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Sas envelopes: Simplify away some redundant state.

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This commit is contained in:
Henrik Rydgård 2014-02-11 11:56:24 +01:00
parent 1e1cd730bd
commit 079f653cff
2 changed files with 15 additions and 42 deletions
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50
Core/HW/SasAudio.cpp
View File

@ -678,47 +678,45 @@ ADSREnvelope::ADSREnvelope()
sustainType(PSP_SAS_ADSR_CURVE_MODE_LINEAR_INCREASE),
sustainLevel(0),
releaseType(PSP_SAS_ADSR_CURVE_MODE_LINEAR_DECREASE),
rate_(0),
type_(0),
state_(STATE_OFF),
height_(0) {
}
void ADSREnvelope::WalkCurve(int type) {
void ADSREnvelope::WalkCurve(int type, int rate) {
s64 expDelta;
switch (type) {
case PSP_SAS_ADSR_CURVE_MODE_LINEAR_INCREASE:
height_ += rate_;
height_ += rate;
break;
case PSP_SAS_ADSR_CURVE_MODE_LINEAR_DECREASE:
height_ -= rate_;
height_ -= rate;
break;
case PSP_SAS_ADSR_CURVE_MODE_LINEAR_BENT:
if (height_ < (s64)PSP_SAS_ENVELOPE_HEIGHT_MAX * 3 / 4) {
height_ += rate_;
height_ += rate;
} else {
height_ += rate_ / 4;
height_ += rate / 4;
}
break;
case PSP_SAS_ADSR_CURVE_MODE_EXPONENT_DECREASE:
expDelta = height_ - PSP_SAS_ENVELOPE_HEIGHT_MAX;
// Flipping the sign so that we can shift in the top bits.
expDelta += (-expDelta * rate_) >> 32;
height_ = expDelta + PSP_SAS_ENVELOPE_HEIGHT_MAX - (rate_ + 3UL) / 4UL;
expDelta += (-expDelta * rate) >> 32;
height_ = expDelta + PSP_SAS_ENVELOPE_HEIGHT_MAX - (rate + 3UL) / 4UL;
break;
case PSP_SAS_ADSR_CURVE_MODE_EXPONENT_INCREASE:
expDelta = height_ - PSP_SAS_ENVELOPE_HEIGHT_MAX;
// Flipping the sign so that we can shift in the top bits.
expDelta += (-expDelta * rate_) >> 32;
expDelta += (-expDelta * rate) >> 32;
height_ = expDelta + 0x4000 + PSP_SAS_ENVELOPE_HEIGHT_MAX;
break;
case PSP_SAS_ADSR_CURVE_MODE_DIRECT:
height_ = rate_; // Simple :)
height_ = rate; // Simple :)
break;
}
}
@ -727,51 +725,31 @@ void ADSREnvelope::SetState(ADSRState state) {
if (height_ > PSP_SAS_ENVELOPE_HEIGHT_MAX) {
height_ = PSP_SAS_ENVELOPE_HEIGHT_MAX;
}
// TODO: Also check for height_ < 0 and set to 0?
state_ = state;
switch (state) {
case STATE_ATTACK:
rate_ = attackRate;
type_ = attackType;
break;
case STATE_DECAY:
rate_ = decayRate;
type_ = decayType;
break;
case STATE_SUSTAIN:
rate_ = sustainRate;
type_ = sustainType;
break;
case STATE_RELEASE:
rate_ = releaseRate;
type_ = releaseType;
break;
case STATE_OFF:
return;
}
}
void ADSREnvelope::Step() {
switch (state_) {
case STATE_ATTACK:
WalkCurve(type_);
WalkCurve(attackType, attackRate);
if (height_ >= PSP_SAS_ENVELOPE_HEIGHT_MAX || height_ < 0)
SetState(STATE_DECAY);
break;
case STATE_DECAY:
WalkCurve(type_);
WalkCurve(decayType, decayRate);
if (height_ < sustainLevel)
SetState(STATE_SUSTAIN);
break;
case STATE_SUSTAIN:
WalkCurve(type_);
WalkCurve(sustainType, sustainRate);
if (height_ <= 0) {
height_ = 0;
SetState(STATE_RELEASE);
}
break;
case STATE_RELEASE:
WalkCurve(type_);
WalkCurve(releaseType, releaseRate);
if (height_ <= 0) {
height_ = 0;
SetState(STATE_OFF);

7
Core/HW/SasAudio.h
View File

@ -135,7 +135,7 @@ public:
ADSREnvelope();
void SetSimpleEnvelope(u32 ADSREnv1, u32 ADSREnv2);
void WalkCurve(int type);
void WalkCurve(int type, int rate);
void KeyOn();
void KeyOff();
@ -164,11 +164,6 @@ public:
private:
void ComputeDuration();
// Internal variables that are recomputed on state changes
// No need to save in state
int rate_;
int type_;
enum ADSRState {
STATE_ATTACK,
STATE_DECAY,