp = 0; + if (opna_ssg_tone_out(ssg, ch)) { + int level = opna_ssg_channel_level(ssg, ch); + previntmp = voltable[level]*5; + } + previntmp *= COEFF; + ssg->prevout[ch] = previntmp - ssg->previn[ch] + ((((int64_t)COEFF)*ssg->prevout[ch]) >> COEFFSH); + ssg->previn[ch] = previntmp; + buf[i*4+ch] = ssg->prevout[ch] >> COEFFSH; + } else { + // YMF288 int level = opna_ssg_channel_level(ssg, ch); - //out += (opna_ssg_tone_out(ssg, ch) ? voltable[level] : -voltable[level]) / 2; - buf[i*4+ch] = (opna_ssg_tone_out(ssg, ch) ? voltable[level] : -voltable[level]) / 4; + if (!opna_ssg_tone_silent(ssg, ch)) { + buf[i*4+ch] = (opna_ssg_tone_out_ymf288(ssg, ch) ? voltable[level] : -voltable[level]); + } else { + buf[i*4+ch] = voltable[level]*2; + } } -#endif } //buf[i] = out / 2; @@ -306,20 +328,34 @@ void opna_ssg_mix_55466( resampler->index &= (1u<<(OPNA_SSG_SINCTABLEBIT+1))-1; memcpy(resampler->buf + OPNA_SSG_SINCTABLELEN*4, resampler->buf, OPNA_SSG_SINCTABLELEN*4*sizeof(*resampler->buf)); int32_t outbuf[3]; - opna_ssg_sinc_calc_func(resampler->index, resampler->buf, outbuf); + if (!ssg->ymf288) { + // OPNA analog: bandlimited sinc resample + opna_ssg_sinc_calc_func(resampler->index, resampler->buf, outbuf); + for (int ch = 0; ch < 3; ch++) { + outbuf[ch] >>= 16; + outbuf[ch] *= 13000; + outbuf[ch] >>= 16; + outbuf[ch] *= ssg->mix; + outbuf[ch] >>= 16; + } + } else { + // YMF288: average of the samples (equivalent to FIR with rectangular function + for (int ch = 0; ch < 3; ch++) { + int ind = (resampler->index & 1) ? BUFINDEX(5) : BUFINDEX(0); + outbuf[ch] = resampler->buf[ind*4+ch]; + for (int s = 0; s < 4; s++) { + outbuf[ch] += resampler->buf[BUFINDEX(s+1)*4+ch] * 2; + } + outbuf[ch] /= 9; + } + } for (int ch = 0; ch < 3; ch++) { - if (oscillo) oscillo[ch].buf[offset+i] = outbuf[ch] >> 15; + if (oscillo) oscillo[ch].buf[offset+i] = outbuf[ch] << 1; int32_t nlevel = outbuf[ch]; - nlevel >>= 16; - nlevel *= 13000; - nlevel >>= 14; if (nlevel < 0) nlevel = -nlevel; if (((unsigned)nlevel) > level[ch]) level[ch] = nlevel; - if (!(ssg->mask & (1<> 2; + if (!(ssg->mask & (1<>= 16; - sample *= 13000; - sample >>= 14; int32_t lo = buf[i*2+0]; int32_t ro = buf[i*2+1]; diff --git a/libopna/opnassg.h b/libopna/opnassg.h index 3077d08..6b1d0cd 100644 --- a/libopna/opnassg.h +++ b/libopna/opnassg.h @@ -3,6 +3,7 @@ #include #include +#include #include "leveldata/leveldata.h" #ifdef __cplusplus @@ -31,6 +32,8 @@ struct opna_ssg { unsigned mask; int32_t previn[3]; int32_t prevout[3]; + uint32_t mix; + bool ymf288; }; struct opna_ssg_resampler { @@ -63,6 +66,21 @@ unsigned opna_ssg_readreg(const struct opna_ssg *ssg, unsigned reg); int opna_ssg_channel_level(const struct opna_ssg *ssg, int ch); unsigned opna_ssg_tone_period(const struct opna_ssg *ssg, int ch); +static inline void opna_ssg_set_ymf288( + struct opna_ssg *ssg, struct opna_ssg_resampler *resampler, bool ymf288) { + // enable bit-perfect with YMF288/OPN3-L mode + if (ssg->ymf288 != ymf288) { + ssg->ymf288 = ymf288; + memset(resampler->buf, 0, sizeof(resampler->buf)); + } +} + +static inline void opna_ssg_set_mix(struct opna_ssg *ssg, uint32_t mix) { + // 0x10000: default (PC-9801-86 equivalent) + // only valid when !ymf288 + ssg->mix = mix; +} + typedef void (*opna_ssg_sinc_calc_func_type)(unsigned resampler_index, const int16_t *inbuf, int32_t *outbuf); extern opna_ssg_sinc_calc_func_type opna_ssg_sinc_calc_func; -- cgit v1.2.3