root/skia/ext/vector_platform_device_emf_win.cc

DEFINITIONS

1. CreateDevice
2. FillBitmapInfoHeader
3. create
4. previous_pen_
5. BeginPlatformPaint
6. drawPaint
7. drawPoints
8. drawRect
9. drawRRect
10. drawPath
11. drawBitmapRect
12. drawBitmap
13. drawSprite
14. gdiCanHandleText
15. fUseGDI
16. useGDI
17. getAscent
18. getTextOutOptions
19. SetSkiaEnsureTypefaceCharactersAccessible
20. EnsureTypefaceCharactersAccessible
21. EnsureExtTextOut
22. drawText
23. size_utf8
24. size_utf16
25. size_glyphid
26. drawPosText
27. drawTextOnPath
28. drawVertices
29. drawDevice
30. ApplyPaint
31. setMatrixClip
32. DrawToNativeContext
33. LoadClipRegion
34. onCreateCompatibleDevice
35. onCreateDevice
36. CreateBrush
37. CreatePen
38. Cleanup
39. SelectObject
40. CreateBrush
41. CreatePen
42. InternalDrawBitmap

// Copyright (c) 2012 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#include "skia/ext/vector_platform_device_emf_win.h"

#include <windows.h>

#include "base/logging.h"
#include "base/strings/string16.h"
#include "skia/ext/bitmap_platform_device.h"
#include "skia/ext/skia_utils_win.h"
#include "third_party/skia/include/core/SkFontHost.h"
#include "third_party/skia/include/core/SkPathEffect.h"
#include "third_party/skia/include/core/SkTemplates.h"
#include "third_party/skia/include/core/SkUtils.h"
#include "third_party/skia/include/ports/SkTypeface_win.h"

namespace skia {

#define CHECK_FOR_NODRAW_ANNOTATION(paint) \
    do { if (paint.isNoDrawAnnotation()) { return; } } while (0)

// static
SkBaseDevice* VectorPlatformDeviceEmf::CreateDevice(
    int width, int height, bool is_opaque, HANDLE shared_section) {
  if (!is_opaque) {
    // TODO(maruel):  http://crbug.com/18382 When restoring a semi-transparent
    // layer, i.e. merging it, we need to rasterize it because GDI doesn't
    // support transparency except for AlphaBlend(). Right now, a
    // BitmapPlatformDevice is created when VectorCanvas think a saveLayers()
    // call is being done. The way to save a layer would be to create an
    // EMF-based VectorDevice and have this device registers the drawing. When
    // playing back the device into a bitmap, do it at the printer's dpi instead
    // of the layout's dpi (which is much lower).
    return BitmapPlatformDevice::Create(width, height, is_opaque,
                                        shared_section);
  }

  // TODO(maruel):  http://crbug.com/18383 Look if it would be worth to
  // increase the resolution by ~10x (any worthy factor) to increase the
  // rendering precision (think about printing) while using a relatively
  // low dpi. This happens because we receive float as input but the GDI
  // functions works with integers. The idea is to premultiply the matrix
  // with this factor and multiply each SkScalar that are passed to
  // SkScalarRound(value) as SkScalarRound(value * 10). Safari is already
  // doing the same for text rendering.
  SkASSERT(shared_section);
  SkBaseDevice* device = VectorPlatformDeviceEmf::create(
      reinterpret_cast<HDC>(shared_section), width, height);
  return device;
}

static void FillBitmapInfoHeader(int width, int height, BITMAPINFOHEADER* hdr) {
  hdr->biSize = sizeof(BITMAPINFOHEADER);
  hdr->biWidth = width;
  hdr->biHeight = -height;  // Minus means top-down bitmap.
  hdr->biPlanes = 1;
  hdr->biBitCount = 32;
  hdr->biCompression = BI_RGB;  // no compression
  hdr->biSizeImage = 0;
  hdr->biXPelsPerMeter = 1;
  hdr->biYPelsPerMeter = 1;
  hdr->biClrUsed = 0;
  hdr->biClrImportant = 0;
}

SkBaseDevice* VectorPlatformDeviceEmf::create(HDC dc, int width, int height) {
  InitializeDC(dc);

  // Link the SkBitmap to the current selected bitmap in the device context.
  SkBitmap bitmap;
  HGDIOBJ selected_bitmap = GetCurrentObject(dc, OBJ_BITMAP);
  bool succeeded = false;
  if (selected_bitmap != NULL) {
    BITMAP bitmap_data;
    if (GetObject(selected_bitmap, sizeof(BITMAP), &bitmap_data) ==
        sizeof(BITMAP)) {
      // The context has a bitmap attached. Attach our SkBitmap to it.
      // Warning: If the bitmap gets unselected from the HDC,
      // VectorPlatformDeviceEmf has no way to detect this, so the HBITMAP
      // could be released while SkBitmap still has a reference to it. Be
      // cautious.
      if (width == bitmap_data.bmWidth &&
          height == bitmap_data.bmHeight) {
        bitmap.setConfig(SkBitmap::kARGB_8888_Config,
                         bitmap_data.bmWidth,
                         bitmap_data.bmHeight,
                         bitmap_data.bmWidthBytes);
        bitmap.setPixels(bitmap_data.bmBits);
        succeeded = true;
      }
    }
  }

  if (!succeeded)
    bitmap.setConfig(SkBitmap::kARGB_8888_Config, width, height);

  return new VectorPlatformDeviceEmf(dc, bitmap);
}

VectorPlatformDeviceEmf::VectorPlatformDeviceEmf(HDC dc, const SkBitmap& bitmap)
    : SkBitmapDevice(bitmap),
      hdc_(dc),
      previous_brush_(NULL),
      previous_pen_(NULL) {
  transform_.reset();
  SetPlatformDevice(this, this);
}

VectorPlatformDeviceEmf::~VectorPlatformDeviceEmf() {
  SkASSERT(previous_brush_ == NULL);
  SkASSERT(previous_pen_ == NULL);
}

HDC VectorPlatformDeviceEmf::BeginPlatformPaint() {
  return hdc_;
}

void VectorPlatformDeviceEmf::drawPaint(const SkDraw& draw,
                                        const SkPaint& paint) {
  // TODO(maruel):  Bypass the current transformation matrix.
  SkRect rect;
  rect.fLeft = 0;
  rect.fTop = 0;
  rect.fRight = SkIntToScalar(width() + 1);
  rect.fBottom = SkIntToScalar(height() + 1);
  drawRect(draw, rect, paint);
}

void VectorPlatformDeviceEmf::drawPoints(const SkDraw& draw,
                                         SkCanvas::PointMode mode,
                                         size_t count,
                                         const SkPoint pts[],
                                         const SkPaint& paint) {
  if (!count)
    return;

  if (mode == SkCanvas::kPoints_PointMode) {
    SkASSERT(false);
    return;
  }

  SkPaint tmp_paint(paint);
  tmp_paint.setStyle(SkPaint::kStroke_Style);

  // Draw a path instead.
  SkPath path;
  switch (mode) {
    case SkCanvas::kLines_PointMode:
      if (count % 2) {
        SkASSERT(false);
        return;
      }
      for (size_t i = 0; i < count / 2; ++i) {
        path.moveTo(pts[2 * i]);
        path.lineTo(pts[2 * i + 1]);
      }
      break;
    case SkCanvas::kPolygon_PointMode:
      path.moveTo(pts[0]);
      for (size_t i = 1; i < count; ++i) {
        path.lineTo(pts[i]);
      }
      break;
    default:
      SkASSERT(false);
      return;
  }
  // Draw the calculated path.
  drawPath(draw, path, tmp_paint);
}

void VectorPlatformDeviceEmf::drawRect(const SkDraw& draw,
                                       const SkRect& rect,
                                       const SkPaint& paint) {
  CHECK_FOR_NODRAW_ANNOTATION(paint);
  if (paint.getPathEffect()) {
    // Draw a path instead.
    SkPath path_orginal;
    path_orginal.addRect(rect);

    // Apply the path effect to the rect.
    SkPath path_modified;
    paint.getFillPath(path_orginal, &path_modified);

    // Removes the path effect from the temporary SkPaint object.
    SkPaint paint_no_effet(paint);
    paint_no_effet.setPathEffect(NULL);

    // Draw the calculated path.
    drawPath(draw, path_modified, paint_no_effet);
    return;
  }

  if (!ApplyPaint(paint)) {
    return;
  }
  HDC dc = BeginPlatformPaint();
  if (!Rectangle(dc, SkScalarRoundToInt(rect.fLeft),
                 SkScalarRoundToInt(rect.fTop),
                 SkScalarRoundToInt(rect.fRight),
                 SkScalarRoundToInt(rect.fBottom))) {
    SkASSERT(false);
  }
  EndPlatformPaint();
  Cleanup();
}

void VectorPlatformDeviceEmf::drawRRect(const SkDraw& draw, const SkRRect& rr,
                                        const SkPaint& paint) {
  SkPath path;
  path.addRRect(rr);
  this->drawPath(draw, path, paint, NULL, true);
}

void VectorPlatformDeviceEmf::drawPath(const SkDraw& draw,
                                       const SkPath& path,
                                       const SkPaint& paint,
                                       const SkMatrix* prePathMatrix,
                                       bool pathIsMutable) {
  CHECK_FOR_NODRAW_ANNOTATION(paint);
  if (paint.getPathEffect()) {
    // Apply the path effect forehand.
    SkPath path_modified;
    paint.getFillPath(path, &path_modified);

    // Removes the path effect from the temporary SkPaint object.
    SkPaint paint_no_effet(paint);
    paint_no_effet.setPathEffect(NULL);

    // Draw the calculated path.
    drawPath(draw, path_modified, paint_no_effet);
    return;
  }

  if (!ApplyPaint(paint)) {
    return;
  }
  HDC dc = BeginPlatformPaint();
  if (PlatformDevice::LoadPathToDC(dc, path)) {
    switch (paint.getStyle()) {
      case SkPaint::kFill_Style: {
        BOOL res = StrokeAndFillPath(dc);
        SkASSERT(res != 0);
        break;
      }
      case SkPaint::kStroke_Style: {
        BOOL res = StrokePath(dc);
        SkASSERT(res != 0);
        break;
      }
      case SkPaint::kStrokeAndFill_Style: {
        BOOL res = StrokeAndFillPath(dc);
        SkASSERT(res != 0);
        break;
      }
      default:
        SkASSERT(false);
        break;
    }
  }
  EndPlatformPaint();
  Cleanup();
}

void VectorPlatformDeviceEmf::drawBitmapRect(const SkDraw& draw,
                                             const SkBitmap& bitmap,
                                             const SkRect* src,
                                             const SkRect& dst,
                                             const SkPaint& paint,
                                             SkCanvas::DrawBitmapRectFlags flags) {
    SkMatrix    matrix;
    SkRect      bitmapBounds, tmpSrc, tmpDst;
    SkBitmap    tmpBitmap;

    bitmapBounds.isetWH(bitmap.width(), bitmap.height());

    // Compute matrix from the two rectangles
    if (src) {
        tmpSrc = *src;
    } else {
        tmpSrc = bitmapBounds;
    }
    matrix.setRectToRect(tmpSrc, dst, SkMatrix::kFill_ScaleToFit);

    const SkBitmap* bitmapPtr = &bitmap;

    // clip the tmpSrc to the bounds of the bitmap, and recompute dstRect if
    // needed (if the src was clipped). No check needed if src==null.
    if (src) {
        if (!bitmapBounds.contains(*src)) {
            if (!tmpSrc.intersect(bitmapBounds)) {
                return; // nothing to draw
            }
            // recompute dst, based on the smaller tmpSrc
            matrix.mapRect(&tmpDst, tmpSrc);
        }

        // since we may need to clamp to the borders of the src rect within
        // the bitmap, we extract a subset.
        // TODO: make sure this is handled in drawrect and remove it from here.
        SkIRect srcIR;
        tmpSrc.roundOut(&srcIR);
        if (!bitmap.extractSubset(&tmpBitmap, srcIR)) {
            return;
        }
        bitmapPtr = &tmpBitmap;

        // Since we did an extract, we need to adjust the matrix accordingly
        SkScalar dx = 0, dy = 0;
        if (srcIR.fLeft > 0) {
            dx = SkIntToScalar(srcIR.fLeft);
        }
        if (srcIR.fTop > 0) {
            dy = SkIntToScalar(srcIR.fTop);
        }
        if (dx || dy) {
            matrix.preTranslate(dx, dy);
        }
    }
    this->drawBitmap(draw, *bitmapPtr, matrix, paint);
}

void VectorPlatformDeviceEmf::drawBitmap(const SkDraw& draw,
                                         const SkBitmap& bitmap,
                                         const SkMatrix& matrix,
                                         const SkPaint& paint) {
  // Load the temporary matrix. This is what will translate, rotate and resize
  // the bitmap.
  SkMatrix actual_transform(transform_);
  actual_transform.preConcat(matrix);
  LoadTransformToDC(hdc_, actual_transform);

  InternalDrawBitmap(bitmap, 0, 0, paint);

  // Restore the original matrix.
  LoadTransformToDC(hdc_, transform_);
}

void VectorPlatformDeviceEmf::drawSprite(const SkDraw& draw,
                                         const SkBitmap& bitmap,
                                         int x, int y,
                                         const SkPaint& paint) {
  SkMatrix identity;
  identity.reset();
  LoadTransformToDC(hdc_, identity);

  InternalDrawBitmap(bitmap, x, y, paint);

  // Restore the original matrix.
  LoadTransformToDC(hdc_, transform_);
}

/////////////////////////////////////////////////////////////////////////

static bool gdiCanHandleText(const SkPaint& paint) {
  return !paint.getShader() &&
         !paint.getPathEffect() &&
         (SkPaint::kFill_Style == paint.getStyle()) &&
         (255 == paint.getAlpha());
}

class SkGDIFontSetup {
 public:
  SkGDIFontSetup() :
      fHDC(NULL),
      fNewFont(NULL),
      fSavedFont(NULL),
      fSavedTextColor(0),
      fUseGDI(false) {
    SkDEBUGCODE(fUseGDIHasBeenCalled = false;)
  }
  ~SkGDIFontSetup();

  // can only be called once
  bool useGDI(HDC hdc, const SkPaint&);

 private:
  HDC      fHDC;
  HFONT    fNewFont;
  HFONT    fSavedFont;
  COLORREF fSavedTextColor;
  bool     fUseGDI;
  SkDEBUGCODE(bool fUseGDIHasBeenCalled;)
};

bool SkGDIFontSetup::useGDI(HDC hdc, const SkPaint& paint) {
  SkASSERT(!fUseGDIHasBeenCalled);
  SkDEBUGCODE(fUseGDIHasBeenCalled = true;)

  fUseGDI = gdiCanHandleText(paint);
  if (fUseGDI) {
    fSavedTextColor = GetTextColor(hdc);
    SetTextColor(hdc, skia::SkColorToCOLORREF(paint.getColor()));

    LOGFONT lf;
    SkLOGFONTFromTypeface(paint.getTypeface(), &lf);
    lf.lfHeight = -SkScalarRoundToInt(paint.getTextSize());
    fNewFont = CreateFontIndirect(&lf);
    fSavedFont = (HFONT)::SelectObject(hdc, fNewFont);
    fHDC = hdc;
  }
  return fUseGDI;
}

SkGDIFontSetup::~SkGDIFontSetup() {
  if (fUseGDI) {
    ::SelectObject(fHDC, fSavedFont);
    ::DeleteObject(fNewFont);
    SetTextColor(fHDC, fSavedTextColor);
  }
}

static SkScalar getAscent(const SkPaint& paint) {
  SkPaint::FontMetrics fm;
  paint.getFontMetrics(&fm);
  return fm.fAscent;
}

// return the options int for ExtTextOut. Only valid if the paint's text
// encoding is not UTF8 (in which case ExtTextOut can't be used).
static UINT getTextOutOptions(const SkPaint& paint) {
  if (SkPaint::kGlyphID_TextEncoding == paint.getTextEncoding()) {
    return ETO_GLYPH_INDEX;
  } else {
    SkASSERT(SkPaint::kUTF16_TextEncoding == paint.getTextEncoding());
    return 0;
  }
}

static SkiaEnsureTypefaceCharactersAccessible
    g_skia_ensure_typeface_characters_accessible = NULL;

SK_API void SetSkiaEnsureTypefaceCharactersAccessible(
    SkiaEnsureTypefaceCharactersAccessible func) {
  // This function is supposed to be called once in process life time.
  SkASSERT(g_skia_ensure_typeface_characters_accessible == NULL);
  g_skia_ensure_typeface_characters_accessible = func;
}

void EnsureTypefaceCharactersAccessible(
    const SkTypeface& typeface, const wchar_t* text, unsigned int text_length) {
  LOGFONT lf;
  SkLOGFONTFromTypeface(&typeface, &lf);
  g_skia_ensure_typeface_characters_accessible(lf, text, text_length);
}

bool EnsureExtTextOut(HDC hdc, int x, int y, UINT options, const RECT * lprect,
                      LPCWSTR text, unsigned int characters, const int * lpDx,
                      SkTypeface* const typeface) {
  bool success = ExtTextOut(hdc, x, y, options, lprect, text, characters, lpDx);
  if (!success) {
    if (typeface) {
      EnsureTypefaceCharactersAccessible(*typeface,
                                         text,
                                         characters);
      success = ExtTextOut(hdc, x, y, options, lprect, text, characters, lpDx);
      if (!success) {
        LOGFONT lf;
        SkLOGFONTFromTypeface(typeface, &lf);
        VLOG(1) << "SkFontHost::EnsureTypefaceCharactersAccessible FAILED for "
                << " FaceName = " << lf.lfFaceName
                << " and characters: " << base::string16(text, characters);
      }
    } else {
      VLOG(1) << "ExtTextOut FAILED for default FaceName "
              << " and characters: " << base::string16(text, characters);
    }
  }
  return success;
}

void VectorPlatformDeviceEmf::drawText(const SkDraw& draw,
                                       const void* text,
                                       size_t byteLength,
                                       SkScalar x,
                                       SkScalar y,
                                       const SkPaint& paint) {
  SkGDIFontSetup setup;
  bool useDrawPath = true;

  if (SkPaint::kUTF8_TextEncoding != paint.getTextEncoding()
      && setup.useGDI(hdc_, paint)) {
    UINT options = getTextOutOptions(paint);
    UINT count = byteLength >> 1;
    useDrawPath = !EnsureExtTextOut(hdc_, SkScalarRoundToInt(x),
        SkScalarRoundToInt(y + getAscent(paint)), options, 0,
        reinterpret_cast<const wchar_t*>(text), count, NULL,
        paint.getTypeface());
  }

  if (useDrawPath) {
    SkPath path;
    paint.getTextPath(text, byteLength, x, y, &path);
    drawPath(draw, path, paint);
  }
}

static size_t size_utf8(const char* text) {
  return SkUTF8_CountUTF8Bytes(text);
}

static size_t size_utf16(const char* text) {
  uint16_t c = *reinterpret_cast<const uint16_t*>(text);
  return SkUTF16_IsHighSurrogate(c) ? 4 : 2;
}

static size_t size_glyphid(const char* text) {
  return 2;
}

void VectorPlatformDeviceEmf::drawPosText(const SkDraw& draw,
                                          const void* text,
                                          size_t len,
                                          const SkScalar pos[],
                                          SkScalar constY,
                                          int scalarsPerPos,
                                          const SkPaint& paint) {
  SkGDIFontSetup setup;
  bool useDrawText = true;

  if (2 == scalarsPerPos
      && SkPaint::kUTF8_TextEncoding != paint.getTextEncoding()
      && setup.useGDI(hdc_, paint)) {
    int startX = SkScalarRoundToInt(pos[0]);
    int startY = SkScalarRoundToInt(pos[1] + getAscent(paint));
    const int count = len >> 1;
    SkAutoSTMalloc<64, INT> storage(count);
    INT* advances = storage.get();
    for (int i = 0; i < count - 1; ++i) {
      advances[i] = SkScalarRoundToInt(pos[2] - pos[0]);
      pos += 2;
    }
    useDrawText = !EnsureExtTextOut(hdc_, startX, startY,
        getTextOutOptions(paint), 0, reinterpret_cast<const wchar_t*>(text),
        count, advances, paint.getTypeface());
  }

  if (useDrawText) {
    size_t (*bytesPerCodePoint)(const char*);
    switch (paint.getTextEncoding()) {
    case SkPaint::kUTF8_TextEncoding:
      bytesPerCodePoint = size_utf8;
      break;
    case SkPaint::kUTF16_TextEncoding:
      bytesPerCodePoint = size_utf16;
      break;
    default:
      SkASSERT(SkPaint::kGlyphID_TextEncoding == paint.getTextEncoding());
      bytesPerCodePoint = size_glyphid;
      break;
    }

    const char* curr = reinterpret_cast<const char*>(text);
    const char* stop = curr + len;
    while (curr < stop) {
      SkScalar y = (1 == scalarsPerPos) ? constY : pos[1];
      size_t bytes = bytesPerCodePoint(curr);
      drawText(draw, curr, bytes, pos[0], y, paint);
      curr += bytes;
      pos += scalarsPerPos;
    }
  }
}

void VectorPlatformDeviceEmf::drawTextOnPath(const SkDraw& draw,
                                             const void* text,
                                             size_t len,
                                             const SkPath& path,
                                             const SkMatrix* matrix,
                                             const SkPaint& paint) {
  // This function isn't used in the code. Verify this assumption.
  SkASSERT(false);
}

void VectorPlatformDeviceEmf::drawVertices(const SkDraw& draw,
                                           SkCanvas::VertexMode vmode,
                                           int vertexCount,
                                           const SkPoint vertices[],
                                           const SkPoint texs[],
                                           const SkColor colors[],
                                           SkXfermode* xmode,
                                           const uint16_t indices[],
                                           int indexCount,
                                           const SkPaint& paint) {
  // This function isn't used in the code. Verify this assumption.
  SkASSERT(false);
}

void VectorPlatformDeviceEmf::drawDevice(const SkDraw& draw,
                                         SkBaseDevice* device,
                                         int x,
                                         int y,
                                         const SkPaint& paint) {
  // TODO(maruel):  http://b/1183870 Playback the EMF buffer at printer's dpi if
  // it is a vectorial device.
  drawSprite(draw, device->accessBitmap(false), x, y, paint);
}

bool VectorPlatformDeviceEmf::ApplyPaint(const SkPaint& paint) {
  // Note: The goal here is to transfert the SkPaint's state to the HDC's state.
  // This function does not execute the SkPaint drawing commands. These should
  // be executed in drawPaint().

  SkPaint::Style style = paint.getStyle();
  if (!paint.getAlpha())
      style = (SkPaint::Style) SkPaint::kStyleCount;

  switch (style) {
    case SkPaint::kFill_Style:
      if (!CreateBrush(true, paint) ||
          !CreatePen(false, paint))
        return false;
      break;
    case SkPaint::kStroke_Style:
      if (!CreateBrush(false, paint) ||
          !CreatePen(true, paint))
        return false;
      break;
    case SkPaint::kStrokeAndFill_Style:
      if (!CreateBrush(true, paint) ||
          !CreatePen(true, paint))
        return false;
      break;
    default:
      if (!CreateBrush(false, paint) ||
          !CreatePen(false, paint))
        return false;
      break;
  }

  /*
  getFlags();
    isAntiAlias();
    isDither()
    isLinearText()
    isSubpixelText()
    isUnderlineText()
    isStrikeThruText()
    isFakeBoldText()
    isDevKernText()
    isFilterBitmap()

  // Skia's text is not used. This should be fixed.
  getTextAlign()
  getTextScaleX()
  getTextSkewX()
  getTextEncoding()
  getFontMetrics()
  getFontSpacing()
  */

  // BUG 1094907: Implement shaders. Shaders currently in use:
  //  SkShader::CreateBitmapShader
  //  SkGradientShader::CreateRadial
  //  SkGradientShader::CreateLinear
  // SkASSERT(!paint.getShader());

  // http://b/1106647 Implement loopers and mask filter. Looper currently in
  // use:
  //   SkBlurDrawLooper is used for shadows.
  // SkASSERT(!paint.getLooper());
  // SkASSERT(!paint.getMaskFilter());

  // http://b/1165900 Implement xfermode.
  // SkASSERT(!paint.getXfermode());

  // The path effect should be processed before arriving here.
  SkASSERT(!paint.getPathEffect());

  // This isn't used in the code. Verify this assumption.
  SkASSERT(!paint.getRasterizer());
  // Reuse code to load Win32 Fonts.
  return true;
}

void VectorPlatformDeviceEmf::setMatrixClip(const SkMatrix& transform,
                                            const SkRegion& region,
                                            const SkClipStack&) {
  transform_ = transform;
  LoadTransformToDC(hdc_, transform_);
  clip_region_ = region;
  if (!clip_region_.isEmpty())
    LoadClipRegion();
}

void VectorPlatformDeviceEmf::DrawToNativeContext(HDC dc, int x, int y,
                                                  const RECT* src_rect) {
  SkASSERT(false);
}

void VectorPlatformDeviceEmf::LoadClipRegion() {
  SkMatrix t;
  t.reset();
  LoadClippingRegionToDC(hdc_, clip_region_, t);
}

#ifdef SK_SUPPORT_LEGACY_COMPATIBLEDEVICE_CONFIG
SkBaseDevice* VectorPlatformDeviceEmf::onCreateCompatibleDevice(
    SkBitmap::Config config, int width, int height, bool isOpaque,
    Usage /*usage*/) {
  SkASSERT(config == SkBitmap::kARGB_8888_Config);
  return VectorPlatformDeviceEmf::CreateDevice(width, height, isOpaque, NULL);
}
#endif

SkBaseDevice* VectorPlatformDeviceEmf::onCreateDevice(const SkImageInfo& info,
                                                      Usage /*usage*/) {
  SkASSERT(info.colorType() == kPMColor_SkColorType);
  return VectorPlatformDeviceEmf::CreateDevice(
      info.width(), info.height(), info.isOpaque(), NULL);
}

bool VectorPlatformDeviceEmf::CreateBrush(bool use_brush, COLORREF color) {
  SkASSERT(previous_brush_ == NULL);
  // We can't use SetDCBrushColor() or DC_BRUSH when drawing to a EMF buffer.
  // SetDCBrushColor() calls are not recorded at all and DC_BRUSH will use
  // WHITE_BRUSH instead.

  if (!use_brush) {
    // Set the transparency.
    if (0 == SetBkMode(hdc_, TRANSPARENT)) {
      SkASSERT(false);
      return false;
    }

    // Select the NULL brush.
    previous_brush_ = SelectObject(GetStockObject(NULL_BRUSH));
    return previous_brush_ != NULL;
  }

  // Set the opacity.
  if (0 == SetBkMode(hdc_, OPAQUE)) {
    SkASSERT(false);
    return false;
  }

  // Create and select the brush.
  previous_brush_ = SelectObject(CreateSolidBrush(color));
  return previous_brush_ != NULL;
}

bool VectorPlatformDeviceEmf::CreatePen(bool use_pen,
                                        COLORREF color,
                                        int stroke_width,
                                        float stroke_miter,
                                        DWORD pen_style) {
  SkASSERT(previous_pen_ == NULL);
  // We can't use SetDCPenColor() or DC_PEN when drawing to a EMF buffer.
  // SetDCPenColor() calls are not recorded at all and DC_PEN will use BLACK_PEN
  // instead.

  // No pen case
  if (!use_pen) {
    previous_pen_ = SelectObject(GetStockObject(NULL_PEN));
    return previous_pen_ != NULL;
  }

  // Use the stock pen if the stroke width is 0.
  if (stroke_width == 0) {
    // Create a pen with the right color.
    previous_pen_ = SelectObject(::CreatePen(PS_SOLID, 0, color));
    return previous_pen_ != NULL;
  }

  // Load a custom pen.
  LOGBRUSH brush;
  brush.lbStyle = BS_SOLID;
  brush.lbColor = color;
  brush.lbHatch = 0;
  HPEN pen = ExtCreatePen(pen_style, stroke_width, &brush, 0, NULL);
  SkASSERT(pen != NULL);
  previous_pen_ = SelectObject(pen);
  if (previous_pen_ == NULL)
    return false;

  if (!SetMiterLimit(hdc_, stroke_miter, NULL)) {
    SkASSERT(false);
    return false;
  }
  return true;
}

void VectorPlatformDeviceEmf::Cleanup() {
  if (previous_brush_) {
    HGDIOBJ result = SelectObject(previous_brush_);
    previous_brush_ = NULL;
    if (result) {
      BOOL res = DeleteObject(result);
      SkASSERT(res != 0);
    }
  }
  if (previous_pen_) {
    HGDIOBJ result = SelectObject(previous_pen_);
    previous_pen_ = NULL;
    if (result) {
      BOOL res = DeleteObject(result);
      SkASSERT(res != 0);
    }
  }
  // Remove any loaded path from the context.
  AbortPath(hdc_);
}

HGDIOBJ VectorPlatformDeviceEmf::SelectObject(HGDIOBJ object) {
  HGDIOBJ result = ::SelectObject(hdc_, object);
  SkASSERT(result != HGDI_ERROR);
  if (result == HGDI_ERROR)
    return NULL;
  return result;
}

bool VectorPlatformDeviceEmf::CreateBrush(bool use_brush,
                                          const SkPaint& paint) {
  // Make sure that for transparent color, no brush is used.
  if (paint.getAlpha() == 0) {
    use_brush = false;
  }

  return CreateBrush(use_brush, SkColorToCOLORREF(paint.getColor()));
}

bool VectorPlatformDeviceEmf::CreatePen(bool use_pen, const SkPaint& paint) {
  // Make sure that for transparent color, no pen is used.
  if (paint.getAlpha() == 0) {
    use_pen = false;
  }

  DWORD pen_style = PS_GEOMETRIC | PS_SOLID;
  switch (paint.getStrokeJoin()) {
    case SkPaint::kMiter_Join:
      // Connects path segments with a sharp join.
      pen_style |= PS_JOIN_MITER;
      break;
    case SkPaint::kRound_Join:
      // Connects path segments with a round join.
      pen_style |= PS_JOIN_ROUND;
      break;
    case SkPaint::kBevel_Join:
      // Connects path segments with a flat bevel join.
      pen_style |= PS_JOIN_BEVEL;
      break;
    default:
      SkASSERT(false);
      break;
  }
  switch (paint.getStrokeCap()) {
    case SkPaint::kButt_Cap:
      // Begin/end contours with no extension.
      pen_style |= PS_ENDCAP_FLAT;
      break;
    case SkPaint::kRound_Cap:
      // Begin/end contours with a semi-circle extension.
      pen_style |= PS_ENDCAP_ROUND;
      break;
    case SkPaint::kSquare_Cap:
      // Begin/end contours with a half square extension.
      pen_style |= PS_ENDCAP_SQUARE;
      break;
    default:
      SkASSERT(false);
      break;
  }

  return CreatePen(use_pen,
                   SkColorToCOLORREF(paint.getColor()),
                   SkScalarRoundToInt(paint.getStrokeWidth()),
                   paint.getStrokeMiter(),
                   pen_style);
}

void VectorPlatformDeviceEmf::InternalDrawBitmap(const SkBitmap& bitmap,
                                                 int x, int y,
                                                 const SkPaint& paint) {
  unsigned char alpha = paint.getAlpha();
  if (alpha == 0)
    return;

  bool is_translucent;
  if (alpha != 255) {
    // ApplyPaint expect an opaque color.
    SkPaint tmp_paint(paint);
    tmp_paint.setAlpha(255);
    if (!ApplyPaint(tmp_paint))
      return;
    is_translucent = true;
  } else {
    if (!ApplyPaint(paint))
      return;
    is_translucent = false;
  }
  int src_size_x = bitmap.width();
  int src_size_y = bitmap.height();
  if (!src_size_x || !src_size_y)
    return;

  // Create a BMP v4 header that we can serialize. We use the shared "V3"
  // fillter to fill the stardard items, then add in the "V4" stuff we want.
  BITMAPV4HEADER bitmap_header;
  memset(&bitmap_header, 0, sizeof(BITMAPV4HEADER));
  FillBitmapInfoHeader(src_size_x, src_size_y,
                       reinterpret_cast<BITMAPINFOHEADER*>(&bitmap_header));
  bitmap_header.bV4Size = sizeof(BITMAPV4HEADER);
  bitmap_header.bV4RedMask   = 0x00ff0000;
  bitmap_header.bV4GreenMask = 0x0000ff00;
  bitmap_header.bV4BlueMask  = 0x000000ff;
  bitmap_header.bV4AlphaMask = 0xff000000;

  SkAutoLockPixels lock(bitmap);
  SkASSERT(bitmap.config() == SkBitmap::kARGB_8888_Config);
  const uint32_t* pixels = static_cast<const uint32_t*>(bitmap.getPixels());
  if (pixels == NULL) {
    SkASSERT(false);
    return;
  }

  if (!is_translucent) {
    int row_length = bitmap.rowBytesAsPixels();
    // There is no quick way to determine if an image is opaque.
    for (int y2 = 0; y2 < src_size_y; ++y2) {
      for (int x2 = 0; x2 < src_size_x; ++x2) {
        if (SkColorGetA(pixels[(y2 * row_length) + x2]) != 255) {
          is_translucent = true;
          y2 = src_size_y;
          break;
        }
      }
    }
  }

  HDC dc = BeginPlatformPaint();
  BITMAPINFOHEADER hdr;
  FillBitmapInfoHeader(src_size_x, src_size_y, &hdr);
  if (is_translucent) {
    // The image must be loaded as a bitmap inside a device context.
    HDC bitmap_dc = ::CreateCompatibleDC(dc);
    void* bits = NULL;
    HBITMAP hbitmap = ::CreateDIBSection(
        bitmap_dc, reinterpret_cast<const BITMAPINFO*>(&hdr),
        DIB_RGB_COLORS, &bits, NULL, 0);

    // static cast to a char so we can do byte ptr arithmatic to
    // get the offset.
    unsigned char* dest_buffer = static_cast<unsigned char *>(bits);

    // We will copy row by row to avoid having to worry about
    // the row strides being different.
    const int dest_row_size = hdr.biBitCount / 8 * hdr.biWidth;
    for (int row = 0; row < bitmap.height(); ++row) {
      int dest_offset = row * dest_row_size;
      // pixels_offset in terms of pixel count.
      int src_offset = row * bitmap.rowBytesAsPixels();
      memcpy(dest_buffer + dest_offset, pixels + src_offset, dest_row_size);
    }
    SkASSERT(hbitmap);
    HGDIOBJ old_bitmap = ::SelectObject(bitmap_dc, hbitmap);

    // After some analysis of IE7's behavior, this is the thing to do. I was
    // sure IE7 was doing so kind of bitmasking due to the way translucent image
    // where renderered but after some windbg tracing, it is being done by the
    // printer driver after all (mostly HP printers). IE7 always use AlphaBlend
    // for bitmasked images. The trick seems to switch the stretching mode in
    // what the driver expects.
    DWORD previous_mode = GetStretchBltMode(dc);
    BOOL result = SetStretchBltMode(dc, COLORONCOLOR);
    SkASSERT(result);
    // Note that this function expect premultiplied colors (!)
    BLENDFUNCTION blend_function = {AC_SRC_OVER, 0, alpha, AC_SRC_ALPHA};
    result = GdiAlphaBlend(dc,
                           x, y,  // Destination origin.
                           src_size_x, src_size_y,  // Destination size.
                           bitmap_dc,
                           0, 0,  // Source origin.
                           src_size_x, src_size_y,  // Source size.
                           blend_function);
    SkASSERT(result);
    result = SetStretchBltMode(dc, previous_mode);
    SkASSERT(result);

    ::SelectObject(bitmap_dc, static_cast<HBITMAP>(old_bitmap));
    DeleteObject(hbitmap);
    DeleteDC(bitmap_dc);
  } else {
    int nCopied = StretchDIBits(dc,
                                x, y,  // Destination origin.
                                src_size_x, src_size_y,
                                0, 0,  // Source origin.
                                src_size_x, src_size_y,  // Source size.
                                pixels,
                                reinterpret_cast<const BITMAPINFO*>(&hdr),
                                DIB_RGB_COLORS,
                                SRCCOPY);
  }
  EndPlatformPaint();
  Cleanup();
}

}  // namespace skia