Debase our Uniscribe code. This moves FontUtils and all our Uniscribe code fr...

webkit/port/platform/graphics/UniscribeHelper.cpp

 // Copyright (c) 2006-2008 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 "config.h"
+#include "UniscribeHelper.h"
+
 #include <windows.h>
 
-#include "base/gfx/uniscribe.h"
+#include "FontUtilsWin.h"
+#include "wtf/Assertions.h"
 
-#include "base/gfx/font_utils.h"
-#include "base/logging.h"
-
-namespace gfx {
+namespace WebCore {
 
 // This function is used to see where word spacing should be applied inside
 // runs. Note that this must match Font::treatAsSpace so we all agree where
 // and how much space this is, so we don't want to do more general Unicode
 // "is this a word break" thing.
-static bool TreatAsSpace(wchar_t c) {
- return c == ' ' || c == '\t' || c == '\n' || c == 0x00A0;
+static bool TreatAsSpace(UChar c)
+{
+   return c == ' ' || c == '\t' || c == '\n' || c == 0x00A0;
 }
 
 // SCRIPT_FONTPROPERTIES contains glyph indices for default, invalid
 // and blank glyphs. Just because ScriptShape succeeds does not mean
 // that a text run is rendered correctly. Some characters may be rendered
 // with default/invalid/blank glyphs. Therefore, we need to check if the glyph
 // array returned by ScriptShape contains any of those glyphs to make
 // sure that the text run is rendered successfully.
 static bool ContainsMissingGlyphs(WORD *glyphs,
                                   int length,
-                                  SCRIPT_FONTPROPERTIES* properties) {
-  for (int i = 0; i < length; ++i) {
-    if (glyphs[i] == properties->wgDefault ||
-        (glyphs[i] == properties->wgInvalid && glyphs[i] != properties->wgBlank))
-      return true;
-  }
+                                  SCRIPT_FONTPROPERTIES* properties)
+{
+    for (int i = 0; i < length; ++i) {
+        if (glyphs[i] == properties->wgDefault ||
+            (glyphs[i] == properties->wgInvalid &&
+             glyphs[i] != properties->wgBlank))
+            return true;
+    }
 
-  return false;
+    return false;
 }
 
 // HFONT is the 'incarnation' of 'everything' about font, but it's an opaque
 // handle and we can't directly query it to make a new HFONT sharing
 // its characteristics (height, style, etc) except for family name.
 // This function uses GetObject to convert HFONT back to LOGFONT,
 // resets the fields of LOGFONT and calculates style to use later
 // for the creation of a font identical to HFONT other than family name.
-static void SetLogFontAndStyle(HFONT hfont, LOGFONT *logfont, int *style) {
-  DCHECK(hfont && logfont);
-  if (!hfont || !logfont)
-    return;
-
-  GetObject(hfont, sizeof(LOGFONT), logfont);
-  // We reset these fields to values appropriate for CreateFontIndirect.
-  // while keeping lfHeight, which is the most important value in creating
-  // a new font similar to hfont.
-  logfont->lfWidth = 0;
-  logfont->lfEscapement = 0;
-  logfont->lfOrientation = 0;
-  logfont->lfCharSet = DEFAULT_CHARSET;
-  logfont->lfOutPrecision = OUT_TT_ONLY_PRECIS;
-  logfont->lfQuality = DEFAULT_QUALITY;  // Honor user's desktop settings.
-  logfont->lfPitchAndFamily = DEFAULT_PITCH | FF_DONTCARE;
-  if (style)
-    *style = gfx::GetStyleFromLogfont(logfont);
-}
-
-UniscribeState::UniscribeState(const wchar_t* input,
-                               int input_length,
-                               bool is_rtl,
-                               HFONT hfont,
-                               SCRIPT_CACHE* script_cache,
-                               SCRIPT_FONTPROPERTIES* font_properties)
-    : input_(input),
-      input_length_(input_length),
-      is_rtl_(is_rtl),
-      hfont_(hfont),
-      script_cache_(script_cache),
-      font_properties_(font_properties),
-      directional_override_(false),
-      inhibit_ligate_(false),
-      letter_spacing_(0),
-      space_width_(0),
-      word_spacing_(0),
-      ascent_(0) {
-  logfont_.lfFaceName[0] = 0;
-}
-
-UniscribeState::~UniscribeState() {
-}
-
-void UniscribeState::InitWithOptionalLengthProtection(bool length_protection) {
-  // We cap the input length and just don't do anything. We'll allocate a lot
-  // of things of the size of the number of characters, so the allocated memory
-  // will be several times the input length. Plus shaping such a large buffer
-  // may be a form of denial of service. No legitimate text should be this long.
-  // It also appears that Uniscribe flatly rejects very long strings, so we
-  // don't lose anything by doing this.
-  //
-  // The input length protection may be disabled by the unit tests to cause
-  // an error condition.
-  static const int kMaxInputLength = 65535;
-  if (input_length_ == 0 ||
-      (length_protection && input_length_ > kMaxInputLength))
-    return;
-
-  FillRuns();
-  FillShapes();
-  FillScreenOrder();
-}
-
-int UniscribeState::Width() const {
-  int width = 0;
-  for (int item_index = 0; item_index < static_cast<int>(runs_->size());
-       item_index++) {
-    width += AdvanceForItem(item_index);
-  }
-  return width;
-}
-
-void UniscribeState::Justify(int additional_space) {
-  // Count the total number of glyphs we have so we know how big to make the
-  // buffers below.
-  int total_glyphs = 0;
-  for (size_t run = 0; run < runs_->size(); run++) {
-    int run_idx = screen_order_[run];
-    total_glyphs += static_cast<int>(shapes_[run_idx].glyph_length());
-  }
-  if (total_glyphs == 0)
-    return;  // Nothing to do.
-
-  // We make one big buffer in screen order of all the glyphs we are drawing
-  // across runs so that the justification function will adjust evenly across
-  // all glyphs.
-  StackVector<SCRIPT_VISATTR, 64> visattr;
-  visattr->resize(total_glyphs);
-  StackVector<int, 64> advances;
-  advances->resize(total_glyphs);
-  StackVector<int, 64> justify;
-  justify->resize(total_glyphs);
-
-  // Build the packed input.
-  int dest_index = 0;
-  for (size_t run = 0; run < runs_->size(); run++) {
-    int run_idx = screen_order_[run];
-    const Shaping& shaping = shapes_[run_idx];
-
-    for (int i = 0; i < shaping.glyph_length(); i++, dest_index++) {
-      memcpy(&visattr[dest_index], &shaping.visattr[i], sizeof(SCRIPT_VISATTR));
-      advances[dest_index] = shaping.advance[i];
-    }
-  }
-
-  // The documentation for ScriptJustify is wrong, the parameter is the space
-  // to add and not the width of the column you want.
-  const int min_kashida = 1;  // How do we decide what this should be?
-  ScriptJustify(&visattr[0], &advances[0], total_glyphs, additional_space,
-                min_kashida, &justify[0]);
-
-  // Now we have to unpack the justification amounts back into the runs so
-  // the glyph indices match.
-  int global_glyph_index = 0;
-  for (size_t run = 0; run < runs_->size(); run++) {
-    int run_idx = screen_order_[run];
-    Shaping& shaping = shapes_[run_idx];
-
-    shaping.justify->resize(shaping.glyph_length());
-    for (int i = 0; i < shaping.glyph_length(); i++, global_glyph_index++)
-      shaping.justify[i] = justify[global_glyph_index];
-  }
-}
-
-int UniscribeState::CharacterToX(int offset) const {
-  HRESULT hr;
-  DCHECK(offset <= input_length_);
-
-  // Our algorithm is to traverse the items in screen order from left to
-  // right, adding in each item's screen width until we find the item with
-  // the requested character in it.
-  int width = 0;
-  for (size_t screen_idx = 0; screen_idx < runs_->size(); screen_idx++) {
-    // Compute the length of this run.
-    int item_idx = screen_order_[screen_idx];
-    const SCRIPT_ITEM& item = runs_[item_idx];
-    const Shaping& shaping = shapes_[item_idx];
-    int item_length = shaping.char_length();
-
-    if (offset >= item.iCharPos && offset <= item.iCharPos + item_length) {
-      // Character offset is in this run.
-      int char_len = offset - item.iCharPos;
-
-      int cur_x = 0;
-      hr = ScriptCPtoX(char_len, FALSE, item_length, shaping.glyph_length(),
-                       &shaping.logs[0], &shaping.visattr[0],
-                       shaping.effective_advances(), &item.a, &cur_x);
-      if (FAILED(hr))
-        return 0;
-
-      width += cur_x + shaping.pre_padding;
-      DCHECK(width >= 0);
-      return width;
-    }
-
-    // Move to the next item.
-    width += AdvanceForItem(item_idx);
-  }
-  DCHECK(width >= 0);
-  return width;
-}
-
-int UniscribeState::XToCharacter(int x) const {
-  // We iterate in screen order until we find the item with the given pixel
-  // position in it. When we find that guy, we ask Uniscribe for the
-  // character index.
-  HRESULT hr;
-  for (size_t screen_idx = 0; screen_idx < runs_->size(); screen_idx++) {
-    int item_idx = screen_order_[screen_idx];
-    int advance_for_item = AdvanceForItem(item_idx);
-
-    // Note that the run may be empty if shaping failed, so we want to skip
-    // over it.
-    const Shaping& shaping = shapes_[item_idx];
-    int item_length = shaping.char_length();
-    if (x <= advance_for_item && item_length > 0) {
-      // The requested offset is within this item.
-      const SCRIPT_ITEM& item = runs_[item_idx];
-
-      // Account for the leading space we've added to this run that Uniscribe
-      // doesn't know about.
-      x -= shaping.pre_padding;
-
-      int char_x = 0;
-      int trailing;
-      hr = ScriptXtoCP(x, item_length, shaping.glyph_length(),
-                       &shaping.logs[0], &shaping.visattr[0],
-                       shaping.effective_advances(), &item.a, &char_x,
-                       &trailing);
-
-      // The character offset is within the item. We need to add the item's
-      // offset to transform it into the space of the TextRun
-      return char_x + item.iCharPos;
-    }
-
-    // The offset is beyond this item, account for its length and move on.
-    x -= advance_for_item;
-  }
-
-  // Error condition, we don't know what to do if we don't have that X
-  // position in any of our items.
-  return 0;
-}
-
-void UniscribeState::Draw(HDC dc, int x, int y, int from, int to) {
-  HGDIOBJ old_font = 0;
-  int cur_x = x;
-  bool first_run = true;
-
-  for (size_t screen_idx = 0; screen_idx < runs_->size(); screen_idx++) {
-    int item_idx = screen_order_[screen_idx];
-    const SCRIPT_ITEM& item = runs_[item_idx];
-    const Shaping& shaping = shapes_[item_idx];
-
-    // Character offsets within this run. THESE MAY NOT BE IN RANGE and may
-    // be negative, etc. The code below handles this.
-    int from_char = from - item.iCharPos;
-    int to_char = to - item.iCharPos;
-
-    // See if we need to draw any characters in this item.
-    if (shaping.char_length() == 0 ||
-        from_char >= shaping.char_length() || to_char <= 0) {
-      // No chars in this item to display.
-      cur_x += AdvanceForItem(item_idx);
-      continue;
-    }
-
-    // Compute the starting glyph within this span. |from| and |to| are
-    // global offsets that may intersect arbitrarily with our local run.
-    int from_glyph, after_glyph;
-    if (item.a.fRTL) {
-      // To compute the first glyph when going RTL, we use |to|.
-      if (to_char >= shaping.char_length()) {
-        // The end of the text is after (to the left) of us.
-        from_glyph = 0;
-      } else {
-        // Since |to| is exclusive, the first character we draw on the left
-        // is actually the one right before (to the right) of |to|.
-        from_glyph = shaping.logs[to_char - 1];
-      }
-
-      // The last glyph is actually the first character in the range.
-      if (from_char <= 0) {
-        // The first character to draw is before (to the right) of this span,
-        // so draw all the way to the end.
-        after_glyph = shaping.glyph_length();
-      } else {
-        // We want to draw everything up until the character to the right of
-        // |from|. To the right is - 1, so we look that up (remember our
-        // character could be more than one glyph, so we can't look up our
-        // glyph and add one).
-        after_glyph = shaping.logs[from_char - 1];
-      }
+static void SetLogFontAndStyle(HFONT hfont, LOGFONT *logfont, int *style)
+{
+    ASSERT(hfont && logfont);
+    if (!hfont || !logfont)
+        return;
+
+    GetObject(hfont, sizeof(LOGFONT), logfont);
+    // We reset these fields to values appropriate for CreateFontIndirect.
+    // while keeping lfHeight, which is the most important value in creating
+    // a new font similar to hfont.
+    logfont->lfWidth = 0;
+    logfont->lfEscapement = 0;
+    logfont->lfOrientation = 0;
+    logfont->lfCharSet = DEFAULT_CHARSET;
+    logfont->lfOutPrecision = OUT_TT_ONLY_PRECIS;
+    logfont->lfQuality = DEFAULT_QUALITY;  // Honor user's desktop settings.
+    logfont->lfPitchAndFamily = DEFAULT_PITCH | FF_DONTCARE;
+    if (style)
+        *style = GetStyleFromLogfont(logfont);
+}
+
+UniscribeHelper::UniscribeHelper(const UChar* input,
+                                int inputLength,
+                                bool isRtl,
+                                HFONT hfont,
+                                SCRIPT_CACHE* scriptCache,
+                                SCRIPT_FONTPROPERTIES* fontProperties)
+    : m_input(input)
+    , m_inputLength(inputLength)
+    , m_isRtl(isRtl)
+    , m_hfont(hfont)
+    , m_scriptCache(scriptCache)
+    , m_fontProperties(fontProperties)
+    , m_directionalOverride(false)
+    , m_inhibitLigate(false)
+    , m_letterSpacing(0)
+    , m_spaceWidth(0)
+    , m_wordSpacing(0)
+    , m_ascent(0)
+{
+    m_logfont.lfFaceName[0] = 0;
+}
+
+UniscribeHelper::~UniscribeHelper()
+{
+}
+
+void UniscribeHelper::InitWithOptionalLengthProtection(bool lengthProtection)
+{
+    // We cap the input length and just don't do anything. We'll allocate a lot
+    // of things of the size of the number of characters, so the allocated
+    // memory will be several times the input length. Plus shaping such a large
+    // buffer may be a form of denial of service. No legitimate text should be
+    // this long.  It also appears that Uniscribe flatly rejects very long
+    // strings, so we don't lose anything by doing this.
+    //
+    // The input length protection may be disabled by the unit tests to cause
+    // an error condition.
+    static const int kMaxInputLength = 65535;
+    if (m_inputLength == 0 ||
+        (lengthProtection && m_inputLength > kMaxInputLength))
+        return;
+
+    FillRuns();
+    FillShapes();
+    FillScreenOrder();
+}
+
+int UniscribeHelper::Width() const
+{
+    int width = 0;
+    for (int item_index = 0; item_index < static_cast<int>(m_runs.size());
+         item_index++) {
+        width += AdvanceForItem(item_index);
+    }
+    return width;
+}
+
+void UniscribeHelper::Justify(int additionalSpace)
+{
+    // Count the total number of glyphs we have so we know how big to make the
+    // buffers below.
+    int totalGlyphs = 0;
+    for (size_t run = 0; run < m_runs.size(); run++) {
+        int run_idx = m_screenOrder[run];
+        totalGlyphs += static_cast<int>(m_shapes[run_idx].glyphLength());
+    }
+    if (totalGlyphs == 0)
+        return;  // Nothing to do.
+
+    // We make one big buffer in screen order of all the glyphs we are drawing
+    // across runs so that the justification function will adjust evenly across
+    // all glyphs.
+    Vector<SCRIPT_VISATTR, 64> visattr;
+    visattr.resize(totalGlyphs);
+    Vector<int, 64> advances;
+    advances.resize(totalGlyphs);
+    Vector<int, 64> justify;
+    justify.resize(totalGlyphs);
+
+    // Build the packed input.
+    int dest_index = 0;
+    for (size_t run = 0; run < m_runs.size(); run++) {
+        int run_idx = m_screenOrder[run];
+        const Shaping& shaping = m_shapes[run_idx];
+
+        for (int i = 0; i < shaping.glyphLength(); i++, dest_index++) {
+            memcpy(&visattr[dest_index], &shaping.m_visattr[i],
+                   sizeof(SCRIPT_VISATTR));
+            advances[dest_index] = shaping.m_advance[i];
+        }
+    }
+
+    // The documentation for ScriptJustify is wrong, the parameter is the space
+    // to add and not the width of the column you want.
+    const int minKashida = 1;  // How do we decide what this should be?
+    ScriptJustify(&visattr[0], &advances[0], totalGlyphs, additionalSpace,
+                  minKashida, &justify[0]);
+
+    // Now we have to unpack the justification amounts back into the runs so
+    // the glyph indices match.
+    int globalGlyphIndex = 0;
+    for (size_t run = 0; run < m_runs.size(); run++) {
+        int run_idx = m_screenOrder[run];
+        Shaping& shaping = m_shapes[run_idx];
+
+        shaping.m_justify.resize(shaping.glyphLength());
+        for (int i = 0; i < shaping.glyphLength(); i++, globalGlyphIndex++)
+            shaping.m_justify[i] = justify[globalGlyphIndex];
+    }
+}
+
+int UniscribeHelper::CharacterToX(int offset) const
+{
+    HRESULT hr;
+    ASSERT(offset <= m_inputLength);
+
+    // Our algorithm is to traverse the items in screen order from left to
+    // right, adding in each item's screen width until we find the item with
+    // the requested character in it.
+    int width = 0;
+    for (size_t screen_idx = 0; screen_idx < m_runs.size(); screen_idx++) {
+        // Compute the length of this run.
+        int itemIdx = m_screenOrder[screen_idx];
+        const SCRIPT_ITEM& item = m_runs[itemIdx];
+        const Shaping& shaping = m_shapes[itemIdx];
+        int itemLength = shaping.charLength();
+
+        if (offset >= item.iCharPos && offset <= item.iCharPos + itemLength) {
+            // Character offset is in this run.
+            int char_len = offset - item.iCharPos;
+
+            int curX = 0;
+            hr = ScriptCPtoX(char_len, FALSE, itemLength,
+                             shaping.glyphLength(),
+                             &shaping.m_logs[0], &shaping.m_visattr[0],
+                             shaping.effectiveAdvances(), &item.a, &curX);
+            if (FAILED(hr))
+                return 0;
+
+            width += curX + shaping.m_prePadding;
+            ASSERT(width >= 0);
+            return width;
+        }
+
+        // Move to the next item.
+        width += AdvanceForItem(itemIdx);
+    }
+    ASSERT(width >= 0);
+    return width;
+}
+
+int UniscribeHelper::XToCharacter(int x) const
+{
+    // We iterate in screen order until we find the item with the given pixel
+    // position in it. When we find that guy, we ask Uniscribe for the
+    // character index.
+    HRESULT hr;
+    for (size_t screen_idx = 0; screen_idx < m_runs.size(); screen_idx++) {
+        int itemIdx = m_screenOrder[screen_idx];
+        int advance_for_item = AdvanceForItem(itemIdx);
+
+        // Note that the run may be empty if shaping failed, so we want to skip
+        // over it.
+        const Shaping& shaping = m_shapes[itemIdx];
+        int itemLength = shaping.charLength();
+        if (x <= advance_for_item && itemLength > 0) {
+            // The requested offset is within this item.
+            const SCRIPT_ITEM& item = m_runs[itemIdx];
+
+            // Account for the leading space we've added to this run that
+            // Uniscribe doesn't know about.
+            x -= shaping.m_prePadding;
+
+            int char_x = 0;
+            int trailing;
+            hr = ScriptXtoCP(x, itemLength, shaping.glyphLength(),
+                             &shaping.m_logs[0], &shaping.m_visattr[0],
+                             shaping.effectiveAdvances(), &item.a, &char_x,
+                             &trailing);
+
+            // The character offset is within the item. We need to add the
+            // item's offset to transform it into the space of the TextRun
+            return char_x + item.iCharPos;
+        }
+
+        // The offset is beyond this item, account for its length and move on.
+        x -= advance_for_item;
+    }
+
+    // Error condition, we don't know what to do if we don't have that X
+    // position in any of our items.
+    return 0;
+}
+
+void UniscribeHelper::Draw(HDC dc, int x, int y, int from, int to)
+{
+    HGDIOBJ oldFont = 0;
+    int curX = x;
+    bool firstRun = true;
+
+    for (size_t screen_idx = 0; screen_idx < m_runs.size(); screen_idx++) {
+        int itemIdx = m_screenOrder[screen_idx];
+        const SCRIPT_ITEM& item = m_runs[itemIdx];
+        const Shaping& shaping = m_shapes[itemIdx];
+
+        // Character offsets within this run. THESE MAY NOT BE IN RANGE and may
+        // be negative, etc. The code below handles this.
+        int fromChar = from - item.iCharPos;
+        int to_char = to - item.iCharPos;
+
+        // See if we need to draw any characters in this item.
+        if (shaping.charLength() == 0 ||
+            fromChar >= shaping.charLength() || to_char <= 0) {
+            // No chars in this item to display.
+            curX += AdvanceForItem(itemIdx);
+            continue;
+        }
+
+        // Compute the starting glyph within this span. |from| and |to| are
+        // global offsets that may intersect arbitrarily with our local run.
+        int fromGlyph, afterGlyph;
+        if (item.a.fRTL) {
+            // To compute the first glyph when going RTL, we use |to|.
+            if (to_char >= shaping.charLength()) {
+                // The end of the text is after (to the left) of us.
+                fromGlyph = 0;
+            } else {
+                // Since |to| is exclusive, the first character we draw on the
+                // left is actually the one right before (to the right) of
+                // |to|.
+                fromGlyph = shaping.m_logs[to_char - 1];
+            }
+
+            // The last glyph is actually the first character in the range.
+            if (fromChar <= 0) {
+                // The first character to draw is before (to the right) of this
+                // span, so draw all the way to the end.
+                afterGlyph = shaping.glyphLength();
+            } else {
+                // We want to draw everything up until the character to the
+                // right of |from|. To the right is - 1, so we look that up
+                // (remember our character could be more than one glyph, so we
+                // can't look up our glyph and add one).
+                afterGlyph = shaping.m_logs[fromChar - 1];
+            }
+        } else {
+            // Easy case, everybody agrees about directions. We only need to
+            // handle boundary conditions to get a range inclusive at the
+            // beginning, and exclusive at the ending. We have to do some
+            // computation to see the glyph one past the end.
+            fromGlyph = shaping.m_logs[fromChar < 0 ? 0 : fromChar];
+            if (to_char >= shaping.charLength())
+                afterGlyph = shaping.glyphLength();
+            else
+                afterGlyph = shaping.m_logs[to_char];
+        }
+
+        // Account for the characters that were skipped in this run. When
+        // WebKit asks us to draw a subset of the run, it actually tells us
+        // to draw at the X offset of the beginning of the run, since it
+        // doesn't know the internal position of any of our characters.
+        const int* effectiveAdvances = shaping.effectiveAdvances();
+        int innerOffset = 0;
+        for (int i = 0; i < fromGlyph; i++)
+            innerOffset += effectiveAdvances[i];
+
+        // Actually draw the glyphs we found.
+        int glyphCount = afterGlyph - fromGlyph;
+        if (fromGlyph >= 0 && glyphCount > 0) {
+            // Account for the preceeding space we need to add to this run. We
+            // don't need to count for the following space because that will be
+            // counted in AdvanceForItem below when we move to the next run.
+            innerOffset += shaping.m_prePadding;
+
+            // Pass NULL in when there is no justification.
+            const int* justify = shaping.m_justify.size() == 0 ?
+                NULL : &shaping.m_justify[fromGlyph];
+
+            if (firstRun) {
+                oldFont = SelectObject(dc, shaping.m_hfont);
+                firstRun = false;
+            } else {
+                SelectObject(dc, shaping.m_hfont);
+            }
+
+            // TODO(brettw) bug 698452: if a half a character is selected,
+            // we should set up a clip rect so we draw the half of the glyph
+            // correctly.
+            // Fonts with different ascents can be used to render different
+            // runs.  'Across-runs' y-coordinate correction needs to be
+            // adjusted for each font.
+            HRESULT hr = S_FALSE;
+            for (int executions = 0; executions < 2; ++executions) {
+                hr = ScriptTextOut(dc, shaping.m_scriptCache,
+                                   curX + innerOffset,
+                                   y - shaping.m_ascentOffset,
+                                   0, NULL, &item.a, NULL, 0,
+                                   &shaping.m_glyphs[fromGlyph],
+                                   glyphCount,
+                                   &shaping.m_advance[fromGlyph],
+                                   justify,
+                                   &shaping.m_offsets[fromGlyph]);
+                if (S_OK != hr && 0 == executions) {
+                    // If this ScriptTextOut is called from the renderer it
+                    // might fail because the sandbox is preventing it from
+                    // opening the font files.  If we are running in the
+                    // renderer, TryToPreloadFont is overridden to ask the
+                    // browser to preload the font for us so we can access it.
+                    TryToPreloadFont(shaping.m_hfont);
+                    continue;
+                }
+                break;
+            }
+
+            ASSERT(S_OK == hr);
+        }
+
+        curX += AdvanceForItem(itemIdx);
+    }
+
+    if (oldFont)
+        SelectObject(dc, oldFont);
+}
+
+WORD UniscribeHelper::FirstGlyphForCharacter(int charOffset) const
+{
+    // Find the run for the given character.
+    for (int i = 0; i < static_cast<int>(m_runs.size()); i++) {
+        int firstChar = m_runs[i].iCharPos;
+        const Shaping& shaping = m_shapes[i];
+        int localOffset = charOffset - firstChar;
+        if (localOffset >= 0 && localOffset < shaping.charLength()) {
+            // The character is in this run, return the first glyph for it
+            // (should generally be the only glyph). It seems Uniscribe gives
+            // glyph 0 for empty, which is what we want to return in the
+            // "missing" case.
+            size_t glyphIndex = shaping.m_logs[localOffset];
+            if (glyphIndex >= shaping.m_glyphs.size()) {
+                // The glyph should be in this run, but the run has too few
+                // actual characters. This can happen when shaping the run
+                // fails, in which case, we should have no data in the logs at
+                // all.
+                ASSERT(shaping.m_glyphs.size() == 0);
+                return 0;
+            }
+            return shaping.m_glyphs[glyphIndex];
+        }
+    }
+    return 0;
+}
+
+void UniscribeHelper::FillRuns()
+{
+    HRESULT hr;
+    m_runs.resize(UNISCRIBE_HELPER_STACK_RUNS);
+
+    SCRIPT_STATE inputState;
+    inputState.uBidiLevel = m_isRtl;
+    inputState.fOverrideDirection = m_directionalOverride;
+    inputState.fInhibitSymSwap = false;
+    inputState.fCharShape = false;  // Not implemented in Uniscribe
+    inputState.fDigitSubstitute = false;  // Do we want this for Arabic?
+    inputState.fInhibitLigate = m_inhibitLigate;
+    inputState.fDisplayZWG = false;  // Don't draw control characters.
+    inputState.fArabicNumContext = m_isRtl;  // Do we want this for Arabic?
+    inputState.fGcpClusters = false;
+    inputState.fReserved = 0;
+    inputState.fEngineReserved = 0;
+    // The psControl argument to ScriptItemize should be non-NULL for RTL text,
+    // per http://msdn.microsoft.com/en-us/library/ms776532.aspx . So use a
+    // SCRIPT_CONTROL that is set to all zeros.  Zero as a locale ID means the
+    // neutral locale per http://msdn.microsoft.com/en-us/library/ms776294.aspx
+    static SCRIPT_CONTROL inputControl = {0, // uDefaultLanguage    :16;
+                                           0, // fContextDigits      :1;
+                                           0, // fInvertPreBoundDir  :1;
+                                           0, // fInvertPostBoundDir :1;
+                                           0, // fLinkStringBefore   :1;
+                                           0, // fLinkStringAfter    :1;
+                                           0, // fNeutralOverride    :1;
+                                           0, // fNumericOverride    :1;
+                                           0, // fLegacyBidiClass    :1;
+                                           0, // fMergeNeutralItems  :1;
+                                           0};// fReserved           :7;
+    // Calling ScriptApplyDigitSubstitution( NULL, &inputControl, &inputState)
+    // here would be appropriate if we wanted to set the language ID, and get
+    // local digit substitution behavior.  For now, don't do it.
+
+    while (true) {
+        int num_items = 0;
+
+        // Ideally, we would have a way to know the runs before and after this
+        // one, and put them into the control parameter of ScriptItemize. This
+        // would allow us to shape characters properly that cross style
+        // boundaries (WebKit bug 6148).
+        //
+        // We tell ScriptItemize that the output list of items is one smaller
+        // than it actually is. According to Mozilla bug 366643, if there is
+        // not enough room in the array on pre-SP2 systems, ScriptItemize will
+        // write one past the end of the buffer.
+        //
+        // ScriptItemize is very strange. It will often require a much larger
+        // ITEM buffer internally than it will give us as output. For example,
+        // it will say a 16-item buffer is not big enough, and will write
+        // interesting numbers into all those items. But when we give it a 32
+        // item buffer and it succeeds, it only has one item output.
+        //
+        // It seems to be doing at least two passes, the first where it puts a
+        // lot of intermediate data into our items, and the second where it
+        // collates them.
+        hr = ScriptItemize(m_input, m_inputLength,
+                           static_cast<int>(m_runs.size()) - 1, &inputControl,
+                           &inputState,
+                           &m_runs[0], &num_items);
+        if (SUCCEEDED(hr)) {
+            m_runs.resize(num_items);
+            break;
+        }
+        if (hr != E_OUTOFMEMORY) {
+            // Some kind of unexpected error.
+            m_runs.resize(0);
+            break;
+        }
+        // There was not enough items for it to write into, expand.
+        m_runs.resize(m_runs.size() * 2);
+    }
+}
+
+bool UniscribeHelper::Shape(const UChar* input,
+                            int itemLength,
+                            int numGlyphs,
+                            SCRIPT_ITEM& run,
+                            Shaping& shaping)
+{
+    HFONT hfont = m_hfont;
+    SCRIPT_CACHE* scriptCache = m_scriptCache;
+    SCRIPT_FONTPROPERTIES* fontProperties = m_fontProperties;
+    int ascent = m_ascent;
+    HDC tempDC = NULL;
+    HGDIOBJ oldFont = 0;
+    HRESULT hr;
+    bool lastFallbackTried = false;
+    bool result;
+
+    int generatedGlyphs = 0;
+
+    // In case HFONT passed in ctor cannot render this run, we have to scan
+    // other fonts from the beginning of the font list.
+    ResetFontIndex();
+
+    // Compute shapes.
+    while (true) {
+        shaping.m_logs.resize(itemLength);
+        shaping.m_glyphs.resize(numGlyphs);
+        shaping.m_visattr.resize(numGlyphs);
+
+        // Firefox sets SCRIPT_ANALYSIS.SCRIPT_STATE.fDisplayZWG to true
+        // here. Is that what we want? It will display control characters.
+        hr = ScriptShape(tempDC, scriptCache, input, itemLength,
+                         numGlyphs, &run.a,
+                         &shaping.m_glyphs[0], &shaping.m_logs[0],
+                         &shaping.m_visattr[0], &generatedGlyphs);
+        if (hr == E_PENDING) {
+            // Allocate the DC.
+            tempDC = GetDC(NULL);
+            oldFont = SelectObject(tempDC, hfont);
+            continue;
+        } else if (hr == E_OUTOFMEMORY) {
+            numGlyphs *= 2;
+            continue;
+        } else if (SUCCEEDED(hr) &&
+                   (lastFallbackTried ||
+                    !ContainsMissingGlyphs(&shaping.m_glyphs[0],
+                    generatedGlyphs, fontProperties))) {
+            break;
+        }
+
+        // The current font can't render this run. clear DC and try
+        // next font.
+        if (tempDC) {
+            SelectObject(tempDC, oldFont);
+            ReleaseDC(NULL, tempDC);
+            tempDC = NULL;
+        }
+
+        if (NextWinFontData(&hfont, &scriptCache, &fontProperties, &ascent)) {
+            // The primary font does not support this run. Try next font.
+            // In case of web page rendering, they come from fonts specified in
+            // CSS stylesheets.
+            continue;
+        } else if (!lastFallbackTried) {
+            lastFallbackTried = true;
+
+            // Generate a last fallback font based on the script of
+            // a character to draw while inheriting size and styles
+            // from the primary font
+            if (!m_logfont.lfFaceName[0])
+                SetLogFontAndStyle(m_hfont, &m_logfont, &m_style);
+
+            // TODO(jungshik): generic type should come from webkit for
+            // UniscribeHelperTextRun (a derived class used in webkit).
+            const UChar *family = GetFallbackFamily(input, itemLength,
+                GENERIC_FAMILY_STANDARD, NULL, NULL);
+            bool font_ok = GetDerivedFontData(family, m_style, &m_logfont,
+                                              &ascent, &hfont, &scriptCache);
+
+            if (!font_ok) {
+                // If this GetDerivedFontData is called from the renderer it
+                // might fail because the sandbox is preventing it from opening
+                // the font files.  If we are running in the renderer,
+                // TryToPreloadFont is overridden to ask the browser to preload
+                // the font for us so we can access it.
+                TryToPreloadFont(hfont);
+
+                // Try again.
+                font_ok = GetDerivedFontData(family, m_style, &m_logfont,
+                                             &ascent, &hfont, &scriptCache);
+                ASSERT(font_ok);
+            }
+
+            // TODO(jungshik) : Currently GetDerivedHFont always returns a
+            // a valid HFONT, but in the future, I may change it to return 0.
+            ASSERT(hfont);
+
+            // We don't need a font_properties for the last resort fallback font
+            // because we don't have anything more to try and are forced to
+            // accept empty glyph boxes. If we tried a series of fonts as
+            // 'last-resort fallback', we'd need it, but currently, we don't.
+            continue;
+        } else if (hr == USP_E_SCRIPT_NOT_IN_FONT) {
+            run.a.eScript = SCRIPT_UNDEFINED;
+            continue;
+        } else if (FAILED(hr)) {
+            // Error shaping.
+            generatedGlyphs = 0;
+            result = false;
+            goto cleanup;
+        }
+    }
+
+    // Sets Windows font data for this run to those corresponding to
+    // a font supporting this run. we don't need to store font_properties
+    // because it's not used elsewhere.
+    shaping.m_hfont = hfont;
+    shaping.m_scriptCache = scriptCache;
+
+    // The ascent of a font for this run can be different from
+    // that of the primary font so that we need to keep track of
+    // the difference per run and take that into account when calling
+    // ScriptTextOut in |Draw|. Otherwise, different runs rendered by
+    // different fonts would not be aligned vertically.
+    shaping.m_ascentOffset = m_ascent ? ascent - m_ascent : 0;
+    result = true;
+
+  cleanup:
+    shaping.m_glyphs.resize(generatedGlyphs);
+    shaping.m_visattr.resize(generatedGlyphs);
+    shaping.m_advance.resize(generatedGlyphs);
+    shaping.m_offsets.resize(generatedGlyphs);
+    if (tempDC) {
+        SelectObject(tempDC, oldFont);
+        ReleaseDC(NULL, tempDC);
+    }
+    // On failure, our logs don't mean anything, so zero those out.
+    if (!result)
+        shaping.m_logs.clear();
+
+    return result;
+}
+
+void UniscribeHelper::FillShapes()
+{
+    m_shapes.resize(m_runs.size());
+    for (size_t i = 0; i < m_runs.size(); i++) {
+        int startItem = m_runs[i].iCharPos;
+        int itemLength = m_inputLength - startItem;
+        if (i < m_runs.size() - 1)
+            itemLength = m_runs[i + 1].iCharPos - startItem;
+
+        int numGlyphs;
+        if (itemLength < UNISCRIBE_HELPER_STACK_CHARS) {
+            // We'll start our buffer sizes with the current stack space
+            // available in our buffers if the current input fits. As long as
+            // it doesn't expand past that we'll save a lot of time mallocing.
+            numGlyphs = UNISCRIBE_HELPER_STACK_CHARS;
+        } else {
+            // When the input doesn't fit, give up with the stack since it will
+            // almost surely not be enough room (unless the input actually
+            // shrinks, which is unlikely) and just start with the length
+            // recommended by the Uniscribe documentation as a "usually fits"
+            // size.
+            numGlyphs = itemLength * 3 / 2 + 16;
+        }
+
+        // Convert a string to a glyph string trying the primary font, fonts in
+        // the fallback list and then script-specific last resort font.
+        Shaping& shaping = m_shapes[i];
+        if (!Shape(&m_input[startItem], itemLength, numGlyphs, m_runs[i],
+                   shaping))
+            continue;
+
+        // Compute placements. Note that offsets is documented incorrectly
+        // and is actually an array.
+
+        // DC that we lazily create if Uniscribe commands us to.
+        // (this does not happen often because scriptCache is already
+        //  updated when calling ScriptShape).
+        HDC tempDC = NULL;
+        HGDIOBJ oldFont = NULL;
+        HRESULT hr;
+        while (true) {
+            shaping.m_prePadding = 0;
+            hr = ScriptPlace(tempDC, shaping.m_scriptCache,
+                             &shaping.m_glyphs[0],
+                             static_cast<int>(shaping.m_glyphs.size()),
+                             &shaping.m_visattr[0], &m_runs[i].a,
+                             &shaping.m_advance[0], &shaping.m_offsets[0],
+                             &shaping.m_abc);
+            if (hr != E_PENDING)
+                break;
+
+            // Allocate the DC and run the loop again.
+            tempDC = GetDC(NULL);
+            oldFont = SelectObject(tempDC, shaping.m_hfont);
+        }
+
+        if (FAILED(hr)) {
+            // Some error we don't know how to handle. Nuke all of our data
+            // since we can't deal with partially valid data later.
+            m_runs.clear();
+            m_shapes.clear();
+            m_screenOrder.clear();
+        }
+
+        if (tempDC) {
+            SelectObject(tempDC, oldFont);
+            ReleaseDC(NULL, tempDC);
+        }
+    }
+
+    AdjustSpaceAdvances();
+
+    if (m_letterSpacing != 0 || m_wordSpacing != 0)
+        ApplySpacing();
+}
+
+void UniscribeHelper::FillScreenOrder()
+{
+    m_screenOrder.resize(m_runs.size());
+
+    // We assume that the input has only one text direction in it.
+    // TODO(brettw) are we sure we want to keep this restriction?
+    if (m_isRtl) {
+        for (int i = 0; i < static_cast<int>(m_screenOrder.size()); i++)
+            m_screenOrder[static_cast<int>(m_screenOrder.size()) - i - 1] = i;
     } else {
-      // Easy case, everybody agrees about directions. We only need to handle
-      // boundary conditions to get a range inclusive at the beginning, and
-      // exclusive at the ending. We have to do some computation to see the
-      // glyph one past the end.
-      from_glyph = shaping.logs[from_char < 0 ? 0 : from_char];
-      if (to_char >= shaping.char_length())
-        after_glyph = shaping.glyph_length();
-      else
-        after_glyph = shaping.logs[to_char];
-    }
-
-    // Account for the characters that were skipped in this run. When
-    // WebKit asks us to draw a subset of the run, it actually tells us
-    // to draw at the X offset of the beginning of the run, since it
-    // doesn't know the internal position of any of our characters.
-    const int* effective_advances = shaping.effective_advances();
-    int inner_offset = 0;
-    for (int i = 0; i < from_glyph; i++)
-      inner_offset += effective_advances[i];
-
-    // Actually draw the glyphs we found.
-    int glyph_count = after_glyph - from_glyph;
-    if (from_glyph >= 0 && glyph_count > 0) {
-      // Account for the preceeding space we need to add to this run. We don't
-      // need to count for the following space because that will be counted
-      // in AdvanceForItem below when we move to the next run.
-      inner_offset += shaping.pre_padding;
-
-      // Pass NULL in when there is no justification.
-      const int* justify = shaping.justify->empty() ?
-          NULL : &shaping.justify[from_glyph];
-
-      if (first_run) {
-        old_font = SelectObject(dc, shaping.hfont_);
-        first_run = false;
-      } else {
-        SelectObject(dc, shaping.hfont_);
-      }
-
-      // TODO(brettw) bug 698452: if a half a character is selected,
-      // we should set up a clip rect so we draw the half of the glyph
-      // correctly.
-      // Fonts with different ascents can be used to render different runs.
-      // 'Across-runs' y-coordinate correction needs to be adjusted
-      // for each font.
-      HRESULT hr = S_FALSE;
-      for (int executions = 0; executions < 2; ++executions) {
-        hr = ScriptTextOut(dc, shaping.script_cache_, cur_x + inner_offset,
-                           y - shaping.ascent_offset_, 0, NULL, &item.a, NULL,
-                           0, &shaping.glyphs[from_glyph],
-                           glyph_count, &shaping.advance[from_glyph],
-                           justify, &shaping.offsets[from_glyph]);
-        if (S_OK != hr && 0 == executions) {
-          // If this ScriptTextOut is called from the renderer it might fail
-          // because the sandbox is preventing it from opening the font files.
-          // If we are running in the renderer, TryToPreloadFont is overridden
-          // to ask the browser to preload the font for us so we can access it.
-          TryToPreloadFont(shaping.hfont_);
-          continue;
-        }
-        break;
-      }
-
-      DCHECK(S_OK == hr);
-
-
-    }
-
-    cur_x += AdvanceForItem(item_idx);
-  }
-
-  if (old_font)
-    SelectObject(dc, old_font);
-}
-
-WORD UniscribeState::FirstGlyphForCharacter(int char_offset) const {
-  // Find the run for the given character.
-  for (int i = 0; i < static_cast<int>(runs_->size()); i++) {
-    int first_char = runs_[i].iCharPos;
-    const Shaping& shaping = shapes_[i];
-    int local_offset = char_offset - first_char;
-    if (local_offset >= 0 && local_offset < shaping.char_length()) {
-      // The character is in this run, return the first glyph for it (should
-      // generally be the only glyph). It seems Uniscribe gives glyph 0 for
-      // empty, which is what we want to return in the "missing" case.
-      size_t glyph_index = shaping.logs[local_offset];
-      if (glyph_index >= shaping.glyphs->size()) {
-        // The glyph should be in this run, but the run has too few actual
-        // characters. This can happen when shaping the run fails, in which
-        // case, we should have no data in the logs at all.
-        DCHECK(shaping.glyphs->empty());
-        return 0;
-      }
-      return shaping.glyphs[glyph_index];
-    }
-  }
-  return 0;
-}
-
-void UniscribeState::FillRuns() {
-  HRESULT hr;
-  runs_->resize(UNISCRIBE_STATE_STACK_RUNS);
-
-  SCRIPT_STATE input_state;
-  input_state.uBidiLevel = is_rtl_;
-  input_state.fOverrideDirection = directional_override_;
-  input_state.fInhibitSymSwap = false;
-  input_state.fCharShape = false;  // Not implemented in Uniscribe
-  input_state.fDigitSubstitute = false;  // Do we want this for Arabic?
-  input_state.fInhibitLigate = inhibit_ligate_;
-  input_state.fDisplayZWG = false;  // Don't draw control characters.
-  input_state.fArabicNumContext = is_rtl_;  // Do we want this for Arabic?
-  input_state.fGcpClusters = false;
-  input_state.fReserved = 0;
-  input_state.fEngineReserved = 0;
-  // The psControl argument to ScriptItemize should be non-NULL for RTL text,
-  // per http://msdn.microsoft.com/en-us/library/ms776532.aspx . So use a
-  // SCRIPT_CONTROL that is set to all zeros.  Zero as a locale ID means the
-  // neutral locale per http://msdn.microsoft.com/en-us/library/ms776294.aspx .
-  static SCRIPT_CONTROL input_control = {0, // uDefaultLanguage    :16;
-                                         0, // fContextDigits      :1;
-                                         0, // fInvertPreBoundDir  :1;
-                                         0, // fInvertPostBoundDir :1;
-                                         0, // fLinkStringBefore   :1;
-                                         0, // fLinkStringAfter    :1;
-                                         0, // fNeutralOverride    :1;
-                                         0, // fNumericOverride    :1;
-                                         0, // fLegacyBidiClass    :1;
-                                         0, // fMergeNeutralItems  :1;
-                                         0};// fReserved           :7;
-  // Calling ScriptApplyDigitSubstitution( NULL, &input_control, &input_state)
-  // here would be appropriate if we wanted to set the language ID, and get
-  // local digit substitution behavior.  For now, don't do it.
-
-  while (true) {
-    int num_items = 0;
-
-    // Ideally, we would have a way to know the runs before and after this
-    // one, and put them into the control parameter of ScriptItemize. This
-    // would allow us to shape characters properly that cross style
-    // boundaries (WebKit bug 6148).
-    //
-    // We tell ScriptItemize that the output list of items is one smaller
-    // than it actually is. According to Mozilla bug 366643, if there is
-    // not enough room in the array on pre-SP2 systems, ScriptItemize will
-    // write one past the end of the buffer.
-    //
-    // ScriptItemize is very strange. It will often require a much larger
-    // ITEM buffer internally than it will give us as output. For example,
-    // it will say a 16-item buffer is not big enough, and will write
-    // interesting numbers into all those items. But when we give it a 32
-    // item buffer and it succeeds, it only has one item output.
-    //
-    // It seems to be doing at least two passes, the first where it puts a
-    // lot of intermediate data into our items, and the second where it
-    // collates them.
-    hr = ScriptItemize(input_, input_length_,
-                       static_cast<int>(runs_->size()) - 1, &input_control, &input_state,
-                       &runs_[0], &num_items);
-    if (SUCCEEDED(hr)) {
-      runs_->resize(num_items);
-      break;
-    }
-    if (hr != E_OUTOFMEMORY) {
-      // Some kind of unexpected error.
-      runs_->resize(0);
-      break;
-    }
-    // There was not enough items for it to write into, expand.
-    runs_->resize(runs_->size() * 2);
-  }
-
-  // Fix up the directions of the items so they're what WebKit thinks
-  // they are. WebKit (and we assume any other caller) always knows what
-  // direction it wants things to be in, and will only give us runs that are in
-  // the same direction. Sometimes, Uniscibe disagrees, for example, if you
-  // have embedded ASCII punctuation in an Arabic string, WebKit will
-  // (correctly) know that is should still be rendered RTL, but Uniscibe might
-  // think LTR is better.
-  //
-  // TODO(brettw) bug 747235:
-  // This workaround fixes the bug but causes spacing problems in other cases.
-  // WebKit sometimes gives us a big run that includes ASCII and Arabic, and
-  // this forcing direction makes those cases incorrect. This seems to happen
-  // during layout only, so it ends up that spacing is incorrect (because being
-  // the wrong direction changes ligatures and stuff).
-  //
-  //for (size_t i = 0; i < runs_->size(); i++)
-  //  runs_[i].a.fRTL = is_rtl_;
-}
-
-
-bool UniscribeState::Shape(const wchar_t* input,
-                           int item_length,
-                           int num_glyphs,
-                           SCRIPT_ITEM& run,
-                           Shaping& shaping) {
-  HFONT hfont = hfont_;
-  SCRIPT_CACHE* script_cache = script_cache_;
-  SCRIPT_FONTPROPERTIES* font_properties = font_properties_;
-  int ascent = ascent_;
-  HDC temp_dc = NULL;
-  HGDIOBJ old_font = 0;
-  HRESULT hr;
-  bool lastFallbackTried = false;
-  bool result;
-
-  int generated_glyphs = 0;
-
-  // In case HFONT passed in ctor cannot render this run, we have to scan
-  // other fonts from the beginning of the font list.
-  ResetFontIndex();
-
-  // Compute shapes.
-  while (true) {
-    shaping.logs->resize(item_length);
-    shaping.glyphs->resize(num_glyphs);
-    shaping.visattr->resize(num_glyphs);
-
-    // Firefox sets SCRIPT_ANALYSIS.SCRIPT_STATE.fDisplayZWG to true
-    // here. Is that what we want? It will display control characters.
-    hr = ScriptShape(temp_dc, script_cache, input, item_length,
-                     num_glyphs, &run.a,
-                     &shaping.glyphs[0], &shaping.logs[0],
-                     &shaping.visattr[0], &generated_glyphs);
-    if (hr == E_PENDING) {
-      // Allocate the DC.
-      temp_dc = GetDC(NULL);
-      old_font = SelectObject(temp_dc, hfont);
-      continue;
-    } else if (hr == E_OUTOFMEMORY) {
-      num_glyphs *= 2;
-      continue;
-    } else if (SUCCEEDED(hr) &&
-               (lastFallbackTried || !ContainsMissingGlyphs(&shaping.glyphs[0],
-                generated_glyphs, font_properties))) {
-      break;
-    }
-
-    // The current font can't render this run. clear DC and try
-    // next font.
-    if (temp_dc) {
-      SelectObject(temp_dc, old_font);
-      ReleaseDC(NULL, temp_dc);
-      temp_dc = NULL;
-    }
-
-    if (NextWinFontData(&hfont, &script_cache, &font_properties, &ascent)) {
-      // The primary font does not support this run. Try next font.
-      // In case of web page rendering, they come from fonts specified in
-      // CSS stylesheets.
-      continue;
-    } else if (!lastFallbackTried) {
-      lastFallbackTried = true;
-
-      // Generate a last fallback font based on the script of
-      // a character to draw while inheriting size and styles
-      // from the primary font
-      if (!logfont_.lfFaceName[0])
-        SetLogFontAndStyle(hfont_, &logfont_, &style_);
-
-      // TODO(jungshik): generic type should come from webkit for
-      // UniscribeStateTextRun (a derived class used in webkit).
-      const wchar_t *family = GetFallbackFamily(input, item_length,
-          GENERIC_FAMILY_STANDARD, NULL, NULL);
-      bool font_ok = GetDerivedFontData(family, style_, &logfont_, &ascent, &hfont, &script_cache);
-
-      if (!font_ok) {
-        // If this GetDerivedFontData is called from the renderer it might fail
-        // because the sandbox is preventing it from opening the font files.
-        // If we are running in the renderer, TryToPreloadFont is overridden to
-        // ask the browser to preload the font for us so we can access it.
-        TryToPreloadFont(hfont);
-
-        // Try again.
-        font_ok = GetDerivedFontData(family, style_, &logfont_, &ascent, &hfont, &script_cache);
-        DCHECK(font_ok);
-      }
-
-      // TODO(jungshik) : Currently GetDerivedHFont always returns a
-      // a valid HFONT, but in the future, I may change it to return 0.
-      DCHECK(hfont);
-
-      // We don't need a font_properties for the last resort fallback font
-      // because we don't have anything more to try and are forced to
-      // accept empty glyph boxes. If we tried a series of fonts as
-      // 'last-resort fallback', we'd need it, but currently, we don't.
-      continue;
-    } else if (hr == USP_E_SCRIPT_NOT_IN_FONT) {
-      run.a.eScript = SCRIPT_UNDEFINED;
-      continue;
-    } else if (FAILED(hr)) {
-      // Error shaping.
-      generated_glyphs = 0;
-      result = false;
-      goto cleanup;
-    }
-  }
-
-  // Sets Windows font data for this run to those corresponding to
-  // a font supporting this run. we don't need to store font_properties
-  // because it's not used elsewhere.
-  shaping.hfont_ = hfont;
-  shaping.script_cache_ = script_cache;
-
-  // The ascent of a font for this run can be different from
-  // that of the primary font so that we need to keep track of
-  // the difference per run and take that into account when calling
-  // ScriptTextOut in |Draw|. Otherwise, different runs rendered by
-  // different fonts would not be aligned vertically.
-  shaping.ascent_offset_ = ascent_ ? ascent - ascent_ : 0;
-  result = true;
-
-cleanup:
-  shaping.glyphs->resize(generated_glyphs);
-  shaping.visattr->resize(generated_glyphs);
-  shaping.advance->resize(generated_glyphs);
-  shaping.offsets->resize(generated_glyphs);
-  if (temp_dc) {
-    SelectObject(temp_dc, old_font);
-    ReleaseDC(NULL, temp_dc);
-  }
-  // On failure, our logs don't mean anything, so zero those out.
-  if (!result)
-    shaping.logs->clear();
-
-  return result;
-}
-
-void UniscribeState::FillShapes() {
-  shapes_->resize(runs_->size());
-  for (size_t i = 0; i < runs_->size(); i++) {
-    int start_item = runs_[i].iCharPos;
-    int item_length = input_length_ - start_item;
-    if (i < runs_->size() - 1)
-      item_length = runs_[i + 1].iCharPos - start_item;
-
-    int num_glyphs;
-    if (item_length < UNISCRIBE_STATE_STACK_CHARS) {
-      // We'll start our buffer sizes with the current stack space available
-      // in our buffers if the current input fits. As long as it
-      // doesn't expand past that we'll save a lot of time mallocing.
-      num_glyphs = UNISCRIBE_STATE_STACK_CHARS;
-    } else {
-      // When the input doesn't fit, give up with the stack since it will
-      // almost surely not be enough room (unless the input actually shrinks,
-      // which is unlikely) and just start with the length recommended by
-      // the Uniscribe documentation as a "usually fits" size.
-      num_glyphs = item_length * 3 / 2 + 16;
-    }
-
-    // Convert a string to a glyph string trying the primary font,
-    // fonts in the fallback list and then script-specific last resort font.
-    Shaping& shaping = shapes_[i];
-    if (!Shape(&input_[start_item], item_length, num_glyphs, runs_[i], shaping))
-      continue;
-
-    // Compute placements. Note that offsets is documented incorrectly
-    // and is actually an array.
-
-    // DC that we lazily create if Uniscribe commands us to.
-    // (this does not happen often because script_cache is already
-    //  updated when calling ScriptShape).
-    HDC temp_dc = NULL;
-    HGDIOBJ old_font = NULL;
-    HRESULT hr;
-    while (true) {
-      shaping.pre_padding = 0;
-      hr = ScriptPlace(temp_dc, shaping.script_cache_, &shaping.glyphs[0],
-                       static_cast<int>(shaping.glyphs->size()),
-                       &shaping.visattr[0], &runs_[i].a,
-                       &shaping.advance[0], &shaping.offsets[0],
-                       &shaping.abc);
-      if (hr != E_PENDING)
-        break;
-
-      // Allocate the DC and run the loop again.
-      temp_dc = GetDC(NULL);
-      old_font = SelectObject(temp_dc, shaping.hfont_);
-    }
-
-    if (FAILED(hr)) {
-      // Some error we don't know how to handle. Nuke all of our data
-      // since we can't deal with partially valid data later.
-      runs_->clear();
-      shapes_->clear();
-      screen_order_->clear();
-    }
-
-    if (temp_dc) {
-      SelectObject(temp_dc, old_font);
-      ReleaseDC(NULL, temp_dc);
-    }
-  }
-
-  AdjustSpaceAdvances();
-
-  if (letter_spacing_ != 0 || word_spacing_ != 0)
-    ApplySpacing();
-}
-
-void UniscribeState::FillScreenOrder() {
-  screen_order_->resize(runs_->size());
-
-  // We assume that the input has only one text direction in it.
-  // TODO(brettw) are we sure we want to keep this restriction?
-  if (is_rtl_) {
-    for (int i = 0; i < static_cast<int>(screen_order_->size()); i++)
-      screen_order_[static_cast<int>(screen_order_->size()) - i - 1] = i;
-  } else {
-    for (int i = 0; i < static_cast<int>(screen_order_->size()); i++)
-      screen_order_[i] = i;
-  }
-}
-
-void UniscribeState::AdjustSpaceAdvances() {
-  if (space_width_ == 0)
-    return;
-
-  int space_width_without_letter_spacing = space_width_ - letter_spacing_;
-
-  // This mostly matches what WebKit's UniscribeController::shapeAndPlaceItem.
-  for (size_t run = 0; run < runs_->size(); run++) {
-    Shaping& shaping = shapes_[run];
-
-    for (int i = 0; i < shaping.char_length(); i++) {
-      if (!TreatAsSpace(input_[runs_[run].iCharPos + i]))
-        continue;
-
-      int glyph_index = shaping.logs[i];
-      int current_advance = shaping.advance[glyph_index];
-      // Don't give zero-width spaces a width.
-      if (!current_advance)
-        continue;
-
-      // current_advance does not include additional letter-spacing, but
-      // space_width does. Here we find out how off we are from the correct
-      // width for the space not including letter-spacing, then just subtract
-      // that diff.
-      int diff = current_advance - space_width_without_letter_spacing;
-      // The shaping can consist of a run of text, so only subtract the
-      // difference in the width of the glyph.
-      shaping.advance[glyph_index] -= diff;
-      shaping.abc.abcB -= diff;
-    }
-  }
-}
-
-void UniscribeState::ApplySpacing() {
-  for (size_t run = 0; run < runs_->size(); run++) {
-    Shaping& shaping = shapes_[run];
-    bool is_rtl = runs_[run].a.fRTL;
-
-    if (letter_spacing_ != 0) {
-      // RTL text gets padded to the left of each character. We increment the
-      // run's advance to make this happen. This will be balanced out by NOT
-      // adding additional advance to the last glyph in the run.
-      if (is_rtl)
-        shaping.pre_padding += letter_spacing_;
-
-      // Go through all the glyphs in this run and increase the "advance" to
-      // account for letter spacing. We adjust letter spacing only on cluster
-      // boundaries.
-      //
-      // This works for most scripts, but may have problems with some indic
-      // scripts. This behavior is better than Firefox or IE for Hebrew.
-      for (int i = 0; i < shaping.glyph_length(); i++) {
-        if (shaping.visattr[i].fClusterStart) {
-          // Ick, we need to assign the extra space so that the glyph comes
-          // first, then is followed by the space. This is opposite for RTL.
-          if (is_rtl) {
-            if (i != shaping.glyph_length() - 1) {
-              // All but the last character just get the spacing applied to
-              // their advance. The last character doesn't get anything,
-              shaping.advance[i] += letter_spacing_;
-              shaping.abc.abcB += letter_spacing_;
+        for (int i = 0; i < static_cast<int>(m_screenOrder.size()); i++)
+            m_screenOrder[i] = i;
+    }
+}
+
+void UniscribeHelper::AdjustSpaceAdvances()
+{
+    if (m_spaceWidth == 0)
+        return;
+
+    int spaceWidthWithoutLetterSpacing = m_spaceWidth - m_letterSpacing;
+
+    // This mostly matches what WebKit's UniscribeController::shapeAndPlaceItem.
+    for (size_t run = 0; run < m_runs.size(); run++) {
+        Shaping& shaping = m_shapes[run];
+
+        for (int i = 0; i < shaping.charLength(); i++) {
+            if (!TreatAsSpace(m_input[m_runs[run].iCharPos + i]))
+                continue;
+
+            int glyphIndex = shaping.m_logs[i];
+            int currentAdvance = shaping.m_advance[glyphIndex];
+            // Don't give zero-width spaces a width.
+            if (!currentAdvance)
+                continue;
+
+            // currentAdvance does not include additional letter-spacing, but
+            // space_width does. Here we find out how off we are from the
+            // correct width for the space not including letter-spacing, then
+            // just subtract that diff.
+            int diff = currentAdvance - spaceWidthWithoutLetterSpacing;
+            // The shaping can consist of a run of text, so only subtract the
+            // difference in the width of the glyph.
+            shaping.m_advance[glyphIndex] -= diff;
+            shaping.m_abc.abcB -= diff;
+        }
+    }
+}
+
+void UniscribeHelper::ApplySpacing()
+{
+    for (size_t run = 0; run < m_runs.size(); run++) {
+        Shaping& shaping = m_shapes[run];
+        bool isRtl = m_runs[run].a.fRTL;
+
+        if (m_letterSpacing != 0) {
+            // RTL text gets padded to the left of each character. We increment
+            // the run's advance to make this happen. This will be balanced out
+            // by NOT adding additional advance to the last glyph in the run.
+            if (isRtl)
+                shaping.m_prePadding += m_letterSpacing;
+
+            // Go through all the glyphs in this run and increase the "advance"
+            // to account for letter spacing. We adjust letter spacing only on
+            // cluster boundaries.
+            //
+            // This works for most scripts, but may have problems with some
+            // indic scripts. This behavior is better than Firefox or IE for
+            // Hebrew.
+            for (int i = 0; i < shaping.glyphLength(); i++) {
+                if (shaping.m_visattr[i].fClusterStart) {
+                    // Ick, we need to assign the extra space so that the glyph
+                    // comes first, then is followed by the space. This is
+                    // opposite for RTL.
+                    if (isRtl) {
+                        if (i != shaping.glyphLength() - 1) {
+                            // All but the last character just get the spacing
+                            // applied to their advance. The last character
+                            // doesn't get anything,
+                            shaping.m_advance[i] += m_letterSpacing;
+                            shaping.m_abc.abcB += m_letterSpacing;
+                        }
+                    } else {
+                        // LTR case is easier, we just add to the advance.
+                        shaping.m_advance[i] += m_letterSpacing;
+                        shaping.m_abc.abcB += m_letterSpacing;
+                    }
+                }
             }
-          } else {
-            // LTR case is easier, we just add to the advance.
-            shaping.advance[i] += letter_spacing_;
-            shaping.abc.abcB += letter_spacing_;
-          }
-        }
-      }
-    }
-
-    // Go through all the characters to find whitespace and insert the extra
-    // wordspacing amount for the glyphs they correspond to.
-    if (word_spacing_ != 0) {
-      for (int i = 0; i < shaping.char_length(); i++) {
-        if (!TreatAsSpace(input_[runs_[run].iCharPos + i]))
-          continue;
-
-        // The char in question is a word separator...
-        int glyph_index = shaping.logs[i];
-
-        // Spaces will not have a glyph in Uniscribe, it will just add
-        // additional advance to the character to the left of the space. The
-        // space's corresponding glyph will be the character following it in
-        // reading order.
-        if (is_rtl) {
-          // In RTL, the glyph to the left of the space is the same as the
-          // first glyph of the following character, so we can just increment
-          // it.
-          shaping.advance[glyph_index] += word_spacing_;
-          shaping.abc.abcB += word_spacing_;
-        } else {
-          // LTR is actually more complex here, we apply it to the previous
-          // character if there is one, otherwise we have to apply it to the
-          // leading space of the run.
-          if (glyph_index == 0) {
-            shaping.pre_padding += word_spacing_;
-          } else {
-            shaping.advance[glyph_index - 1] += word_spacing_;
-            shaping.abc.abcB += word_spacing_;
-          }
-        }
-      }
-    }  // word_spacing_ != 0
-
-    // Loop for next run...
-  }
+        }
+
+        // Go through all the characters to find whitespace and insert the
+        // extra wordspacing amount for the glyphs they correspond to.
+        if (m_wordSpacing != 0) {
+            for (int i = 0; i < shaping.charLength(); i++) {
+                if (!TreatAsSpace(m_input[m_runs[run].iCharPos + i]))
+                    continue;
+
+                // The char in question is a word separator...
+                int glyphIndex = shaping.m_logs[i];
+
+                // Spaces will not have a glyph in Uniscribe, it will just add
+                // additional advance to the character to the left of the
+                // space. The space's corresponding glyph will be the character
+                // following it in reading order.
+                if (isRtl) {
+                    // In RTL, the glyph to the left of the space is the same
+                    // as the first glyph of the following character, so we can
+                    // just increment it.
+                    shaping.m_advance[glyphIndex] += m_wordSpacing;
+                    shaping.m_abc.abcB += m_wordSpacing;
+                } else {
+                    // LTR is actually more complex here, we apply it to the
+                    // previous character if there is one, otherwise we have to
+                    // apply it to the leading space of the run.
+                    if (glyphIndex == 0) {
+                        shaping.m_prePadding += m_wordSpacing;
+                    } else {
+                        shaping.m_advance[glyphIndex - 1] += m_wordSpacing;
+                        shaping.m_abc.abcB += m_wordSpacing;
+                    }
+                }
+            }
+        }  // m_wordSpacing != 0
+
+        // Loop for next run...
+    }
 }
 
 // The advance is the ABC width of the run
-int UniscribeState::AdvanceForItem(int item_index) const {
-  int accum = 0;
-  const Shaping& shaping = shapes_[item_index];
-
-  if (shaping.justify->empty()) {
-    // Easy case with no justification, the width is just the ABC width of      t               
-    // the run. (The ABC width is the sum of the advances).
-    return shaping.abc.abcA + shaping.abc.abcB + shaping.abc.abcC +
-        shaping.pre_padding;
-  }
-
-  // With justification, we use the justified amounts instead. The
-  // justification array contains both the advance and the extra space
-  // added for justification, so is the width we want.
-  int justification = 0;
-  for (size_t i = 0; i < shaping.justify->size(); i++)
-    justification += shaping.justify[i];
-
-  return shaping.pre_padding + justification;
-}
-
-}  // namespace gfx
-
+int UniscribeHelper::AdvanceForItem(int item_index) const
+{
+    int accum = 0;
+    const Shaping& shaping = m_shapes[item_index];
+
+    if (shaping.m_justify.size() == 0) {
+        // Easy case with no justification, the width is just the ABC width of
+        // the run. (The ABC width is the sum of the advances).
+        return shaping.m_abc.abcA + shaping.m_abc.abcB +
+               shaping.m_abc.abcC + shaping.m_prePadding;
+    }
+
+    // With justification, we use the justified amounts instead. The
+    // justification array contains both the advance and the extra space
+    // added for justification, so is the width we want.
+    int justification = 0;
+    for (size_t i = 0; i < shaping.m_justify.size(); i++)
+        justification += shaping.m_justify[i];
+
+    return shaping.m_prePadding + justification;
+}
+
+}  // namespace WebCore