Setting DMG initial volume while playing cuts the note

[copyrat90]

Setting the DMG initial envelop volume while already playing a note cuts the note away. But it's not cut on the actual GBA hardware.

Playback Recordings

Hardware

https://github.com/skylersaleh/SkyEmu/assets/34793045/a2e2205a-0479-4e40-9e96-37b4b5b1749b

SkyEmu

https://github.com/skylersaleh/SkyEmu/assets/34793045/9e7eec6b-67c3-4446-9583-8d0a2d33a9f2

Test ROM

volume_set_midplay.zip

Code

This snippet should be compile fine with devkitARM + libtonc.

#include <tonc.h>

int main(void) {
    irq_init(NULL);
    irq_enable(II_VBLANK);

    REG_SNDSTAT = SSTAT_ENABLE;
    REG_SNDDSCNT = SDS_DMG100;
    REG_SNDDMGCNT = SDMG_LVOL(7) | SDMG_RVOL(7) | SDMG_LSQR1 | SDMG_RSQR1;

    REG_SND1CNT = SSQR_IVOL(15) | SSQR_TIME(0);
    REG_SND1FREQ = SFREQ_RESET | SFREQ_RATE(416);

    int wait = 45;
    while (1) {
        if (--wait == 0) {
            REG_SND1CNT = SSQR_IVOL(7) | SSQR_TIME(0);
        }
        VBlankIntrWait();
    }
}