devkitSMS/PSGlib/src/PSGRestoreVolumes.c at 8d0027647924afcf644c7101e9c5601e97ca20df · sverx/devkitSMS · GitHub

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
/* **************************************************
   PSGlib - C programming library for the SEGA PSG
   ( part of devkitSMS - github.com/sverx/devkitSMS )
   ************************************************** */

#include "PSGlib.h"
#include "PSGlib_extern.h"

void PSGSilenceChannels (void) {
/* *********************************************************************
  silence all the PSG channels
*/
  PSGPort=PSGLatch|PSGChannel0|PSGVolumeData|0x0F;
  PSGPort=PSGLatch|PSGChannel1|PSGVolumeData|0x0F;
  PSGPort=PSGLatch|PSGChannel2|PSGVolumeData|0x0F;
  PSGPort=PSGLatch|PSGChannel3|PSGVolumeData|0x0F;
}

void PSGRestoreVolumes (void) {
/* *********************************************************************
  restore the PSG channels volumes (if a tune or an SFX uses them!)
*/
  if (PSGChannelSFX & SFX_CHANNEL0)
    PSGPort=PSGLatch|PSGChannel0|PSGVolumeData|(((PSGSFXChan0Volume&0x0F)+PSGSFXVolumeAttenuation>15)?15:(PSGSFXChan0Volume&0x0F)+PSGSFXVolumeAttenuation);
  else if (PSGMusicStatus)
    PSGPort=PSGLatch|PSGChannel0|PSGVolumeData|(((PSGChan0Volume&0x0F)+PSGMusicVolumeAttenuation>15)?15:(PSGChan0Volume&0x0F)+PSGMusicVolumeAttenuation);
  if (PSGChannelSFX & SFX_CHANNEL1)
    PSGPort=PSGLatch|PSGChannel1|PSGVolumeData|(((PSGSFXChan1Volume&0x0F)+PSGSFXVolumeAttenuation>15)?15:(PSGSFXChan1Volume&0x0F)+PSGSFXVolumeAttenuation);
  else if (PSGMusicStatus)
    PSGPort=PSGLatch|PSGChannel1|PSGVolumeData|(((PSGChan1Volume&0x0F)+PSGMusicVolumeAttenuation>15)?15:(PSGChan1Volume&0x0F)+PSGMusicVolumeAttenuation);
  if (PSGChannelSFX & SFX_CHANNEL2)
    PSGPort=PSGLatch|PSGChannel2|PSGVolumeData|(((PSGSFXChan2Volume&0x0F)+PSGSFXVolumeAttenuation>15)?15:(PSGSFXChan2Volume&0x0F)+PSGSFXVolumeAttenuation);
  else if (PSGMusicStatus)
    PSGPort=PSGLatch|PSGChannel2|PSGVolumeData|(((PSGChan2Volume&0x0F)+PSGMusicVolumeAttenuation>15)?15:(PSGChan2Volume&0x0F)+PSGMusicVolumeAttenuation);
  if (PSGChannelSFX & SFX_CHANNEL3)
    PSGPort=PSGLatch|PSGChannel3|PSGVolumeData|(((PSGSFXChan3Volume&0x0F)+PSGSFXVolumeAttenuation>15)?15:(PSGSFXChan3Volume&0x0F)+PSGSFXVolumeAttenuation);
  else if (PSGMusicStatus)
    PSGPort=PSGLatch|PSGChannel3|PSGVolumeData|(((PSGChan3Volume&0x0F)+PSGMusicVolumeAttenuation>15)?15:(PSGChan3Volume&0x0F)+PSGMusicVolumeAttenuation);
}