diff options
Diffstat (limited to 'src/devices/sound/c6280.cpp')
-rw-r--r-- | src/devices/sound/c6280.cpp | 250 |
1 files changed, 131 insertions, 119 deletions
diff --git a/src/devices/sound/c6280.cpp b/src/devices/sound/c6280.cpp index 644269e01f7..c156033dce8 100644 --- a/src/devices/sound/c6280.cpp +++ b/src/devices/sound/c6280.cpp @@ -42,125 +42,131 @@ #include <algorithm> -void c6280_device::sound_stream_update(sound_stream &stream, std::vector<read_stream_view> const &inputs, std::vector<write_stream_view> &outputs) +void c6280_device::sound_stream_update(sound_stream &stream) { - const u8 lmal = (m_balance >> 4) & 0x0f; - const u8 rmal = (m_balance >> 0) & 0x0f; + // Fast method if none of the channels are enabled (most Data East arcade games) + if (!(m_enabled & 0x3f)) + return; - /* Clear buffer */ - outputs[0].fill(0); - outputs[1].fill(0); + static const u8 scale_tab[16] = + { + 0x00, 0x03, 0x05, 0x07, 0x09, 0x0b, 0x0d, 0x0f, + 0x10, 0x13, 0x15, 0x17, 0x19, 0x1b, 0x1d, 0x1f + }; - for (int ch = 0; ch < 6; ch++) + const u8 lmal = scale_tab[(m_balance >> 4) & 0x0f]; + const u8 rmal = scale_tab[(m_balance >> 0) & 0x0f]; + + for (int i = 0; i < stream.samples(); i++) { - channel *chan = &m_channel[ch]; - /* Only look at enabled channels */ - if (chan->control & 0x80) + s32 lout = 0, rout = 0; + for (int ch = 0; ch < 6; ch++) { - const u8 lal = (chan->balance >> 4) & 0x0f; - const u8 ral = (chan->balance >> 0) & 0x0f; - const u8 al = (chan->control >> 1) & 0x0f; // only high 4 bit is affected to calculating volume, low 1 bit is independent + // Only look at enabled channels + if (BIT(m_enabled, ch)) + { + channel &chan = m_channel[ch]; - // verified from both patent and manual - int vll = (0xf - lmal) + (0xf - al) + (0xf - lal); - if (vll > 0xf) vll = 0xf; + const u8 lal = scale_tab[(chan.balance >> 4) & 0x0f]; + const u8 ral = scale_tab[(chan.balance >> 0) & 0x0f]; + const u8 al = chan.control & 0x1f; - int vlr = (0xf - rmal) + (0xf - al) + (0xf - ral); - if (vlr > 0xf) vlr = 0xf; + // Verified from both patent and manual + int vll = (0x1f - lmal) + (0x1f - al) + (0x1f - lal); + if (vll > 0x1f) vll = 0x1f; - vll = m_volume_table[(vll << 1) | (~chan->control & 1)]; - vlr = m_volume_table[(vlr << 1) | (~chan->control & 1)]; + int vlr = (0x1f - rmal) + (0x1f - al) + (0x1f - ral); + if (vlr > 0x1f) vlr = 0x1f; - /* Check channel mode */ - if ((ch >= 4) && (chan->noise_control & 0x80)) - { - /* Noise mode */ - const u32 step = (chan->noise_control & 0x1f) ^ 0x1f; - for (int i = 0; i < outputs[0].samples(); i += 1) + vll = m_volume_table[vll]; + vlr = m_volume_table[vlr]; + + // Check channel mode + if ((ch >= 4) && BIT(chan.noise_control, 7)) { - s16 data = BIT(chan->noise_seed, 0) ? 0x1f : 0; - chan->noise_counter--; - if (chan->noise_counter <= 0) + // Noise mode + const u32 step = (chan.noise_control & 0x1f) ^ 0x1f; + const s16 data = BIT(chan.noise_seed, 0) ? 0x1f : 0; + chan.noise_counter--; + if (chan.noise_counter <= 0) { - chan->noise_counter = step << 6; // 32 * 2 - const u32 seed = chan->noise_seed; + chan.noise_counter = step << 6; // 32 * 2 + const u32 seed = chan.noise_seed; // based on Charles MacDonald's research - chan->noise_seed = (seed >> 1) | ((BIT(seed, 0) ^ BIT(seed, 1) ^ BIT(seed, 11) ^ BIT(seed, 12) ^ BIT(seed, 17)) << 17); + chan.noise_seed = (seed >> 1) | ((BIT(seed, 0) ^ BIT(seed, 1) ^ BIT(seed, 11) ^ BIT(seed, 12) ^ BIT(seed, 17)) << 17); } - outputs[0].add_int(i, s16(vll * (data - 16)), 32768); - outputs[1].add_int(i, s16(vlr * (data - 16)), 32768); + lout += vll * (data - 16); + rout += vlr * (data - 16); } - } - else - if (chan->control & 0x40) - { - /* DDA mode */ - for (int i = 0; i < outputs[0].samples(); i++) + else if (BIT(chan.control, 6)) { - outputs[0].add_int(i, s16(vll * (chan->dda - 16)), 32768); - outputs[1].add_int(i, s16(vlr * (chan->dda - 16)), 32768); + // DDA mode + lout += vll * (chan.dda - 16); + rout += vlr * (chan.dda - 16); } - } - else - { - if ((m_lfo_control & 3) && (ch < 2)) + else { - if (ch == 0) // CH 0 only, CH 1 is muted + if ((m_lfo_control & 3) && (ch < 2)) { - /* Waveform mode with LFO */ - channel *lfo_srcchan = &m_channel[1]; - channel *lfo_dstchan = &m_channel[0]; - const u16 lfo_step = lfo_srcchan->frequency ? lfo_srcchan->frequency : 0x1000; - for (int i = 0; i < outputs[0].samples(); i += 1) + if (ch == 0) { - s32 step = lfo_dstchan->frequency ? lfo_dstchan->frequency : 0x1000; - if (m_lfo_control & 0x80) // reset LFO + // Waveform mode with LFO + channel &lfo_srcchan = m_channel[1]; + channel &lfo_dstchan = m_channel[0]; + const u16 lfo_step = lfo_srcchan.frequency ? lfo_srcchan.frequency : 0x1000; + s32 step = lfo_dstchan.frequency ? lfo_dstchan.frequency : 0x1000; + if (BIT(m_lfo_control, 7)) // reset LFO { - lfo_srcchan->tick = lfo_step * m_lfo_frequency; - lfo_srcchan->index = 0; + lfo_srcchan.tick = lfo_step * m_lfo_frequency; + lfo_srcchan.index = 0; } else { - const s16 lfo_data = lfo_srcchan->waveform[lfo_srcchan->index]; - lfo_srcchan->tick--; - if (lfo_srcchan->tick <= 0) + const s16 lfo_data = lfo_srcchan.waveform[lfo_srcchan.index]; + lfo_srcchan.tick--; + if (lfo_srcchan.tick <= 0) { - lfo_srcchan->tick = lfo_step * m_lfo_frequency; // verified from manual - lfo_srcchan->index = (lfo_srcchan->index + 1) & 0x1f; + lfo_srcchan.tick = lfo_step * m_lfo_frequency; // verified from manual + lfo_srcchan.index = (lfo_srcchan.index + 1) & 0x1f; } - step += ((lfo_data - 16) << (((m_lfo_control & 3)-1)<<1)); // verified from manual + step += ((lfo_data - 16) << (((m_lfo_control & 3) - 1) << 1)); // verified from manual } - const s16 data = lfo_dstchan->waveform[lfo_dstchan->index]; - lfo_dstchan->tick--; - if (lfo_dstchan->tick <= 0) + const s16 data = lfo_dstchan.waveform[lfo_dstchan.index]; + lfo_dstchan.tick--; + if (lfo_dstchan.tick <= 0) { - lfo_dstchan->tick = step; - lfo_dstchan->index = (lfo_dstchan->index + 1) & 0x1f; + lfo_dstchan.tick = step; + lfo_dstchan.index = (lfo_dstchan.index + 1) & 0x1f; } - outputs[0].add_int(i, s16(vll * (data - 16)), 32768); - outputs[1].add_int(i, s16(vlr * (data - 16)), 32768); + lout += vll * (data - 16); + rout += vlr * (data - 16); + } + else if (ch == 1) // NOT muted even when LFO is on + { + const s16 data = chan.waveform[chan.index]; + lout += vll * (data - 16); + rout += vlr * (data - 16); } } - } - else - { - /* Waveform mode */ - const u32 step = chan->frequency ? chan->frequency : 0x1000; - for (int i = 0; i < outputs[0].samples(); i += 1) + else { - const s16 data = chan->waveform[chan->index]; - chan->tick--; - if (chan->tick <= 0) + // Waveform mode + const u32 step = chan.frequency ? chan.frequency : 0x1000; + const s16 data = chan.waveform[chan.index]; + chan.tick--; + if (chan.tick <= 0) { - chan->tick = step; - chan->index = (chan->index + 1) & 0x1f; + chan.tick = step; + chan.index = (chan.index + 1) & 0x1f; } - outputs[0].add_int(i, s16(vll * (data - 16)), 32768); - outputs[1].add_int(i, s16(vlr * (data - 16)), 32768); + lout += vll * (data - 16); + rout += vlr * (data - 16); } } } } + stream.put_int(0, i, lout, 32768); + stream.put_int(1, i, rout, 32768); } } @@ -215,73 +221,77 @@ void c6280_device::sound_stream_update(sound_stream &stream, std::vector<read_st void c6280_device::c6280_w(offs_t offset, uint8_t data) { - channel *chan = &m_channel[m_select]; + channel &chan = m_channel[m_select]; - /* Update stream */ + // Update stream m_stream->update(); switch (offset & 0x0f) { - case 0x00: /* Channel select */ + case 0x00: // Channel select m_select = data & 0x07; break; - case 0x01: /* Global balance */ - m_balance = data; + case 0x01: // Global balance + m_balance = data; break; - case 0x02: /* Channel frequency (LSB) */ - chan->frequency = (chan->frequency & 0x0f00) | data; + case 0x02: // Channel frequency (LSB) + chan.frequency = (chan.frequency & 0x0f00) | data; break; - case 0x03: /* Channel frequency (MSB) */ - chan->frequency = (chan->frequency & 0x00ff) | ((data << 8) & 0x0f00); + case 0x03: // Channel frequency (MSB) + chan.frequency = (chan.frequency & 0x00ff) | ((data << 8) & 0x0f00); break; - case 0x04: /* Channel control (key-on, DDA mode, volume) */ + case 0x04: // Channel control (key-on, DDA mode, volume) - /* 1-to-0 transition of DDA bit resets waveform index */ - if ((chan->control & 0x40) && ((data & 0x40) == 0)) + // 1-to-0 transition of DDA bit resets waveform index + if (BIT(chan.control, 6) && BIT(~data, 6)) { - chan->index = 0; + chan.index = 0; } - if (((chan->control & 0x80) == 0) && (data & 0x80)) + if (BIT(~chan.control, 7) && BIT(data, 7)) { - chan->tick = chan->frequency; + chan.tick = chan.frequency; } - chan->control = data; + chan.control = data; + + // Cache channel enable flag + m_enabled &= ~(1 << m_select); + m_enabled |= BIT(data, 7) << m_select; break; - case 0x05: /* Channel balance */ - chan->balance = data; + case 0x05: // Channel balance + chan.balance = data; break; - case 0x06: /* Channel waveform data */ + case 0x06: // Channel waveform data - switch (chan->control & 0x40) + switch (chan.control & 0x40) { case 0x00: // Waveform - chan->waveform[chan->index & 0x1f] = data & 0x1f; - if (!(chan->control & 0x80)) // TODO : wave pointer is increased at writing data when sound playback is off?? - chan->index = (chan->index + 1) & 0x1f; + chan.waveform[chan.index & 0x1f] = data & 0x1f; + if (BIT(~chan.control, 7)) // TODO : wave pointer is increased at writing data when sound playback is off?? + chan.index = (chan.index + 1) & 0x1f; break; case 0x40: // Direct D/A - chan->dda = data & 0x1f; + chan.dda = data & 0x1f; break; } break; - case 0x07: /* Noise control (enable, frequency) */ - chan->noise_control = data; + case 0x07: // Noise control (enable, frequency) + chan.noise_control = data; break; - case 0x08: /* LFO frequency */ + case 0x08: // LFO frequency m_lfo_frequency = data; break; - case 0x09: /* LFO control (enable, mode) */ + case 0x09: // LFO control (enable, mode) m_lfo_control = data; break; @@ -309,11 +319,12 @@ void c6280_device::device_clock_changed() void c6280_device::device_start() { - /* Loudest volume level for table */ + // Loudest volume level for table double level = 65535.0 / 6.0 / 32.0; - /* Clear context */ + // Clear context m_select = 0; + m_enabled = 0; m_balance = 0; m_lfo_frequency = 0; m_lfo_control = 0; @@ -321,17 +332,18 @@ void c6280_device::device_start() m_stream = stream_alloc(0, 2, clock()); - /* Make volume table */ - /* PSG has 48dB volume range spread over 32 steps */ + // Make volume table + // PSG has 48dB volume range spread over 32 steps double step = 48.0 / 32.0; - for (int i = 0; i < 30; i++) + for (int i = 0; i < 31; i++) { m_volume_table[i] = (u16)level; level /= pow(10.0, step / 20.0); } - m_volume_table[30] = m_volume_table[31] = 0; + m_volume_table[31] = 0; save_item(NAME(m_select)); + save_item(NAME(m_enabled)); save_item(NAME(m_balance)); save_item(NAME(m_lfo_frequency)); save_item(NAME(m_lfo_control)); @@ -352,9 +364,9 @@ void c6280_device::device_reset() { for (int ch = 0; ch < 6; ch++) { - channel *chan = &m_channel[ch]; - chan->index = 0; + channel &chan = m_channel[ch]; + chan.index = 0; if (ch >= 4) - chan->noise_seed = 1; + chan.noise_seed = 1; } } |