Addition of PositionCache module which adds cacing of string

to position information and segments long pieces of text so they
can be handled more efficiently.

16 files changed, 1021 insertions, 568 deletions

diff --git a/gtk/ScintillaGTK.cxx b/gtk/ScintillaGTK.cxx
index 71c7b342f..7a1aab337 100644
--- a/gtk/ScintillaGTK.cxx
+++ b/gtk/ScintillaGTK.cxx
@@ -43,6 +43,7 @@
 #include "Decoration.h"
 #include "CharClassify.h"
 #include "Document.h"
+#include "PositionCache.h"
 #include "Editor.h"
 #include "SString.h"
 #include "ScintillaBase.h"
diff --git a/gtk/deps.mak b/gtk/deps.mak
index f8fa285fd..8fe88e266 100644
--- a/gtk/deps.mak
+++ b/gtk/deps.mak
@@ -1,9 +1,7 @@
-PlatGTK.o: PlatGTK.cxx  \
-   ../include/Platform.h \
+PlatGTK.o: PlatGTK.cxx \
   ../include/Scintilla.h ../include/ScintillaWidget.h \
   ../src/UniConversion.h ../src/XPM.h Converter.h
-ScintillaGTK.o: ScintillaGTK.cxx  \
-   ../include/Platform.h \
+ScintillaGTK.o: ScintillaGTK.cxx \
   ../include/Scintilla.h ../include/ScintillaWidget.h \
   ../include/SciLexer.h ../include/PropSet.h ../include/SString.h \
   ../include/Accessor.h ../include/KeyWords.h ../src/ContractionState.h \
@@ -11,9 +9,10 @@ ScintillaGTK.o: ScintillaGTK.cxx  \
   ../src/CellBuffer.h ../src/CallTip.h ../src/KeyMap.h ../src/Indicator.h \
   ../src/XPM.h ../src/LineMarker.h ../src/Style.h ../src/AutoComplete.h \
   ../src/ViewStyle.h ../src/RunStyles.h ../src/Decoration.h \
-  ../src/CharClassify.h ../src/Document.h ../src/Editor.h \
-  ../include/SString.h ../src/ScintillaBase.h ../src/UniConversion.h \
-  scintilla-marshal.h ../src/ExternalLexer.h Converter.h
+  ../src/CharClassify.h ../src/Document.h ../src/PositionCache.h \
+  ../src/Editor.h ../include/SString.h ../src/ScintillaBase.h \
+  ../src/UniConversion.h scintilla-marshal.h ../src/ExternalLexer.h \
+  Converter.h
 AutoComplete.o: ../src/AutoComplete.cxx ../include/Platform.h \
   ../include/PropSet.h ../include/SString.h ../src/AutoComplete.h
 CallTip.o: ../src/CallTip.cxx ../include/Platform.h \
@@ -43,7 +42,8 @@ Editor.o: ../src/Editor.cxx ../include/Platform.h ../include/Scintilla.h \
   ../src/Partitioning.h ../src/CellBuffer.h ../src/KeyMap.h \
   ../src/RunStyles.h ../src/Indicator.h ../src/XPM.h ../src/LineMarker.h \
   ../src/Style.h ../src/ViewStyle.h ../src/CharClassify.h \
-  ../src/Decoration.h ../src/Document.h ../src/Editor.h
+  ../src/Decoration.h ../src/Document.h ../src/PositionCache.h \
+  ../src/Editor.h
 ExternalLexer.o: ../src/ExternalLexer.cxx ../include/Platform.h \
   ../include/Scintilla.h ../include/SciLexer.h ../include/PropSet.h \
   ../include/SString.h ../include/Accessor.h ../src/DocumentAccessor.h \
@@ -137,6 +137,9 @@ LexFortran.o: ../src/LexFortran.cxx ../include/Platform.h \
   ../include/PropSet.h ../include/SString.h ../include/Accessor.h \
   ../src/StyleContext.h ../include/KeyWords.h ../include/Scintilla.h \
   ../include/SciLexer.h
+LexGAP.o: ../src/LexGAP.cxx ../include/Platform.h ../include/PropSet.h \
+  ../include/SString.h ../include/Accessor.h ../src/StyleContext.h \
+  ../include/KeyWords.h ../include/Scintilla.h ../include/SciLexer.h
 LexGui4Cli.o: ../src/LexGui4Cli.cxx ../include/Platform.h \
   ../include/PropSet.h ../include/SString.h ../include/Accessor.h \
   ../src/StyleContext.h ../include/KeyWords.h ../include/Scintilla.h \
@@ -260,6 +263,13 @@ LexYAML.o: ../src/LexYAML.cxx ../include/Platform.h ../include/PropSet.h \
   ../include/KeyWords.h ../include/Scintilla.h ../include/SciLexer.h
 LineMarker.o: ../src/LineMarker.cxx ../include/Platform.h \
   ../include/Scintilla.h ../src/XPM.h ../src/LineMarker.h
+PositionCache.o: ../src/PositionCache.cxx ../include/Platform.h \
+  ../include/Scintilla.h ../src/ContractionState.h ../src/SVector.h \
+  ../src/SplitVector.h ../src/Partitioning.h ../src/CellBuffer.h \
+  ../src/KeyMap.h ../src/RunStyles.h ../src/Indicator.h ../src/XPM.h \
+  ../src/LineMarker.h ../src/Style.h ../src/ViewStyle.h \
+  ../src/CharClassify.h ../src/Decoration.h ../src/Document.h \
+  ../src/PositionCache.h
 PropSet.o: ../src/PropSet.cxx ../include/Platform.h ../include/PropSet.h \
   ../include/SString.h
 RESearch.o: ../src/RESearch.cxx ../src/CharClassify.h ../src/RESearch.h
@@ -274,7 +284,8 @@ ScintillaBase.o: ../src/ScintillaBase.cxx ../include/Platform.h \
   ../src/CellBuffer.h ../src/CallTip.h ../src/KeyMap.h ../src/Indicator.h \
   ../src/XPM.h ../src/LineMarker.h ../src/Style.h ../src/ViewStyle.h \
   ../src/AutoComplete.h ../src/CharClassify.h ../src/Decoration.h \
-  ../src/Document.h ../src/Editor.h ../src/ScintillaBase.h
+  ../src/Document.h ../src/PositionCache.h ../src/Editor.h \
+  ../src/ScintillaBase.h
 StyleContext.o: ../src/StyleContext.cxx ../include/Platform.h \
   ../include/PropSet.h ../include/SString.h ../include/Accessor.h \
   ../src/StyleContext.h
diff --git a/gtk/makefile b/gtk/makefile
index eb7dec885..52a88f4e7 100644
--- a/gtk/makefile
+++ b/gtk/makefile
@@ -80,12 +80,12 @@ clean:
 	rm -f *.o $(COMPLIB)
 
 deps:
-	$(CC) -MM $(CONFIGFLAGS) $(CXXFLAGS) *.cxx ../src/*.cxx >deps.mak
+	$(CC) -MM $(CONFIGFLAGS) $(CXXFLAGS) *.cxx ../src/*.cxx | sed -e 's/\/usr.* //' | grep [a-zA-Z] >deps.mak
 
 $(COMPLIB): DocumentAccessor.o WindowAccessor.o KeyWords.o StyleContext.o \
 	CharClassify.o Decoration.o Document.o CallTip.o \
 	ScintillaBase.o ContractionState.o Editor.o ExternalLexer.o PropSet.o PlatGTK.o \
-	KeyMap.o LineMarker.o ScintillaGTK.o CellBuffer.o ViewStyle.o \
+	KeyMap.o LineMarker.o PositionCache.o ScintillaGTK.o CellBuffer.o ViewStyle.o \
 	RESearch.o RunStyles.o Style.o Indicator.o AutoComplete.o UniConversion.o XPM.o \
 	$(MARSHALLER) $(LEXOBJS)
 	$(AR) rc $@ $^
diff --git a/gtk/scintilla.mak b/gtk/scintilla.mak
index deb3df2ea..1f2dcc798 100644
--- a/gtk/scintilla.mak
+++ b/gtk/scintilla.mak
@@ -128,6 +128,7 @@ SOBJS=\
 	$(DIR_O)\KeyMap.obj \
 	$(DIR_O)\LineMarker.obj \
 	$(DIR_O)\PlatGTK.obj \
+	$(DIR_O)\PositionCache.obj \
 	$(MARSHALLER) \
 	$(DIR_O)\RESearch.obj \
 	$(DIR_O)\RunStyles.obj \
@@ -222,6 +223,7 @@ LOBJS=\
 	$(DIR_O)\KeyWords.obj \
 	$(DIR_O)\LineMarker.obj \
 	$(DIR_O)\PlatGTK.obj \
+	$(DIR_O)\PositionCache.obj \
 	$(MARSHALLER) \
 	$(DIR_O)\RESearch.obj \
 	$(DIR_O)\RunStyles.obj \
@@ -324,7 +326,7 @@ $(DIR_O)\Editor.obj: ../src/Editor.cxx ../include/Platform.h ../include/Scintill
   ../src/Partitioning.h ../src/CellBuffer.h ../src/KeyMap.h \
   ../src/RunStyles.h ../src/Indicator.h ../src/XPM.h ../src/LineMarker.h \
   ../src/Style.h ../src/ViewStyle.h ../src/CharClassify.h \
-  ../src/Document.h ../src/Editor.h
+  ../src/Document.h ../src/Editor.h ../src/PositionCache.h
 
 $(DIR_O)\ExternalLexer.obj: ../src/ExternalLexer.cxx ../include/Platform.h \
   ../include/Scintilla.h ../include/SciLexer.h ../include/PropSet.h \
@@ -478,6 +480,13 @@ $(DIR_O)\LineMarker.obj: ../src/LineMarker.cxx ../include/Platform.h \
 $(DIR_O)\PlatGTK.obj: PlatGTK.cxx ../include/Platform.h \
   ../src/UniConversion.h ../src/XPM.h
 
+$(DIR_O)\PositionCache.obj: ../src/Editor.cxx ../include/Platform.h ../include/Scintilla.h \
+  ../src/ContractionState.h ../src/SVector.h ../src/SplitVector.h \
+  ../src/Partitioning.h ../src/CellBuffer.h ../src/KeyMap.h \
+  ../src/RunStyles.h ../src/Indicator.h ../src/XPM.h ../src/LineMarker.h \
+  ../src/Style.h ../src/ViewStyle.h ../src/CharClassify.h \
+  ../src/Decoration.h ../src/Document.h ../src/Editor.h ../src/PositionCache.h
+
 $(DIR_O)\PropSet.obj: ../src/PropSet.cxx ../include/Platform.h ../include/PropSet.h \
   ../include/SString.h
 
diff --git a/include/Scintilla.h b/include/Scintilla.h
index 81a7b814d..c50528b72 100644
--- a/include/Scintilla.h
+++ b/include/Scintilla.h
@@ -657,6 +657,8 @@ typedef sptr_t (*SciFnDirect)(sptr_t ptr, unsigned int iMessage, uptr_t wParam,
 #define SCI_INDICATORVALUEAT 2507
 #define SCI_INDICATORSTART 2508
 #define SCI_INDICATOREND 2509
+#define SCI_SETPOSITIONCACHE 2514
+#define SCI_GETPOSITIONCACHE 2515
 #define SCI_STARTRECORD 3001
 #define SCI_STOPRECORD 3002
 #define SCI_SETLEXER 4001
diff --git a/include/Scintilla.iface b/include/Scintilla.iface
index 7d21f41b3..b932a33f6 100644
--- a/include/Scintilla.iface
+++ b/include/Scintilla.iface
@@ -1775,6 +1775,12 @@ fun int IndicatorStart=2508(int indicator, int position)
 # Where does a particular indicator end?
 fun int IndicatorEnd=2509(int indicator, int position)
 
+# Set number of entries in position cache
+set void SetPositionCache=2514(int size,)
+
+# How many entries are allocated to the position cache?
+get int GetPositionCache=2515(,)
+
 # Start notifying the container of all key presses and commands.
 fun void StartRecord=3001(,)
 
diff --git a/src/Editor.cxx b/src/Editor.cxx
index 46684a7fc..6af15a297 100644
--- a/src/Editor.cxx
+++ b/src/Editor.cxx
@@ -32,6 +32,7 @@
 #include "CharClassify.h"
 #include "Decoration.h"
 #include "Document.h"
+#include "PositionCache.h"
 #include "Editor.h"
 
 #ifdef SCI_NAMESPACE
@@ -78,266 +79,9 @@ ticking(false), ticksToWait(0), tickerID(0) {}
 Idler::Idler() :
 state(false), idlerID(0) {}
 
-LineLayout::LineLayout(int maxLineLength_) :
-	lineStarts(0),
-	lenLineStarts(0),
-	lineNumber(-1),
-	inCache(false),
-	maxLineLength(-1),
-	numCharsInLine(0),
-	validity(llInvalid),
-	xHighlightGuide(0),
-	highlightColumn(0),
-	selStart(0),
-	selEnd(0),
-	containsCaret(false),
-	edgeColumn(0),
-	chars(0),
-	styles(0),
-	styleBitsSet(0),
-	indicators(0),
-	positions(0),
-	hsStart(0),
-	hsEnd(0),
-	widthLine(wrapWidthInfinite),
-	lines(1) {
-	Resize(maxLineLength_);
-}
-
-LineLayout::~LineLayout() {
-	Free();
-}
-
-void LineLayout::Resize(int maxLineLength_) {
-	if (maxLineLength_ > maxLineLength) {
-		Free();
-		chars = new char[maxLineLength_ + 1];
-		styles = new unsigned char[maxLineLength_ + 1];
-		indicators = new char[maxLineLength_ + 1];
-		// Extra position allocated as sometimes the Windows
-		// GetTextExtentExPoint API writes an extra element.
-		positions = new int[maxLineLength_ + 1 + 1];
-		maxLineLength = maxLineLength_;
-	}
-}
-
-void LineLayout::Free() {
-	delete []chars;
-	chars = 0;
-	delete []styles;
-	styles = 0;
-	delete []indicators;
-	indicators = 0;
-	delete []positions;
-	positions = 0;
-	delete []lineStarts;
-	lineStarts = 0;
-}
-
-void LineLayout::Invalidate(validLevel validity_) {
-	if (validity > validity_)
-		validity = validity_;
-}
-
-void LineLayout::SetLineStart(int line, int start) {
-	if ((line >= lenLineStarts) && (line != 0)) {
-		int newMaxLines = line + 20;
-		int *newLineStarts = new int[newMaxLines];
-		if (!newLineStarts)
-			return;
-		for (int i = 0; i < newMaxLines; i++) {
-			if (i < lenLineStarts)
-				newLineStarts[i] = lineStarts[i];
-			else
-				newLineStarts[i] = 0;
-		}
-		delete []lineStarts;
-		lineStarts = newLineStarts;
-		lenLineStarts = newMaxLines;
-	}
-	lineStarts[line] = start;
-}
-
-void LineLayout::SetBracesHighlight(Range rangeLine, Position braces[],
-                                    char bracesMatchStyle, int xHighlight) {
-	if (rangeLine.ContainsCharacter(braces[0])) {
-		int braceOffset = braces[0] - rangeLine.start;
-		if (braceOffset < numCharsInLine) {
-			bracePreviousStyles[0] = styles[braceOffset];
-			styles[braceOffset] = bracesMatchStyle;
-		}
-	}
-	if (rangeLine.ContainsCharacter(braces[1])) {
-		int braceOffset = braces[1] - rangeLine.start;
-		if (braceOffset < numCharsInLine) {
-			bracePreviousStyles[1] = styles[braceOffset];
-			styles[braceOffset] = bracesMatchStyle;
-		}
-	}
-	if ((braces[0] >= rangeLine.start && braces[1] <= rangeLine.end) ||
-	        (braces[1] >= rangeLine.start && braces[0] <= rangeLine.end)) {
-		xHighlightGuide = xHighlight;
-	}
-}
-
-void LineLayout::RestoreBracesHighlight(Range rangeLine, Position braces[]) {
-	if (rangeLine.ContainsCharacter(braces[0])) {
-		int braceOffset = braces[0] - rangeLine.start;
-		if (braceOffset < numCharsInLine) {
-			styles[braceOffset] = bracePreviousStyles[0];
-		}
-	}
-	if (rangeLine.ContainsCharacter(braces[1])) {
-		int braceOffset = braces[1] - rangeLine.start;
-		if (braceOffset < numCharsInLine) {
-			styles[braceOffset] = bracePreviousStyles[1];
-		}
-	}
-	xHighlightGuide = 0;
-}
-
-LineLayoutCache::LineLayoutCache() :
-	level(0), length(0), size(0), cache(0),
-	allInvalidated(false), styleClock(-1), useCount(0) {
-	Allocate(0);
-}
-
-LineLayoutCache::~LineLayoutCache() {
-	Deallocate();
-}
-
-void LineLayoutCache::Allocate(int length_) {
-	PLATFORM_ASSERT(cache == NULL);
-	allInvalidated = false;
-	length = length_;
-	size = length;
-	if (size > 1) {
-		size = (size / 16 + 1) * 16;
-	}
-	if (size > 0) {
-		cache = new LineLayout * [size];
-	}
-	for (int i = 0; i < size; i++)
-		cache[i] = 0;
-}
-
-void LineLayoutCache::AllocateForLevel(int linesOnScreen, int linesInDoc) {
-	PLATFORM_ASSERT(useCount == 0);
-	int lengthForLevel = 0;
-	if (level == llcCaret) {
-		lengthForLevel = 1;
-	} else if (level == llcPage) {
-		lengthForLevel = linesOnScreen + 1;
-	} else if (level == llcDocument) {
-		lengthForLevel = linesInDoc;
-	}
-	if (lengthForLevel > size) {
-		Deallocate();
-		Allocate(lengthForLevel);
-	} else {
-		if (lengthForLevel < length) {
-			for (int i = lengthForLevel; i < length; i++) {
-				delete cache[i];
-				cache[i] = 0;
-			}
-		}
-		length = lengthForLevel;
-	}
-	PLATFORM_ASSERT(length == lengthForLevel);
-	PLATFORM_ASSERT(cache != NULL || length == 0);
-}
-
-void LineLayoutCache::Deallocate() {
-	PLATFORM_ASSERT(useCount == 0);
-	for (int i = 0; i < length; i++)
-		delete cache[i];
-	delete []cache;
-	cache = 0;
-	length = 0;
-	size = 0;
-}
-
-void LineLayoutCache::Invalidate(LineLayout::validLevel validity_) {
-	if (cache && !allInvalidated) {
-		for (int i = 0; i < length; i++) {
-			if (cache[i]) {
-				cache[i]->Invalidate(validity_);
-			}
-		}
-		if (validity_ == LineLayout::llInvalid) {
-			allInvalidated = true;
-		}
-	}
-}
-
-void LineLayoutCache::SetLevel(int level_) {
-	allInvalidated = false;
-	if ((level_ != -1) && (level != level_)) {
-		level = level_;
-		Deallocate();
-	}
-}
-
-LineLayout *LineLayoutCache::Retrieve(int lineNumber, int lineCaret, int maxChars, int styleClock_,
-                                      int linesOnScreen, int linesInDoc) {
-	AllocateForLevel(linesOnScreen, linesInDoc);
-	if (styleClock != styleClock_) {
-		Invalidate(LineLayout::llCheckTextAndStyle);
-		styleClock = styleClock_;
-	}
-	allInvalidated = false;
-	int pos = -1;
-	LineLayout *ret = 0;
-	if (level == llcCaret) {
-		pos = 0;
-	} else if (level == llcPage) {
-		if (lineNumber == lineCaret) {
-			pos = 0;
-		} else if (length > 1) {
-			pos = 1 + (lineNumber % (length - 1));
-		}
-	} else if (level == llcDocument) {
-		pos = lineNumber;
-	}
-	if (pos >= 0) {
-		PLATFORM_ASSERT(useCount == 0);
-		if (cache && (pos < length)) {
-			if (cache[pos]) {
-				if ((cache[pos]->lineNumber != lineNumber) ||
-				        (cache[pos]->maxLineLength < maxChars)) {
-					delete cache[pos];
-					cache[pos] = 0;
-				}
-			}
-			if (!cache[pos]) {
-				cache[pos] = new LineLayout(maxChars);
-			}
-			if (cache[pos]) {
-				cache[pos]->lineNumber = lineNumber;
-				cache[pos]->inCache = true;
-				ret = cache[pos];
-				useCount++;
-			}
-		}
-	}
-
-	if (!ret) {
-		ret = new LineLayout(maxChars);
-		ret->lineNumber = lineNumber;
-	}
-
-	return ret;
-}
-
-void LineLayoutCache::Dispose(LineLayout *ll) {
-	allInvalidated = false;
-	if (ll) {
-		if (!ll->inCache) {
-			delete ll;
-		} else {
-			useCount--;
-		}
-	}
+static inline bool IsControlCharacter(int ch) {
+	// iscntrl returns true for lots of chars > 127 which are displayable
+	return ch >= 0 && ch < ' ';
 }
 
 Editor::Editor() {
@@ -450,6 +194,7 @@ Editor::Editor() {
 	hsEnd = -1;
 
 	llc.SetLevel(LineLayoutCache::llcCaret);
+	posCache.SetSize(0x400);
 }
 
 Editor::~Editor() {
@@ -482,6 +227,7 @@ void Editor::InvalidateStyleData() {
 	palette.Release();
 	DropGraphics();
 	llc.Invalidate(LineLayout::llInvalid);
+	posCache.Clear();
 	if (selType == selRectangle) {
 		xStartSelect = XFromPosition(anchor);
 		xEndSelect = XFromPosition(currentPos);
@@ -554,11 +300,6 @@ int Editor::MaxScrollPos() {
 	}
 }
 
-static inline bool IsControlCharacter(int ch) {
-	// iscntrl returns true for lots of chars > 127 which are displayable
-	return ch >= 0 && ch < ' ';
-}
-
 const char *ControlCharacterString(unsigned char ch) {
 	const char *reps[] = {
 		"NUL", "SOH", "STX", "ETX", "EOT", "ENQ", "ACK", "BEL",
@@ -738,10 +479,6 @@ void Editor::SetTopLine(int topLineNew) {
 	posTopLine = pdoc->LineStart(cs.DocFromDisplay(topLine));
 }
 
-static inline bool IsEOLChar(char ch) {
-	return (ch == '\r') || (ch == '\n');
-}
-
 int Editor::PositionFromLocation(Point pt) {
 	RefreshStyleData();
 	pt.x = pt.x - vs.fixedColumnWidth + xOffset;
@@ -764,18 +501,19 @@ int Editor::PositionFromLocation(Point pt) {
 		int subLine = visibleLine - lineStartSet;
 		if (subLine < ll->lines) {
 			int lineStart = ll->LineStart(subLine);
-			int lineEnd = ll->LineStart(subLine + 1);
+			int lineEnd = ll->LineLastVisible(subLine);
 			int subLineStart = ll->positions[lineStart];
 
 			if (actualWrapVisualStartIndent != 0) {
 				if (lineStart != 0)	// Wrapped
 					pt.x -= actualWrapVisualStartIndent * vs.aveCharWidth;
 			}
-			for (int i = lineStart; i < lineEnd; i++) {
-				if (pt.x < (((ll->positions[i] + ll->positions[i + 1]) / 2) - subLineStart) ||
-				        IsEOLChar(ll->chars[i])) {
+			int i = ll->FindBefore(pt.x + subLineStart, lineStart, lineEnd);
+			while (i < lineEnd) {
+				if ((pt.x + subLineStart) < ((ll->positions[i] + ll->positions[i + 1]) / 2)) {
 					return pdoc->MovePositionOutsideChar(i + posLineStart, 1);
 				}
+				i++;
 			}
 			return lineEnd + posLineStart;
 		}
@@ -813,18 +551,19 @@ int Editor::PositionFromLocationClose(Point pt) {
 		int subLine = visibleLine - lineStartSet;
 		if (subLine < ll->lines) {
 			int lineStart = ll->LineStart(subLine);
-			int lineEnd = ll->LineStart(subLine + 1);
+			int lineEnd = ll->LineLastVisible(subLine);
 			int subLineStart = ll->positions[lineStart];
 
 			if (actualWrapVisualStartIndent != 0) {
 				if (lineStart != 0)	// Wrapped
 					pt.x -= actualWrapVisualStartIndent * vs.aveCharWidth;
 			}
-			for (int i = lineStart; i < lineEnd; i++) {
-				if (pt.x < (((ll->positions[i] + ll->positions[i + 1]) / 2) - subLineStart) ||
-				        IsEOLChar(ll->chars[i])) {
+			int i = ll->FindBefore(pt.x + subLineStart, lineStart, lineEnd);
+			while (i < lineEnd) {
+				if ((pt.x + subLineStart) < ((ll->positions[i] + ll->positions[i + 1]) / 2)) {
 					return pdoc->MovePositionOutsideChar(i + posLineStart, 1);
 				}
+				i++;
 			}
 			if (pt.x < (ll->positions[lineEnd] - subLineStart)) {
 				return pdoc->MovePositionOutsideChar(lineEnd + posLineStart, 1);
@@ -853,19 +592,20 @@ int Editor::PositionFromLineX(int lineDoc, int x) {
 		retVal = ll->numCharsInLine + posLineStart;
 		int subLine = 0;
 		int lineStart = ll->LineStart(subLine);
-		int lineEnd = ll->LineStart(subLine + 1);
+		int lineEnd = ll->LineLastVisible(subLine);
 		int subLineStart = ll->positions[lineStart];
 
 		if (actualWrapVisualStartIndent != 0) {
 			if (lineStart != 0)	// Wrapped
 				x -= actualWrapVisualStartIndent * vs.aveCharWidth;
 		}
-		for (int i = lineStart; i < lineEnd; i++) {
-			if (x < (((ll->positions[i] + ll->positions[i + 1]) / 2) - subLineStart) ||
-			        IsEOLChar(ll->chars[i])) {
+		int i = ll->FindBefore(x + subLineStart, lineStart, lineEnd);
+		while (i < lineEnd) {
+			if ((x + subLineStart) < ((ll->positions[i] + ll->positions[i + 1]) / 2)) {
 				retVal = pdoc->MovePositionOutsideChar(i + posLineStart, 1);
 				break;
 			}
+			i++;
 		}
 	}
 	return retVal;
@@ -1929,10 +1669,6 @@ void DrawTabArrow(Surface *surface, PRectangle rcTab, int ymid) {
 	surface->LineTo(xhead, ymid + ydiff);
 }
 
-static bool IsSpaceOrTab(char ch) {
-	return ch == ' ' || ch == '\t';
-}
-
 LineLayout *Editor::RetrieveLineLayout(int lineNumber) {
 	int posLineStart = pdoc->LineStart(lineNumber);
 	int posLineEnd = pdoc->LineStart(lineNumber + 1);
@@ -1951,6 +1687,7 @@ LineLayout *Editor::RetrieveLineLayout(int lineNumber) {
 void Editor::LayoutLine(int line, Surface *surface, ViewStyle &vstyle, LineLayout *ll, int width) {
 	if (!ll)
 		return;
+
 	PLATFORM_ASSERT(line < pdoc->LinesTotal());
 	PLATFORM_ASSERT(ll->chars != NULL);
 	int posLineStart = pdoc->LineStart(line);
@@ -2086,7 +1823,7 @@ void Editor::LayoutLine(int line, Surface *surface, ViewStyle &vstyle, LineLayou
 							ll->positions[charInLine + 1] = vstyle.styles[ll->styles[charInLine]].spaceWidth;
 						} else {
 							lastSegItalics = vstyle.styles[ll->styles[charInLine]].italic;
-							surface->MeasureWidths(vstyle.styles[ll->styles[charInLine]].font, ll->chars + startseg,
+							posCache.MeasureWidths(surface, vstyle, ll->styles[charInLine], ll->chars + startseg,
 							                       lenSeg, ll->positions + startseg + 1);
 						}
 					}
@@ -2126,8 +1863,6 @@ void Editor::LayoutLine(int line, Surface *surface, ViewStyle &vstyle, LineLayou
 			}
 			ll->lines = 0;
 			// Calculate line start positions based upon width.
-			// For now this is simplistic - wraps on byte rather than character and
-			// in the middle of words. Should search for spaces or style changes.
 			int lastGoodBreak = 0;
 			int lastLineStart = 0;
 			int startOffset = 0;
@@ -2508,60 +2243,64 @@ void Editor::DrawLine(Surface *surface, ViewStyle &vsDraw, int line, int lineVis
 		}
 	}
 
-	int i;
+	// Does not take margin into account but not significant
+	int xStartVisible = subLineStart - xStart;
+
+	BreakFinder bfBack(ll, lineStart, lineEnd, posLineStart, xStartVisible);
+	int next = bfBack.First();
 
 	// Background drawing loop
-	for (i = lineStart; twoPhaseDraw && (i < lineEnd); i++) {
+	while (twoPhaseDraw && (next < lineEnd)) {
 
+		startseg = next;
+		next = bfBack.Next();
+		int i = next - 1;
 		int iDoc = i + posLineStart;
-		// If there is the end of a style run for any reason
-		if ((ll->styles[i] != ll->styles[i + 1]) ||
-		        i == (lineEnd - 1) ||
-		        IsControlCharacter(ll->chars[i]) || IsControlCharacter(ll->chars[i + 1]) ||
-		        ((ll->selStart != ll->selEnd) && ((iDoc + 1 == ll->selStart) || (iDoc + 1 == ll->selEnd))) ||
-		        (i == (ll->edgeColumn - 1))) {
-			rcSegment.left = ll->positions[startseg] + xStart - subLineStart;
-			rcSegment.right = ll->positions[i + 1] + xStart - subLineStart;
-			// Only try to draw if really visible - enhances performance by not calling environment to
-			// draw strings that are completely past the right side of the window.
-			if ((rcSegment.left <= rcLine.right) && (rcSegment.right >= rcLine.left)) {
-				int styleMain = ll->styles[i];
-				bool inSelection = (iDoc >= ll->selStart) && (iDoc < ll->selEnd) && (ll->selStart != ll->selEnd);
-				bool inHotspot = (ll->hsStart != -1) && (iDoc >= ll->hsStart) && (iDoc < ll->hsEnd);
-				ColourAllocated textBack = TextBackground(vsDraw, overrideBackground, background, inSelection, inHotspot, styleMain, i, ll);
-				if (ll->chars[i] == '\t') {
-					// Tab display
-					if (drawWhitespaceBackground &&
-					        (!inIndentation || vsDraw.viewWhitespace == wsVisibleAlways))
-						textBack = vsDraw.whitespaceBackground.allocated;
-					surface->FillRectangle(rcSegment, textBack);
-				} else if (IsControlCharacter(ll->chars[i])) {
-					// Control character display
-					inIndentation = false;
-					surface->FillRectangle(rcSegment, textBack);
-				} else {
-					// Normal text display
-					surface->FillRectangle(rcSegment, textBack);
-					if (vsDraw.viewWhitespace != wsInvisible ||
-					        (inIndentation && vsDraw.viewIndentationGuides)) {
-						for (int cpos = 0; cpos <= i - startseg; cpos++) {
-							if (ll->chars[cpos + startseg] == ' ') {
-								if (drawWhitespaceBackground &&
-								        (!inIndentation || vsDraw.viewWhitespace == wsVisibleAlways)) {
-									PRectangle rcSpace(ll->positions[cpos + startseg] + xStart, rcSegment.top,
-									                   ll->positions[cpos + startseg + 1] + xStart, rcSegment.bottom);
-									surface->FillRectangle(rcSpace, vsDraw.whitespaceBackground.allocated);
-								}
-							} else {
-								inIndentation = false;
+
+		rcSegment.left = ll->positions[startseg] + xStart - subLineStart;
+		rcSegment.right = ll->positions[i + 1] + xStart - subLineStart;
+		// Only try to draw if really visible - enhances performance by not calling environment to
+		// draw strings that are completely past the right side of the window.
+		if ((rcSegment.left <= rcLine.right) && (rcSegment.right >= rcLine.left)) {
+			// Clip to line rectangle, since may have a huge position which will not work with some platforms
+			rcSegment.left = Platform::Maximum(rcSegment.left, rcLine.left);
+			rcSegment.right = Platform::Minimum(rcSegment.right, rcLine.right);
+
+			int styleMain = ll->styles[i];
+			bool inSelection = (iDoc >= ll->selStart) && (iDoc < ll->selEnd) && (ll->selStart != ll->selEnd);
+			bool inHotspot = (ll->hsStart != -1) && (iDoc >= ll->hsStart) && (iDoc < ll->hsEnd);
+			ColourAllocated textBack = TextBackground(vsDraw, overrideBackground, background, inSelection, inHotspot, styleMain, i, ll);
+			if (ll->chars[i] == '\t') {
+				// Tab display
+				if (drawWhitespaceBackground &&
+				        (!inIndentation || vsDraw.viewWhitespace == wsVisibleAlways))
+					textBack = vsDraw.whitespaceBackground.allocated;
+				surface->FillRectangle(rcSegment, textBack);
+			} else if (IsControlCharacter(ll->chars[i])) {
+				// Control character display
+				inIndentation = false;
+				surface->FillRectangle(rcSegment, textBack);
+			} else {
+				// Normal text display
+				surface->FillRectangle(rcSegment, textBack);
+				if (vsDraw.viewWhitespace != wsInvisible ||
+				        (inIndentation && vsDraw.viewIndentationGuides)) {
+					for (int cpos = 0; cpos <= i - startseg; cpos++) {
+						if (ll->chars[cpos + startseg] == ' ') {
+							if (drawWhitespaceBackground &&
+							        (!inIndentation || vsDraw.viewWhitespace == wsVisibleAlways)) {
+								PRectangle rcSpace(ll->positions[cpos + startseg] + xStart, rcSegment.top,
+								                   ll->positions[cpos + startseg + 1] + xStart, rcSegment.bottom);
+								surface->FillRectangle(rcSpace, vsDraw.whitespaceBackground.allocated);
 							}
+						} else {
+							inIndentation = false;
 						}
 					}
 				}
-			} else if (rcSegment.left > rcLine.right) {
-				break;
 			}
-			startseg = i + 1;
+		} else if (rcSegment.left > rcLine.right) {
+			break;
 		}
 	}
 
@@ -2581,160 +2320,159 @@ void Editor::DrawLine(Surface *surface, ViewStyle &vsDraw, int line, int lineVis
 	}
 
 	inIndentation = subLine == 0;	// Do not handle indentation except on first subline.
-	startseg = ll->LineStart(subLine);
 	// Foreground drawing loop
-	for (i = lineStart; i < lineEnd; i++) {
+	BreakFinder bfFore(ll, lineStart, lineEnd, posLineStart, xStartVisible);
+	next = bfFore.First();
+
+	while (next < lineEnd) {
+
+		startseg = next;
+		next = bfFore.Next();
+		int i = next - 1;
 
 		int iDoc = i + posLineStart;
-		// If there is the end of a style run for any reason
-		if ((ll->styles[i] != ll->styles[i + 1]) ||
-		        i == (lineEnd - 1) ||
-		        IsControlCharacter(ll->chars[i]) || IsControlCharacter(ll->chars[i + 1]) ||
-		        ((ll->selStart != ll->selEnd) && ((iDoc + 1 == ll->selStart) || (iDoc + 1 == ll->selEnd))) ||
-		        (i == (ll->edgeColumn - 1))) {
-			rcSegment.left = ll->positions[startseg] + xStart - subLineStart;
-			rcSegment.right = ll->positions[i + 1] + xStart - subLineStart;
-			// Only try to draw if really visible - enhances performance by not calling environment to
-			// draw strings that are completely past the right side of the window.
-			if ((rcSegment.left <= rcLine.right) && (rcSegment.right >= rcLine.left)) {
-				int styleMain = ll->styles[i];
-				ColourAllocated textFore = vsDraw.styles[styleMain].fore.allocated;
-				Font &textFont = vsDraw.styles[styleMain].font;
-				//hotspot foreground
-				if (ll->hsStart != -1 && iDoc >= ll->hsStart && iDoc < hsEnd) {
-					if (vsDraw.hotspotForegroundSet)
-						textFore = vsDraw.hotspotForeground.allocated;
+
+		rcSegment.left = ll->positions[startseg] + xStart - subLineStart;
+		rcSegment.right = ll->positions[i + 1] + xStart - subLineStart;
+		// Only try to draw if really visible - enhances performance by not calling environment to
+		// draw strings that are completely past the right side of the window.
+		if ((rcSegment.left <= rcLine.right) && (rcSegment.right >= rcLine.left)) {
+			int styleMain = ll->styles[i];
+			ColourAllocated textFore = vsDraw.styles[styleMain].fore.allocated;
+			Font &textFont = vsDraw.styles[styleMain].font;
+			//hotspot foreground
+			if (ll->hsStart != -1 && iDoc >= ll->hsStart && iDoc < hsEnd) {
+				if (vsDraw.hotspotForegroundSet)
+					textFore = vsDraw.hotspotForeground.allocated;
+			}
+			bool inSelection = (iDoc >= ll->selStart) && (iDoc < ll->selEnd) && (ll->selStart != ll->selEnd);
+			if (inSelection && (vsDraw.selforeset)) {
+				textFore = vsDraw.selforeground.allocated;
+			}
+			bool inHotspot = (ll->hsStart != -1) && (iDoc >= ll->hsStart) && (iDoc < ll->hsEnd);
+			ColourAllocated textBack = TextBackground(vsDraw, overrideBackground, background, inSelection, inHotspot, styleMain, i, ll);
+			if (ll->chars[i] == '\t') {
+				// Tab display
+				if (!twoPhaseDraw) {
+					if (drawWhitespaceBackground &&
+					        (!inIndentation || vsDraw.viewWhitespace == wsVisibleAlways))
+						textBack = vsDraw.whitespaceBackground.allocated;
+					surface->FillRectangle(rcSegment, textBack);
 				}
-				bool inSelection = (iDoc >= ll->selStart) && (iDoc < ll->selEnd) && (ll->selStart != ll->selEnd);
-				if (inSelection && (vsDraw.selforeset)) {
-					textFore = vsDraw.selforeground.allocated;
+				if ((vsDraw.viewWhitespace != wsInvisible) || ((inIndentation && vsDraw.viewIndentationGuides))) {
+					if (vsDraw.whitespaceForegroundSet)
+						textFore = vsDraw.whitespaceForeground.allocated;
+					surface->PenColour(textFore);
 				}
-				bool inHotspot = (ll->hsStart != -1) && (iDoc >= ll->hsStart) && (iDoc < ll->hsEnd);
-				ColourAllocated textBack = TextBackground(vsDraw, overrideBackground, background, inSelection, inHotspot, styleMain, i, ll);
-				if (ll->chars[i] == '\t') {
-					// Tab display
-					if (!twoPhaseDraw) {
-						if (drawWhitespaceBackground &&
-						        (!inIndentation || vsDraw.viewWhitespace == wsVisibleAlways))
-							textBack = vsDraw.whitespaceBackground.allocated;
-						surface->FillRectangle(rcSegment, textBack);
-					}
-					if ((vsDraw.viewWhitespace != wsInvisible) || ((inIndentation && vsDraw.viewIndentationGuides))) {
-						if (vsDraw.whitespaceForegroundSet)
-							textFore = vsDraw.whitespaceForeground.allocated;
-						surface->PenColour(textFore);
-					}
-					if (inIndentation && vsDraw.viewIndentationGuides) {
-						for (int xIG = ll->positions[i] / indentWidth * indentWidth; xIG < ll->positions[i + 1]; xIG += indentWidth) {
-							if (xIG >= ll->positions[i] && xIG > 0) {
-								DrawIndentGuide(surface, lineVisible, vsDraw.lineHeight, xIG + xStart, rcSegment,
-								                (ll->xHighlightGuide == xIG));
-							}
+				if (inIndentation && vsDraw.viewIndentationGuides) {
+					for (int xIG = ll->positions[i] / indentWidth * indentWidth; xIG < ll->positions[i + 1]; xIG += indentWidth) {
+						if (xIG >= ll->positions[i] && xIG > 0) {
+							DrawIndentGuide(surface, lineVisible, vsDraw.lineHeight, xIG + xStart, rcSegment,
+							                (ll->xHighlightGuide == xIG));
 						}
 					}
-					if (vsDraw.viewWhitespace != wsInvisible) {
-						if (!inIndentation || vsDraw.viewWhitespace == wsVisibleAlways) {
-							PRectangle rcTab(rcSegment.left + 1, rcSegment.top + 4,
-							                 rcSegment.right - 1, rcSegment.bottom - vsDraw.maxDescent);
-							DrawTabArrow(surface, rcTab, rcSegment.top + vsDraw.lineHeight / 2);
-						}
+				}
+				if (vsDraw.viewWhitespace != wsInvisible) {
+					if (!inIndentation || vsDraw.viewWhitespace == wsVisibleAlways) {
+						PRectangle rcTab(rcSegment.left + 1, rcSegment.top + 4,
+						                 rcSegment.right - 1, rcSegment.bottom - vsDraw.maxDescent);
+						DrawTabArrow(surface, rcTab, rcSegment.top + vsDraw.lineHeight / 2);
 					}
-				} else if (IsControlCharacter(ll->chars[i])) {
-					// Control character display
-					inIndentation = false;
-					if (controlCharSymbol < 32) {
-						// Draw the character
-						const char *ctrlChar = ControlCharacterString(ll->chars[i]);
-						if (!twoPhaseDraw) {
-							surface->FillRectangle(rcSegment, textBack);
-						}
-						int normalCharHeight = surface->Ascent(ctrlCharsFont) -
-						                       surface->InternalLeading(ctrlCharsFont);
-						PRectangle rcCChar = rcSegment;
-						rcCChar.left = rcCChar.left + 1;
-						rcCChar.top = rcSegment.top + vsDraw.maxAscent - normalCharHeight;
-						rcCChar.bottom = rcSegment.top + vsDraw.maxAscent + 1;
-						PRectangle rcCentral = rcCChar;
-						rcCentral.top++;
-						rcCentral.bottom--;
-						surface->FillRectangle(rcCentral, textFore);
-						PRectangle rcChar = rcCChar;
-						rcChar.left++;
-						rcChar.right--;
-						surface->DrawTextClipped(rcChar, ctrlCharsFont,
-						                         rcSegment.top + vsDraw.maxAscent, ctrlChar, istrlen(ctrlChar),
-						                         textBack, textFore);
-					} else {
-						char cc[2] = { static_cast<char>(controlCharSymbol), '\0' };
-						surface->DrawTextNoClip(rcSegment, ctrlCharsFont,
-						                        rcSegment.top + vsDraw.maxAscent,
-						                        cc, 1, textBack, textFore);
+				}
+			} else if (IsControlCharacter(ll->chars[i])) {
+				// Control character display
+				inIndentation = false;
+				if (controlCharSymbol < 32) {
+					// Draw the character
+					const char *ctrlChar = ControlCharacterString(ll->chars[i]);
+					if (!twoPhaseDraw) {
+						surface->FillRectangle(rcSegment, textBack);
 					}
+					int normalCharHeight = surface->Ascent(ctrlCharsFont) -
+					                       surface->InternalLeading(ctrlCharsFont);
+					PRectangle rcCChar = rcSegment;
+					rcCChar.left = rcCChar.left + 1;
+					rcCChar.top = rcSegment.top + vsDraw.maxAscent - normalCharHeight;
+					rcCChar.bottom = rcSegment.top + vsDraw.maxAscent + 1;
+					PRectangle rcCentral = rcCChar;
+					rcCentral.top++;
+					rcCentral.bottom--;
+					surface->FillRectangle(rcCentral, textFore);
+					PRectangle rcChar = rcCChar;
+					rcChar.left++;
+					rcChar.right--;
+					surface->DrawTextClipped(rcChar, ctrlCharsFont,
+					                         rcSegment.top + vsDraw.maxAscent, ctrlChar, istrlen(ctrlChar),
+					                         textBack, textFore);
 				} else {
-					// Normal text display
-					if (vsDraw.styles[styleMain].visible) {
-						if (twoPhaseDraw) {
-							surface->DrawTextTransparent(rcSegment, textFont,
-							                             rcSegment.top + vsDraw.maxAscent, ll->chars + startseg,
-							                             i - startseg + 1, textFore);
-						} else {
-							surface->DrawTextNoClip(rcSegment, textFont,
-							                        rcSegment.top + vsDraw.maxAscent, ll->chars + startseg,
-							                        i - startseg + 1, textFore, textBack);
-						}
+					char cc[2] = { static_cast<char>(controlCharSymbol), '\0' };
+					surface->DrawTextNoClip(rcSegment, ctrlCharsFont,
+					                        rcSegment.top + vsDraw.maxAscent,
+					                        cc, 1, textBack, textFore);
+				}
+			} else {
+				// Normal text display
+				if (vsDraw.styles[styleMain].visible) {
+					if (twoPhaseDraw) {
+						surface->DrawTextTransparent(rcSegment, textFont,
+						                             rcSegment.top + vsDraw.maxAscent, ll->chars + startseg,
+						                             i - startseg + 1, textFore);
+					} else {
+						surface->DrawTextNoClip(rcSegment, textFont,
+						                        rcSegment.top + vsDraw.maxAscent, ll->chars + startseg,
+						                        i - startseg + 1, textFore, textBack);
 					}
-					if (vsDraw.viewWhitespace != wsInvisible ||
-					        (inIndentation && vsDraw.viewIndentationGuides)) {
-						for (int cpos = 0; cpos <= i - startseg; cpos++) {
-							if (ll->chars[cpos + startseg] == ' ') {
-								if (vsDraw.viewWhitespace != wsInvisible) {
-									if (vsDraw.whitespaceForegroundSet)
-										textFore = vsDraw.whitespaceForeground.allocated;
-									if (!inIndentation || vsDraw.viewWhitespace == wsVisibleAlways) {
-										int xmid = (ll->positions[cpos + startseg] + ll->positions[cpos + startseg + 1]) / 2;
-										if (!twoPhaseDraw && drawWhitespaceBackground &&
-										        (!inIndentation || vsDraw.viewWhitespace == wsVisibleAlways)) {
-											textBack = vsDraw.whitespaceBackground.allocated;
-											PRectangle rcSpace(ll->positions[cpos + startseg] + xStart, rcSegment.top, ll->positions[cpos + startseg + 1] + xStart, rcSegment.bottom);
-											surface->FillRectangle(rcSpace, textBack);
-										}
-										PRectangle rcDot(xmid + xStart - subLineStart, rcSegment.top + vsDraw.lineHeight / 2, 0, 0);
-										rcDot.right = rcDot.left + 1;
-										rcDot.bottom = rcDot.top + 1;
-										surface->FillRectangle(rcDot, textFore);
+				}
+				if (vsDraw.viewWhitespace != wsInvisible ||
+				        (inIndentation && vsDraw.viewIndentationGuides)) {
+					for (int cpos = 0; cpos <= i - startseg; cpos++) {
+						if (ll->chars[cpos + startseg] == ' ') {
+							if (vsDraw.viewWhitespace != wsInvisible) {
+								if (vsDraw.whitespaceForegroundSet)
+									textFore = vsDraw.whitespaceForeground.allocated;
+								if (!inIndentation || vsDraw.viewWhitespace == wsVisibleAlways) {
+									int xmid = (ll->positions[cpos + startseg] + ll->positions[cpos + startseg + 1]) / 2;
+									if (!twoPhaseDraw && drawWhitespaceBackground &&
+									        (!inIndentation || vsDraw.viewWhitespace == wsVisibleAlways)) {
+										textBack = vsDraw.whitespaceBackground.allocated;
+										PRectangle rcSpace(ll->positions[cpos + startseg] + xStart, rcSegment.top, ll->positions[cpos + startseg + 1] + xStart, rcSegment.bottom);
+										surface->FillRectangle(rcSpace, textBack);
 									}
+									PRectangle rcDot(xmid + xStart - subLineStart, rcSegment.top + vsDraw.lineHeight / 2, 0, 0);
+									rcDot.right = rcDot.left + 1;
+									rcDot.bottom = rcDot.top + 1;
+									surface->FillRectangle(rcDot, textFore);
 								}
-								if (inIndentation && vsDraw.viewIndentationGuides) {
-									int startSpace = ll->positions[cpos + startseg];
-									if (startSpace > 0 && (startSpace % indentWidth == 0)) {
-										DrawIndentGuide(surface, lineVisible, vsDraw.lineHeight, startSpace + xStart, rcSegment,
-										                (ll->xHighlightGuide == ll->positions[cpos + startseg]));
-									}
+							}
+							if (inIndentation && vsDraw.viewIndentationGuides) {
+								int startSpace = ll->positions[cpos + startseg];
+								if (startSpace > 0 && (startSpace % indentWidth == 0)) {
+									DrawIndentGuide(surface, lineVisible, vsDraw.lineHeight, startSpace + xStart, rcSegment,
+									                (ll->xHighlightGuide == ll->positions[cpos + startseg]));
 								}
-							} else {
-								inIndentation = false;
 							}
+						} else {
+							inIndentation = false;
 						}
 					}
 				}
-				if (ll->hsStart != -1 && vsDraw.hotspotUnderline && iDoc >= ll->hsStart && iDoc < ll->hsEnd ) {
-					PRectangle rcUL = rcSegment;
-					rcUL.top = rcUL.top + vsDraw.maxAscent + 1;
-					rcUL.bottom = rcUL.top + 1;
-					if (vsDraw.hotspotForegroundSet)
-						surface->FillRectangle(rcUL, vsDraw.hotspotForeground.allocated);
-					else
-						surface->FillRectangle(rcUL, textFore);
-				} else if (vsDraw.styles[styleMain].underline) {
-					PRectangle rcUL = rcSegment;
-					rcUL.top = rcUL.top + vsDraw.maxAscent + 1;
-					rcUL.bottom = rcUL.top + 1;
+			}
+			if (ll->hsStart != -1 && vsDraw.hotspotUnderline && iDoc >= ll->hsStart && iDoc < ll->hsEnd ) {
+				PRectangle rcUL = rcSegment;
+				rcUL.top = rcUL.top + vsDraw.maxAscent + 1;
+				rcUL.bottom = rcUL.top + 1;
+				if (vsDraw.hotspotForegroundSet)
+					surface->FillRectangle(rcUL, vsDraw.hotspotForeground.allocated);
+				else
 					surface->FillRectangle(rcUL, textFore);
-				}
-			} else if (rcSegment.left > rcLine.right) {
-				break;
+			} else if (vsDraw.styles[styleMain].underline) {
+				PRectangle rcUL = rcSegment;
+				rcUL.top = rcUL.top + vsDraw.maxAscent + 1;
+				rcUL.bottom = rcUL.top + 1;
+				surface->FillRectangle(rcUL, textFore);
 			}
-			startseg = i + 1;
+		} else if (rcSegment.left > rcLine.right) {
+			break;
 		}
 	}
 
@@ -2752,6 +2490,8 @@ void Editor::DrawLine(Surface *surface, ViewStyle &vsDraw, int line, int lineVis
 		if (startPosSel < endPosSel) {
 			rcSegment.left = xStart + ll->positions[startPosSel - posLineStart] - subLineStart;
 			rcSegment.right = xStart + ll->positions[endPosSel - posLineStart] - subLineStart;
+			rcSegment.left = Platform::Maximum(rcSegment.left, rcLine.left);
+			rcSegment.right = Platform::Minimum(rcSegment.right, rcLine.right);
 			SimpleAlphaRectangle(surface, rcSegment, SelectionBackground(vsDraw), vsDraw.selAlpha);
 		}
 	}
@@ -3267,6 +3007,9 @@ long Editor::FormatRange(bool draw, RangeToFormat *pfr) {
 		return 0;
 	}
 
+	// Can't use measurements cached for screen
+	posCache.Clear();
+
 	ViewStyle vsPrint(vs);
 
 	// Modify the view style for printing as do not normally want any of the transient features to be printed
@@ -3431,6 +3174,9 @@ long Editor::FormatRange(bool draw, RangeToFormat *pfr) {
 		++lineDoc;
 	}
 
+	// Clear cache so measurements are not used for screen
+	posCache.Clear();
+
 	return nPrintPos;
 }
 
@@ -6632,6 +6378,13 @@ sptr_t Editor::WndProc(unsigned int iMessage, uptr_t wParam, sptr_t lParam) {
 	case SCI_GETLAYOUTCACHE:
 		return llc.GetLevel();
 
+	case SCI_SETPOSITIONCACHE:
+		posCache.SetSize(0x400);
+		break;
+
+	case SCI_GETPOSITIONCACHE:
+		return posCache.GetSize();
+
 	case SCI_SETSCROLLWIDTH:
 		PLATFORM_ASSERT(wParam > 0);
 		if ((wParam > 0) && (wParam != static_cast<unsigned int >(scrollWidth))) {
diff --git a/src/Editor.h b/src/Editor.h
index a31777611..213b0e361 100644
--- a/src/Editor.h
+++ b/src/Editor.h
@@ -46,92 +46,6 @@ public:
 };
 
 /**
- */
-class LineLayout {
-private:
-	friend class LineLayoutCache;
-	int *lineStarts;
-	int lenLineStarts;
-	/// Drawing is only performed for @a maxLineLength characters on each line.
-	int lineNumber;
-	bool inCache;
-public:
-	enum { wrapWidthInfinite = 0x7ffffff };
-	int maxLineLength;
-	int numCharsInLine;
-	enum validLevel { llInvalid, llCheckTextAndStyle, llPositions, llLines } validity;
-	int xHighlightGuide;
-	bool highlightColumn;
-	int selStart;
-	int selEnd;
-	bool containsCaret;
-	int edgeColumn;
-	char *chars;
-	unsigned char *styles;
-	int styleBitsSet;
-	char *indicators;
-	int *positions;
-	char bracePreviousStyles[2];
-
-	// Hotspot support
-	int hsStart;
-	int hsEnd;
-
-	// Wrapped line support
-	int widthLine;
-	int lines;
-
-	LineLayout(int maxLineLength_);
-	virtual ~LineLayout();
-	void Resize(int maxLineLength_);
-	void Free();
-	void Invalidate(validLevel validity_);
-	int LineStart(int line) {
-		if (line <= 0) {
-			return 0;
-		} else if ((line >= lines) || !lineStarts) {
-			return numCharsInLine;
-		} else {
-			return lineStarts[line];
-		}
-	}
-	void SetLineStart(int line, int start);
-	void SetBracesHighlight(Range rangeLine, Position braces[],
-		char bracesMatchStyle, int xHighlight);
-	void RestoreBracesHighlight(Range rangeLine, Position braces[]);
-};
-
-/**
- */
-class LineLayoutCache {
-	int level;
-	int length;
-	int size;
-	LineLayout **cache;
-	bool allInvalidated;
-	int styleClock;
-	int useCount;
-	void Allocate(int length_);
-	void AllocateForLevel(int linesOnScreen, int linesInDoc);
-public:
-	LineLayoutCache();
-	virtual ~LineLayoutCache();
-	void Deallocate();
-	enum {
-		llcNone=SC_CACHE_NONE,
-		llcCaret=SC_CACHE_CARET,
-		llcPage=SC_CACHE_PAGE,
-		llcDocument=SC_CACHE_DOCUMENT
-	};
-	void Invalidate(LineLayout::validLevel validity_);
-	void SetLevel(int level_);
-	int GetLevel() { return level; }
-	LineLayout *Retrieve(int lineNumber, int lineCaret, int maxChars, int styleClock_,
-		int linesOnScreen, int linesInDoc);
-	void Dispose(LineLayout *ll);
-};
-
-/**
  * Hold a piece of text selected for copying or dragging.
  * The text is expected to hold a terminating '\0' and this is counted in len.
  */
@@ -233,6 +147,7 @@ protected:	// ScintillaBase subclass needs access to much of Editor
 	Surface *pixmapIndentGuideHighlight;
 
 	LineLayoutCache llc;
+	PositionCache posCache;
 
 	KeyMap kmap;
 
diff --git a/src/PositionCache.cxx b/src/PositionCache.cxx
new file mode 100644
index 000000000..01b8f68f1
--- /dev/null
+++ b/src/PositionCache.cxx
@@ -0,0 +1,586 @@
+// Scintilla source code edit control
+/** @file PositionCache.cxx
+ ** Classes for caching layout information.
+ **/
+// Copyright 1998-2007 by Neil Hodgson <neilh@scintilla.org>
+// The License.txt file describes the conditions under which this software may be distributed.
+
+#include <stdlib.h>
+#include <string.h>
+#include <stdio.h>
+#include <ctype.h>
+
+#include "Platform.h"
+
+#include "Scintilla.h"
+
+#include "ContractionState.h"
+#include "SVector.h"
+#include "SplitVector.h"
+#include "Partitioning.h"
+#include "CellBuffer.h"
+#include "KeyMap.h"
+#include "RunStyles.h"
+#include "Indicator.h"
+#include "XPM.h"
+#include "LineMarker.h"
+#include "Style.h"
+#include "ViewStyle.h"
+#include "CharClassify.h"
+#include "Decoration.h"
+#include "Document.h"
+#include "PositionCache.h"
+
+static inline bool IsControlCharacter(int ch) {
+	// iscntrl returns true for lots of chars > 127 which are displayable
+	return ch >= 0 && ch < ' ';
+}
+
+LineLayout::LineLayout(int maxLineLength_) :
+	lineStarts(0),
+	lenLineStarts(0),
+	lineNumber(-1),
+	inCache(false),
+	maxLineLength(-1),
+	numCharsInLine(0),
+	validity(llInvalid),
+	xHighlightGuide(0),
+	highlightColumn(0),
+	selStart(0),
+	selEnd(0),
+	containsCaret(false),
+	edgeColumn(0),
+	chars(0),
+	styles(0),
+	styleBitsSet(0),
+	indicators(0),
+	positions(0),
+	hsStart(0),
+	hsEnd(0),
+	widthLine(wrapWidthInfinite),
+	lines(1) {
+	Resize(maxLineLength_);
+}
+
+LineLayout::~LineLayout() {
+	Free();
+}
+
+void LineLayout::Resize(int maxLineLength_) {
+	if (maxLineLength_ > maxLineLength) {
+		Free();
+		chars = new char[maxLineLength_ + 1];
+		styles = new unsigned char[maxLineLength_ + 1];
+		indicators = new char[maxLineLength_ + 1];
+		// Extra position allocated as sometimes the Windows
+		// GetTextExtentExPoint API writes an extra element.
+		positions = new int[maxLineLength_ + 1 + 1];
+		maxLineLength = maxLineLength_;
+	}
+}
+
+void LineLayout::Free() {
+	delete []chars;
+	chars = 0;
+	delete []styles;
+	styles = 0;
+	delete []indicators;
+	indicators = 0;
+	delete []positions;
+	positions = 0;
+	delete []lineStarts;
+	lineStarts = 0;
+}
+
+void LineLayout::Invalidate(validLevel validity_) {
+	if (validity > validity_)
+		validity = validity_;
+}
+
+int LineLayout::LineStart(int line) const {
+	if (line <= 0) {
+		return 0;
+	} else if ((line >= lines) || !lineStarts) {
+		return numCharsInLine;
+	} else {
+		return lineStarts[line];
+	}
+}
+
+int LineLayout::LineLastVisible(int line) const {
+	if (line < 0) {
+		return 0;
+	} else if ((line >= lines-1) || !lineStarts) {
+		int startLine = LineStart(line);
+		int endLine = numCharsInLine;
+		while ((endLine > startLine) && IsEOLChar(chars[endLine-1])) {
+			endLine--;
+		}
+		return endLine;
+	} else {
+		return lineStarts[line+1];
+	}
+}
+
+void LineLayout::SetLineStart(int line, int start) {
+	if ((line >= lenLineStarts) && (line != 0)) {
+		int newMaxLines = line + 20;
+		int *newLineStarts = new int[newMaxLines];
+		if (!newLineStarts)
+			return;
+		for (int i = 0; i < newMaxLines; i++) {
+			if (i < lenLineStarts)
+				newLineStarts[i] = lineStarts[i];
+			else
+				newLineStarts[i] = 0;
+		}
+		delete []lineStarts;
+		lineStarts = newLineStarts;
+		lenLineStarts = newMaxLines;
+	}
+	lineStarts[line] = start;
+}
+
+void LineLayout::SetBracesHighlight(Range rangeLine, Position braces[],
+                                    char bracesMatchStyle, int xHighlight) {
+	if (rangeLine.ContainsCharacter(braces[0])) {
+		int braceOffset = braces[0] - rangeLine.start;
+		if (braceOffset < numCharsInLine) {
+			bracePreviousStyles[0] = styles[braceOffset];
+			styles[braceOffset] = bracesMatchStyle;
+		}
+	}
+	if (rangeLine.ContainsCharacter(braces[1])) {
+		int braceOffset = braces[1] - rangeLine.start;
+		if (braceOffset < numCharsInLine) {
+			bracePreviousStyles[1] = styles[braceOffset];
+			styles[braceOffset] = bracesMatchStyle;
+		}
+	}
+	if ((braces[0] >= rangeLine.start && braces[1] <= rangeLine.end) ||
+	        (braces[1] >= rangeLine.start && braces[0] <= rangeLine.end)) {
+		xHighlightGuide = xHighlight;
+	}
+}
+
+void LineLayout::RestoreBracesHighlight(Range rangeLine, Position braces[]) {
+	if (rangeLine.ContainsCharacter(braces[0])) {
+		int braceOffset = braces[0] - rangeLine.start;
+		if (braceOffset < numCharsInLine) {
+			styles[braceOffset] = bracePreviousStyles[0];
+		}
+	}
+	if (rangeLine.ContainsCharacter(braces[1])) {
+		int braceOffset = braces[1] - rangeLine.start;
+		if (braceOffset < numCharsInLine) {
+			styles[braceOffset] = bracePreviousStyles[1];
+		}
+	}
+	xHighlightGuide = 0;
+}
+
+int LineLayout::FindBefore(int x, int lower, int upper) const {
+	do {
+		int middle = (upper + lower + 1) / 2; 	// Round high
+		int posMiddle = positions[middle];
+		if (x < posMiddle) {
+			upper = middle - 1;
+		} else {
+			lower = middle;
+		}
+	} while (lower < upper);
+	return lower;
+}
+
+LineLayoutCache::LineLayoutCache() :
+	level(0), length(0), size(0), cache(0),
+	allInvalidated(false), styleClock(-1), useCount(0) {
+	Allocate(0);
+}
+
+LineLayoutCache::~LineLayoutCache() {
+	Deallocate();
+}
+
+void LineLayoutCache::Allocate(int length_) {
+	PLATFORM_ASSERT(cache == NULL);
+	allInvalidated = false;
+	length = length_;
+	size = length;
+	if (size > 1) {
+		size = (size / 16 + 1) * 16;
+	}
+	if (size > 0) {
+		cache = new LineLayout * [size];
+	}
+	for (int i = 0; i < size; i++)
+		cache[i] = 0;
+}
+
+void LineLayoutCache::AllocateForLevel(int linesOnScreen, int linesInDoc) {
+	PLATFORM_ASSERT(useCount == 0);
+	int lengthForLevel = 0;
+	if (level == llcCaret) {
+		lengthForLevel = 1;
+	} else if (level == llcPage) {
+		lengthForLevel = linesOnScreen + 1;
+	} else if (level == llcDocument) {
+		lengthForLevel = linesInDoc;
+	}
+	if (lengthForLevel > size) {
+		Deallocate();
+		Allocate(lengthForLevel);
+	} else {
+		if (lengthForLevel < length) {
+			for (int i = lengthForLevel; i < length; i++) {
+				delete cache[i];
+				cache[i] = 0;
+			}
+		}
+		length = lengthForLevel;
+	}
+	PLATFORM_ASSERT(length == lengthForLevel);
+	PLATFORM_ASSERT(cache != NULL || length == 0);
+}
+
+void LineLayoutCache::Deallocate() {
+	PLATFORM_ASSERT(useCount == 0);
+	for (int i = 0; i < length; i++)
+		delete cache[i];
+	delete []cache;
+	cache = 0;
+	length = 0;
+	size = 0;
+}
+
+void LineLayoutCache::Invalidate(LineLayout::validLevel validity_) {
+	if (cache && !allInvalidated) {
+		for (int i = 0; i < length; i++) {
+			if (cache[i]) {
+				cache[i]->Invalidate(validity_);
+			}
+		}
+		if (validity_ == LineLayout::llInvalid) {
+			allInvalidated = true;
+		}
+	}
+}
+
+void LineLayoutCache::SetLevel(int level_) {
+	allInvalidated = false;
+	if ((level_ != -1) && (level != level_)) {
+		level = level_;
+		Deallocate();
+	}
+}
+
+LineLayout *LineLayoutCache::Retrieve(int lineNumber, int lineCaret, int maxChars, int styleClock_,
+                                      int linesOnScreen, int linesInDoc) {
+	AllocateForLevel(linesOnScreen, linesInDoc);
+	if (styleClock != styleClock_) {
+		Invalidate(LineLayout::llCheckTextAndStyle);
+		styleClock = styleClock_;
+	}
+	allInvalidated = false;
+	int pos = -1;
+	LineLayout *ret = 0;
+	if (level == llcCaret) {
+		pos = 0;
+	} else if (level == llcPage) {
+		if (lineNumber == lineCaret) {
+			pos = 0;
+		} else if (length > 1) {
+			pos = 1 + (lineNumber % (length - 1));
+		}
+	} else if (level == llcDocument) {
+		pos = lineNumber;
+	}
+	if (pos >= 0) {
+		PLATFORM_ASSERT(useCount == 0);
+		if (cache && (pos < length)) {
+			if (cache[pos]) {
+				if ((cache[pos]->lineNumber != lineNumber) ||
+				        (cache[pos]->maxLineLength < maxChars)) {
+					delete cache[pos];
+					cache[pos] = 0;
+				}
+			}
+			if (!cache[pos]) {
+				cache[pos] = new LineLayout(maxChars);
+			}
+			if (cache[pos]) {
+				cache[pos]->lineNumber = lineNumber;
+				cache[pos]->inCache = true;
+				ret = cache[pos];
+				useCount++;
+			}
+		}
+	}
+
+	if (!ret) {
+		ret = new LineLayout(maxChars);
+		ret->lineNumber = lineNumber;
+	}
+
+	return ret;
+}
+
+void LineLayoutCache::Dispose(LineLayout *ll) {
+	allInvalidated = false;
+	if (ll) {
+		if (!ll->inCache) {
+			delete ll;
+		} else {
+			useCount--;
+		}
+	}
+}
+
+void BreakFinder::Insert(int val) {
+	if (val > nextBreak) {
+		for (unsigned int j = 0; j<saeLen; j++) {
+			if (val == selAndEdge[j]) {
+				return;
+			} if (val < selAndEdge[j]) {
+				for (unsigned int k = saeLen; j>k; k--) {
+					selAndEdge[k] = selAndEdge[k-1];
+				}
+				saeLen++;
+				selAndEdge[j] = val;
+				return;
+			}
+		}
+		// Not less than any so append
+		selAndEdge[saeLen++] = val;
+	}
+}
+
+BreakFinder::BreakFinder(LineLayout *ll_, int lineStart_, int lineEnd_, int posLineStart_, int xStart) :
+	ll(ll_),
+	lineStart(lineStart_),
+	lineEnd(lineEnd_),
+	posLineStart(posLineStart_),
+	nextBreak(lineStart_),
+	saeLen(0),
+	saeCurrentPos(0),
+	saeNext(0),
+	subBreak(-1) {
+	for (unsigned int j=0; j < sizeof(selAndEdge) / sizeof(selAndEdge[0]); j++) {
+		selAndEdge[j] = 0;
+	}
+
+	// Search for first visible break
+	// First find the first visible character
+	nextBreak = ll->FindBefore(xStart, lineStart, lineEnd);
+	// Now back to a style break
+	while ((nextBreak > lineStart) && (ll->styles[nextBreak] == ll->styles[nextBreak - 1])) {
+		nextBreak--;
+	}
+
+	if (ll->selStart != ll->selEnd) {
+		Insert(ll->selStart - posLineStart - 1);
+		Insert(ll->selEnd - posLineStart - 1);
+	}
+
+	Insert(ll->edgeColumn - 1);
+	Insert(lineEnd - 1);
+	saeNext = (saeLen > 0) ? selAndEdge[0] : -1;
+}
+
+int BreakFinder::First() {
+	return nextBreak;
+}
+
+int BreakFinder::Next() {
+	if (subBreak == -1) {
+		int prev = nextBreak;
+		while (nextBreak < lineEnd) {
+			if ((ll->styles[nextBreak] != ll->styles[nextBreak + 1]) ||
+					(nextBreak == saeNext) ||
+					IsControlCharacter(ll->chars[nextBreak]) || IsControlCharacter(ll->chars[nextBreak + 1])) {
+				if (nextBreak == saeNext) {
+					saeCurrentPos++;
+					saeNext = (saeLen > saeCurrentPos) ? selAndEdge[saeCurrentPos] : -1;
+				}
+				nextBreak++;
+				if ((nextBreak - prev) < lengthStartSubdivision) {
+					return nextBreak;
+				}
+				break;
+			}
+			nextBreak++;
+		}
+		if ((nextBreak - prev) < lengthStartSubdivision) {
+			return nextBreak;
+		}
+		subBreak = prev;
+	}
+	// Splitting up a long run from prev to nextBreak in lots of approximately lengthEachSubdivision.
+	// For very long runs add extra breaks after spaces or if no spaces before low punctuation.
+	if ((nextBreak - subBreak) <= lengthEachSubdivision) {
+		subBreak = -1;
+		return nextBreak;
+	} else {
+		int lastGoodBreak = -1;
+		int lastOKBreak = -1;
+		int j;
+		for (j = subBreak + 1; j <= nextBreak; j++) {
+			if (IsSpaceOrTab(ll->chars[j - 1]) && !IsSpaceOrTab(ll->chars[j])) {
+				lastGoodBreak = j;
+			}
+			if (ll->chars[j] < 'A') {
+				lastOKBreak = j;
+			}
+			if (((j - subBreak) >= lengthEachSubdivision) && ((lastGoodBreak >= 0) || (lastOKBreak >= 0))) {
+				break;
+			}
+		}
+		if (lastGoodBreak >= 0) {
+			subBreak = lastGoodBreak;
+		} else if (lastOKBreak >= 0) {
+			subBreak = lastOKBreak;
+		} else {
+			subBreak = nextBreak;
+		}
+		if (subBreak >= nextBreak) {
+			subBreak = -1;
+			return nextBreak;
+		} else {
+			return subBreak;
+		}
+	}
+}
+
+PositionCacheEntry::PositionCacheEntry() :
+	styleNumber(0), len(0), clock(0), positions(0) {
+}
+
+void PositionCacheEntry::Set(unsigned int styleNumber_, const char *s_,
+	unsigned int len_, int *positions_, unsigned int clock_) {
+	Clear();
+	styleNumber = styleNumber_;
+	len = len_;
+	clock = clock_;
+	if (s_ && positions_) {
+		positions = new short[len + (len + 1) / 2];
+		for (unsigned int i=0;i<len;i++) {
+			positions[i] = static_cast<short>(positions_[i]);
+		}
+		memcpy(reinterpret_cast<char *>(positions + len), s_, len);
+	}
+}
+
+PositionCacheEntry::~PositionCacheEntry() {
+	Clear();
+}
+
+void PositionCacheEntry::Clear() {
+	delete []positions;
+	positions = 0;
+	styleNumber = 0;
+	len = 0;
+	clock = 0;
+}
+
+bool PositionCacheEntry::Retrieve(unsigned int styleNumber_, const char *s_,
+	unsigned int len_, int *positions_) const {
+	if ((styleNumber == styleNumber_) && (len == len_) &&
+		(memcmp(reinterpret_cast<char *>(positions + len), s_, len)== 0)) {
+		for (unsigned int i=0;i<len;i++) {
+			positions_[i] = positions[i];
+		}
+		return true;
+	} else {
+		return false;
+	}
+}
+
+int PositionCacheEntry::Hash(unsigned int styleNumber, const char *s, unsigned int len) {
+	unsigned int ret = s[0] << 7;
+	for (unsigned int i=0; i<len; i++) {
+		ret *= 1000003;
+		ret ^= s[i];
+	}
+	ret *= 1000003;
+	ret ^= len;
+	ret *= 1000003;
+	ret ^= styleNumber;
+	return ret;
+}
+
+bool PositionCacheEntry::NewerThan(const PositionCacheEntry &other) {
+	return clock > other.clock;
+}
+
+void PositionCacheEntry::ResetClock() {
+	if (clock > 0) {
+		clock = 1;
+	}
+}
+
+PositionCache::PositionCache() {
+	size = 0x400;
+	clock = 1;
+	pces = new PositionCacheEntry[size];
+	allClear = true;
+}
+
+PositionCache::~PositionCache() {
+	Clear();
+	delete []pces;
+}
+
+void PositionCache::Clear() {
+	if (!allClear) {
+		for (size_t i=0;i<size;i++) {
+			pces[i].Clear();
+		}
+	}
+	clock = 1;
+	allClear = true;
+}
+
+void PositionCache::SetSize(size_t size_) {
+	Clear();
+	delete []pces;
+	size = size_;
+	pces = new PositionCacheEntry[size];
+}
+
+void PositionCache::MeasureWidths(Surface *surface, ViewStyle &vstyle, unsigned int styleNumber,
+	const char *s, unsigned int len, int *positions) {
+	allClear = false;
+	int probe = -1;
+	if ((size > 0) && (len < 30)) {
+		// Only store short strings in the cache so it doesn't churn with
+		// long comments with only a single comment.
+
+		// Two way associative: try two probe positions.
+		int hashValue = PositionCacheEntry::Hash(styleNumber, s, len);
+		probe = hashValue % size;
+		if (pces[probe].Retrieve(styleNumber, s, len, positions)) {
+			return;
+		}
+		int probe2 = (hashValue * 37) % size;
+		if (pces[probe2].Retrieve(styleNumber, s, len, positions)) {
+			return;
+		}
+		// Not found. Choose the oldest of the two slots to replace
+		if (pces[probe].NewerThan(pces[probe2])) {
+			probe = probe2;
+		}
+	}
+	surface->MeasureWidths(vstyle.styles[styleNumber].font, s, len, positions);
+	if (probe >= 0) {
+		clock++;
+		if (clock > 60000) {
+			// Since there are only 16 bits for the clock, wrap it round and
+			// reset all cache entries so none get stuck with a high clock.
+			for (size_t i=0;i<size;i++) {
+				pces[i].ResetClock();
+			}
+			clock = 2;
+		}
+		pces[probe].Set(styleNumber, s, len, positions, clock);
+	}
+}
diff --git a/src/PositionCache.h b/src/PositionCache.h
new file mode 100644
index 000000000..fc261fbbc
--- /dev/null
+++ b/src/PositionCache.h
@@ -0,0 +1,154 @@
+// Scintilla source code edit control
+/** @file PositionCache.h
+ ** Classes for caching layout information.
+ **/
+// Copyright 1998-2007 by Neil Hodgson <neilh@scintilla.org>
+// The License.txt file describes the conditions under which this software may be distributed.
+
+#ifndef POSITIONCACHE_H
+#define POSITIONCACHE_H
+
+static inline bool IsEOLChar(char ch) {
+	return (ch == '\r') || (ch == '\n');
+}
+
+/**
+ */
+class LineLayout {
+private:
+	friend class LineLayoutCache;
+	int *lineStarts;
+	int lenLineStarts;
+	/// Drawing is only performed for @a maxLineLength characters on each line.
+	int lineNumber;
+	bool inCache;
+public:
+	enum { wrapWidthInfinite = 0x7ffffff };
+	int maxLineLength;
+	int numCharsInLine;
+	enum validLevel { llInvalid, llCheckTextAndStyle, llPositions, llLines } validity;
+	int xHighlightGuide;
+	bool highlightColumn;
+	int selStart;
+	int selEnd;
+	bool containsCaret;
+	int edgeColumn;
+	char *chars;
+	unsigned char *styles;
+	int styleBitsSet;
+	char *indicators;
+	int *positions;
+	char bracePreviousStyles[2];
+
+	// Hotspot support
+	int hsStart;
+	int hsEnd;
+
+	// Wrapped line support
+	int widthLine;
+	int lines;
+
+	LineLayout(int maxLineLength_);
+	virtual ~LineLayout();
+	void Resize(int maxLineLength_);
+	void Free();
+	void Invalidate(validLevel validity_);
+	int LineStart(int line) const;
+	int LineLastVisible(int line) const;
+	void SetLineStart(int line, int start);
+	void SetBracesHighlight(Range rangeLine, Position braces[],
+		char bracesMatchStyle, int xHighlight);
+	void RestoreBracesHighlight(Range rangeLine, Position braces[]);
+	int FindBefore(int x, int lower, int upper) const;
+};
+
+/**
+ */
+class LineLayoutCache {
+	int level;
+	int length;
+	int size;
+	LineLayout **cache;
+	bool allInvalidated;
+	int styleClock;
+	int useCount;
+	void Allocate(int length_);
+	void AllocateForLevel(int linesOnScreen, int linesInDoc);
+public:
+	LineLayoutCache();
+	virtual ~LineLayoutCache();
+	void Deallocate();
+	enum {
+		llcNone=SC_CACHE_NONE,
+		llcCaret=SC_CACHE_CARET,
+		llcPage=SC_CACHE_PAGE,
+		llcDocument=SC_CACHE_DOCUMENT
+	};
+	void Invalidate(LineLayout::validLevel validity_);
+	void SetLevel(int level_);
+	int GetLevel() { return level; }
+	LineLayout *Retrieve(int lineNumber, int lineCaret, int maxChars, int styleClock_,
+		int linesOnScreen, int linesInDoc);
+	void Dispose(LineLayout *ll);
+};
+
+class PositionCacheEntry {
+	unsigned int styleNumber:8;
+	unsigned int len:8;
+	unsigned int clock:16;
+	short *positions;
+public:
+	PositionCacheEntry();
+	~PositionCacheEntry();
+	void Set(unsigned int styleNumber_, const char *s_, unsigned int len_, int *positions_, unsigned int clock);
+	void Clear();
+	bool Retrieve(unsigned int styleNumber_, const char *s_, unsigned int len_, int *positions_) const;
+	static int Hash(unsigned int styleNumber, const char *s, unsigned int len);
+	bool NewerThan(const PositionCacheEntry &other);
+	void ResetClock();
+};
+
+// Class to break a line of text into shorter runs at sensible places.
+class BreakFinder {
+	// If a whole run is longer than lengthStartSubdivision then subdivide
+	// into smaller runs at spaces or punctuation.
+	enum { lengthStartSubdivision = 10 };
+	// Try to make each subdivided run lengthEachSubdivision or shorter.
+	enum { lengthEachSubdivision = 5 };
+	LineLayout *ll;
+	int lineStart;
+	int lineEnd;
+	int posLineStart;
+	int nextBreak;
+	int selAndEdge[5];
+	unsigned int saeLen;
+	unsigned int saeCurrentPos;
+	int saeNext;
+	int subBreak;
+	void Insert(int val);
+public:
+	BreakFinder(LineLayout *ll_, int lineStart_, int lineEnd_, int posLineStart_, int xStart);
+	int First();
+	int Next();
+};
+
+class PositionCache {
+	PositionCacheEntry *pces;
+	size_t size;
+	unsigned int clock;
+	bool allClear;
+public:
+	PositionCache();
+	~PositionCache();
+	void Clear();
+	void SetSize(size_t size_);
+	int GetSize() { return size; }
+	void MeasureWidths(Surface *surface, ViewStyle &vstyle, unsigned int styleNumber,
+		const char *s, unsigned int len, int *positions);
+};
+
+inline bool IsSpaceOrTab(int ch) {
+	return ch == ' ' || ch == '\t';
+}
+
+#endif
diff --git a/src/ScintillaBase.cxx b/src/ScintillaBase.cxx
index e0ac652fb..e2dd9473e 100644
--- a/src/ScintillaBase.cxx
+++ b/src/ScintillaBase.cxx
@@ -37,6 +37,7 @@
 #include "CharClassify.h"
 #include "Decoration.h"
 #include "Document.h"
+#include "PositionCache.h"
 #include "Editor.h"
 #include "ScintillaBase.h"
 
diff --git a/vcbuild/SciLexer.dsp b/vcbuild/SciLexer.dsp
index 4a3b01c8a..015835908 100644
--- a/vcbuild/SciLexer.dsp
+++ b/vcbuild/SciLexer.dsp
@@ -402,6 +402,10 @@ SOURCE=..\win32\PlatWin.cxx
 # End Source File
 # Begin Source File
 
+SOURCE=..\src\PositionCache.cxx
+# End Source File
+# Begin Source File
+
 SOURCE=..\src\PropSet.cxx
 # End Source File
 # Begin Source File
diff --git a/win32/ScintillaWin.cxx b/win32/ScintillaWin.cxx
index 6d7f1268d..248513e18 100644
--- a/win32/ScintillaWin.cxx
+++ b/win32/ScintillaWin.cxx
@@ -45,6 +45,7 @@
 #include "CharClassify.h"
 #include "Decoration.h"
 #include "Document.h"
+#include "PositionCache.h"
 #include "Editor.h"
 #include "ScintillaBase.h"
 #include "UniConversion.h"
diff --git a/win32/makefile b/win32/makefile
index c9da20826..63b30dd56 100644
--- a/win32/makefile
+++ b/win32/makefile
@@ -64,14 +64,14 @@ LexTADS3.o LexTCL.o LexTeX.o LexVB.o LexVerilog.o LexVHDL.o LexYAML.o
 
 SOBJS	= ScintillaWin.o ScintillaBase.o Editor.o CharClassify.o Decoration.o \
 	Document.o ContractionState.o CellBuffer.o CallTip.o \
-	ScintRes.o PlatWin.o KeyMap.o Indicator.o LineMarker.o RESearch.o RunStyles.o \
+	ScintRes.o PlatWin.o PositionCache.o KeyMap.o Indicator.o LineMarker.o RESearch.o RunStyles.o \
 	Style.o ViewStyle.o AutoComplete.o UniConversion.o PropSet.o XPM.o
 $(COMPONENT): $(SOBJS) Scintilla.def
 	$(DLLWRAP) --add-stdcall-alias --target i386-mingw32 -o $@ $(SOBJS) $(LDFLAGS) -s --relocatable
 
 LOBJS	= ScintillaWinL.o ScintillaBaseL.o Editor.o CharClassify.o Decoration.o \
 	Document.o ContractionState.o CellBuffer.o CallTip.o \
-	ScintRes.o PlatWin.o KeyMap.o Indicator.o LineMarker.o RESearch.o RunStyles.o \
+	ScintRes.o PlatWin.o PositionCache.o KeyMap.o Indicator.o LineMarker.o RESearch.o RunStyles.o \
 	Style.o ViewStyle.o AutoComplete.o UniConversion.o KeyWords.o \
 	DocumentAccessor.o PropSet.o ExternalLexer.o StyleContext.o XPM.o $(LEXOBJS)
 $(LEXCOMPONENT): $(LOBJS) Scintilla.def
diff --git a/win32/scintilla.mak b/win32/scintilla.mak
index da3c506bd..b6b4749ef 100644
--- a/win32/scintilla.mak
+++ b/win32/scintilla.mak
@@ -99,6 +99,7 @@ SOBJS=\
 	$(DIR_O)\KeyMap.obj \
 	$(DIR_O)\LineMarker.obj \
 	$(DIR_O)\PlatWin.obj \
+	$(DIR_O)\PositionCache.obj \
 	$(DIR_O)\PropSet.obj \
 	$(DIR_O)\RESearch.obj \
 	$(DIR_O)\RunStyles.obj \
@@ -193,6 +194,7 @@ LOBJS=\
 	$(DIR_O)\KeyWords.obj \
 	$(DIR_O)\LineMarker.obj \
 	$(DIR_O)\PlatWin.obj \
+	$(DIR_O)\PositionCache.obj \
 	$(DIR_O)\PropSet.obj \
 	$(DIR_O)\RESearch.obj \
 	$(DIR_O)\RunStyles.obj \
@@ -280,7 +282,7 @@ $(DIR_O)\Editor.obj: ../src/Editor.cxx ../include/Platform.h ../include/Scintill
   ../src/Partitioning.h ../src/CellBuffer.h ../src/KeyMap.h \
   ../src/RunStyles.h ../src/Indicator.h ../src/XPM.h ../src/LineMarker.h \
   ../src/Style.h ../src/ViewStyle.h ../src/CharClassify.h \
-  ../src/Decoration.h ../src/Document.h ../src/Editor.h
+  ../src/Decoration.h ../src/Document.h ../src/Editor.h ../src/PositionCache.h
 $(DIR_O)\ExternalLexer.obj: ../src/ExternalLexer.cxx ../include/Platform.h \
   ../include/Scintilla.h ../include/SciLexer.h ../include/PropSet.h \
   ../include/SString.h ../include/Accessor.h ../src/DocumentAccessor.h \
@@ -427,6 +429,12 @@ $(DIR_O)\LineMarker.obj: ../src/LineMarker.cxx ../include/Platform.h \
   ../include/Scintilla.h ../src/XPM.h ../src/LineMarker.h
 $(DIR_O)\PlatWin.obj: PlatWin.cxx ../include/Platform.h PlatformRes.h \
   ../src/UniConversion.h ../src/XPM.h
+$(DIR_O)\PositionCache.obj: ../src/Editor.cxx ../include/Platform.h ../include/Scintilla.h \
+  ../src/ContractionState.h ../src/SVector.h ../src/SplitVector.h \
+  ../src/Partitioning.h ../src/CellBuffer.h ../src/KeyMap.h \
+  ../src/RunStyles.h ../src/Indicator.h ../src/XPM.h ../src/LineMarker.h \
+  ../src/Style.h ../src/ViewStyle.h ../src/CharClassify.h \
+  ../src/Decoration.h ../src/Document.h ../src/Editor.h ../src/PositionCache.h
 $(DIR_O)\PropSet.obj: ../src/PropSet.cxx ../include/Platform.h ../include/PropSet.h \
   ../include/SString.h
 $(DIR_O)\RESearch.obj: ../src/RESearch.cxx ../src/CharClassify.h ../src/RESearch.h
diff --git a/win32/scintilla_vc6.mak b/win32/scintilla_vc6.mak
index 2a35235e3..9b9c9b356 100644
--- a/win32/scintilla_vc6.mak
+++ b/win32/scintilla_vc6.mak
@@ -101,6 +101,7 @@ SOBJS=\
 	$(DIR_O)\KeyMap.obj \
 	$(DIR_O)\LineMarker.obj \
 	$(DIR_O)\PlatWin.obj \
+	$(DIR_O)\PositionCache.obj \
 	$(DIR_O)\PropSet.obj \
 	$(DIR_O)\RESearch.obj \
 	$(DIR_O)\RunStyles.obj \
@@ -195,6 +196,7 @@ LOBJS=\
 	$(DIR_O)\KeyWords.obj \
 	$(DIR_O)\LineMarker.obj \
 	$(DIR_O)\PlatWin.obj \
+	$(DIR_O)\PositionCache.obj \
 	$(DIR_O)\RunStyles.obj \
 	$(DIR_O)\RESearch.obj \
 	$(DIR_O)\PropSet.obj \