fix volume scaling

SourceX/miniwin/dsound.cpp

@@ -74,8 +74,7 @@ HRESULT DirectSoundBuffer::Play(DWORD dwReserved1, DWORD dwPriority, DWORD dwFla
 	}
 
 	Mix_Volume(channel, volume);
-	int panned = 255 - 255 * abs(pan) / 10000;
-	Mix_SetPanning(channel, pan <= 0 ? 255 : panned, pan >= 0 ? 255 : panned);
+	Mix_SetPanning(channel, pan <= 0 ? 255 : abs(pan), pan >= 0 ? 255 : pan);
 
 	return DVL_DS_OK;
 };
@@ -87,14 +86,15 @@ HRESULT DirectSoundBuffer::SetFormat(LPCWAVEFORMATEX pcfxFormat)
 
 HRESULT DirectSoundBuffer::SetVolume(LONG lVolume)
 {
-	volume = MIX_MAX_VOLUME - MIX_MAX_VOLUME * lVolume / VOLUME_MIN;
+	volume = pow(10, lVolume / 2000.0) * MIX_MAX_VOLUME;
 
 	return DVL_DS_OK;
 };
 
 HRESULT DirectSoundBuffer::SetPan(LONG lPan)
 {
-	pan = lPan;
+	pan = copysign(pow(10, -abs(lPan) / 2000.0) * 255, lPan);
+
 	return DVL_DS_OK;
 };