Merge pull request #103 from davidgiven/visualiser

Add a simple disk visualiser.

doc/using.md

@@ -225,6 +225,21 @@ Commands which normally take `--source` or `--dest` get a sensible default if
 left unspecified. `fluxengine read ibm` on its own will read drive 0 and
 write an `ibm.img` file.
 
+## Visualisation
+
+When doing a read (either from a real disk or from a flux file) you can use
+`--write-svg=output.svg` to write out a graphical visualisation of where the
+sectors are on the disk. Here's a IBM PC 1232kB disk:
+
+![A disk visualisation](./visualiser.svg)
+
+Blue represents data, light blue a header, and red is a bad sector. Side zero
+is on the left and side one is on the right.
+
+The visualiser is extremely primitive and you have to explicitly tell it how
+big your disk is, in milliseconds. The default is 200ms (for a normal 3.5"
+disk). For a 5.25" disk, use `--visualiser-period=166`.
+
 ## Extra programs
 
 Supplied with FluxEngine, but not part of FluxEngine, are some little tools I

lib/decoders/decoders.cc

@@ -43,19 +43,25 @@ void AbstractDecoder::decodeToSectors(Track& track)
 
         recordStart = fmr.tell();
         decodeSectorRecord();
-        pushRecord(recordStart, fmr.tell());
+        Fluxmap::Position recordEnd = fmr.tell();
+        pushRecord(recordStart, recordEnd);
         if (sector.status == Sector::DATA_MISSING)
         {
             /* The data is in a separate record. */
 
+            sector.headerStartTime = recordStart.ns();
+            sector.headerEndTime = recordEnd.ns();
             r = advanceToNextRecord();
             if (r == DATA_RECORD)
             {
                 recordStart = fmr.tell();
                 decodeDataRecord();
-                pushRecord(recordStart, fmr.tell());
+                recordEnd = fmr.tell();
+                pushRecord(recordStart, recordEnd);
             }
         }
+        sector.dataStartTime = recordStart.ns();
+        sector.dataEndTime = recordEnd.ns();
 
         if (sector.status != Sector::MISSING)
             track.sectors.push_back(sector);

lib/reader.cc

@@ -9,6 +9,7 @@
 #include "decoders/decoders.h"
 #include "sector.h"
 #include "sectorset.h"
+#include "visualiser.h"
 #include "record.h"
 #include "image.h"
 #include "bytes.h"
@@ -17,7 +18,7 @@
 #include "imagewriter/imagewriter.h"
 #include "fmt/format.h"
 
-FlagGroup readerFlags { &hardwareFluxSourceFlags, &fluxmapReaderFlags };
+FlagGroup readerFlags { &hardwareFluxSourceFlags, &fluxmapReaderFlags, &visualiserFlags };
 
 static DataSpecFlag source(
     { "--source", "-s" },
@@ -34,6 +35,11 @@ static StringFlag destination(
     "write the raw magnetic flux to this file",
     "");
 
+static StringFlag visualise(
+	{ "--write-svg" },
+	"write a visualisation of the disk to this file",
+	"");
+
 static SettableFlag justRead(
 	{ "--just-read" },
 	"just read the disk and do no further processing");
@@ -143,7 +149,7 @@ static void replace_sector(std::unique_ptr<Sector>& replacing, Sector& replaceme
 			return;
 		}
 	}
-	if (!replacing || (replacing->status != Sector::OK))
+	if (!replacing || ((replacing->status != Sector::OK) && (replacement.status == Sector::OK)))
 	{
 		if (!replacing)
 			replacing.reset(new Sector);
@@ -253,6 +259,9 @@ void readDiskCommand(AbstractDecoder& decoder)
         std::cout << size << " bytes decoded." << std::endl;
     }
 
+	if (!visualise.get().empty())
+		visualiseSectorsToFile(allSectors, visualise.get());
+
     writeSectorsToFile(allSectors, outputSpec);
 	if (failures)
 		std::cerr << "Warning: some sectors could not be decoded." << std::endl;

lib/sector.h

@@ -27,6 +27,10 @@ class Sector
 	Status status = Status::INTERNAL_ERROR;
     Fluxmap::Position position;
     nanoseconds_t clock = 0;
+    nanoseconds_t headerStartTime = 0;
+    nanoseconds_t headerEndTime = 0;
+    nanoseconds_t dataStartTime = 0;
+    nanoseconds_t dataEndTime = 0;
     int physicalTrack = 0;
     int physicalSide = 0;
     int logicalTrack = 0;

lib/sectorset.h

@@ -17,6 +17,9 @@ class SectorSet
 	std::unique_ptr<Sector>& get(int track, int head, int sector);
 	Sector* get(int track, int head, int sector) const;
 
+	const std::map<const key_t, std::unique_ptr<Sector>>& get() const
+	{ return _data; }
+
 	void calculateSize(
 		unsigned& numTracks, unsigned& numHeads, unsigned& numSectors,
 		unsigned& sectorSize) const;

lib/visualiser.cc

@@ -0,0 +1,95 @@
+#define _USE_MATH_DEFINES
+#include "globals.h"
+#include "image.h"
+#include "sector.h"
+#include "sectorset.h"
+#include "visualiser.h"
+#include "fmt/format.h"
+#include "flags.h"
+#include <iostream>
+#include <fstream>
+#include <math.h>
+
+FlagGroup visualiserFlags;
+
+static IntFlag period(
+    { "--visualiser-period" },
+    "rotational period for use by the visualiser (milliseconds)",
+    200);
+
+static const int SIZE = 480;
+static const int BORDER = 10;
+static const int RADIUS = (SIZE/2) - (BORDER/2);
+static const int CORE = 50;
+static const int TRACKS = 83;
+static const double TRACK_SPACING = double(RADIUS-CORE) / TRACKS;
+
+void visualiseSectorsToFile(const SectorSet& sectors, const std::string& filename)
+{
+    std::cout << "writing visualisation\n";
+    std::ofstream f(filename, std::ios::out);
+    if (!f.is_open())
+        Error() << "cannot open visualisation file";
+
+    f << fmt::format("<svg xmlns=\"http://www.w3.org/2000/svg\" viewBox=\"{0} {1} {2} {3}\">",
+        0, 0, SIZE*2, SIZE);
+
+    const double radians_per_ns = 2.0*M_PI / (period*1e6);
+
+    auto drawSide = [&](int side)
+    {
+        f << fmt::format("<g transform='matrix(1 0 0 -1 {} {})'>", SIZE/2 + (side*SIZE), SIZE/2);
+        f << fmt::format("<circle cx='0' cy='0' r='{}' stroke='none' fill='#ccc'/>", RADIUS);
+
+        for (int physicalTrack = 0; physicalTrack < TRACKS; physicalTrack++)
+        {
+            double radius = CORE + physicalTrack*TRACK_SPACING;
+            f << fmt::format("<circle cx='0' cy='0' r='{}' stroke='#888' stroke-width='0.5' fill='none'/>", radius);
+
+            auto drawArc = [&](const std::unique_ptr<Sector>& sector, nanoseconds_t start, nanoseconds_t end, const std::string& colour)
+            {
+                start %= period*1000000;
+                end %= period*1000000;
+                if (end < start)
+                    end += period*1000000;
+
+                double theta1 = start * radians_per_ns;
+                double theta2 = end * radians_per_ns;
+                int large = (theta2 - theta1) >= M_PI;
+
+                f << fmt::format("\n<!-- {} {} = {} {} -->", start, end, theta1, theta2);
+                f << fmt::format("<path fill='none' stroke='{}' stroke-width='1.5' d='", colour);
+                f << fmt::format("M {} {} ", cos(theta1)*radius, sin(theta1)*radius);
+                f << fmt::format("A {0} {0} 0 {3} 1 {1} {2}", radius, cos(theta2)*radius, sin(theta2)*radius, large);
+                f << fmt::format("'><title>Track {} Head {} Sector {}; {}ms to {}ms</title></path>",
+                    sector->logicalTrack, sector->logicalSide, sector->logicalSector,
+                    start/1e6, end/1e6);
+            };
+
+            /* Sadly, SectorSets aren't indexable by physical track. */
+            for (const auto& e : sectors.get())
+            {
+                const auto& sector = e.second;
+                if ((sector->physicalSide == side) && (sector->physicalTrack == physicalTrack))
+                {
+                    const char* colour = "#f00";
+                    if (sector->status == Sector::OK)
+                        colour = "#00f";
+                    if (sector->headerStartTime && sector->headerEndTime)
+                        drawArc(sector, sector->headerStartTime, sector->headerEndTime, "#0ff");
+                    if (sector->dataStartTime && sector->dataEndTime)
+                        drawArc(sector, sector->dataStartTime, sector->dataEndTime, colour);
+                }
+            }
+        }
+
+        f << "</g>";
+    };
+
+    f << fmt::format("<rect x='0' y='0' width='{}' height='{}' stroke='none' fill='#fff'/>", SIZE*2, SIZE);
+
+    drawSide(0);
+    drawSide(1);
+
+    f << "</svg>";
+}

lib/visualiser.h

@@ -0,0 +1,12 @@
+#ifndef VISUALISER_H
+#define VISUALISER_H
+
+#include "flags.h"
+
+class SectorSet;
+
+extern FlagGroup visualiserFlags;
+
+extern void visualiseSectorsToFile(const SectorSet& sectors, const std::string& filename);
+
+#endif

mkninja.sh

@@ -183,6 +183,7 @@ buildlibrary libbackend.a \
     lib/sectorset.cc \
     lib/sql.cc \
     lib/usb.cc \
+    lib/visualiser.cc \
     lib/writer.cc \
 
 buildlibrary libfrontend.a \