diff options
Diffstat (limited to 'engines/kyra')
| -rw-r--r-- | engines/kyra/sound_adlib.cpp | 52 |
1 files changed, 31 insertions, 21 deletions
diff --git a/engines/kyra/sound_adlib.cpp b/engines/kyra/sound_adlib.cpp index dda58f9353..767d4330a6 100644 --- a/engines/kyra/sound_adlib.cpp +++ b/engines/kyra/sound_adlib.cpp @@ -127,7 +127,7 @@ private: uint8 unk24; uint8 unk25; uint8 unk28; - uint8 unk23; + uint8 algorithm; uint8 unk39; uint8 unk40; uint8 unk3; @@ -157,7 +157,7 @@ private: void update1(uint8 unk1, OutputState &state); void updateAndOutput1(uint8 rawNote, OutputState &state, bool flag = false); - void updateAndOutput2(uint8 unk1, uint8 *dataptr, OutputState &state); + void setInstrument(uint8 regOffset, uint8 *dataptr, OutputState &state); void updateAndOutput3(OutputState &state); void adjustVolume(OutputState &state); @@ -771,38 +771,48 @@ void AdlibDriver::updateAndOutput1(uint8 rawNote, OutputState &state, bool flag) writeOPL(0xB0 + _curTable, state.regBx); } -void AdlibDriver::updateAndOutput2(uint8 unk1, uint8 *dataptr, OutputState &state) { - debugC(9, kDebugLevelSound, "updateAndOutput2(%d, %p, %d)", unk1, (const void *)dataptr, &state - _outputTables); +void AdlibDriver::setInstrument(uint8 regOffset, uint8 *dataptr, OutputState &state) { + debugC(9, kDebugLevelSound, "setInstrument(%d, %p, %d)", regOffset, (const void *)dataptr, &state - _outputTables); // Amplitude Modulation / Vibrato / Envelope Generator Type / // Keyboard Scaling Rate / Modulator Frequency Multiple - writeOPL(0x20 + unk1, *dataptr++); - writeOPL(0x23 + unk1, *dataptr++); + writeOPL(0x20 + regOffset, *dataptr++); + writeOPL(0x23 + regOffset, *dataptr++); uint8 temp = *dataptr++; // Feedback / Algorithm + + // It is very likely that _curTable really does refer to the same + // channel as regOffset, but there's only one Cx register per channel. + writeOPL(0xC0 + _curTable, temp); - state.unk23 = temp & 1; + // The algorithm bit. I don't pretend to understand this fully, but + // "If set to 0, operator 1 modulates operator 2. In this case, + // operator 2 is the only one producing sound. If set to 1, both + // operators produce sound directly. Complex sounds are more easily + // created if the algorithm is set to 0." + + state.algorithm = temp & 1; // Waveform Select - writeOPL(0xE0 + unk1, *dataptr++); - writeOPL(0xE3 + unk1, *dataptr++); + writeOPL(0xE0 + regOffset, *dataptr++); + writeOPL(0xE3 + regOffset, *dataptr++); state.unk24 = *dataptr++; state.unk25 = *dataptr++; // Level Key Scaling / Total Level - writeOPL(0x40 + unk1, calculateLowByte1(state)); - writeOPL(0x43 + unk1, calculateLowByte2(state)); + writeOPL(0x40 + regOffset, calculateLowByte1(state)); + writeOPL(0x43 + regOffset, calculateLowByte2(state)); // Attack Rate / Decay Rate - writeOPL(0x60 + unk1, *dataptr++); - writeOPL(0x63 + unk1, *dataptr++); + writeOPL(0x60 + regOffset, *dataptr++); + writeOPL(0x63 + regOffset, *dataptr++); // Sustain Level / Release Rate - writeOPL(0x80 + unk1, *dataptr++); - writeOPL(0x83 + unk1, *dataptr++); + writeOPL(0x80 + regOffset, *dataptr++); + writeOPL(0x83 + regOffset, *dataptr++); } void AdlibDriver::updateAndOutput3(OutputState &state) { @@ -825,7 +835,7 @@ void AdlibDriver::adjustVolume(OutputState &state) { // Level Key Scaling / Total Level writeOPL(0x43 + _outputTable[_curTable], lowByte); - if (state.unk23) { + if (state.algorithm) { lowByte = calculateLowByte1(state); // Level Key Scaling / Total Level @@ -916,7 +926,7 @@ void AdlibDriver::stateCallback2_1(OutputState &state) { uint8 AdlibDriver::calculateLowByte1(OutputState &state) { int8 value = state.unk24 & 0x3F; - if (state.unk23) { + if (state.algorithm) { value += state.unk26; value += state.unk27; value += state.unk28; @@ -1077,7 +1087,7 @@ int AdlibDriver::updateCallback16(uint8 *&dataptr, OutputState &state, uint8 val int AdlibDriver::updateCallback17(uint8 *&dataptr, OutputState &state, uint8 value) { uint8 *ptr = _soundData; ptr += READ_LE_UINT16(_soundData + (value << 1) + 0x1F4); - updateAndOutput2(_unkOutputByte1, ptr, state); + setInstrument(_unkOutputByte1, ptr, state); return 0; } @@ -1353,7 +1363,7 @@ int AdlibDriver::updateCallback48(uint8 *&dataptr, OutputState &state, uint8 val _unkOutputByte1 = _outputTable[6]; _unkValue6 = *(ptr + 6); - updateAndOutput2(_unkOutputByte1, ptr, state); + setInstrument(_unkOutputByte1, ptr, state); entry = *dataptr++ << 1; ptr = _soundData + READ_LE_UINT16(_soundData + entry + 0x1F4); @@ -1363,7 +1373,7 @@ int AdlibDriver::updateCallback48(uint8 *&dataptr, OutputState &state, uint8 val _unkValue7 = entry = *(ptr + 5); _unkValue8 = entry = *(ptr + 6); - updateAndOutput2(_unkOutputByte1, ptr, state); + setInstrument(_unkOutputByte1, ptr, state); entry = *dataptr++ << 1; ptr = _soundData + READ_LE_UINT16(_soundData + entry + 0x1F4); @@ -1373,7 +1383,7 @@ int AdlibDriver::updateCallback48(uint8 *&dataptr, OutputState &state, uint8 val _unkValue9 = entry = *(ptr + 5); _unkValue10 = entry = *(ptr + 6); - updateAndOutput2(_unkOutputByte1, ptr, state); + setInstrument(_unkOutputByte1, ptr, state); // Octave / F-Number / Key-On for channels 6, 7 and 8 |