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author | Tobias Gunkel | 2011-12-20 13:18:27 +0100 |
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committer | Tobias Gunkel | 2011-12-22 12:08:28 +0100 |
commit | 3a9f2c5f5bb817b4acbe279aedae938679634257 (patch) | |
tree | a510d3c1afa2a613e65fcd96d65698f4347c3903 /engines/scumm | |
parent | 7d551c9e6e8c5a46086f9da5e601561c434bafe0 (diff) | |
download | scummvm-rg350-3a9f2c5f5bb817b4acbe279aedae938679634257.tar.gz scummvm-rg350-3a9f2c5f5bb817b4acbe279aedae938679634257.tar.bz2 scummvm-rg350-3a9f2c5f5bb817b4acbe279aedae938679634257.zip |
SCUMM: Use finer grained sound updates for player_appleII
This reduces the needed buffer size for the biggest type4 sound from 170kB to only 2 bytes
Diffstat (limited to 'engines/scumm')
-rw-r--r-- | engines/scumm/player_appleII.cpp | 99 | ||||
-rw-r--r-- | engines/scumm/player_appleII.h | 1 |
2 files changed, 59 insertions, 41 deletions
diff --git a/engines/scumm/player_appleII.cpp b/engines/scumm/player_appleII.cpp index a027b522b5..b566012d73 100644 --- a/engines/scumm/player_appleII.cpp +++ b/engines/scumm/player_appleII.cpp @@ -183,73 +183,90 @@ public: _params = params; _updateRemain1 = 80; _updateRemain2 = 10; + _count = 0; } virtual bool update() { // D170 // while (_state.params[0] != 0x01) if (_params[0] != 0x01) { - _update(_params[0], _params[1], _params[2]); - _params += 3; + if (_count == 0) // prepare next loop + nextLoop(_params[0], _params[1], _params[2]); + if (loopIteration()) // loop finished -> fetch next parameter set + _params += 3; return false; } return true; } private: - void _update(byte param0, byte param1, byte param2) { // D1A2 - uint16 count = (-param2 << 8) | 0x3; - byte bitmask1 = 0x3; - byte bitmask2 = 0x3; + /* + * prepare for next parameter set loop + */ + void nextLoop(byte param0, byte param1, byte param2) { // LD182 + _count = (-param2 << 8) | 0x3; + + _bitmask1 = 0x3; + _bitmask2 = 0x3; - byte updateInterval2 = param0; - if (updateInterval2 == 0) - bitmask2 = 0x0; - - byte updateInterval1 = param1; - if (updateInterval1 == 0) { - bitmask1 = 0x0; - if (bitmask2 != 0) { - bitmask1 = bitmask2; - bitmask2 = 0; - updateInterval1 = updateInterval2; + _updateInterval2 = param0; + if (_updateInterval2 == 0) + _bitmask2 = 0x0; + + _updateInterval1 = param1; + if (_updateInterval1 == 0) { + _bitmask1 = 0x0; + if (_bitmask2 != 0) { + _bitmask1 = _bitmask2; + _bitmask2 = 0; + _updateInterval1 = _updateInterval2; } } - byte speakerShiftReg = 0; - - while (true) { - --_updateRemain1; - --_updateRemain2; + _speakerShiftReg = 0; + } - if (_updateRemain2 == 0) { - _updateRemain2 = updateInterval2; - // use only first voice's data (bitmask1) if both voices are triggered - if (_updateRemain1 != 0) { - speakerShiftReg ^= bitmask2; - } + /* + * perform one loop iteration + * Returns true if loop finished + */ + bool loopIteration() { // D1A2 + --_updateRemain1; + --_updateRemain2; + + if (_updateRemain2 == 0) { + _updateRemain2 = _updateInterval2; + // use only first voice's data (bitmask1) if both voices are triggered + if (_updateRemain1 != 0) { + _speakerShiftReg ^= _bitmask2; } + } - if (_updateRemain1 == 0) { - _updateRemain1 = updateInterval1; - speakerShiftReg ^= bitmask1; - } + if (_updateRemain1 == 0) { + _updateRemain1 = _updateInterval1; + _speakerShiftReg ^= _bitmask1; + } - if (speakerShiftReg & 0x1) - _player->speakerToggle(); - speakerShiftReg >>= 1; - _player->generateSamples(42); /* actually 42.5 */ + if (_speakerShiftReg & 0x1) + _player->speakerToggle(); + _speakerShiftReg >>= 1; + _player->generateSamples(42); /* actually 42.5 */ - ++count; - if (count == 0) { - return; - } - } + ++_count; + return (_count == 0); } protected: const byte *_params; + byte _updateRemain1; byte _updateRemain2; + + uint16 _count; + byte _bitmask1; + byte _bitmask2; + byte _updateInterval1; + byte _updateInterval2; + byte _speakerShiftReg; }; /* diff --git a/engines/scumm/player_appleII.h b/engines/scumm/player_appleII.h index 91c7935f76..f0b148ef86 100644 --- a/engines/scumm/player_appleII.h +++ b/engines/scumm/player_appleII.h @@ -282,6 +282,7 @@ public: AppleII_SoundFunction() {} virtual ~AppleII_SoundFunction() {} virtual void init(Player_AppleII *player, const byte *params) = 0; + /* returns true if finished */ virtual bool update() = 0; protected: Player_AppleII *_player; |