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flopimg: Fix issues when wrapping in generate_bitstream_from_track which were especially damaging for apple drivers

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Olivier Galibert 2022-04-19 17:53:17 +02:00
parent 6d3c4ff49a
commit 5b17570612
1 changed files with 119 additions and 69 deletions
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188
src/lib/formats/flopimg.cpp
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@ -1316,92 +1316,142 @@ std::vector<bool> floppy_image_format_t::generate_bitstream_from_track(int track
return trackbuf;
}
// Start at the write splice
uint32_t splice = image->get_write_splice_position(track, head, subtrack);
int cur_pos = splice;
int cur_entry = 0;
while(cur_entry < int(tbuf.size())-1 && (tbuf[cur_entry+1] & floppy_image::TIME_MASK) < cur_pos)
cur_entry++;
class pll {
private:
const std::vector<uint32_t> &tbuf;
int cur_pos;
int cur_entry;
int period;
int period_adjust_base;
int min_period;
int max_period;
int phase_adjust;
int freq_hist;
bool next_is_first;
int period = cell_size;
int period_adjust_base = period * 0.05;
public:
pll(const std::vector<uint32_t> &_tbuf, int cell_size) : tbuf(_tbuf) {
period = cell_size;
period_adjust_base = period * 0.05;
int min_period = int(cell_size*0.75);
int max_period = int(cell_size*1.25);
int phase_adjust = 0;
int freq_hist = 0;
min_period = int(cell_size*0.75);
max_period = int(cell_size*1.25);
phase_adjust = 0;
freq_hist = 0;
uint32_t scanned = 0;
while(scanned < 200000000) {
// Note that only MG_F edges are taken into account, the rest is ignored.
// The lack of MG_F has been tested for previously.
while((tbuf[cur_entry] & floppy_image::MG_MASK) != floppy_image::MG_F) {
cur_entry ++;
if(cur_entry == tbuf.size())
cur_entry = 0;
// Try to go back 16 flux changes from the end of the track, or at most at the start
int flux_to_step = 16;
cur_entry = tbuf.size()-1;
while(cur_entry > 0 && flux_to_step) {
if((tbuf[cur_entry] & floppy_image::MG_MASK) == floppy_image::MG_F)
flux_to_step --;
cur_entry--;
}
// Go back by half-a-period
cur_pos = (tbuf[cur_entry] & floppy_image::TIME_MASK) - period/2;
// Adjust the entry accordingly
while(cur_entry > 0 && (cur_pos > (tbuf[cur_entry] & floppy_image::TIME_MASK)))
cur_entry --;
// Now go to the next flux change from there (the no-MG_F case has been handled earlier)
while((tbuf[cur_entry] & floppy_image::MG_MASK) != floppy_image::MG_F)
cur_entry ++;
next_is_first = false;
}
int edge = tbuf[cur_entry] & floppy_image::TIME_MASK;
if(edge < cur_pos)
edge += 200000000;
int next = cur_pos + period + phase_adjust;
scanned += period + phase_adjust;
std::pair<bool, bool> get() {
bool bit, first;
int edge = tbuf[cur_entry] & floppy_image::TIME_MASK;
if(edge < cur_pos)
edge += 200000000;
int next = cur_pos + period + phase_adjust;
if(edge >= next) {
// No transition in the window means 0 and pll in free run mode
trackbuf.push_back(false);
phase_adjust = 0;
if(edge >= next) {
// No transition in the window means 0 and pll in free run mode
bit = false;
phase_adjust = 0;
} else {
// Transition in the window means 1, and the pll is adjusted
trackbuf.push_back(true);
} else {
// Transition in the window means 1, and the pll is adjusted
bit = true;
int delta = edge - (next - period/2);
int delta = edge - (next - period/2);
phase_adjust = 0.65*delta;
phase_adjust = 0.65*delta;
if(delta < 0) {
if(freq_hist < 0)
freq_hist--;
else
freq_hist = -1;
} else if(delta > 0) {
if(freq_hist > 0)
freq_hist++;
else
freq_hist = 1;
} else
freq_hist = 0;
if(delta < 0) {
if(freq_hist < 0)
freq_hist--;
else
freq_hist = -1;
} else if(delta > 0) {
if(freq_hist > 0)
freq_hist++;
else
freq_hist = 1;
} else
freq_hist = 0;
if(freq_hist) {
int afh = freq_hist < 0 ? -freq_hist : freq_hist;
if(afh > 1) {
int aper = period_adjust_base*delta/period;
if(!aper)
aper = freq_hist < 0 ? -1 : 1;
period += aper;
if(freq_hist) {
int afh = freq_hist < 0 ? -freq_hist : freq_hist;
if(afh > 1) {
int aper = period_adjust_base*delta/period;
if(!aper)
aper = freq_hist < 0 ? -1 : 1;
period += aper;
if(period < min_period)
period = min_period;
else if(period > max_period)
period = max_period;
if(period < min_period)
period = min_period;
else if(period > max_period)
period = max_period;
}
}
}
}
cur_pos = next;
if(cur_pos >= 200000000) {
cur_pos -= 200000000;
cur_entry = 0;
}
while(cur_entry < int(tbuf.size())-1 && (tbuf[cur_entry] & floppy_image::TIME_MASK) < cur_pos)
cur_entry++;
first = next_is_first;
next_is_first = false;
// Wrap around
if(cur_entry == int(tbuf.size())-1 &&
(tbuf[cur_entry] & floppy_image::TIME_MASK) < cur_pos)
cur_entry = 0;
cur_pos = next;
if(cur_pos >= 200000000) {
cur_pos -= 200000000;
cur_entry = 0;
if(cur_pos >= period/2)
first = true;
else
next_is_first = true;
}
while(cur_entry < int(tbuf.size())-1 && (tbuf[cur_entry] & floppy_image::TIME_MASK) < cur_pos)
cur_entry++;
// Wrap around
if(cur_entry == int(tbuf.size())-1 &&
(tbuf[cur_entry] & floppy_image::TIME_MASK) < cur_pos)
cur_entry = 0;
return std::make_pair(bit, first);
}
};
pll cpll(tbuf, cell_size);
for(;;) {
auto r = cpll.get();
if(r.second) {
trackbuf.push_back(r.first);
break;
}
}
for(;;) {
auto r = cpll.get();
if(r.second)
break;
trackbuf.push_back(r.first);
}
return trackbuf;
}