private int CalculateVolume(SoundChannel soundChannel)
{
short[] dissolveData = null;
switch (this.Preferences.SoundDissolve)
{
case 2:
dissolveData = this.dissolveDataV2;
break;
case 3:
default:
dissolveData = this.dissolveDataV3;
break;
}
int volume = soundChannel.Attenuation;
if (volume != 0x0f)
{
if (soundChannel.DissolveCount != 0xffff)
{
int val = dissolveData[soundChannel.DissolveCount];
if (val == -100)
{
// end of list
soundChannel.DissolveCount = 0xffff;
soundChannel.Attenuation = soundChannel.AttenuationCopy;
volume = soundChannel.Attenuation;
}
else
{
soundChannel.DissolveCount++;
volume += val;
if (volume < 0)
{
volume = 0;
}
if (volume > 0x0f)
{
volume = 0x0f;
}
soundChannel.AttenuationCopy = volume;
volume &= 0x0f;
if (this.Preferences.SoundReadVariable)
{
volume += this.State.Variables[Variables.SoundVolume];
}
if (volume > 0x0f)
{
volume = 0x0f;
}
}
}
if (volume < 8)
{
volume += 2;
}
}
return(volume);
}
internal int FillChannel(int channel, Tone tone)
{
if (!this.State.Flags[Flags.SoundOn])
{
return(-1);
}
SoundChannel soundChannel = this.soundChannels[channel];
if (soundChannel.Avail == 0)
{
return(-1);
}
byte[] soundData = soundChannel.Data;
while (soundChannel.Duration == 0 && soundChannel.Duration != 0xffff)
{
int offset = soundChannel.DataIndex;
if (offset >= (soundData.Length - 2))
{
soundChannel.Duration = 0xffff;
break;
}
soundChannel.Duration = (soundData[offset + 1] * 0x100) + soundData[offset];
if (soundChannel.Duration != 0 && soundChannel.Duration != 0xffff)
{
// Only tone channels dissolve
if (channel != 3 && this.Preferences.SoundDissolve != 0)
{
soundChannel.DissolveCount = 0;
}
// Volume
soundChannel.Attenuation = soundData[offset + 4] & 0x0f;
// Frequency
if (channel < 3)
{
soundChannel.FreqCount = (ushort)(soundData[offset + 2] & 0x3f);
soundChannel.FreqCount <<= 4;
soundChannel.FreqCount |= (byte)(soundData[offset + 3] & 0x0f);
soundChannel.GenType = PcmSoundDriver.GenerateTone;
}
else
{
byte noiseType = (byte)(soundData[offset + 3] & 0x04);
soundChannel.GenType = noiseType != 0 ? PcmSoundDriver.GenerateWhite : PcmSoundDriver.GeneratePeriod;
int noiseFreq = (byte)(soundData[offset + 3] & 0x03);
switch (noiseFreq)
{
case 0:
soundChannel.FreqCount = 32;
break;
case 1:
soundChannel.FreqCount = 64;
break;
case 2:
soundChannel.FreqCount = 128;
break;
case 3:
soundChannel.FreqCount = this.soundChannels[2].FreqCount * 2;
break;
}
}
}
soundChannel.DataIndex += 5;
}
if (soundChannel.Duration != 0xffff)
{
tone.FrequencyCount = soundChannel.FreqCount;
tone.Attenuation = this.CalculateVolume(soundChannel);
tone.Type = soundChannel.GenType;
soundChannel.Duration--;
}
else
{
soundChannel.Avail = 0;
soundChannel.Attenuation = 0x0f; // silent
soundChannel.AttenuationCopy = 0x0f;
return(-1);
}
return(0);
}