From ca10026adebdb4e74364e8d503f6dd484d2abf3a Mon Sep 17 00:00:00 2001
From: Stephen White <pi1541contact@gmail.com>
Date: Sun, 17 Nov 2019 14:54:30 +1100
Subject: [PATCH] Added option DisplayTracks

Displays a rough layout of data for a disk image on the Pi's HDMI screen.
---
 src/FileBrowser.cpp | 49 +++++++++++++++++++++++++++++++++++++++++++++
 src/options.cpp     |  2 ++
 src/options.h       |  2 ++
 3 files changed, 53 insertions(+)

diff --git a/src/FileBrowser.cpp b/src/FileBrowser.cpp
index ff841e9..5b2ff78 100644
--- a/src/FileBrowser.cpp
+++ b/src/FileBrowser.cpp
@@ -1473,6 +1473,55 @@ void FileBrowser::DisplayDiskInfo(DiskImage* diskImage, const char* filenameForI
 
 	ClearScreen();
 
+	if (options.DisplayTracks())
+	{
+		for (track = 0; track < HALF_TRACK_COUNT; track += 2)
+		{
+			int yoffset = screenMain->ScaleY(400);
+			unsigned index;
+			unsigned length = diskImage->TrackLength(track);
+			unsigned countSync = 0;
+
+			u8 shiftReg = 0;
+			for (index = 0; index < length / 8; ++index)
+			{
+				RGBA colour;
+				unsigned count1s = 0;
+				bool sync = false;
+
+				int bit;
+
+				for (bit = 0; bit < 64; ++bit)
+				{
+					if (bit % 8 == 0)
+						shiftReg = diskImage->GetNextByte(track, index * 8 + bit / 8);
+
+					if (shiftReg & 0x80)
+					{
+						count1s++;
+						countSync++;
+						if (countSync == 10)
+							sync = true;
+					}
+					else
+					{
+						countSync = 0;
+					}
+					shiftReg <<= 1;
+				}
+
+				if (sync)
+					colour = RGBA(0xff, 0x00, 0x00, 0xFF);
+				else
+					colour = RGBA(0x00, (unsigned char)((float)count1s / 64.0f * 255.0f), 0x00, 0xFF);
+
+				screenMain->DrawRectangle(index, (track >> 1) * 4 + yoffset, index + 1, (track >> 1) * 4 + 4 + yoffset, colour);
+			}
+		}
+	}
+
+	track = 18;
+
 	if (diskImage->GetDecodedSector(track, sectorNo, buffer))
 	{
 		track = buffer[0];
diff --git a/src/options.cpp b/src/options.cpp
index 18ebba9..1e7ad3b 100644
--- a/src/options.cpp
+++ b/src/options.cpp
@@ -128,6 +128,7 @@ Options::Options(void)
 	, disableSD2IECCommands(0)
 	, supportUARTInput(0)
 	, graphIEC(0)
+	, displayTracks(0)
 	, quickBoot(0)
 	, showOptions(0)
 	, displayPNGIcons(0)
@@ -218,6 +219,7 @@ void Options::Process(char* buffer)
 		ELSE_CHECK_DECIMAL_OPTION(disableSD2IECCommands)
 		ELSE_CHECK_DECIMAL_OPTION(supportUARTInput)
 		ELSE_CHECK_DECIMAL_OPTION(graphIEC)
+		ELSE_CHECK_DECIMAL_OPTION(displayTracks)
 		ELSE_CHECK_DECIMAL_OPTION(quickBoot)
 		ELSE_CHECK_DECIMAL_OPTION(showOptions)
 		ELSE_CHECK_DECIMAL_OPTION(displayPNGIcons)
diff --git a/src/options.h b/src/options.h
index c3c8249..374dda0 100644
--- a/src/options.h
+++ b/src/options.h
@@ -60,6 +60,7 @@ public:
 	inline unsigned int GetSupportUARTInput() const { return supportUARTInput; }
 
 	inline unsigned int GraphIEC() const { return graphIEC; }
+	inline unsigned int DisplayTracks() const { return displayTracks; }
 	inline unsigned int QuickBoot() const { return quickBoot; }
 	inline unsigned int ShowOptions() const { return showOptions; }
 	inline unsigned int DisplayPNGIcons() const { return displayPNGIcons; }
@@ -128,6 +129,7 @@ private:
 	unsigned int disableSD2IECCommands;
 	unsigned int supportUARTInput;
 	unsigned int graphIEC;
+	unsigned int displayTracks;
 	unsigned int quickBoot;
 	unsigned int showOptions;
 	unsigned int displayPNGIcons;