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Adds fuzzy but marking through the GetTrackWithSectors interface.

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This commit is contained in:
Thomas Harte 2020-01-19 21:41:10 -05:00
parent b0f7b762af
commit 357137918d
1 changed files with 29 additions and 5 deletions
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34
Storage/Disk/Encodings/MFM/Encoder.cpp
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@ -186,6 +186,7 @@ template<class T> std::shared_ptr<Storage::Disk::Track>
total_sector_bytes += size_t(128 << sector->size) + 2;
}
// Seek appropriate gap sizes, if the defaults don't allow all data to fit.
while(true) {
const size_t size =
mark_size +
@ -234,7 +235,6 @@ template<class T> std::shared_ptr<Storage::Disk::Track>
for(std::size_t c = 0; c < pre_data_mark_bytes; c++) shifter.add_byte(0x00);
// Data, if attached.
// TODO: allow for weak/fuzzy data.
if(!sector->samples.empty()) {
if(sector->is_deleted)
shifter.add_deleted_data_address_mark();
@ -243,8 +243,30 @@ template<class T> std::shared_ptr<Storage::Disk::Track>
std::size_t c = 0;
std::size_t declared_length = static_cast<std::size_t>(128 << sector->size);
for(c = 0; c < sector->samples[0].size() && c < declared_length; c++) {
shifter.add_byte(sector->samples[0][c]);
if(sector->samples.size() > 1) {
// For each byte, mark as fuzzy any bits that differ. Which isn't exactly the
// same thing as obeying the multiple samples, as it discards the implied
// probabilities of different values.
for(c = 0; c < sector->samples[0].size() && c < declared_length; c++) {
auto sample_iterator = sector->samples.begin();
uint8_t value = (*sample_iterator)[c], fuzzy_mask = 0;
++sample_iterator;
while(sample_iterator != sector->samples.end()) {
// Mark as fuzzy any bits that differ here from the
// canonical value, and zero them out in the original.
// That might cause them to retrigger, but who cares?
fuzzy_mask |= value ^ (*sample_iterator)[c];
value &= ~fuzzy_mask;
++sample_iterator;
}
shifter.add_byte(sector->samples[0][c], fuzzy_mask);
}
} else {
for(c = 0; c < sector->samples[0].size() && c < declared_length; c++) {
shifter.add_byte(sector->samples[0][c]);
}
}
for(; c < declared_length; c++) {
shifter.add_byte(0x00);
@ -278,8 +300,10 @@ void Encoder::output_short(uint16_t value, uint16_t fuzzy_mask) {
if(write_fuzzy_bits) {
assert(fuzzy_target_);
// Zero-fill the bits to date, to cover any shorts written without fuzzy bits.
// Zero-fill the bits to date, to cover any shorts written without fuzzy bits,
// and make sure the value has a 0 anywhere it should be fuzzy.
fuzzy_target_->resize(target_->size());
value &= ~fuzzy_mask;
}
uint16_t mask = 0x8000;
@ -291,7 +315,7 @@ void Encoder::output_short(uint16_t value, uint16_t fuzzy_mask) {
}
void Encoder::add_crc(bool incorrectly) {
uint16_t crc_value = crc_generator_.get_value();
const uint16_t crc_value = crc_generator_.get_value();
add_byte(crc_value >> 8);
add_byte((crc_value & 0xff) ^ (incorrectly ? 1 : 0));
}