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OPL: ymfm core, part 1

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tildearrow 2023-11-22 19:28:36 -05:00
parent 1bcdedda3e
commit 955682b240
9 changed files with 467 additions and 29 deletions
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4
src/engine/platform/sound/ymfm/ymfm_fm.h
View file

@ -305,6 +305,8 @@ public:
// simple getters for debugging
fm_operator<RegisterType> *debug_operator(uint32_t index) const { return m_op[index]; }
int32_t debug_output(uint32_t index) const { return m_output[index]; }
int32_t debug_special1() const { return m_special1; }
int32_t debug_special2() const { return m_special2; }
private:
// helper to add values to the outputs based on channel enables
@ -343,6 +345,8 @@ private:
RegisterType &m_regs; // direct reference to registers
fm_engine_base<RegisterType> &m_owner; // reference to the owning engine
mutable int32_t m_output[4];
mutable int32_t m_special1;
mutable int32_t m_special2;
};

12
src/engine/platform/sound/ymfm/ymfm_fm.ipp
View file

@ -808,7 +808,9 @@ fm_channel<RegisterType>::fm_channel(fm_engine_base<RegisterType> &owner, uint32
m_op{ nullptr, nullptr, nullptr, nullptr },
m_regs(owner.regs()),
m_owner(owner),
m_output{ 0, 0, 0, 0 }
m_output{ 0, 0, 0, 0 },
m_special1(0),
m_special2(0)
{
}
@ -1139,13 +1141,13 @@ void fm_channel<RegisterType>::output_rhythm_ch7(uint32_t phase_select, output_d
// and a combination of noise and the operator 13/17 phase select
// to compute the phase
uint32_t phase = (phase_select << 9) | (0xd0 >> (2 * (noise_state ^ phase_select)));
int32_t result = m_op[0]->compute_volume(phase, am_offset) >> rshift;
int32_t result = m_special1 = m_op[0]->compute_volume(phase, am_offset) >> rshift;
// Snare Drum: this uses the envelope from operator 16 (channel 7),
// and a combination of noise and operator 13 phase to pick a phase
uint32_t op13phase = m_op[0]->phase();
phase = (0x100 << bitfield(op13phase, 8)) ^ (noise_state << 8);
result += m_op[1]->compute_volume(phase, am_offset) >> rshift;
result += m_special2 = m_op[1]->compute_volume(phase, am_offset) >> rshift;
result = clamp(result, -clipmax - 1, clipmax);
// add to the output
@ -1166,12 +1168,12 @@ void fm_channel<RegisterType>::output_rhythm_ch8(uint32_t phase_select, output_d
uint32_t am_offset = m_regs.lfo_am_offset(m_choffs);
// Tom Tom: this is just a single operator processed normally
int32_t result = m_op[0]->compute_volume(m_op[0]->phase(), am_offset) >> rshift;
int32_t result = m_special1 = m_op[0]->compute_volume(m_op[0]->phase(), am_offset) >> rshift;
// Top Cymbal: this uses the envelope from operator 17 (channel 8),
// and the operator 13/17 phase select to compute the phase
uint32_t phase = 0x100 | (phase_select << 9);
result += m_op[1]->compute_volume(phase, am_offset) >> rshift;
result += m_special2 = m_op[1]->compute_volume(phase, am_offset) >> rshift;
result = clamp(result, -clipmax - 1, clipmax);
// add to the output

9
src/engine/platform/sound/ymfm/ymfm_opl.h
View file

@ -528,6 +528,8 @@ public:
// generate samples of sound
void generate(output_data *output, uint32_t numsamples = 1);
fm_engine* debug_fm_engine() { return &m_fm; }
protected:
// internal state
uint8_t m_address; // address register
@ -575,6 +577,9 @@ public:
// generate samples of sound
void generate(output_data *output, uint32_t numsamples = 1);
fm_engine* debug_fm_engine() { return &m_fm; }
adpcm_b_engine* debug_adpcm_b_engine() { return &m_adpcm_b; }
protected:
// internal state
uint8_t m_address; // address register
@ -623,6 +628,8 @@ public:
// generate samples of sound
void generate(output_data *output, uint32_t numsamples = 1);
fm_engine* debug_fm_engine() { return &m_fm; }
protected:
// internal state
uint8_t m_address; // address register
@ -670,6 +677,8 @@ public:
// generate samples of sound
void generate(output_data *output, uint32_t numsamples = 1);
fm_engine* debug_fm_engine() { return &m_fm; }
protected:
// internal state
uint16_t m_address; // address register