void Player_SID::useSwapVars(int channel) { // $5342
if (channel >= 3)
return;
swapVars(channel, 0);
setSIDFreqAS(channel);
if (pulseWidthSwapped) {
swapVars(channel+4, 1);
setSIDFreqAS(channel+4);
}
if (filterSwapped) {
swapVars(3, 2);
// resonating filter freq. or voice-to-filter mapping?
SIDReg23 = (SIDReg23Stuff & 0xf0) | BITMASK[channel];
SID_Write(23, SIDReg23);
// filter props
SIDReg24 = (SIDReg24 & 0x0f) | SIDReg24_HiNibble;
SID_Write(24, SIDReg24);
// filter freq.
SID_Write(21, LOBYTE_(freqReg[3]));
SID_Write(22, HIBYTE_(freqReg[3]));
} else {
SIDReg23 = SIDReg23Stuff & BITMASK_INV[channel];
SID_Write(23, SIDReg23);
}
swapPrepared = false;
pulseWidthSwapped = false;
keepSwapVars = false;
SIDReg24_HiNibble = 0;
filterSwapped = false;
}
void Player_SID::update() { // $481B
if (initializing)
return;
if (_soundInQueue) {
for (int i = 6; i >= 0; --i) {
if (_soundQueue[i] != -1)
processSongData(i);
}
_soundInQueue = false;
}
// no sound
if (busyChannelBits == 0)
return;
for (int i = 6; i >= 0; --i) {
if (busyChannelBits & BITMASK[i]) {
updateFreq(i);
}
}
// seems to be used for background (prio=1?) sounds.
// If a bg sound cannot be played because all SID
// voices are used by higher priority sounds, the
// bg sound's state is updated here so it will be at
// the correct state when a voice is available again.
if (swapPrepared) {
swapVars(0, 0);
swapVarLoaded = true;
updateFreq(0);
swapVars(0, 0);
if (pulseWidthSwapped) {
swapVars(4, 1);
updateFreq(4);
swapVars(4, 1);
}
swapVarLoaded = false;
}
for (int i = 6; i >= 0; --i) {
if (busyChannelBits & BITMASK[i])
setSIDWaveCtrlReg(i);
};
if (isMusicPlaying) {
handleMusicBuffer();
}
return;
}
void deleteVar(int i) {
if(i<MAX_VARS) {
size--;
free(env[i]);
for(; i<size; i++) {
swapVars(i, i+1);
}
env[size] = NULL;
}
}
void Player_SID::prepareSwapVars(int channel) { // $52E5
if (channel >= 4)
return;
if (channel < 3) {
if (!keepSwapVars) {
resetSwapVars();
}
swapVars(channel, 0);
if (busyChannelBits & BITMASK[channel+4]) {
swapVars(channel+4, 1);
pulseWidthSwapped = true;
}
} else if (channel == 3) {
SIDReg24_HiNibble = SIDReg24 & 0x70;
resetSwapVars();
keepSwapVars = true;
swapVars(3, 2);
filterSwapped = true;
}
swapPrepared = true;
}
