Relocates and cleans up what is currently written of Apple GCR handling as the encoder.

A decoder will be forthcoming.

Storage/Disk/DiskImage/Formats/AppleDSK.cpp

@@ -9,7 +9,7 @@
 #include "AppleDSK.hpp"
 
 #include "../../Track/PCMTrack.hpp"
-#include "../../Encodings/AppleGCR.hpp"
+#include "../../Encodings/AppleGCR/Encoder.hpp"
 
 using namespace Storage::Disk;
 

Storage/Disk/DiskImage/Formats/NIB.cpp

@@ -9,7 +9,7 @@
 #include "NIB.hpp"
 
 #include "../../Track/PCMTrack.hpp"
-#include "../../Encodings/AppleGCR.hpp"
+#include "../../Encodings/AppleGCR/Encoder.hpp"
 
 #include <vector>
 

Storage/Disk/Encodings/AppleGCR.hpp

@@ -1,73 +0,0 @@
-//
-//  AppleGCR.hpp
-//  Clock Signal
-//
-//  Created by Thomas Harte on 21/04/2018.
-//  Copyright © 2018 Thomas Harte. All rights reserved.
-//
-
-#ifndef AppleGCR_hpp
-#define AppleGCR_hpp
-
-#include <cstdint>
-#include "../../Disk/Track/PCMSegment.hpp"
-
-namespace Storage {
-namespace Encodings {
-
-namespace AppleGCR {
-
-	/*!
-		@returns the eight-bit 13-sector GCR encoding for the low five bits of @c value.
-	*/
-//	unsigned int five_and_three_encoding_for_value(int value);
-
-	/*!
-		@returns the eight-bit 16-sector GCR encoding for the low six bits of @c value.
-	*/
-//	unsigned int six_and_two_encoding_for_value(int value);
-
-	/*!
-		A block is defined to be five source bytes, which encodes to eight GCR bytes.
-	*/
-//	void encode_five_and_three_block(uint8_t *destination, uint8_t *source);
-
-	/*!
-		A block is defined to be three source bytes, which encodes to four GCR bytes.
-	*/
-//	void encode_six_and_two_block(uint8_t *destination, uint8_t *source);
-
-	/*!
-		@returns the four bit nibble for the five-bit GCR @c quintet if a valid GCR value; INT_MAX otherwise.
-	*/
-//	unsigned int decoding_from_quintet(unsigned int quintet);
-
-	/*!
-		@returns the byte composed by splitting the dectet into two qintets, decoding each and composing the resulting nibbles.
-	*/
-//	unsigned int decoding_from_dectet(unsigned int dectet);
-
-	/// Describes the standard three-byte prologue that begins a header.
-	const uint8_t header_prologue[3] = {0xd5, 0xaa, 0x96};
-	/// Describes the standard three-byte prologue that begins a data section.
-	const uint8_t data_prologue[3] = {0xd5, 0xaa, 0xad};
-	/// Describes the epilogue that ends both data sections and headers.
-	const uint8_t epilogue[3] = {0xde, 0xaa, 0xeb};
-
-	/*!
-		Produces the Apple-standard '4 and 4' per-sector header. This is the same
-		for both the 13- and 16-sector formats, and is 112 bits long.
-	*/
-	Storage::Disk::PCMSegment header(uint8_t volume, uint8_t track, uint8_t sector);
-
-	Storage::Disk::PCMSegment six_and_two_data(const uint8_t *source);
-	Storage::Disk::PCMSegment six_and_two_sync(int length);
-
-	Storage::Disk::PCMSegment five_and_three_data(const uint8_t *source);
-	Storage::Disk::PCMSegment five_and_three_sync(int length);
-}
-
-}
-}
-
-#endif /* AppleGCR_hpp */

Storage/Disk/Encodings/AppleGCR/Encoder.cpp

@@ -6,11 +6,11 @@
 //  Copyright © 2018 Thomas Harte. All rights reserved.
 //
 
-#include "AppleGCR.hpp"
+#include "Encoder.hpp"
 
 namespace {
 
-const unsigned int five_and_three_mapping[] = {
+const uint8_t five_and_three_mapping[] = {
 	0xab, 0xad, 0xae, 0xaf, 0xb5, 0xb6, 0xb7, 0xba,
 	0xbb, 0xbd, 0xbe, 0xbf, 0xd6, 0xd7, 0xda, 0xdb,
 	0xdd, 0xde, 0xdf, 0xea, 0xeb, 0xed, 0xee, 0xef,
@@ -53,26 +53,6 @@ Storage::Disk::PCMSegment sync(int length, int bit_size) {
 
 using namespace Storage::Encodings;
 
-
-/*void AppleGCR::encode_five_and_three_block(uint8_t *destination, uint8_t *source) {
-	destination[0] = static_cast<uint8_t>(five_and_three_encoding_for_value( source[0] >> 3 ));
-	destination[1] = static_cast<uint8_t>(five_and_three_encoding_for_value( (source[0] << 2) | (source[1] >> 6) ));
-	destination[2] = static_cast<uint8_t>(five_and_three_encoding_for_value( source[1] >> 1 ));
-	destination[3] = static_cast<uint8_t>(five_and_three_encoding_for_value( (source[1] << 4) | (source[2] >> 4) ));
-	destination[4] = static_cast<uint8_t>(five_and_three_encoding_for_value( (source[2] << 1) | (source[3] >> 7) ));
-	destination[5] = static_cast<uint8_t>(five_and_three_encoding_for_value( source[3] >> 2 ));
-	destination[6] = static_cast<uint8_t>(five_and_three_encoding_for_value( (source[3] << 3) | (source[4] >> 5) ));
-	destination[7] = static_cast<uint8_t>(five_and_three_encoding_for_value( source[4] ));
-}*/
-
-
-/*void AppleGCR::encode_six_and_two_block(uint8_t *destination, uint8_t *source) {
-	destination[0] = static_cast<uint8_t>(six_and_two_encoding_for_value( source[0] >> 2 ));
-	destination[1] = static_cast<uint8_t>(six_and_two_encoding_for_value( (source[0] << 4) | (source[1] >> 4) ));
-	destination[2] = static_cast<uint8_t>(six_and_two_encoding_for_value( (source[1] << 2) | (source[2] >> 6) ));
-	destination[3] = static_cast<uint8_t>(six_and_two_encoding_for_value( source[2] ));
-}*/
-
 Storage::Disk::PCMSegment AppleGCR::six_and_two_sync(int length) {
 	return sync(length, 10);
 }
@@ -132,6 +112,11 @@ Storage::Disk::PCMSegment AppleGCR::five_and_three_data(const uint8_t *source) {
 //		destination_pointer += 8;
 //	}
 
+	// Map five-bit values up to full bytes.
+	for(std::size_t c = 0; c < 410; ++c) {
+		segment.data[3 + c] = five_and_three_mapping[segment.data[3 + c]];
+	}
+
 	return segment;
 }
 

Storage/Disk/Encodings/AppleGCR/Encoder.hpp

@@ -0,0 +1,60 @@
+//
+//  AppleGCR.hpp
+//  Clock Signal
+//
+//  Created by Thomas Harte on 21/04/2018.
+//  Copyright © 2018 Thomas Harte. All rights reserved.
+//
+
+#ifndef AppleGCR_hpp
+#define AppleGCR_hpp
+
+#include <cstdint>
+#include "../../../Disk/Track/PCMSegment.hpp"
+
+namespace Storage {
+namespace Encodings {
+namespace AppleGCR {
+
+/// Describes the standard three-byte prologue that begins a header.
+const uint8_t header_prologue[3] = {0xd5, 0xaa, 0x96};
+/// Describes the standard three-byte prologue that begins a data section.
+const uint8_t data_prologue[3] = {0xd5, 0xaa, 0xad};
+/// Describes the epilogue that ends both data sections and headers.
+const uint8_t epilogue[3] = {0xde, 0xaa, 0xeb};
+
+/*!
+	Produces the Apple-standard four-and-four per-sector header. This is the same
+	for both the 13- and 16-sector formats, and is 112 bits long.
+*/
+Storage::Disk::PCMSegment header(uint8_t volume, uint8_t track, uint8_t sector);
+
+/*!
+	Produces the data section of a six-and-two format sector; the segment returned
+	will be 2,792 bits long, encoding the first 256 bytes from @c source.
+*/
+Storage::Disk::PCMSegment six_and_two_data(const uint8_t *source);
+
+/*!
+	Produces @c length sync six-and-two format sync bytes. The segment returned
+	is @c 10*length bits long.
+*/
+Storage::Disk::PCMSegment six_and_two_sync(int length);
+
+/*!
+	Produces the data section of a five-and-three format sector; the segment returned
+	will be 3,336 bits long, encoding the first 256 bytes from @c source.
+*/
+Storage::Disk::PCMSegment five_and_three_data(const uint8_t *source);
+
+/*!
+	Produces @c length sync five-and-three format sync bytes. The segment returned
+	is @c 9*length bits long.
+*/
+Storage::Disk::PCMSegment five_and_three_sync(int length);
+
+}
+}
+}
+
+#endif /* AppleGCR_hpp */