mirror of
https://github.com/SourMesen/Mesen2.git
synced 2025-04-02 10:21:44 -04:00
929d4dcc20
-Super Mario Land 2 - Pops in menu are fixed by immediately updating APU output after a write -Perfect Dark - Low voice volume is fixed by having the correct output when the channels are disabled (but DAC is still enabled) -Daiku no Gen - Low voice volume is fixed by keeping square channel output to digital 0 (= analog 1) until its first tick after being enabled (the game does not let the channel tick at all while the voice sample is playing)
88 lines
No EOL
2.5 KiB
C++
88 lines
No EOL
2.5 KiB
C++
#pragma once
|
|
#include "pch.h"
|
|
|
|
class GbEnvelope
|
|
{
|
|
public:
|
|
template<typename T, typename U>
|
|
static void ClockEnvelope(T& state, U& channel)
|
|
{
|
|
uint8_t timer = state.EnvTimer;
|
|
if(state.EnvTimer == 0 || --state.EnvTimer == 0) {
|
|
if(state.EnvPeriod > 0 && !state.EnvStopped) {
|
|
if(state.EnvRaiseVolume && state.Volume < 0x0F) {
|
|
state.Volume++;
|
|
} else if(!state.EnvRaiseVolume && state.Volume > 0) {
|
|
state.Volume--;
|
|
} else {
|
|
state.EnvStopped = true;
|
|
}
|
|
|
|
//Clocking envelope should update output immediately (based on div_trigger_volume/channel_4_volume_div tests)
|
|
channel.UpdateOutput();
|
|
|
|
state.EnvTimer = state.EnvPeriod;
|
|
if(timer == 0) {
|
|
//When the timer was already 0 (because period was 0), it looks like the next
|
|
//clock occurs earlier than expected.
|
|
//This fixes the last test result in channel_1_nrx2_glitch (but may be incorrect)
|
|
state.EnvTimer--;
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
template<typename T, typename U>
|
|
static void WriteRegister(T& state, uint8_t value, U& channel)
|
|
{
|
|
bool raiseVolume = (value & 0x08) != 0;
|
|
uint8_t period = value & 0x07;
|
|
|
|
if((value & 0xF8) == 0) {
|
|
state.Enabled = false;
|
|
state.Output = 0;
|
|
} else {
|
|
//This implementation of the Zombie mode behavior differs from the description
|
|
//found here: https://gbdev.gg8.se/wiki/articles/Gameboy_sound_hardware
|
|
//Instead, it's based on the behavior of the channel_1_nrx2_glitch test and
|
|
//and SameBoy's implementation of the glitch
|
|
bool preventIncrement = false;
|
|
if(raiseVolume != state.EnvRaiseVolume) {
|
|
if(raiseVolume) {
|
|
if(!state.EnvStopped && state.EnvPeriod == 0) {
|
|
state.Volume ^= 0x0F;
|
|
} else {
|
|
state.Volume = 14 - state.Volume;
|
|
}
|
|
preventIncrement = true;
|
|
} else {
|
|
//"If the mode was changed (add to subtract or subtract to add), volume is set to 16 - volume."
|
|
state.Volume = 16 - state.Volume;
|
|
}
|
|
|
|
//"Only the low 4 bits of volume are kept"
|
|
state.Volume &= 0xF;
|
|
}
|
|
|
|
if(!state.EnvStopped && !preventIncrement) {
|
|
if(state.EnvPeriod == 0 && (period || raiseVolume)) {
|
|
if(raiseVolume) {
|
|
//"If the old envelope period was zero and the envelope is still doing automatic updates, volume is incremented by 1"
|
|
state.Volume++;
|
|
} else {
|
|
state.Volume--;
|
|
}
|
|
|
|
//"Only the low 4 bits of volume are kept"
|
|
state.Volume &= 0xF;
|
|
}
|
|
}
|
|
}
|
|
|
|
state.EnvPeriod = period;
|
|
state.EnvRaiseVolume = raiseVolume;
|
|
state.EnvVolume = (value & 0xF0) >> 4;
|
|
|
|
channel.UpdateOutput();
|
|
}
|
|
}; |