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Gericom / GBARunner3

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Fix restarting GB Audio envelope when writing to register #137

Closed Dartz150 closed 6 months ago

Dartz150 commented 6 months ago

As discussed here, this adds nextStep being updated in _writeEnvelope, so it emulates the same behavior observed in real GBA hardware, where the envelope updates even after it has been started.

This fixes Wario Land 4 jump sound sfx playing incorrectly, and the homebrew demo linked below.

https://github.com/mgba-emu/mgba/files/13360772/F0_F7_no_retrig.zip

Additionally, it's worth noting that the GBA hardware in NDS/3DS experiences this bug, as it doesn't behave like a GBA, so it never updates the envelopes after starting them, which was the behavior prior to this change in GBARunner3 as well.

Tested on the following games which use the GB Channels intensively, with no observed regressions:

Wario Land 4 Mega Man & Bass Mega Man: Battle Network Mario Kart Super Circuit Game & Watch Gallery 4 The Legend of Zelda: The Minish Cap Bomber Man MAX 2: Blue Advance Castlevania: Harmony of Dissonance GT Advance Championship Racing

And soundtest1.gba to compare against real GBA hardware:

soundtest1.zip

Play any sound and change Envlp Step Dir from Inc to Dec without playing the sound again, it should be correctly updated in real GBA hardware and this bug fix applied, but on NDS/3DS it should make an infinite beep sound instead, which is the expected bug.

endrift commented 3 months ago

My fix for this issue caused a regression, noticeable in the audio of Super Mario Advance 4. See https://github.com/mgba-emu/mgba/issues/3164

Dartz150 commented 3 months ago

My fix for this issue caused a regression, noticeable in the audio of Super Mario Advance 4. See mgba-emu/mgba#3164

I couldn't reproduce this in GBARunner3, sound plays totally fine on the latest commit addae4d