diff options
| -rw-r--r-- | engines/sci/sound/drivers/pc9801.cpp | 74 |
1 files changed, 44 insertions, 30 deletions
diff --git a/engines/sci/sound/drivers/pc9801.cpp b/engines/sci/sound/drivers/pc9801.cpp index 87a997b1f9..8a1521a0e2 100644 --- a/engines/sci/sound/drivers/pc9801.cpp +++ b/engines/sci/sound/drivers/pc9801.cpp @@ -553,17 +553,21 @@ void SoundChannel_PC9801::processSounds() { } if (_flags & kChanVbrDecrease) { - int16 s = _vbrCur - (_vbrDecrStep & 0xFF); - _vbrCur = s & 0xFF; - if (s >= 0) + uint8 sL = _vbrDecrStep & 0xFF; + uint8 sH = _vbrDecrStep >> 8; + bool ovrflow = (sL > _vbrCur); + _vbrCur -= sL; + if (!ovrflow) return; - _vbrFrequencyModifier -= ((_vbrDecrStep >> 8) + 1); - } else { - uint16 s = _vbrCur + (_vbrIncrStep & 0xFF); - _vbrCur = s & 0xFF; - if (s <= 255) + _vbrFrequencyModifier -= (sH + 1); + } else { + uint8 sL = _vbrDecrStep & 0xFF; + uint8 sH = _vbrDecrStep >> 8; + bool ovrflow = (sL + _vbrCur > 255); + _vbrCur += sL; + if (!ovrflow) return; - _vbrFrequencyModifier += ((_vbrIncrStep >> 8) + 1); + _vbrFrequencyModifier += (sH + 1); } sendFrequency(); @@ -794,23 +798,31 @@ void SoundChannel_PC9801_FM2OP::processSounds() { } if (_flags & kChanVbrDecrease) { - int16 s = _vbrCur - (_vbrDecrStep & 0xFF); - _vbrCur = s & 0xFF; - if (s < 0) - _vbrFrequencyModifier -= ((_vbrDecrStep >> 8) + 1); - s = _vbrCur2 - (_vbrDecrStep2 & 0xFF); - _vbrCur2 = s & 0xFF; - if (s < 0) - _vbrFrequencyModifier2 -= ((_vbrDecrStep2 >> 8) + 1); + uint8 sL = _vbrDecrStep & 0xFF; + uint8 sH = _vbrDecrStep >> 8; + bool ovrflow = (sL > _vbrCur); + _vbrCur -= sL; + if (ovrflow) + _vbrFrequencyModifier -= (sH + 1); + sL = _vbrDecrStep2 & 0xFF; + sH = _vbrDecrStep2 >> 8; + ovrflow = (sL > _vbrCur2); + _vbrCur2 -= sL; + if (ovrflow) + _vbrFrequencyModifier2 -= (sH + 1); } else { - uint16 s = _vbrCur + (_vbrIncrStep & 0xFF); - _vbrCur = s & 0xFF; - if (s > 255) - _vbrFrequencyModifier += ((_vbrIncrStep >> 8) + 1); - s = _vbrCur2 + (_vbrIncrStep2 & 0xFF); - _vbrCur2 = s & 0xFF; - if (s > 255) - _vbrFrequencyModifier2 += ((_vbrIncrStep2 >> 8) + 1); + uint8 sL = _vbrDecrStep & 0xFF; + uint8 sH = _vbrDecrStep >> 8; + bool ovrflow = (sL + _vbrCur > 255); + _vbrCur += sL; + if (ovrflow) + _vbrFrequencyModifier += (sH + 1); + sL = _vbrDecrStep2 & 0xFF; + sH = _vbrDecrStep2 >> 8; + ovrflow = (sL + _vbrCur2 > 255); + _vbrCur2 += sL; + if (ovrflow) + _vbrFrequencyModifier2 += (sH + 1); } sendFrequency(); @@ -958,7 +970,7 @@ void SoundChannel_PC9801_SSG::processSounds() { if (_ssgEnvelopeState == (kEnvSSG_keyOn | kEnvSSG_decay)) { _ssgLevel = _selectedInstrument[15]; _ssgSpeed = _selectedInstrument[16]; - vol = (uint8)CLIP<int16>(vol + (int8)(_selectedInstrument[20] << 4), 0, 255); + vol = (uint8)CLIP<int16>(vol + (int8)((_selectedInstrument[20] & 0x0F) << 4), 0, 255); } } @@ -1523,7 +1535,8 @@ void MidiDriver_PC9801::initTrack(SciSpan<const byte> &header) { for (int i = 0; i < _numChan; ++i) _chan[i]->reset(); - uint8 caps = *header++; + uint8 readPos = 0; + uint8 caps = header.getInt8At(readPos++); int numChan = (caps == 2) ? 15 : 16; if (caps != 0 && caps != 2) return; @@ -1531,9 +1544,10 @@ void MidiDriver_PC9801::initTrack(SciSpan<const byte> &header) { for (int i = 0; i < numChan; ++i) { _parts[i]->controlChangeVolume(103); - uint8 num = (_internalVersion == 1) ? (*header & 0x7F): 1; - header++; - uint8 flags = *header++; + uint8 num = (_internalVersion == 1) ? (header.getInt8At(readPos) & 0x7F) : 1; + readPos++; + uint8 flags = header.getInt8At(readPos); + readPos++; if (flags & _channelMask1 && num) _parts[i]->addChannels(num, -1, 0); |