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SPU: Implement ADSR

Browse Source
pull/22/head
Connor McLaughlin 6 years ago
parent 3912e0e8d6
commit a3446b8275
2 changed files with 156 additions and 17 deletions
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131
src/core/spu.cpp
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@ -283,7 +283,7 @@ void SPU::WriteVoiceRegister(u32 offset, u16 value)
Assert(voice_index < 24);
Voice& voice = m_voices[voice_index];
if (voice.key_on)
if (voice.IsOn())
m_system->Synchronize();
switch (reg_index)
@ -318,14 +318,14 @@ void SPU::WriteVoiceRegister(u32 offset, u16 value)
case 0x08: // adsr low
{
Log_WarningPrintf("SPU voice %u ADSR low <- 0x%04X", voice_index, value);
Log_DebugPrintf("SPU voice %u ADSR low <- 0x%04X", voice_index, value);
voice.regs.adsr.bits_low = value;
}
break;
case 0x0A: // adsr high
{
Log_WarningPrintf("SPU voice %u ADSR high <- 0x%04X", voice_index, value);
Log_DebugPrintf("SPU voice %u ADSR high <- 0x%04X", voice_index, value);
voice.regs.adsr.bits_high = value;
}
break;
@ -404,14 +404,113 @@ void SPU::Execute(TickCount ticks)
void SPU::Voice::KeyOn()
{
current_address = regs.adpcm_start_address;
regs.adsr_volume = 0;
has_samples = false;
key_on = true;
SetADSRPhase(ADSRPhase::Attack);
}
void SPU::Voice::KeyOff()
{
has_samples = false;
key_on = false;
if (adsr_phase == ADSRPhase::Off)
return;
SetADSRPhase(ADSRPhase::Release);
}
SPU::ADSRPhase SPU::GetNextADSRPhase(ADSRPhase phase)
{
switch (phase)
{
case ADSRPhase::Attack:
// attack -> decay
return ADSRPhase::Decay;
case ADSRPhase::Decay:
// decay -> sustain
return ADSRPhase::Sustain;
case ADSRPhase::Sustain:
// sustain stays in sustain until key off
return ADSRPhase::Sustain;
default:
case ADSRPhase::Release:
// end of release disables the voice
return ADSRPhase::Off;
}
}
void SPU::Voice::SetADSRPhase(ADSRPhase phase)
{
adsr_phase = phase;
switch (phase)
{
case ADSRPhase::Off:
adsr_target = {};
break;
case ADSRPhase::Attack:
adsr_target.level = 32767; // 0 -> max
adsr_target.step = regs.adsr.attack_step + 4;
adsr_target.shift = regs.adsr.attack_shift;
adsr_target.decreasing = false;
adsr_target.exponential = regs.adsr.attack_exponential;
break;
case ADSRPhase::Decay:
adsr_target.level = (u32(regs.adsr.sustain_level.GetValue()) + 1) * 0x800; // max -> sustain level
adsr_target.step = 0;
adsr_target.shift = regs.adsr.decay_shift;
adsr_target.decreasing = true;
adsr_target.exponential = true;
break;
case ADSRPhase::Sustain:
adsr_target.level = regs.adsr.sustain_direction_decrease ? -1 : 1;
adsr_target.step = 0;
adsr_target.shift = regs.adsr.sustain_shift;
adsr_target.decreasing = regs.adsr.sustain_direction_decrease;
adsr_target.exponential = regs.adsr.sustain_exponential;
break;
case ADSRPhase::Release:
adsr_target.level = 0;
adsr_target.step = 0;
adsr_target.shift = regs.adsr.release_shift;
adsr_target.decreasing = true;
adsr_target.exponential = regs.adsr.release_exponential;
break;
default:
break;
}
const s32 step = adsr_target.decreasing ? (-8 + adsr_target.step) : (7 - adsr_target.step);
adsr_ticks = 1 << std::max<s16>(0, adsr_target.shift - 11);
adsr_ticks_remaining = adsr_ticks;
adsr_step = step << std::max<s16>(0, 11 - adsr_target.shift);
}
void SPU::Voice::TickADSR()
{
adsr_ticks_remaining--;
if (adsr_ticks_remaining <= 0)
{
const s32 new_volume = s32(regs.adsr_volume) + s32(adsr_step);
regs.adsr_volume = static_cast<s16>(std::clamp<s32>(new_volume, ADSR_MIN_VOLUME, ADSR_MAX_VOLUME));
const bool reached_target =
adsr_target.decreasing ? (new_volume <= adsr_target.level) : (new_volume >= adsr_target.level);
if (adsr_phase != ADSRPhase::Sustain && reached_target)
{
// next phase
SetADSRPhase(GetNextADSRPhase(adsr_phase));
}
else
{
adsr_ticks_remaining = adsr_ticks;
}
}
}
void SPU::Voice::DecodeBlock()
@ -575,7 +674,7 @@ void SPU::DecodeADPCMBlock(const ADPCMBlock& block, SampleFormat out_samples[NUM
std::tuple<SPU::SampleFormat, SPU::SampleFormat> SPU::SampleVoice(u32 voice_index)
{
Voice& voice = m_voices[voice_index];
if (!voice.key_on)
if (!voice.IsOn())
return std::make_tuple<s16, s16>(0, 0);
if (!voice.has_samples)
@ -624,10 +723,13 @@ std::tuple<SPU::SampleFormat, SPU::SampleFormat> SPU::SampleVoice(u32 voice_inde
}
// TODO: Volume
const float adsr_volume = S16ToFloat(voice.regs.adsr_volume);
voice.TickADSR();
const s32 sample = voice.Interpolate();
// s32 sample = voice.SampleBlock(voice.counter.sample_index);
const s16 sample16 = Clamp16(sample);
const float samplef = S16ToFloat(sample16);
const float samplef = S16ToFloat(sample16) * adsr_volume;
// apply volume
const float volume_left = S16ToFloat(voice.regs.volume_left.GetVolume());
@ -672,7 +774,7 @@ void SPU::DrawDebugWindow()
if (!m_debug_window_open)
return;
ImGui::SetNextWindowSize(ImVec2(700, 400), ImGuiCond_FirstUseEver);
ImGui::SetNextWindowSize(ImVec2(800, 400), ImGuiCond_FirstUseEver);
if (!ImGui::Begin("SPU State", &m_debug_window_open))
{
ImGui::End();
@ -682,14 +784,15 @@ void SPU::DrawDebugWindow()
// draw voice states
if (ImGui::CollapsingHeader("Voice State", ImGuiTreeNodeFlags_DefaultOpen))
{
static constexpr u32 NUM_COLUMNS = 11;
static constexpr u32 NUM_COLUMNS = 12;
ImGui::Columns(NUM_COLUMNS);
// headers
static constexpr std::array<const char*, NUM_COLUMNS> column_titles = {
{"#", "InterpIndex", "SampleIndex", "CurAddr", "StartAddr", "RepeatAddr", "SampleRate", "VolLeft", "VolRight",
"ADSR", "ADSRVol"}};
"ADSR", "ADSRPhase", "ADSRVol"}};
static constexpr std::array<const char*, 5> adsr_phases = {{"Off", "Attack", "Decay", "Sustain", "Release"}};
for (u32 i = 0; i < NUM_COLUMNS; i++)
{
ImGui::TextUnformatted(column_titles[i]);
@ -700,7 +803,7 @@ void SPU::DrawDebugWindow()
for (u32 voice_index = 0; voice_index < NUM_VOICES; voice_index++)
{
const Voice& v = m_voices[voice_index];
ImVec4 color = v.key_on ? ImVec4(1.0f, 1.0f, 1.0f, 1.0f) : ImVec4(0.5f, 0.5f, 0.5f, 1.0f);
ImVec4 color = v.IsOn() ? ImVec4(1.0f, 1.0f, 1.0f, 1.0f) : ImVec4(0.5f, 0.5f, 0.5f, 1.0f);
ImGui::TextColored(color, "%u", ZeroExtend32(voice_index));
ImGui::NextColumn();
ImGui::TextColored(color, "%u", ZeroExtend32(v.counter.interpolation_index.GetValue()));
@ -721,7 +824,9 @@ void SPU::DrawDebugWindow()
ImGui::NextColumn();
ImGui::TextColored(color, "%08X", v.regs.adsr.bits);
ImGui::NextColumn();
ImGui::TextColored(color, "%04X", ZeroExtend32(v.regs.adsr_volume));
ImGui::TextColored(color, adsr_phases[static_cast<u8>(v.adsr_phase)]);
ImGui::NextColumn();
ImGui::TextColored(color, "%d", ZeroExtend32(v.regs.adsr_volume));
ImGui::NextColumn();
}

42
src/core/spu.h
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@ -46,6 +46,8 @@ private:
static constexpr u32 NUM_SAMPLES_PER_ADPCM_BLOCK = 28;
static constexpr u32 SAMPLE_RATE = 44100;
static constexpr u32 SYSCLK_TICKS_PER_SPU_TICK = MASTER_CLOCK / SAMPLE_RATE; // 0x300
static constexpr s16 ADSR_MIN_VOLUME = 0;
static constexpr s16 ADSR_MAX_VOLUME = 0x7FFF;
enum class RAMTransferMode : u8
{
@ -99,7 +101,7 @@ private:
BitField<u32, u8, 0, 4> sustain_level;
BitField<u32, u8, 4, 4> decay_shift;
BitField<u32, u8, 8, 2> attack_step;
BitField<u32, u8, 10, 6> attack_shift;
BitField<u32, u8, 10, 5> attack_shift;
BitField<u32, bool, 15, 1> attack_exponential;
BitField<u32, u8, 16, 5> release_shift;
@ -140,7 +142,7 @@ private:
u16 adpcm_start_address; // multiply by 8
ADSRRegister adsr;
u16 adsr_volume;
s16 adsr_volume;
u16 adpcm_repeat_address; // multiply by 8
};
@ -187,6 +189,24 @@ private:
u8 GetNibble(u32 index) const { return (data[index / 2] >> ((index % 2) * 4)) & 0x0F; }
};
enum class ADSRPhase : u8
{
Off = 0,
Attack = 1,
Decay = 2,
Sustain = 3,
Release = 4
};
struct ADSRTarget
{
s32 level;
s16 step;
u8 shift;
bool decreasing;
bool exponential;
};
struct Voice
{
u16 current_address;
@ -197,8 +217,14 @@ private:
std::array<SampleFormat, 3> previous_block_last_samples;
std::array<s32, 2> adpcm_state;
bool has_samples;
bool key_on;
ADSRPhase adsr_phase;
ADSRTarget adsr_target;
TickCount adsr_ticks;
TickCount adsr_ticks_remaining;
s16 adsr_step;
bool has_samples;
bool IsOn() const { return adsr_phase != ADSRPhase::Off; }
void KeyOn();
void KeyOff();
@ -206,8 +232,16 @@ private:
void DecodeBlock();
SampleFormat SampleBlock(s32 index) const;
s16 Interpolate() const;
// Switches to the specified phase, filling in target.
void SetADSRPhase(ADSRPhase phase);
// Updates the ADSR volume/phase.
void TickADSR();
};
static ADSRPhase GetNextADSRPhase(ADSRPhase phase);
u16 ReadVoiceRegister(u32 offset);
void WriteVoiceRegister(u32 offset, u16 value);

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