# HG changeset patch
# User Bram Moolenaar <bram@vim.org>
# Date 1407329550 -7200
# Node ID 1bff71d202621d97acc4ef21ce9f47b78f68bda3
# Parent  e21d20c8500f092324a948244f4664cbe8a324ab
updated for version 7.4.393
Problem:    Text drawing on newer MS-Windows systems is suboptimal.  Some
	    multi-byte characters are not displayed, even though the same font
	    in Notepad can display them. (Srinath Avadhanula)
Solution:   Add the 'renderoptions' option to enable Direct-X drawing. (Taro
	    Muraoka)

diff --git a/runtime/doc/eval.txt b/runtime/doc/eval.txt
--- a/runtime/doc/eval.txt
+++ b/runtime/doc/eval.txt
@@ -6622,6 +6622,7 @@ dialog_con		Compiled with console dialog
 dialog_gui		Compiled with GUI dialog support.
 diff			Compiled with |vimdiff| and 'diff' support.
 digraphs		Compiled with support for digraphs.
+directx			Compiled with support for Direct-X and 'renderoptions'.
 dnd			Compiled with support for the "~ register |quote_~|.
 dos16			16 bits DOS version of Vim.
 dos32			32 bits DOS (DJGPP) version of Vim.
diff --git a/runtime/doc/options.txt b/runtime/doc/options.txt
--- a/runtime/doc/options.txt
+++ b/runtime/doc/options.txt
@@ -5650,6 +5650,77 @@ A jump table for the options with a shor
 	this option at the default "on".  Only switch it off when working with
 	old Vi scripts.
 
+                                               *'renderoptions'* *'rop'*
+'renderoptions' 'rop'	string  (default: empty)
+			global
+			{not in Vi}
+			{only available when compiled with GUI and DIRECTX on
+			MS-Windows}
+	Select a text renderer and set its options.  The options depend on the
+	renderer.
+
+	Syntax: >
+		set rop=type:{renderer}(,{name}:{value})*
+<
+	Currently, only one optional renderer is available.
+
+	render	behavior    ~
+	directx	Vim will draw text using DirectX (DirectWrite).  It makes
+		drawn glyphs more beautiful than default GDI.
+		It requires 'encoding' is "utf-8", and only works on
+		MS-Windows Vista or newer version.
+
+		Options:
+		  name	    meaning		type	value       ~
+		  gamma	    gamma		float	1.0 - 2.2 (maybe)
+		  contrast  enhancedContrast	float	(unknown)
+		  level	    clearTypeLevel	float	(unknown)
+		  geom	    pixelGeometry	int	0 - 2 (see below)
+		  renmode   renderingMode	int	0 - 6 (see below)
+		  taamode   textAntialiasMode	int	0 - 3 (see below)
+
+		See this URL for detail:
+		  http://msdn.microsoft.com/en-us/library/dd368190.aspx
+
+		For geom: structure of a device pixel.
+		  0 - DWRITE_PIXEL_GEOMETRY_FLAT
+		  1 - DWRITE_PIXEL_GEOMETRY_RGB
+		  2 - DWRITE_PIXEL_GEOMETRY_BGR
+
+		See this URL for detail:
+		  http://msdn.microsoft.com/en-us/library/dd368114.aspx
+
+		For renmode: method of rendering glyphs.
+		  0 - DWRITE_RENDERING_MODE_DEFAULT
+		  1 - DWRITE_RENDERING_MODE_ALIASED
+		  2 - DWRITE_RENDERING_MODE_GDI_CLASSIC
+		  3 - DWRITE_RENDERING_MODE_GDI_NATURAL
+		  4 - DWRITE_RENDERING_MODE_NATURAL
+		  5 - DWRITE_RENDERING_MODE_NATURAL_SYMMETRIC
+		  6 - DWRITE_RENDERING_MODE_OUTLINE
+
+		See this URL for detail:
+		  http://msdn.microsoft.com/en-us/library/dd368118.aspx
+
+		For taamode: antialiasing mode used for drawing text.
+		  0 - D2D1_TEXT_ANTIALIAS_MODE_DEFAULT
+		  1 - D2D1_TEXT_ANTIALIAS_MODE_CLEARTYPE
+		  2 - D2D1_TEXT_ANTIALIAS_MODE_GRAYSCALE
+		  3 - D2D1_TEXT_ANTIALIAS_MODE_ALIASED
+
+		See this URL for detail:
+		  http://msdn.microsoft.com/en-us/library/dd368170.aspx
+
+		Example: >
+		  set encoding=utf-8
+		  set gfn=Ricty_Diminished:h12:cSHIFTJIS
+		  set rop=type:directx
+<
+		If select a raster font (Courier, Terminal or FixedSys) to
+		'guifont', it fallbacks to be drawn by GDI automatically.
+
+	Other render types are currently not supported.
+
 						*'report'*
 'report'		number	(default 2)
 			global
diff --git a/runtime/doc/various.txt b/runtime/doc/various.txt
--- a/runtime/doc/various.txt
+++ b/runtime/doc/various.txt
@@ -337,6 +337,7 @@ N  *+dialog_con*	Support for |:confirm| 
 N  *+dialog_con_gui*	Support for |:confirm| with GUI and console dialog.
 N  *+diff*		|vimdiff| and 'diff'
 N  *+digraphs*		|digraphs| *E196*
+m  *+directx*		Win32 GUI only: DirectX and |'renderoptions'|
    *+dnd*		Support for DnD into the "~ register |quote_~|.
 B  *+emacs_tags*	|emacs-tags| files
 N  *+eval*		expression evaluation |eval.txt|
diff --git a/src/Make_cyg.mak b/src/Make_cyg.mak
--- a/src/Make_cyg.mak
+++ b/src/Make_cyg.mak
@@ -8,6 +8,7 @@
 # Cygwin application use the Makefile (just like on Unix).
 #
 # GUI		no or yes: set to yes if you want the GUI version (yes)
+# DIRECTX	no or yes: set to yes if you want use DirectWrite (no)
 # PERL		define to path to Perl dir to get Perl support (not defined)
 #   PERL_VER	  define to version of Perl being used (56)
 #   DYNAMIC_PERL  no or yes: set to yes to load the Perl DLL dynamically (yes)
@@ -88,6 +89,10 @@ ifndef ARCH
 ARCH = i386
 endif
 
+ifndef DIRECTX
+DIRECTX = no
+endif
+
 ifndef WINVER
 WINVER = 0x0500
 endif
@@ -470,6 +475,15 @@ endif
 endif
 
 ##############################
+ifeq (yes, $(DIRECTX))
+# Only allow DIRECTX for a GUI build.
+DEFINES += -DFEAT_DIRECTX -DDYNAMIC_DIRECTX
+EXTRA_OBJS += $(OUTDIR)/gui_dwrite.o
+EXTRA_LIBS += -ld2d1 -ldwrite
+USE_STDCPLUS = yes
+endif
+
+##############################
 ifdef XPM
 # Only allow XPM for a GUI build.
 DEFINES += -DFEAT_XPM_W32
@@ -495,11 +509,7 @@ ifeq (yes, $(OLE))
 DEFINES += -DFEAT_OLE
 EXTRA_OBJS += $(OUTDIR)/if_ole.o
 EXTRA_LIBS += -loleaut32
-ifeq (yes, $(STATIC_STDCPLUS))
-EXTRA_LIBS += -Wl,-Bstatic -lstdc++ -Wl,-Bdynamic
-else
-EXTRA_LIBS += -lstdc++
-endif
+USE_STDCPLUS = yes
 endif
 
 ##############################
@@ -513,6 +523,15 @@ MKDIR = mkdir
 DIRSLASH = \\
 endif
 
+##############################
+ifeq (yes, $(USE_STDCPLUS))
+ifeq (yes, $(STATIC_STDCPLUS))
+EXTRA_LIBS += -Wl,-Bstatic -lstdc++ -Wl,-Bdynamic
+else
+EXTRA_LIBS += -lstdc++
+endif
+endif
+
 #>>>>> end of choices
 ###########################################################################
 
@@ -643,6 +662,9 @@ distclean: clean
 $(OUTDIR)/gui_w32.o:	gui_w32.c gui_w48.c $(INCL)
 	$(CC) -c $(CFLAGS) gui_w32.c -o $(OUTDIR)/gui_w32.o
 
+$(OUTDIR)/gui_dwrite.o:	gui_dwrite.cpp $(INCL) gui_dwrite.h
+	$(CC) -c $(CFLAGS) gui_dwrite.cpp -o $(OUTDIR)/gui_dwrite.o
+
 $(OUTDIR)/if_cscope.o:	if_cscope.c $(INCL) if_cscope.h
 	$(CC) -c $(CFLAGS) if_cscope.c -o $(OUTDIR)/if_cscope.o
 
diff --git a/src/Make_ming.mak b/src/Make_ming.mak
--- a/src/Make_ming.mak
+++ b/src/Make_ming.mak
@@ -31,6 +31,8 @@ DEBUG=no
 OPTIMIZE=MAXSPEED
 # set to yes to make gvim, no for vim
 GUI=yes
+# set to yes if you want to use DirectWrite (DirectX)
+DIRECTX=no
 # FEATURES=[TINY | SMALL  | NORMAL | BIG | HUGE]
 # Set to TINY to make minimal version (few features).
 FEATURES=BIG
@@ -456,6 +458,14 @@ endif
 endif
 endif
 
+# DirectWrite (DirectX)
+ifeq ($(DIRECTX),yes)
+# Only allow DirectWrite for a GUI build.
+ifeq (yes, $(GUI))
+DEFINES += -DFEAT_DIRECTX -DDYNAMIC_DIRECTX
+endif
+endif
+
 # Only allow XPM for a GUI build.
 ifeq (yes, $(GUI))
 
@@ -593,6 +603,14 @@ OBJ += $(OUTDIR)/netbeans.o
 LIB += -lwsock32
 endif
 endif
+ifeq ($(DIRECTX),yes)
+# Only allow DIRECTX for a GUI build.
+ifeq (yes, $(GUI))
+OBJ += $(OUTDIR)/gui_dwrite.o
+LIB += -ld2d1 -ldwrite
+USE_STDCPLUS = yes
+endif
+endif
 ifdef XPM
 # Only allow XPM for a GUI build.
 ifeq (yes, $(GUI))
@@ -650,11 +668,7 @@ endif
 ifeq (yes, $(OLE))
 LIB += -loleaut32
 OBJ += $(OUTDIR)/if_ole.o
-ifeq (yes, $(STATIC_STDCPLUS))
-LIB += -Wl,-Bstatic -lstdc++ -Wl,-Bdynamic
-else
-LIB += -lstdc++
-endif
+USE_STDCPLUS = yes
 endif
 
 ifeq (yes, $(MBYTE))
@@ -678,6 +692,14 @@ endif
 DEFINES+=-DDYNAMIC_ICONV
 endif
 
+ifeq (yes, $(USE_STDCPLUS))
+ifeq (yes, $(STATIC_STDCPLUS))
+LIB += -Wl,-Bstatic -lstdc++ -Wl,-Bdynamic
+else
+LIB += -lstdc++
+endif
+endif
+
 all: $(TARGET) vimrun.exe xxd/xxd.exe install.exe uninstal.exe GvimExt/gvimext.dll
 
 vimrun.exe: vimrun.c
@@ -751,6 +773,9 @@ INCL = vim.h feature.h os_win32.h os_dos
 $(OUTDIR)/gui_w32.o:	gui_w32.c gui_w48.c $(INCL)
 	$(CC) -c $(CFLAGS) gui_w32.c -o $(OUTDIR)/gui_w32.o
 
+$(OUTDIR)/gui_dwrite.o:	gui_dwrite.cpp $(INCL) gui_dwrite.h
+	$(CC) -c $(CFLAGS) gui_dwrite.cpp -o $(OUTDIR)/gui_dwrite.o
+
 $(OUTDIR)/if_cscope.o:	if_cscope.c $(INCL) if_cscope.h
 	$(CC) -c $(CFLAGS) if_cscope.c -o $(OUTDIR)/if_cscope.o
 
diff --git a/src/Make_mvc.mak b/src/Make_mvc.mak
--- a/src/Make_mvc.mak
+++ b/src/Make_mvc.mak
@@ -24,6 +24,9 @@
 #
 #	GUI interface: GUI=yes (default is no)
 #
+#	GUI with DirectWrite(DirectX): DIRECTX=yes
+#	  (default is no, requires GUI=yes)
+#
 #	OLE interface: OLE=yes (usually with GUI=yes)
 #
 #	Multibyte support: MBYTE=yes (default is no)
@@ -168,6 +171,9 @@ OBJDIR = .\ObjG
 !else
 OBJDIR = .\ObjC
 !endif
+!if "$(DIRECTX)" == "yes"
+OBJDIR = $(OBJDIR)X
+!endif
 !if "$(OLE)" == "yes"
 OBJDIR = $(OBJDIR)O
 !endif
@@ -292,6 +298,13 @@ NBDEBUG_SRC	= nbdebug.c
 NETBEANS_LIB	= WSock32.lib
 !endif
 
+# DirectWrite(DirectX)
+!if "$(DIRECTX)" == "yes"
+DIRECTX_DEFS	= -DFEAT_DIRECTX -DDYNAMIC_DIRECTX
+DIRECTX_INCL	= gui_dwrite.h
+DIRECTX_OBJ	= $(OUTDIR)\gui_dwrite.obj
+!endif
+
 !ifndef XPM
 # XPM is not set, use the included xpm files, depending on the architecture.
 !if "$(CPU)" == "AMD64"
@@ -642,6 +655,12 @@ GUI_LIB = \
 SUBSYSTEM = console
 !endif
 
+!if "$(GUI)" == "yes" && "$(DIRECTX)" == "yes"
+CFLAGS = $(CFLAGS) $(DIRECTX_DEFS)
+GUI_INCL = $(GUI_INCL) $(DIRECTX_INCL)
+GUI_OBJ = $(GUI_OBJ) $(DIRECTX_OBJ)
+!endif
+
 # iconv.dll library (dynamically loaded)
 !ifndef ICONV
 ICONV = yes
@@ -1107,6 +1126,8 @@ testclean:
 
 $(OUTDIR)/gui_w32.obj:	$(OUTDIR) gui_w32.c gui_w48.c $(INCL) $(GUI_INCL)
 
+$(OUTDIR)/gui_dwrite.obj:	$(OUTDIR) gui_dwrite.cpp $(INCL) $(GUI_INCL)
+
 $(OUTDIR)/if_cscope.obj: $(OUTDIR) if_cscope.c  $(INCL)
 
 $(OUTDIR)/if_lua.obj: $(OUTDIR) if_lua.c  $(INCL)
diff --git a/src/eval.c b/src/eval.c
--- a/src/eval.c
+++ b/src/eval.c
@@ -12464,6 +12464,9 @@ f_has(argvars, rettv)
 #ifdef FEAT_DIGRAPHS
 	"digraphs",
 #endif
+#ifdef FEAT_DIRECTX
+	"directx",
+#endif
 #ifdef FEAT_DND
 	"dnd",
 #endif
diff --git a/src/gui_dwrite.cpp b/src/gui_dwrite.cpp
new file mode 100644
--- /dev/null
+++ b/src/gui_dwrite.cpp
@@ -0,0 +1,901 @@
+/* vi:set ts=8 sts=4 sw=4 noet: */
+/*
+ * Author: MURAOKA Taro <koron.kaoriya@gmail.com>
+ *
+ * Contributors:
+ *  - Ken Takata
+ *
+ * Copyright (C) 2013 MURAOKA Taro <koron.kaoriya@gmail.com>
+ * THIS FILE IS DISTRIBUTED UNDER THE VIM LICENSE.
+ */
+
+#define WIN32_LEAN_AND_MEAN
+
+#ifndef DYNAMIC_DIRECTX
+# if WINVER < 0x0600
+#  error WINVER must be 0x0600 or above to use DirectWrite(DirectX)
+# endif
+#endif
+
+#include <windows.h>
+#include <crtdbg.h>
+#include <assert.h>
+#include <math.h>
+#include <d2d1.h>
+#include <d2d1helper.h>
+#include <dwrite.h>
+
+#include "gui_dwrite.h"
+
+#ifdef __MINGW32__
+# define __maybenull	SAL__maybenull
+# define __in		SAL__in
+# define __out		SAL__out
+#endif
+
+#ifdef DYNAMIC_DIRECTX
+extern "C" HINSTANCE vimLoadLib(char *name);
+
+typedef int (WINAPI *PGETUSERDEFAULTLOCALENAME)(LPWSTR, int);
+typedef HRESULT (WINAPI *PD2D1CREATEFACTORY)(D2D1_FACTORY_TYPE,
+	REFIID, const D2D1_FACTORY_OPTIONS *, void **);
+typedef HRESULT (WINAPI *PDWRITECREATEFACTORY)(DWRITE_FACTORY_TYPE,
+	REFIID, IUnknown **);
+
+static HINSTANCE hD2D1DLL = NULL;
+static HINSTANCE hDWriteDLL = NULL;
+
+static PGETUSERDEFAULTLOCALENAME pGetUserDefaultLocaleName = NULL;
+static PD2D1CREATEFACTORY pD2D1CreateFactory = NULL;
+static PDWRITECREATEFACTORY pDWriteCreateFactory = NULL;
+
+#define GetUserDefaultLocaleName	(*pGetUserDefaultLocaleName)
+#define D2D1CreateFactory		(*pD2D1CreateFactory)
+#define DWriteCreateFactory		(*pDWriteCreateFactory)
+
+    static void
+unload(HINSTANCE &hinst)
+{
+    if (hinst != NULL)
+    {
+	FreeLibrary(hinst);
+	hinst = NULL;
+    }
+}
+#endif // DYNAMIC_DIRECTX
+
+template <class T> inline void SafeRelease(T **ppT)
+{
+    if (*ppT)
+    {
+	(*ppT)->Release();
+	*ppT = NULL;
+    }
+}
+
+struct GdiTextRendererContext
+{
+    // const fields.
+    COLORREF color;
+    FLOAT cellWidth;
+
+    // working fields.
+    FLOAT offsetX;
+};
+
+    static DWRITE_PIXEL_GEOMETRY
+ToPixelGeometry(int value)
+{
+    switch (value)
+    {
+	default:
+	case 0:
+	    return DWRITE_PIXEL_GEOMETRY_FLAT;
+	case 1:
+	    return DWRITE_PIXEL_GEOMETRY_RGB;
+	case 2:
+	    return DWRITE_PIXEL_GEOMETRY_BGR;
+    }
+}
+
+    static int
+ToInt(DWRITE_PIXEL_GEOMETRY value)
+{
+    switch (value)
+    {
+	case DWRITE_PIXEL_GEOMETRY_FLAT:
+	    return 0;
+	case DWRITE_PIXEL_GEOMETRY_RGB:
+	    return 1;
+	case DWRITE_PIXEL_GEOMETRY_BGR:
+	    return 2;
+	default:
+	    return -1;
+    }
+}
+
+    static DWRITE_RENDERING_MODE
+ToRenderingMode(int value)
+{
+    switch (value)
+    {
+	default:
+	case 0:
+	    return DWRITE_RENDERING_MODE_DEFAULT;
+	case 1:
+	    return DWRITE_RENDERING_MODE_ALIASED;
+	case 2:
+	    return DWRITE_RENDERING_MODE_CLEARTYPE_GDI_CLASSIC;
+	case 3:
+	    return DWRITE_RENDERING_MODE_CLEARTYPE_GDI_NATURAL;
+	case 4:
+	    return DWRITE_RENDERING_MODE_CLEARTYPE_NATURAL;
+	case 5:
+	    return DWRITE_RENDERING_MODE_CLEARTYPE_NATURAL_SYMMETRIC;
+	case 6:
+	    return DWRITE_RENDERING_MODE_OUTLINE;
+    }
+}
+
+    static D2D1_TEXT_ANTIALIAS_MODE
+ToTextAntialiasMode(int value)
+{
+    switch (value)
+    {
+	default:
+	case 0:
+	    return D2D1_TEXT_ANTIALIAS_MODE_DEFAULT;
+	case 1:
+	    return D2D1_TEXT_ANTIALIAS_MODE_CLEARTYPE;
+	case 2:
+	    return D2D1_TEXT_ANTIALIAS_MODE_GRAYSCALE;
+	case 3:
+	    return D2D1_TEXT_ANTIALIAS_MODE_ALIASED;
+    }
+}
+
+    static int
+ToInt(DWRITE_RENDERING_MODE value)
+{
+    switch (value)
+    {
+	case DWRITE_RENDERING_MODE_DEFAULT:
+	    return 0;
+	case DWRITE_RENDERING_MODE_ALIASED:
+	    return 1;
+	case DWRITE_RENDERING_MODE_CLEARTYPE_GDI_CLASSIC:
+	    return 2;
+	case DWRITE_RENDERING_MODE_CLEARTYPE_GDI_NATURAL:
+	    return 3;
+	case DWRITE_RENDERING_MODE_CLEARTYPE_NATURAL:
+	    return 4;
+	case DWRITE_RENDERING_MODE_CLEARTYPE_NATURAL_SYMMETRIC:
+	    return 5;
+	case DWRITE_RENDERING_MODE_OUTLINE:
+	    return 6;
+	default:
+	    return -1;
+    }
+}
+
+class AdjustedGlyphRun : public DWRITE_GLYPH_RUN
+{
+private:
+    FLOAT mDelta;
+    FLOAT *mAdjustedAdvances;
+
+public:
+    AdjustedGlyphRun(
+	    const DWRITE_GLYPH_RUN *glyphRun,
+	    FLOAT cellWidth) :
+	DWRITE_GLYPH_RUN(*glyphRun),
+	mDelta(0.0f),
+	mAdjustedAdvances(new FLOAT[glyphRun->glyphCount])
+    {
+	assert(cellWidth != 0.0f);
+	for (UINT32 i = 0; i < glyphRun->glyphCount; ++i)
+	{
+	    FLOAT orig = glyphRun->glyphAdvances[i];
+	    FLOAT adjusted = adjustToCell(orig, cellWidth);
+	    mAdjustedAdvances[i] = adjusted;
+	    mDelta += adjusted - orig;
+	}
+	glyphAdvances = mAdjustedAdvances;
+    }
+
+    ~AdjustedGlyphRun(void)
+    {
+	delete[] mAdjustedAdvances;
+    }
+
+    FLOAT getDelta(void) const
+    {
+	return mDelta;
+    }
+
+    static FLOAT adjustToCell(FLOAT value, FLOAT cellWidth)
+    {
+	int cellCount = (int)floor(value / cellWidth + 0.5f);
+	if (cellCount < 1)
+	    cellCount = 1;
+	return cellCount * cellWidth;
+    }
+};
+
+class GdiTextRenderer : public IDWriteTextRenderer
+{
+public:
+    GdiTextRenderer(
+	    IDWriteBitmapRenderTarget* bitmapRenderTarget,
+	    IDWriteRenderingParams* renderingParams) :
+	cRefCount_(0),
+	pRenderTarget_(bitmapRenderTarget),
+	pRenderingParams_(renderingParams)
+    {
+	pRenderTarget_->AddRef();
+	pRenderingParams_->AddRef();
+	AddRef();
+    }
+
+    ~GdiTextRenderer()
+    {
+	SafeRelease(&pRenderTarget_);
+	SafeRelease(&pRenderingParams_);
+    }
+
+    IFACEMETHOD(IsPixelSnappingDisabled)(
+	__maybenull void* clientDrawingContext,
+	__out BOOL* isDisabled)
+    {
+	*isDisabled = FALSE;
+	return S_OK;
+    }
+
+    IFACEMETHOD(GetCurrentTransform)(
+	__maybenull void* clientDrawingContext,
+	__out DWRITE_MATRIX* transform)
+    {
+	//forward the render target's transform
+	pRenderTarget_->GetCurrentTransform(transform);
+	return S_OK;
+    }
+
+    IFACEMETHOD(GetPixelsPerDip)(
+	__maybenull void* clientDrawingContext,
+	__out FLOAT* pixelsPerDip)
+    {
+	*pixelsPerDip = pRenderTarget_->GetPixelsPerDip();
+	return S_OK;
+    }
+
+    IFACEMETHOD(DrawGlyphRun)(
+	__maybenull void* clientDrawingContext,
+	FLOAT baselineOriginX,
+	FLOAT baselineOriginY,
+	DWRITE_MEASURING_MODE measuringMode,
+	__in DWRITE_GLYPH_RUN const* glyphRun,
+	__in DWRITE_GLYPH_RUN_DESCRIPTION const* glyphRunDescription,
+	IUnknown* clientDrawingEffect)
+    {
+	HRESULT hr = S_OK;
+
+	GdiTextRendererContext *context =
+	    reinterpret_cast<GdiTextRendererContext*>(clientDrawingContext);
+
+	AdjustedGlyphRun adjustedGlyphRun(glyphRun, context->cellWidth);
+
+	// Pass on the drawing call to the render target to do the real work.
+	RECT dirtyRect = {0};
+
+	hr = pRenderTarget_->DrawGlyphRun(
+		baselineOriginX + context->offsetX,
+		baselineOriginY,
+		measuringMode,
+		&adjustedGlyphRun,
+		pRenderingParams_,
+		context->color,
+		&dirtyRect);
+
+	context->offsetX += adjustedGlyphRun.getDelta();
+
+	return hr;
+    }
+
+    IFACEMETHOD(DrawUnderline)(
+	__maybenull void* clientDrawingContext,
+	FLOAT baselineOriginX,
+	FLOAT baselineOriginY,
+	__in DWRITE_UNDERLINE const* underline,
+	IUnknown* clientDrawingEffect)
+    {
+	return E_NOTIMPL;
+    }
+
+    IFACEMETHOD(DrawStrikethrough)(
+	__maybenull void* clientDrawingContext,
+	FLOAT baselineOriginX,
+	FLOAT baselineOriginY,
+	__in DWRITE_STRIKETHROUGH const* strikethrough,
+	IUnknown* clientDrawingEffect)
+    {
+	return E_NOTIMPL;
+    }
+
+    IFACEMETHOD(DrawInlineObject)(
+	__maybenull void* clientDrawingContext,
+	FLOAT originX,
+	FLOAT originY,
+	IDWriteInlineObject* inlineObject,
+	BOOL isSideways,
+	BOOL isRightToLeft,
+	IUnknown* clientDrawingEffect)
+    {
+	return E_NOTIMPL;
+    }
+
+public:
+    IFACEMETHOD_(unsigned long, AddRef) ()
+    {
+	return InterlockedIncrement(&cRefCount_);
+    }
+
+    IFACEMETHOD_(unsigned long, Release) ()
+    {
+	long newCount = InterlockedDecrement(&cRefCount_);
+
+	if (newCount == 0)
+	{
+	    delete this;
+	    return 0;
+	}
+	return newCount;
+    }
+
+    IFACEMETHOD(QueryInterface)(
+	IID const& riid,
+	void** ppvObject)
+    {
+	if (__uuidof(IDWriteTextRenderer) == riid)
+	{
+	    *ppvObject = this;
+	}
+	else if (__uuidof(IDWritePixelSnapping) == riid)
+	{
+	    *ppvObject = this;
+	}
+	else if (__uuidof(IUnknown) == riid)
+	{
+	    *ppvObject = this;
+	}
+	else
+	{
+	    *ppvObject = NULL;
+	    return E_FAIL;
+	}
+
+	return S_OK;
+    }
+
+private:
+    unsigned long cRefCount_;
+    IDWriteBitmapRenderTarget* pRenderTarget_;
+    IDWriteRenderingParams* pRenderingParams_;
+};
+
+struct DWriteContext {
+    FLOAT mDpiScaleX;
+    FLOAT mDpiScaleY;
+    bool mDrawing;
+
+    ID2D1Factory *mD2D1Factory;
+
+    ID2D1DCRenderTarget *mRT;
+    ID2D1SolidColorBrush *mBrush;
+
+    IDWriteFactory *mDWriteFactory;
+    IDWriteGdiInterop *mGdiInterop;
+    IDWriteRenderingParams *mRenderingParams;
+    IDWriteTextFormat *mTextFormat;
+
+    HFONT mLastHFont;
+    DWRITE_FONT_WEIGHT mFontWeight;
+    DWRITE_FONT_STYLE mFontStyle;
+
+    D2D1_TEXT_ANTIALIAS_MODE mTextAntialiasMode;
+
+    // METHODS
+
+    DWriteContext();
+
+    virtual ~DWriteContext();
+
+    HRESULT SetLOGFONT(const LOGFONTW &logFont, float fontSize);
+
+    void SetFont(HFONT hFont);
+
+    void SetFont(const LOGFONTW &logFont);
+
+    void DrawText(HDC hdc, const WCHAR* text, int len,
+	int x, int y, int w, int h, int cellWidth, COLORREF color);
+
+    float PixelsToDipsX(int x);
+
+    float PixelsToDipsY(int y);
+
+    void SetRenderingParams(
+	    const DWriteRenderingParams *params);
+
+    DWriteRenderingParams *GetRenderingParams(
+	    DWriteRenderingParams *params);
+};
+
+DWriteContext::DWriteContext() :
+    mDpiScaleX(1.f),
+    mDpiScaleY(1.f),
+    mDrawing(false),
+    mD2D1Factory(NULL),
+    mRT(NULL),
+    mBrush(NULL),
+    mDWriteFactory(NULL),
+    mGdiInterop(NULL),
+    mRenderingParams(NULL),
+    mTextFormat(NULL),
+    mLastHFont(NULL),
+    mFontWeight(DWRITE_FONT_WEIGHT_NORMAL),
+    mFontStyle(DWRITE_FONT_STYLE_NORMAL),
+    mTextAntialiasMode(D2D1_TEXT_ANTIALIAS_MODE_DEFAULT)
+{
+    HRESULT hr;
+
+    HDC screen = ::GetDC(0);
+    mDpiScaleX = ::GetDeviceCaps(screen, LOGPIXELSX) / 96.0f;
+    mDpiScaleY = ::GetDeviceCaps(screen, LOGPIXELSY) / 96.0f;
+    ::ReleaseDC(0, screen);
+
+    hr = D2D1CreateFactory(D2D1_FACTORY_TYPE_SINGLE_THREADED,
+	    __uuidof(ID2D1Factory), NULL,
+	    reinterpret_cast<void**>(&mD2D1Factory));
+    _RPT2(_CRT_WARN, "D2D1CreateFactory: hr=%p p=%p\n", hr, mD2D1Factory);
+
+    if (SUCCEEDED(hr))
+    {
+	D2D1_RENDER_TARGET_PROPERTIES props = {
+	    D2D1_RENDER_TARGET_TYPE_DEFAULT,
+	    { DXGI_FORMAT_B8G8R8A8_UNORM, D2D1_ALPHA_MODE_IGNORE },
+	    0, 0,
+	    D2D1_RENDER_TARGET_USAGE_NONE,
+	    D2D1_FEATURE_LEVEL_DEFAULT
+	};
+	hr = mD2D1Factory->CreateDCRenderTarget(&props, &mRT);
+	_RPT2(_CRT_WARN, "CreateDCRenderTarget: hr=%p p=%p\n", hr, mRT);
+    }
+
+    if (SUCCEEDED(hr))
+    {
+	hr = mRT->CreateSolidColorBrush(
+		D2D1::ColorF(D2D1::ColorF::Black),
+		&mBrush);
+	_RPT2(_CRT_WARN, "CreateSolidColorBrush: hr=%p p=%p\n", hr, mBrush);
+    }
+
+    if (SUCCEEDED(hr))
+    {
+	hr = DWriteCreateFactory(
+		DWRITE_FACTORY_TYPE_SHARED,
+		__uuidof(IDWriteFactory),
+		reinterpret_cast<IUnknown**>(&mDWriteFactory));
+	_RPT2(_CRT_WARN, "DWriteCreateFactory: hr=%p p=%p\n", hr,
+		mDWriteFactory);
+    }
+
+    if (SUCCEEDED(hr))
+    {
+	hr = mDWriteFactory->GetGdiInterop(&mGdiInterop);
+	_RPT2(_CRT_WARN, "GetGdiInterop: hr=%p p=%p\n", hr, mGdiInterop);
+    }
+
+    if (SUCCEEDED(hr))
+    {
+	hr = mDWriteFactory->CreateRenderingParams(&mRenderingParams);
+	_RPT2(_CRT_WARN, "CreateRenderingParams: hr=%p p=%p\n", hr,
+		mRenderingParams);
+    }
+}
+
+DWriteContext::~DWriteContext()
+{
+    SafeRelease(&mTextFormat);
+    SafeRelease(&mRenderingParams);
+    SafeRelease(&mGdiInterop);
+    SafeRelease(&mDWriteFactory);
+    SafeRelease(&mBrush);
+    SafeRelease(&mRT);
+    SafeRelease(&mD2D1Factory);
+}
+
+    HRESULT
+DWriteContext::SetLOGFONT(const LOGFONTW &logFont, float fontSize)
+{
+    // Most of this function is copy from: http://msdn.microsoft.com/en-us/library/windows/desktop/dd941783(v=vs.85).aspx
+    HRESULT hr = S_OK;
+
+    IDWriteFont *font = NULL;
+    IDWriteFontFamily *fontFamily = NULL;
+    IDWriteLocalizedStrings *localizedFamilyNames = NULL;
+
+    if (SUCCEEDED(hr))
+    {
+	hr = mGdiInterop->CreateFontFromLOGFONT(&logFont, &font);
+    }
+
+    // Get the font family to which this font belongs.
+    if (SUCCEEDED(hr))
+    {
+	hr = font->GetFontFamily(&fontFamily);
+    }
+
+    // Get the family names. This returns an object that encapsulates one or
+    // more names with the same meaning but in different languages.
+    if (SUCCEEDED(hr))
+    {
+	hr = fontFamily->GetFamilyNames(&localizedFamilyNames);
+    }
+
+    // Get the family name at index zero. If we were going to display the name
+    // we'd want to try to find one that matched the use locale, but for
+    // purposes of creating a text format object any language will do.
+
+    wchar_t familyName[100];
+    if (SUCCEEDED(hr))
+    {
+	hr = localizedFamilyNames->GetString(0, familyName,
+		ARRAYSIZE(familyName));
+    }
+
+    if (SUCCEEDED(hr))
+    {
+	// If no font size was passed in use the lfHeight of the LOGFONT.
+	if (fontSize == 0)
+	{
+	    // Convert from pixels to DIPs.
+	    fontSize = PixelsToDipsY(logFont.lfHeight);
+	    if (fontSize < 0)
+	    {
+		// Negative lfHeight represents the size of the em unit.
+		fontSize = -fontSize;
+	    }
+	    else
+	    {
+		// Positive lfHeight represents the cell height (ascent +
+		// descent).
+		DWRITE_FONT_METRICS fontMetrics;
+		font->GetMetrics(&fontMetrics);
+
+		// Convert the cell height (ascent + descent) from design units
+		// to ems.
+		float cellHeight = static_cast<float>(
+			fontMetrics.ascent + fontMetrics.descent)
+					       / fontMetrics.designUnitsPerEm;
+
+		// Divide the font size by the cell height to get the font em
+		// size.
+		fontSize /= cellHeight;
+	    }
+	}
+    }
+
+    // The text format includes a locale name. Ideally, this would be the
+    // language of the text, which may or may not be the same as the primary
+    // language of the user. However, for our purposes the user locale will do.
+    wchar_t localeName[LOCALE_NAME_MAX_LENGTH];
+    if (SUCCEEDED(hr))
+    {
+	if (GetUserDefaultLocaleName(localeName, LOCALE_NAME_MAX_LENGTH) == 0)
+	    hr = HRESULT_FROM_WIN32(GetLastError());
+    }
+
+    if (SUCCEEDED(hr))
+    {
+	// Create the text format object.
+	hr = mDWriteFactory->CreateTextFormat(
+		familyName,
+		NULL, // no custom font collection
+		font->GetWeight(),
+		font->GetStyle(),
+		font->GetStretch(),
+		fontSize,
+		localeName,
+		&mTextFormat);
+    }
+
+    if (SUCCEEDED(hr))
+    {
+	mFontWeight = static_cast<DWRITE_FONT_WEIGHT>(logFont.lfWeight);
+	mFontStyle = logFont.lfItalic ? DWRITE_FONT_STYLE_ITALIC
+	    : DWRITE_FONT_STYLE_NORMAL;
+    }
+
+    SafeRelease(&localizedFamilyNames);
+    SafeRelease(&fontFamily);
+    SafeRelease(&font);
+
+    return hr;
+}
+
+    void
+DWriteContext::SetFont(HFONT hFont)
+{
+    if (mLastHFont != hFont)
+    {
+	LOGFONTW lf;
+	if (GetObjectW(hFont, sizeof(lf), &lf))
+	{
+	    SetFont(lf);
+	    mLastHFont = hFont;
+	}
+    }
+}
+
+    void
+DWriteContext::SetFont(const LOGFONTW &logFont)
+{
+    SafeRelease(&mTextFormat);
+    mLastHFont = NULL;
+
+    HRESULT hr = SetLOGFONT(logFont, 0.f);
+
+    if (SUCCEEDED(hr))
+	hr = mTextFormat->SetTextAlignment(DWRITE_TEXT_ALIGNMENT_LEADING);
+
+    if (SUCCEEDED(hr))
+	hr = mTextFormat->SetParagraphAlignment(
+		DWRITE_PARAGRAPH_ALIGNMENT_CENTER);
+
+    if (SUCCEEDED(hr))
+	hr = mTextFormat->SetWordWrapping(DWRITE_WORD_WRAPPING_NO_WRAP);
+}
+
+    void
+DWriteContext::DrawText(HDC hdc, const WCHAR* text, int len,
+	int x, int y, int w, int h, int cellWidth, COLORREF color)
+{
+    HRESULT hr = S_OK;
+    IDWriteBitmapRenderTarget *bmpRT = NULL;
+
+    // Skip when any fonts are not set.
+    if (mTextFormat == NULL)
+	return;
+
+    // Check possibility of zero divided error.
+    if (cellWidth == 0 || mDpiScaleX == 0.0f || mDpiScaleY == 0.0f)
+	return;
+
+    if (SUCCEEDED(hr))
+	hr = mGdiInterop->CreateBitmapRenderTarget(hdc, w, h, &bmpRT);
+
+    if (SUCCEEDED(hr))
+    {
+	IDWriteTextLayout *textLayout = NULL;
+
+	HDC memdc = bmpRT->GetMemoryDC();
+	BitBlt(memdc, 0, 0, w, h, hdc, x, y, SRCCOPY);
+
+	hr = mDWriteFactory->CreateGdiCompatibleTextLayout(
+		text, len, mTextFormat, PixelsToDipsX(w),
+		PixelsToDipsY(h), mDpiScaleX, NULL, TRUE, &textLayout);
+
+	if (SUCCEEDED(hr))
+	{
+	    DWRITE_TEXT_RANGE textRange = { 0, len };
+	    textLayout->SetFontWeight(mFontWeight, textRange);
+	    textLayout->SetFontStyle(mFontStyle, textRange);
+	}
+
+	if (SUCCEEDED(hr))
+	{
+	    GdiTextRenderer *renderer = new GdiTextRenderer(bmpRT,
+		    mRenderingParams);
+	    GdiTextRendererContext data = {
+		color,
+		PixelsToDipsX(cellWidth),
+		0.0f
+	    };
+	    textLayout->Draw(&data, renderer, 0, 0);
+	    SafeRelease(&renderer);
+	}
+
+	BitBlt(hdc, x, y, w, h, memdc, 0, 0, SRCCOPY);
+
+	SafeRelease(&textLayout);
+    }
+
+    SafeRelease(&bmpRT);
+}
+
+    float
+DWriteContext::PixelsToDipsX(int x)
+{
+    return x / mDpiScaleX;
+}
+
+    float
+DWriteContext::PixelsToDipsY(int y)
+{
+    return y / mDpiScaleY;
+}
+
+    void
+DWriteContext::SetRenderingParams(
+	const DWriteRenderingParams *params)
+{
+    if (mDWriteFactory == NULL)
+	return;
+
+    IDWriteRenderingParams *renderingParams = NULL;
+    D2D1_TEXT_ANTIALIAS_MODE textAntialiasMode =
+	D2D1_TEXT_ANTIALIAS_MODE_DEFAULT;
+    HRESULT hr;
+    if (params != NULL)
+    {
+	hr = mDWriteFactory->CreateCustomRenderingParams(params->gamma,
+		params->enhancedContrast, params->clearTypeLevel,
+		ToPixelGeometry(params->pixelGeometry),
+		ToRenderingMode(params->renderingMode), &renderingParams);
+	textAntialiasMode = ToTextAntialiasMode(params->textAntialiasMode);
+    }
+    else
+	hr = mDWriteFactory->CreateRenderingParams(&renderingParams);
+    if (SUCCEEDED(hr) && renderingParams != NULL)
+    {
+	SafeRelease(&mRenderingParams);
+	mRenderingParams = renderingParams;
+	mTextAntialiasMode = textAntialiasMode;
+    }
+}
+
+    DWriteRenderingParams *
+DWriteContext::GetRenderingParams(
+	DWriteRenderingParams *params)
+{
+    if (params != NULL && mRenderingParams != NULL)
+    {
+	params->gamma = mRenderingParams->GetGamma();
+	params->enhancedContrast = mRenderingParams->GetEnhancedContrast();
+	params->clearTypeLevel = mRenderingParams->GetClearTypeLevel();
+	params->pixelGeometry = ToInt(mRenderingParams->GetPixelGeometry());
+	params->renderingMode = ToInt(mRenderingParams->GetRenderingMode());
+	params->textAntialiasMode = mTextAntialiasMode;
+    }
+    return params;
+}
+
+////////////////////////////////////////////////////////////////////////////
+// PUBLIC C INTERFACES
+
+    void
+DWrite_Init(void)
+{
+#ifdef DYNAMIC_DIRECTX
+    // Load libraries.
+    hD2D1DLL = vimLoadLib(const_cast<char*>("d2d1.dll"));
+    hDWriteDLL = vimLoadLib(const_cast<char*>("dwrite.dll"));
+    if (hD2D1DLL == NULL || hDWriteDLL == NULL)
+    {
+	DWrite_Final();
+	return;
+    }
+    // Get address of procedures.
+    pGetUserDefaultLocaleName = (PGETUSERDEFAULTLOCALENAME)GetProcAddress(
+	    GetModuleHandle("kernel32.dll"), "GetUserDefaultLocaleName");
+    pD2D1CreateFactory = (PD2D1CREATEFACTORY)GetProcAddress(hD2D1DLL,
+	    "D2D1CreateFactory");
+    pDWriteCreateFactory = (PDWRITECREATEFACTORY)GetProcAddress(hDWriteDLL,
+	    "DWriteCreateFactory");
+#endif
+}
+
+    void
+DWrite_Final(void)
+{
+#ifdef DYNAMIC_DIRECTX
+    pGetUserDefaultLocaleName = NULL;
+    pD2D1CreateFactory = NULL;
+    pDWriteCreateFactory = NULL;
+    unload(hDWriteDLL);
+    unload(hD2D1DLL);
+#endif
+}
+
+    DWriteContext *
+DWriteContext_Open(void)
+{
+#ifdef DYNAMIC_DIRECTX
+    if (pGetUserDefaultLocaleName == NULL || pD2D1CreateFactory == NULL
+	    || pDWriteCreateFactory == NULL)
+	return NULL;
+#endif
+    return new DWriteContext();
+}
+
+    void
+DWriteContext_BeginDraw(DWriteContext *ctx)
+{
+    if (ctx != NULL && ctx->mRT != NULL)
+    {
+	ctx->mRT->BeginDraw();
+	ctx->mRT->SetTransform(D2D1::IdentityMatrix());
+	ctx->mDrawing = true;
+    }
+}
+
+    void
+DWriteContext_BindDC(DWriteContext *ctx, HDC hdc, RECT *rect)
+{
+    if (ctx != NULL && ctx->mRT != NULL)
+    {
+	ctx->mRT->BindDC(hdc, rect);
+	ctx->mRT->SetTextAntialiasMode(ctx->mTextAntialiasMode);
+    }
+}
+
+    void
+DWriteContext_SetFont(DWriteContext *ctx, HFONT hFont)
+{
+    if (ctx != NULL)
+    {
+	ctx->SetFont(hFont);
+    }
+}
+
+    void
+DWriteContext_DrawText(
+	DWriteContext *ctx,
+	HDC hdc,
+	const WCHAR* text,
+	int len,
+	int x,
+	int y,
+	int w,
+	int h,
+	int cellWidth,
+	COLORREF color)
+{
+    if (ctx != NULL)
+	ctx->DrawText(hdc, text, len, x, y, w, h, cellWidth, color);
+}
+
+    void
+DWriteContext_EndDraw(DWriteContext *ctx)
+{
+    if (ctx != NULL && ctx->mRT != NULL)
+    {
+	ctx->mRT->EndDraw();
+	ctx->mDrawing = false;
+    }
+}
+
+    void
+DWriteContext_Close(DWriteContext *ctx)
+{
+    delete ctx;
+}
+
+    void
+DWriteContext_SetRenderingParams(
+	DWriteContext *ctx,
+	const DWriteRenderingParams *params)
+{
+    if (ctx != NULL)
+	ctx->SetRenderingParams(params);
+}
+
+    DWriteRenderingParams *
+DWriteContext_GetRenderingParams(
+	DWriteContext *ctx,
+	DWriteRenderingParams *params)
+{
+    if (ctx != NULL)
+	return ctx->GetRenderingParams(params);
+    else
+	return NULL;
+}
diff --git a/src/gui_dwrite.h b/src/gui_dwrite.h
new file mode 100644
--- /dev/null
+++ b/src/gui_dwrite.h
@@ -0,0 +1,85 @@
+/* vi:set ts=8 sts=4 sw=4 noet: */
+/*
+ * Author: MURAOKA Taro <koron.kaoriya@gmail.com>
+ *
+ * Contributors:
+ *  - Ken Takata
+ *
+ * Copyright (C) 2013 MURAOKA Taro <koron.kaoriya@gmail.com>
+ * THIS FILE IS DISTRIBUTED UNDER THE VIM LICENSE.
+ */
+
+#ifndef GUI_DWRITE_H
+#define GUI_DWRITE_H
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+typedef struct DWriteContext DWriteContext;
+
+typedef struct DWriteRenderingParams {
+    float gamma;
+    float enhancedContrast;
+    float clearTypeLevel;
+    /*
+     * pixelGeometry:
+     *	0 - DWRITE_PIXEL_GEOMETRY_FLAT
+     *	1 - DWRITE_PIXEL_GEOMETRY_RGB
+     *	2 - DWRITE_PIXEL_GEOMETRY_BGR
+     */
+    int pixelGeometry;
+    /*
+     * renderingMode:
+     *	0 - DWRITE_RENDERING_MODE_DEFAULT
+     *	1 - DWRITE_RENDERING_MODE_ALIASED
+     *	2 - DWRITE_RENDERING_MODE_CLEARTYPE_GDI_CLASSIC
+     *	3 - DWRITE_RENDERING_MODE_CLEARTYPE_GDI_NATURAL
+     *	4 - DWRITE_RENDERING_MODE_CLEARTYPE_NATURAL
+     *	5 - DWRITE_RENDERING_MODE_CLEARTYPE_NATURAL_SYMMETRIC
+     *	6 - DWRITE_RENDERING_MODE_OUTLINE
+     */
+    int renderingMode;
+    /*
+     * antialiasMode:
+     *	0 - D2D1_TEXT_ANTIALIAS_MODE_DEFAULT
+     *	1 - D2D1_TEXT_ANTIALIAS_MODE_CLEARTYPE
+     *	2 - D2D1_TEXT_ANTIALIAS_MODE_GRAYSCALE
+     *	3 - D2D1_TEXT_ANTIALIAS_MODE_ALIASED
+     */
+    int textAntialiasMode;
+} DWriteRenderingParams;
+
+void DWrite_Init(void);
+void DWrite_Final(void);
+
+DWriteContext *DWriteContext_Open(void);
+void DWriteContext_BeginDraw(DWriteContext *ctx);
+void DWriteContext_BindDC(DWriteContext *ctx, HDC hdc, RECT *rect);
+void DWriteContext_SetFont(DWriteContext *ctx, HFONT hFont);
+void DWriteContext_DrawText(
+	DWriteContext *ctx,
+	HDC hdc,
+	const WCHAR* text,
+	int len,
+	int x,
+	int y,
+	int w,
+	int h,
+	int cellWidth,
+	COLORREF color);
+void DWriteContext_EndDraw(DWriteContext *ctx);
+void DWriteContext_Close(DWriteContext *ctx);
+
+void DWriteContext_SetRenderingParams(
+	DWriteContext *ctx,
+	const DWriteRenderingParams *params);
+
+DWriteRenderingParams *DWriteContext_GetRenderingParams(
+	DWriteContext *ctx,
+	DWriteRenderingParams *params);
+
+#ifdef __cplusplus
+}
+#endif
+#endif/*GUI_DWRITE_H*/
diff --git a/src/gui_w32.c b/src/gui_w32.c
--- a/src/gui_w32.c
+++ b/src/gui_w32.c
@@ -25,6 +25,145 @@
 
 #include "vim.h"
 
+#if defined(FEAT_DIRECTX)
+# include "gui_dwrite.h"
+#endif
+
+#if defined(FEAT_DIRECTX) || defined(PROTO)
+static DWriteContext *s_dwc = NULL;
+static int s_directx_enabled = 0;
+static int s_directx_load_attempted = 0;
+# define IS_ENABLE_DIRECTX() (s_directx_enabled && s_dwc != NULL)
+
+    int
+directx_enabled(void)
+{
+    if (s_dwc != NULL)
+	return 1;
+    else if (s_directx_load_attempted)
+	return 0;
+    /* load DirectX */
+    DWrite_Init();
+    s_directx_load_attempted = 1;
+    s_dwc = DWriteContext_Open();
+    return s_dwc != NULL ? 1 : 0;
+}
+#endif
+
+#if defined(FEAT_RENDER_OPTIONS) || defined(PROTO)
+    int
+gui_mch_set_rendering_options(char_u *s)
+{
+#ifdef FEAT_DIRECTX
+    int	    retval = FAIL;
+    char_u  *p, *q;
+
+    int	    dx_enable = 0;
+    int	    dx_flags = 0;
+    float   dx_gamma = 0.0f;
+    float   dx_contrast = 0.0f;
+    float   dx_level = 0.0f;
+    int	    dx_geom = 0;
+    int	    dx_renmode = 0;
+    int	    dx_taamode = 0;
+
+    /* parse string as rendering options. */
+    for (p = s; p != NULL && *p != NUL; )
+    {
+	char_u  item[256];
+	char_u  name[128];
+	char_u  value[128];
+
+	copy_option_part(&p, item, sizeof(item), ","); 
+	if (p == NULL)
+	    break;
+	q = &item[0];
+	copy_option_part(&q, name, sizeof(name), ":");
+	if (q == NULL)
+	    return FAIL;
+	copy_option_part(&q, value, sizeof(value), ":");
+
+	if (STRCMP(name, "type") == 0)
+	{
+	    if (STRCMP(value, "directx") == 0)
+		dx_enable = 1;
+	    else
+		return FAIL;
+	}
+	else if (STRCMP(name, "gamma") == 0)
+	{
+	    dx_flags |= 1 << 0;
+	    dx_gamma = (float)atof(value);
+	}
+	else if (STRCMP(name, "contrast") == 0)
+	{
+	    dx_flags |= 1 << 1;
+	    dx_contrast = (float)atof(value);
+	}
+	else if (STRCMP(name, "level") == 0)
+	{
+	    dx_flags |= 1 << 2;
+	    dx_level = (float)atof(value);
+	}
+	else if (STRCMP(name, "geom") == 0)
+	{
+	    dx_flags |= 1 << 3;
+	    dx_geom = atoi(value);
+	    if (dx_geom < 0 || dx_geom > 2)
+		return FAIL;
+	}
+	else if (STRCMP(name, "renmode") == 0)
+	{
+	    dx_flags |= 1 << 4;
+	    dx_renmode = atoi(value);
+	    if (dx_renmode < 0 || dx_renmode > 6)
+		return FAIL;
+	}
+	else if (STRCMP(name, "taamode") == 0)
+	{
+	    dx_flags |= 1 << 5;
+	    dx_taamode = atoi(value);
+	    if (dx_taamode < 0 || dx_taamode > 3)
+		return FAIL;
+	}
+	else
+	    return FAIL;
+    }
+
+    /* Enable DirectX/DirectWrite */
+    if (dx_enable)
+    {
+	if (!directx_enabled())
+	    return FAIL;
+	DWriteContext_SetRenderingParams(s_dwc, NULL);
+	if (dx_flags)
+	{
+	    DWriteRenderingParams param;
+	    DWriteContext_GetRenderingParams(s_dwc, &param);
+	    if (dx_flags & (1 << 0))
+		param.gamma = dx_gamma;
+	    if (dx_flags & (1 << 1))
+		param.enhancedContrast = dx_contrast;
+	    if (dx_flags & (1 << 2))
+		param.clearTypeLevel = dx_level;
+	    if (dx_flags & (1 << 3))
+		param.pixelGeometry = dx_geom;
+	    if (dx_flags & (1 << 4))
+		param.renderingMode = dx_renmode;
+	    if (dx_flags & (1 << 5))
+		param.textAntialiasMode = dx_taamode;
+	    DWriteContext_SetRenderingParams(s_dwc, &param);
+	}
+    }
+    s_directx_enabled = dx_enable;
+
+    return OK;
+#else
+    return FAIL;
+#endif
+}
+#endif
+
 /*
  * These are new in Windows ME/XP, only defined in recent compilers.
  */
@@ -1624,6 +1763,11 @@ gui_mch_init(void)
     set_vim_var_nr(VV_WINDOWID, HandleToLong(s_hwnd));
 #endif
 
+#ifdef FEAT_RENDER_OPTIONS
+    if (p_rop)
+	(void)gui_mch_set_rendering_options(p_rop);
+#endif
+
 theend:
     /* Display any pending error messages */
     display_errors();
@@ -1695,9 +1839,9 @@ gui_mch_set_shellsize(int width, int hei
 
     /* compute the size of the outside of the window */
     win_width = width + (GetSystemMetrics(SM_CXFRAME) +
-                         GetSystemMetrics(SM_CXPADDEDBORDER)) * 2;
+			 GetSystemMetrics(SM_CXPADDEDBORDER)) * 2;
     win_height = height + (GetSystemMetrics(SM_CYFRAME) +
-                           GetSystemMetrics(SM_CXPADDEDBORDER)) * 2
+			   GetSystemMetrics(SM_CXPADDEDBORDER)) * 2
 			+ GetSystemMetrics(SM_CYCAPTION)
 #ifdef FEAT_MENU
 			+ gui_mswin_get_menu_height(FALSE)
@@ -2239,6 +2383,9 @@ gui_mch_draw_string(
 #endif
     HPEN	hpen, old_pen;
     int		y;
+#ifdef FEAT_DIRECTX
+    int		font_is_ttf_or_vector = 0;
+#endif
 
 #ifndef MSWIN16_FASTTEXT
     /*
@@ -2326,6 +2473,20 @@ gui_mch_draw_string(
     SetTextColor(s_hdc, gui.currFgColor);
     SelectFont(s_hdc, gui.currFont);
 
+#ifdef FEAT_DIRECTX
+    if (IS_ENABLE_DIRECTX())
+    {
+	TEXTMETRIC tm;
+
+	GetTextMetrics(s_hdc, &tm);
+	if (tm.tmPitchAndFamily & (TMPF_TRUETYPE | TMPF_VECTOR))
+	{
+	    font_is_ttf_or_vector = 1;
+	    DWriteContext_SetFont(s_dwc, (HFONT)gui.currFont);
+	}
+    }
+#endif
+
     if (pad_size != Columns || padding == NULL || padding[0] != gui.char_width)
     {
 	vim_free(padding);
@@ -2360,6 +2521,14 @@ gui_mch_draw_string(
 	    if (text[n] >= 0x80)
 		break;
 
+#if defined(FEAT_DIRECTX)
+    /* Quick hack to enable DirectWrite.  To use DirectWrite (antialias), it is
+     * required that unicode drawing routine, currently.  So this forces it
+     * enabled. */
+    if (enc_utf8 && IS_ENABLE_DIRECTX())
+	n = 0; /* Keep n < len, to enter block for unicode. */
+#endif
+
     /* Check if the Unicode buffer exists and is big enough.  Create it
      * with the same length as the multi-byte string, the number of wide
      * characters is always equal or smaller. */
@@ -2418,8 +2587,17 @@ gui_mch_draw_string(
 	    i += utfc_ptr2len_len(text + i, len - i);
 	    ++clen;
 	}
-	ExtTextOutW(s_hdc, TEXT_X(col), TEXT_Y(row),
-			   foptions, pcliprect, unicodebuf, wlen, unicodepdy);
+#if defined(FEAT_DIRECTX)
+	if (IS_ENABLE_DIRECTX() && font_is_ttf_or_vector)
+	{
+	    DWriteContext_DrawText(s_dwc, s_hdc, unicodebuf, wlen,
+		    TEXT_X(col), TEXT_Y(row), FILL_X(cells), FILL_Y(1),
+		    gui.char_width, gui.currFgColor);
+	}
+	else
+#endif
+	    ExtTextOutW(s_hdc, TEXT_X(col), TEXT_Y(row),
+		    foptions, pcliprect, unicodebuf, wlen, unicodepdy);
 	len = cells;	/* used for underlining */
     }
     else if ((enc_codepage > 0 && (int)GetACP() != enc_codepage) || enc_latin9)
@@ -2549,14 +2727,14 @@ gui_mch_get_screen_dimensions(int *scree
 
     *screen_w = workarea_rect.right - workarea_rect.left
 		- (GetSystemMetrics(SM_CXFRAME) +
-                   GetSystemMetrics(SM_CXPADDEDBORDER)) * 2;
+		   GetSystemMetrics(SM_CXPADDEDBORDER)) * 2;
 
     /* FIXME: dirty trick: Because the gui_get_base_height() doesn't include
      * the menubar for MSwin, we subtract it from the screen height, so that
      * the window size can be made to fit on the screen. */
     *screen_h = workarea_rect.bottom - workarea_rect.top
 		- (GetSystemMetrics(SM_CYFRAME) +
-                   GetSystemMetrics(SM_CXPADDEDBORDER)) * 2
+		   GetSystemMetrics(SM_CXPADDEDBORDER)) * 2
 		- GetSystemMetrics(SM_CYCAPTION)
 #ifdef FEAT_MENU
 		- gui_mswin_get_menu_height(FALSE)
@@ -3188,13 +3366,13 @@ gui_mch_dialog(
 	GetWindowRect(s_hwnd, &rect);
 	maxDialogWidth = rect.right - rect.left
 				   - (GetSystemMetrics(SM_CXFRAME) +
-                                      GetSystemMetrics(SM_CXPADDEDBORDER)) * 2;
+				      GetSystemMetrics(SM_CXPADDEDBORDER)) * 2;
 	if (maxDialogWidth < DLG_MIN_MAX_WIDTH)
 	    maxDialogWidth = DLG_MIN_MAX_WIDTH;
 
 	maxDialogHeight = rect.bottom - rect.top
 				   - (GetSystemMetrics(SM_CYFRAME) +
-                                      GetSystemMetrics(SM_CXPADDEDBORDER)) * 4
+				      GetSystemMetrics(SM_CXPADDEDBORDER)) * 4
 				   - GetSystemMetrics(SM_CYCAPTION);
 	if (maxDialogHeight < DLG_MIN_MAX_HEIGHT)
 	    maxDialogHeight = DLG_MIN_MAX_HEIGHT;
@@ -3351,11 +3529,11 @@ gui_mch_dialog(
     /* Restrict the size to a maximum.  Causes a scrollbar to show up. */
     if (dlgheight > maxDialogHeight)
     {
-        msgheight = msgheight - (dlgheight - maxDialogHeight);
-        dlgheight = maxDialogHeight;
-        scroll_flag = WS_VSCROLL;
-        /* Make sure scrollbar doesn't appear in the middle of the dialog */
-        messageWidth = dlgwidth - DLG_ICON_WIDTH - 3 * dlgPaddingX;
+	msgheight = msgheight - (dlgheight - maxDialogHeight);
+	dlgheight = maxDialogHeight;
+	scroll_flag = WS_VSCROLL;
+	/* Make sure scrollbar doesn't appear in the middle of the dialog */
+	messageWidth = dlgwidth - DLG_ICON_WIDTH - 3 * dlgPaddingX;
     }
 
     add_word(PixelToDialogY(dlgheight));
diff --git a/src/gui_w48.c b/src/gui_w48.c
--- a/src/gui_w48.c
+++ b/src/gui_w48.c
@@ -2785,6 +2785,10 @@ gui_mch_show_popupmenu_at(vimmenu_T *men
 
 	out_flush();	    /* make sure all output has been processed */
 	(void)BeginPaint(hwnd, &ps);
+#if defined(FEAT_DIRECTX)
+	if (IS_ENABLE_DIRECTX())
+	    DWriteContext_BeginDraw(s_dwc);
+#endif
 
 #ifdef FEAT_MBYTE
 	/* prevent multi-byte characters from misprinting on an invalid
@@ -2800,9 +2804,20 @@ gui_mch_show_popupmenu_at(vimmenu_T *men
 #endif
 
 	if (!IsRectEmpty(&ps.rcPaint))
+	{
+#if defined(FEAT_DIRECTX)
+	    if (IS_ENABLE_DIRECTX())
+		DWriteContext_BindDC(s_dwc, s_hdc, &ps.rcPaint);
+#endif
 	    gui_redraw(ps.rcPaint.left, ps.rcPaint.top,
 		    ps.rcPaint.right - ps.rcPaint.left + 1,
 		    ps.rcPaint.bottom - ps.rcPaint.top + 1);
+	}
+
+#if defined(FEAT_DIRECTX)
+	if (IS_ENABLE_DIRECTX())
+	    DWriteContext_EndDraw(s_dwc);
+#endif
 	EndPaint(hwnd, &ps);
     }
 }
@@ -3043,6 +3058,12 @@ gui_mch_insert_lines(
     void
 gui_mch_exit(int rc)
 {
+#if defined(FEAT_DIRECTX)
+    DWriteContext_Close(s_dwc);
+    DWrite_Final();
+    s_dwc = NULL;
+#endif
+
     ReleaseDC(s_textArea, s_hdc);
     DeleteObject(s_brush);
 
diff --git a/src/option.c b/src/option.c
--- a/src/option.c
+++ b/src/option.c
@@ -2124,6 +2124,15 @@ static struct vimoption
     {"remap",	    NULL,   P_BOOL|P_VI_DEF,
 			    (char_u *)&p_remap, PV_NONE,
 			    {(char_u *)TRUE, (char_u *)0L} SCRIPTID_INIT},
+    {"renderoptions", "rop", P_STRING|P_COMMA|P_RCLR|P_VI_DEF,
+#ifdef FEAT_RENDER_OPTIONS
+			    (char_u *)&p_rop, PV_NONE,
+			    {(char_u *)"", (char_u *)0L}
+#else
+			    (char_u *)NULL, PV_NONE,
+			    {(char_u *)NULL, (char_u *)0L}
+#endif
+			    SCRIPTID_INIT},
     {"report",	    NULL,   P_NUM|P_VI_DEF,
 			    (char_u *)&p_report, PV_NONE,
 			    {(char_u *)2L, (char_u *)0L} SCRIPTID_INIT},
@@ -6999,6 +7008,14 @@ did_set_string_option(opt_idx, varp, new
     }
 #endif
 
+#if defined(FEAT_RENDER_OPTIONS)
+    else if (varp == &p_rop && gui.in_use)
+    {
+	if (!gui_mch_set_rendering_options(p_rop))
+	    errmsg = e_invarg;
+    }
+#endif
+
     /* Options that are a list of flags. */
     else
     {
diff --git a/src/option.h b/src/option.h
--- a/src/option.h
+++ b/src/option.h
@@ -655,6 +655,9 @@ EXTERN long	p_rdt;		/* 'redrawtime' */
 #endif
 EXTERN int	p_remap;	/* 'remap' */
 EXTERN long	p_re;		/* 'regexpengine' */
+#ifdef FEAT_RENDER_OPTIONS
+EXTERN char_u	*p_rop;		/* 'renderoptions' */
+#endif
 EXTERN long	p_report;	/* 'report' */
 #if defined(FEAT_WINDOWS) && defined(FEAT_QUICKFIX)
 EXTERN long	p_pvh;		/* 'previewheight' */
diff --git a/src/proto/gui_w32.pro b/src/proto/gui_w32.pro
--- a/src/proto/gui_w32.pro
+++ b/src/proto/gui_w32.pro
@@ -1,4 +1,6 @@
 /* gui_w32.c */
+int directx_enabled __ARGS((void));
+int gui_mch_set_rendering_options __ARGS((char_u *s));
 void gui_mch_set_blinking __ARGS((long wait, long on, long off));
 void gui_mch_stop_blink __ARGS((void));
 void gui_mch_start_blink __ARGS((void));
diff --git a/src/version.c b/src/version.c
--- a/src/version.c
+++ b/src/version.c
@@ -189,6 +189,13 @@ static char *(features[]) =
 #else
 	"-digraphs",
 #endif
+#ifdef FEAT_GUI_W32
+# ifdef FEAT_DIRECTX
+	"+directx",
+# else
+	"-directx",
+# endif
+#endif
 #ifdef FEAT_DND
 	"+dnd",
 #else
@@ -735,6 +742,8 @@ static char *(features[]) =
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    393,
+/**/
     392,
 /**/
     391,
diff --git a/src/vim.h b/src/vim.h
--- a/src/vim.h
+++ b/src/vim.h
@@ -134,6 +134,13 @@
 # endif
 #endif
 
+/* Check support for rendering options */
+#ifdef FEAT_GUI
+# if defined(FEAT_DIRECTX)
+#  define FEAT_RENDER_OPTIONS
+# endif
+#endif
+
 /* Visual Studio 2005 has 'deprecated' many of the standard CRT functions */
 #if _MSC_VER >= 1400
 # define _CRT_SECURE_NO_DEPRECATE