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Got the basic sound pipeline pumping, just enough for static-level audio seemingly to work. Berzerk VE says "intruder alert, intruder alert", anyway.

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This commit is contained in:
Thomas Harte 2016-06-01 19:27:04 -04:00
parent 8623dc2833
commit 40c4544fb7
2 changed files with 76 additions and 7 deletions
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75
Machines/Atari2600/Atari2600.cpp
View File

@ -25,7 +25,8 @@ Machine::Machine() :
_tiaInputValue{0xff, 0xff},
_upcomingEventsPointer(0),
_objectCounterPointer(0),
_stateByTime(_stateByExtendTime[0])
_stateByTime(_stateByExtendTime[0]),
_cycles_since_speaker_update(0)
{
memset(_collisions, 0xff, sizeof(_collisions));
set_reset_line(true);
@ -414,6 +415,7 @@ unsigned int Machine::perform_bus_operation(CPU6502::BusOperation operation, uin
}
output_pixels(cycles_run_for);
_cycles_since_speaker_update += cycles_run_for;
if(operation != CPU6502::BusOperation::Ready) {
@ -449,10 +451,6 @@ unsigned int Machine::perform_bus_operation(CPU6502::BusOperation operation, uin
returnValue &= _ram[address&0x7f];
} else {
_ram[address&0x7f] = *value;
// if((address&0x7f) == (0x9a&0x7f))
// {
// printf("[9a] <- %02x\n", *value);
// }
}
}
@ -498,6 +496,8 @@ unsigned int Machine::perform_bus_operation(CPU6502::BusOperation operation, uin
case 0x03:
// Reset is delayed by four cycles.
_horizontalTimer = horizontalTimerPeriod - 4;
// TODO: audio will now be out of synchronisation — fix
break;
case 0x04:
@ -585,6 +585,21 @@ unsigned int Machine::perform_bus_operation(CPU6502::BusOperation operation, uin
_upcomingEvents[(_upcomingEventsPointer + 4)%number_of_upcoming_events].counter = decodedAddress - 0x10;
break;
case 0x15: case 0x16:
update_audio();
_speaker.set_control(decodedAddress - 0x15, *value);
break;
case 0x17: case 0x18:
update_audio();
_speaker.set_divider(decodedAddress - 0x17, *value);
break;
case 0x19: case 0x1a:
update_audio();
_speaker.set_volume(decodedAddress - 0x19, *value);
break;
case 0x1c:
_ballGraphicsEnable[1] = _ballGraphicsEnable[0];
case 0x1b: {
@ -765,3 +780,53 @@ void Machine::set_rom(size_t length, const uint8_t *data)
_romPages[2] = &_rom[2048 & romMask];
_romPages[3] = &_rom[3072 & romMask];
}
#pragma mark - Audio
void Machine::update_audio()
{
_speaker.run_for_cycles(_cycles_since_speaker_update / 114);
_cycles_since_speaker_update %= 114;
}
void Machine::synchronise()
{
update_audio();
}
void Atari2600::Speaker::set_volume(int channel, uint8_t volume)
{
_volume[channel] = volume & 0xf;
}
void Atari2600::Speaker::set_divider(int channel, uint8_t divider)
{
_divider[channel] = divider & 0x1f;
}
void Atari2600::Speaker::set_control(int channel, uint8_t control)
{
_control[channel] = control & 0xf;
}
void Atari2600::Speaker::get_samples(unsigned int number_of_samples, int16_t *target)
{
for(unsigned int c = 0; c < number_of_samples; c++)
{
target[c] = 0;
for(int channel = 0; channel < 2; channel++)
{
if(!_control[channel])
{
target[c] += _volume[channel] * 1024;
}
else
{
}
}
}
}
void Atari2600::Speaker::skip_samples(unsigned int number_of_samples)
{
}

8
Machines/Atari2600/Atari2600.hpp
View File

@ -48,7 +48,7 @@ class Machine: public CPU6502::Processor<Machine>, public CRTMachine::Machine {
// to satisfy CPU6502::Processor
unsigned int perform_bus_operation(CPU6502::BusOperation operation, uint16_t address, uint8_t *value);
void synchronise() {}
void synchronise();
// to satisfy CRTMachine::Machine
virtual void setup_output(float aspect_ratio);
@ -159,10 +159,14 @@ class Machine: public CPU6502::Processor<Machine>, public CRTMachine::Machine {
uint8_t get_output_pixel();
void update_timers(int mask);
// Outputs
// outputs
Outputs::CRT::CRT *_crt;
Speaker _speaker;
// speaker backlog accumlation counter
unsigned int _cycles_since_speaker_update;
void update_audio();
// latched output state
unsigned int _lastOutputStateDuration;
OutputState _stateByExtendTime[2][57];