From d581294479b842bd0d074785adf39dc0f327140f Mon Sep 17 00:00:00 2001
From: Thomas Harte <thomas.harte@gmail.com>
Date: Fri, 30 Dec 2016 19:59:23 -0500
Subject: [PATCH] Added `get_track` to get the PLL output for a complete track.

---
 Storage/Disk/Encodings/MFM.cpp | 43 +++++++++++++++++++++++++++++++++-
 Storage/Disk/Encodings/MFM.hpp | 12 ++++++++++
 2 files changed, 54 insertions(+), 1 deletion(-)

diff --git a/Storage/Disk/Encodings/MFM.cpp b/Storage/Disk/Encodings/MFM.cpp
index d1740baeb..f7b0de008 100644
--- a/Storage/Disk/Encodings/MFM.cpp
+++ b/Storage/Disk/Encodings/MFM.cpp
@@ -267,7 +267,7 @@ Parser::Parser(bool is_mfm, const std::shared_ptr<Storage::Disk::Track> &track)
 	drive->set_disk_with_track(track);
 }
 
-std::shared_ptr<Storage::Encodings::MFM::Sector> Parser::get_sector(uint8_t track, uint8_t sector)
+void Parser::seek_to_track(uint8_t track)
 {
 	int difference = (int)track - (int)track_;
 	track_ = track;
@@ -279,10 +279,20 @@ std::shared_ptr<Storage::Encodings::MFM::Sector> Parser::get_sector(uint8_t trac
 
 		for(int c = 0; c < difference; c++) step(direction);
 	}
+}
 
+std::shared_ptr<Storage::Encodings::MFM::Sector> Parser::get_sector(uint8_t track, uint8_t sector)
+{
+	seek_to_track(track);
 	return get_sector(sector);
 }
 
+std::vector<uint8_t> Parser::get_track(uint8_t track, size_t &number_of_bits)
+{
+	seek_to_track(track);
+	return get_track(number_of_bits);
+}
+
 void Parser::process_input_bit(int value, unsigned int cycles_since_index_hole)
 {
 	shift_register_ = ((shift_register_ << 1) | (unsigned int)value) & 0xffff;
@@ -311,6 +321,37 @@ uint8_t Parser::get_next_byte()
 	return byte;
 }
 
+std::vector<uint8_t> Parser::get_track(size_t &number_of_bits)
+{
+	std::vector<uint8_t> result;
+	number_of_bits = 0;
+
+	// align to the first index hole
+	index_count_ = 0;
+	while(!index_count_) run_for_cycles(1);
+
+	// capture every bit until the next index hole
+	index_count_ = 0;
+	while(1)
+	{
+		// wait until either another bit or the index hole arrives
+		bit_count_ = 0;
+		while(!bit_count_ && !index_count_) TimedEventLoop::run_for_cycles(1);
+
+		// if that was the index hole then finish
+		if(index_count_) break;
+
+		// otherwise, add another bit to the collection
+		int bit = number_of_bits & 7;
+		if(!bit) result.push_back(0);
+		result[number_of_bits >> 3] |= (shift_register_&1) << (7 - bit);
+		number_of_bits++;
+	}
+
+	return result;
+}
+
+
 std::shared_ptr<Storage::Encodings::MFM::Sector> Parser::get_next_sector()
 {
 	std::shared_ptr<Storage::Encodings::MFM::Sector> sector(new Storage::Encodings::MFM::Sector);
diff --git a/Storage/Disk/Encodings/MFM.hpp b/Storage/Disk/Encodings/MFM.hpp
index f1545407d..0f0240566 100644
--- a/Storage/Disk/Encodings/MFM.hpp
+++ b/Storage/Disk/Encodings/MFM.hpp
@@ -73,6 +73,15 @@ class Parser: public Storage::Disk::Controller {
 		*/
 		std::shared_ptr<Storage::Encodings::MFM::Sector> get_sector(uint8_t track, uint8_t sector);
 
+		/*!
+			Attempts to read the track at @c track, starting from the index hole.
+
+			All PLL-recognised bits are returned, filling their respective bytes from MSB to LSB.
+			
+			@returns a vector of data found. Also sets @c number_of_bits to the bit count.
+		*/
+		std::vector<uint8_t> get_track(uint8_t track, size_t &number_of_bits);
+
 	private:
 		Parser(bool is_mfm);
 
@@ -84,11 +93,14 @@ class Parser: public Storage::Disk::Controller {
 		NumberTheory::CRC16 crc_generator_;
 		bool is_mfm_;
 
+		void seek_to_track(uint8_t track);
 		void process_input_bit(int value, unsigned int cycles_since_index_hole);
 		void process_index_hole();
 		uint8_t get_next_byte();
+
 		std::shared_ptr<Storage::Encodings::MFM::Sector> get_next_sector();
 		std::shared_ptr<Storage::Encodings::MFM::Sector> get_sector(uint8_t sector);
+		std::vector<uint8_t> get_track(size_t &number_of_bits);
 };