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SPU: Implement ADSR

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This commit is contained in:
Connor McLaughlin
2019-10-11 16:05:34 +10:00
parent 3912e0e8d6
commit a3446b8275
2 changed files with 156 additions and 17 deletions
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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);