Merge WebKit at r75315: Initial merge by git.

Change-Id: I570314b346ce101c935ed22a626b48c2af266b84

1 files changed, 465 insertions, 0 deletions

diff --git a/Source/WebCore/platform/graphics/win/UniscribeController.cpp b/Source/WebCore/platform/graphics/win/UniscribeController.cpp
new file mode 100644
index 0000000..ab32150
--- /dev/null
+++ b/Source/WebCore/platform/graphics/win/UniscribeController.cpp
@@ -0,0 +1,465 @@
+/*
+ * Copyright (C) 2007, 2008, 2009, 2010 Apple Inc. All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY APPLE INC. AND ITS CONTRIBUTORS ``AS IS''
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
+ * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
+ * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL APPLE INC. OR ITS CONTRIBUTORS
+ * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
+ * THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include "config.h"
+#include "UniscribeController.h"
+#include "Font.h"
+#include "SimpleFontData.h"
+#include <wtf/MathExtras.h>
+
+using namespace std;
+
+namespace WebCore {
+
+// FIXME: Rearchitect this to be more like WidthIterator in Font.cpp.  Have an advance() method
+// that does stuff in that method instead of doing everything in the constructor.  Have advance()
+// take the GlyphBuffer as an arg so that we don't have to populate the glyph buffer when
+// measuring.
+UniscribeController::UniscribeController(const Font* font, const TextRun& run, HashSet<const SimpleFontData*>* fallbackFonts)
+    : m_font(*font)
+    , m_run(run)
+    , m_fallbackFonts(fallbackFonts)
+    , m_minGlyphBoundingBoxX(numeric_limits<float>::max())
+    , m_maxGlyphBoundingBoxX(numeric_limits<float>::min())
+    , m_minGlyphBoundingBoxY(numeric_limits<float>::max())
+    , m_maxGlyphBoundingBoxY(numeric_limits<float>::min())
+    , m_end(run.length())
+    , m_currentCharacter(0)
+    , m_runWidthSoFar(0)
+    , m_padding(run.padding())
+    , m_computingOffsetPosition(false)
+    , m_includePartialGlyphs(false)
+    , m_offsetX(0)
+    , m_offsetPosition(0)
+{
+    if (!m_padding)
+        m_padPerSpace = 0;
+    else {
+        float numSpaces = 0;
+        for (int s = 0; s < m_run.length(); s++) {
+            if (Font::treatAsSpace(m_run[s]))
+                numSpaces++;
+        }
+
+        if (numSpaces == 0)
+            m_padPerSpace = 0;
+        else
+            m_padPerSpace = m_padding / numSpaces;
+    }
+
+    // Null out our uniscribe structs
+    resetControlAndState();
+}
+
+int UniscribeController::offsetForPosition(int x, bool includePartialGlyphs)
+{
+    m_computingOffsetPosition = true;
+    m_includePartialGlyphs = includePartialGlyphs;
+    m_offsetX = x;
+    m_offsetPosition = 0;
+    advance(m_run.length());
+    if (m_computingOffsetPosition) {
+        // The point is to the left or to the right of the entire run.
+        if (m_offsetX >= m_runWidthSoFar && m_run.ltr() || m_offsetX < 0 && m_run.rtl())
+            m_offsetPosition = m_end;
+    }
+    m_computingOffsetPosition = false;
+    return m_offsetPosition;
+}
+
+void UniscribeController::advance(unsigned offset, GlyphBuffer* glyphBuffer)
+{
+    // FIXME: We really want to be using a newer version of Uniscribe that supports the new OpenType
+    // functions.  Those functions would allow us to turn off kerning and ligatures.  Without being able
+    // to do that, we will have buggy line breaking and metrics when simple and complex text are close
+    // together (the complex code path will narrow the text because of kerning and ligatures and then
+    // when bidi processing splits into multiple runs, the simple portions will get wider and cause us to
+    // spill off the edge of a line).
+    if (static_cast<int>(offset) > m_end)
+        offset = m_end;
+
+    // Itemize the string.
+    const UChar* cp = m_run.data(m_currentCharacter);
+    int length = offset - m_currentCharacter;
+    if (length <= 0)
+        return;
+
+    unsigned baseCharacter = m_currentCharacter;
+
+    // We break up itemization of the string by fontData and (if needed) the use of small caps.
+
+    // FIXME: It's inconsistent that we use logical order when itemizing, since this
+    // does not match normal RTL.
+
+    // FIXME: This function should decode surrogate pairs. Currently it makes little difference that
+    // it does not because the font cache on Windows does not support non-BMP characters.
+    Vector<UChar, 256> smallCapsBuffer;
+    if (m_font.isSmallCaps())
+        smallCapsBuffer.resize(length);
+
+    unsigned indexOfFontTransition = m_run.rtl() ? length - 1 : 0;
+    const UChar* curr = m_run.rtl() ? cp + length  - 1 : cp;
+    const UChar* end = m_run.rtl() ? cp - 1 : cp + length;
+
+    const SimpleFontData* fontData;
+    const SimpleFontData* nextFontData = m_font.glyphDataForCharacter(*curr, false).fontData;
+
+    UChar newC = 0;
+
+    bool isSmallCaps;
+    bool nextIsSmallCaps = m_font.isSmallCaps() && !(U_GET_GC_MASK(*curr) & U_GC_M_MASK) && (newC = u_toupper(*curr)) != *curr;
+
+    if (nextIsSmallCaps)
+        smallCapsBuffer[curr - cp] = newC;
+
+    while (true) {
+        curr = m_run.rtl() ? curr - 1 : curr + 1;
+        if (curr == end)
+            break;
+
+        fontData = nextFontData;
+        isSmallCaps = nextIsSmallCaps;
+        int index = curr - cp;
+        UChar c = *curr;
+
+        bool forceSmallCaps = isSmallCaps && (U_GET_GC_MASK(c) & U_GC_M_MASK);
+        nextFontData = m_font.glyphDataForCharacter(*curr, false, forceSmallCaps ? SmallCapsVariant : AutoVariant).fontData;
+        if (m_font.isSmallCaps()) {
+            nextIsSmallCaps = forceSmallCaps || (newC = u_toupper(c)) != c;
+            if (nextIsSmallCaps)
+                smallCapsBuffer[index] = forceSmallCaps ? c : newC;
+        }
+
+        if (m_fallbackFonts && nextFontData != fontData && fontData != m_font.primaryFont())
+            m_fallbackFonts->add(fontData);
+
+        if (nextFontData != fontData || nextIsSmallCaps != isSmallCaps) {
+            int itemStart = m_run.rtl() ? index + 1 : indexOfFontTransition;
+            int itemLength = m_run.rtl() ? indexOfFontTransition - index : index - indexOfFontTransition;
+            m_currentCharacter = baseCharacter + itemStart;
+            itemizeShapeAndPlace((isSmallCaps ? smallCapsBuffer.data() : cp) + itemStart, itemLength, fontData, glyphBuffer);
+            indexOfFontTransition = index;
+        }
+    }
+    
+    int itemLength = m_run.rtl() ? indexOfFontTransition + 1 : length - indexOfFontTransition;
+    if (itemLength) {
+        if (m_fallbackFonts && nextFontData != m_font.primaryFont())
+            m_fallbackFonts->add(nextFontData);
+
+        int itemStart = m_run.rtl() ? 0 : indexOfFontTransition;
+        m_currentCharacter = baseCharacter + itemStart;
+        itemizeShapeAndPlace((nextIsSmallCaps ? smallCapsBuffer.data() : cp) + itemStart, itemLength, nextFontData, glyphBuffer);
+    }
+
+    m_currentCharacter = baseCharacter + length;
+}
+
+void UniscribeController::itemizeShapeAndPlace(const UChar* cp, unsigned length, const SimpleFontData* fontData, GlyphBuffer* glyphBuffer)
+{
+    // ScriptItemize (in Windows XP versions prior to SP2) can overflow by 1.  This is why there is an extra empty item
+    // hanging out at the end of the array
+    m_items.resize(6);
+    int numItems = 0;
+    while (ScriptItemize(cp, length, m_items.size() - 1, &m_control, &m_state, m_items.data(), &numItems) == E_OUTOFMEMORY) {
+        m_items.resize(m_items.size() * 2);
+        resetControlAndState();
+    }
+    m_items.resize(numItems + 1);
+
+    if (m_run.rtl()) {
+        for (int i = m_items.size() - 2; i >= 0; i--) {
+            if (!shapeAndPlaceItem(cp, i, fontData, glyphBuffer))
+                return;
+        }
+    } else {
+        for (unsigned i = 0; i < m_items.size() - 1; i++) {
+            if (!shapeAndPlaceItem(cp, i, fontData, glyphBuffer))
+                return;
+        }
+    }
+}
+
+void UniscribeController::resetControlAndState()
+{
+    memset(&m_control, 0, sizeof(SCRIPT_CONTROL));
+    memset(&m_state, 0, sizeof(SCRIPT_STATE));
+
+    // Set up the correct direction for the run.
+    m_state.uBidiLevel = m_run.rtl();
+    
+    // Lock the correct directional override.
+    m_state.fOverrideDirection = m_run.directionalOverride();
+}
+
+bool UniscribeController::shapeAndPlaceItem(const UChar* cp, unsigned i, const SimpleFontData* fontData, GlyphBuffer* glyphBuffer)
+{
+    // Determine the string for this item.
+    const UChar* str = cp + m_items[i].iCharPos;
+    int len = m_items[i+1].iCharPos - m_items[i].iCharPos;
+    SCRIPT_ITEM item = m_items[i];
+
+    // Set up buffers to hold the results of shaping the item.
+    Vector<WORD> glyphs;
+    Vector<WORD> clusters;
+    Vector<SCRIPT_VISATTR> visualAttributes;
+    clusters.resize(len);
+     
+    // Shape the item.
+    // The recommended size for the glyph buffer is 1.5 * the character length + 16 in the uniscribe docs.
+    // Apparently this is a good size to avoid having to make repeated calls to ScriptShape.
+    glyphs.resize(1.5 * len + 16);
+    visualAttributes.resize(glyphs.size());
+
+    if (!shape(str, len, item, fontData, glyphs, clusters, visualAttributes))
+        return true;
+
+    // We now have a collection of glyphs.
+    Vector<GOFFSET> offsets;
+    Vector<int> advances;
+    offsets.resize(glyphs.size());
+    advances.resize(glyphs.size());
+    int glyphCount = 0;
+    HRESULT placeResult = ScriptPlace(0, fontData->scriptCache(), glyphs.data(), glyphs.size(), visualAttributes.data(),
+                                      &item.a, advances.data(), offsets.data(), 0);
+    if (placeResult == E_PENDING) {
+        // The script cache isn't primed with enough info yet.  We need to select our HFONT into
+        // a DC and pass the DC in to ScriptPlace.
+        HDC hdc = GetDC(0);
+        HFONT hfont = fontData->platformData().hfont();
+        HFONT oldFont = (HFONT)SelectObject(hdc, hfont);
+        placeResult = ScriptPlace(hdc, fontData->scriptCache(), glyphs.data(), glyphs.size(), visualAttributes.data(),
+                                  &item.a, advances.data(), offsets.data(), 0);
+        SelectObject(hdc, oldFont);
+        ReleaseDC(0, hdc);
+    }
+    
+    if (FAILED(placeResult) || glyphs.isEmpty())
+        return true;
+
+    // Convert all chars that should be treated as spaces to use the space glyph.
+    // We also create a map that allows us to quickly go from space glyphs or rounding
+    // hack glyphs back to their corresponding characters.
+    Vector<int> spaceCharacters(glyphs.size());
+    spaceCharacters.fill(-1);
+    Vector<int> roundingHackCharacters(glyphs.size());
+    roundingHackCharacters.fill(-1);
+    Vector<int> roundingHackWordBoundaries(glyphs.size());
+    roundingHackWordBoundaries.fill(-1);
+
+    const float cLogicalScale = fontData->platformData().useGDI() ? 1.0f : 32.0f;
+    unsigned logicalSpaceWidth = fontData->spaceWidth() * cLogicalScale;
+    float roundedSpaceWidth = roundf(fontData->spaceWidth());
+
+    for (int k = 0; k < len; k++) {
+        UChar ch = *(str + k);
+        bool treatAsSpace = Font::treatAsSpace(ch);
+        bool treatAsZeroWidthSpace = ch == zeroWidthSpace || Font::treatAsZeroWidthSpace(ch);
+        if (treatAsSpace || treatAsZeroWidthSpace) {
+            // Substitute in the space glyph at the appropriate place in the glyphs
+            // array.
+            glyphs[clusters[k]] = fontData->spaceGlyph();
+            advances[clusters[k]] = treatAsSpace ? logicalSpaceWidth : 0;
+            if (treatAsSpace)
+                spaceCharacters[clusters[k]] = m_currentCharacter + k + item.iCharPos;
+        }
+
+        if (Font::isRoundingHackCharacter(ch))
+            roundingHackCharacters[clusters[k]] = m_currentCharacter + k + item.iCharPos;
+
+        int boundary = k + m_currentCharacter + item.iCharPos;
+        if (boundary < m_run.length()) {
+            // When at the last character in the str, don't look one past the end for a rounding hack character.
+            // Instead look ahead to the first character of next item, if there is a next one. 
+            if (k + 1 == len) {
+                if (i + 2 < m_items.size() // Check for at least 2 items remaining. The last item is a terminating item containing no characters.
+                    && Font::isRoundingHackCharacter(*(cp + m_items[i + 1].iCharPos)))
+                    roundingHackWordBoundaries[clusters[k]] = boundary;
+            } else if (Font::isRoundingHackCharacter(*(str + k + 1)))
+                roundingHackWordBoundaries[clusters[k]] = boundary;
+        }
+    }
+
+    // Populate our glyph buffer with this information.
+    bool hasExtraSpacing = m_font.letterSpacing() || m_font.wordSpacing() || m_padding;
+    
+    float leftEdge = m_runWidthSoFar;
+
+    for (unsigned k = 0; k < glyphs.size(); k++) {
+        Glyph glyph = glyphs[k];
+        float advance = advances[k] / cLogicalScale;
+        float offsetX = offsets[k].du / cLogicalScale;
+        float offsetY = offsets[k].dv / cLogicalScale;
+
+        // Match AppKit's rules for the integer vs. non-integer rendering modes.
+        float roundedAdvance = roundf(advance);
+        if (!m_font.isPrinterFont() && !fontData->isSystemFont()) {
+            advance = roundedAdvance;
+            offsetX = roundf(offsetX);
+            offsetY = roundf(offsetY);
+        }
+
+        advance += fontData->syntheticBoldOffset();
+
+        // We special case spaces in two ways when applying word rounding.
+        // First, we round spaces to an adjusted width in all fonts.
+        // Second, in fixed-pitch fonts we ensure that all glyphs that
+        // match the width of the space glyph have the same width as the space glyph.
+        if (roundedAdvance == roundedSpaceWidth && (fontData->pitch() == FixedPitch || glyph == fontData->spaceGlyph()) &&
+            m_run.applyWordRounding())
+            advance = fontData->adjustedSpaceWidth();
+
+        if (hasExtraSpacing) {
+            // If we're a glyph with an advance, go ahead and add in letter-spacing.
+            // That way we weed out zero width lurkers.  This behavior matches the fast text code path.
+            if (advance && m_font.letterSpacing())
+                advance += m_font.letterSpacing();
+
+            // Handle justification and word-spacing.
+            int characterIndex = spaceCharacters[k];
+            // characterIndex is left at the initial value of -1 for glyphs that do not map back to treated-as-space characters.
+            if (characterIndex != -1) {
+                // Account for padding. WebCore uses space padding to justify text.
+                // We distribute the specified padding over the available spaces in the run.
+                if (m_padding) {
+                    // Use leftover padding if not evenly divisible by number of spaces.
+                    if (m_padding < m_padPerSpace) {
+                        advance += m_padding;
+                        m_padding = 0;
+                    } else {
+                        float previousPadding = m_padding;
+                        m_padding -= m_padPerSpace;
+                        advance += roundf(previousPadding) - roundf(m_padding);
+                    }
+                }
+
+                // Account for word-spacing.
+                if (characterIndex > 0 && !Font::treatAsSpace(*m_run.data(characterIndex - 1)) && m_font.wordSpacing())
+                    advance += m_font.wordSpacing();
+            }
+        }
+
+        // Deal with the float/integer impedance mismatch between CG and WebCore. "Words" (characters 
+        // followed by a character defined by isRoundingHackCharacter()) are always an integer width.
+        // We adjust the width of the last character of a "word" to ensure an integer width.
+        // Force characters that are used to determine word boundaries for the rounding hack
+        // to be integer width, so the following words will start on an integer boundary.
+        int roundingHackIndex = roundingHackCharacters[k];
+        if (m_run.applyWordRounding() && roundingHackIndex != -1)
+            advance = ceilf(advance);
+
+        // Check to see if the next character is a "rounding hack character", if so, adjust the
+        // width so that the total run width will be on an integer boundary.
+        int position = m_currentCharacter + len;
+        bool lastGlyph = (k == glyphs.size() - 1) && (m_run.rtl() ? i == 0 : i == m_items.size() - 2) && (position >= m_end);
+        if ((m_run.applyWordRounding() && roundingHackWordBoundaries[k] != -1) ||
+            (m_run.applyRunRounding() && lastGlyph)) { 
+            float totalWidth = m_runWidthSoFar + advance;
+            advance += ceilf(totalWidth) - totalWidth;
+        }
+
+        m_runWidthSoFar += advance;
+
+        // FIXME: We need to take the GOFFSETS for combining glyphs and store them in the glyph buffer
+        // as well, so that when the time comes to draw those glyphs, we can apply the appropriate
+        // translation.
+        if (glyphBuffer) {
+            FloatSize size(offsetX, -offsetY);
+            glyphBuffer->add(glyph, fontData, advance, &size);
+        }
+
+        FloatRect glyphBounds = fontData->boundsForGlyph(glyph);
+        glyphBounds.move(m_glyphOrigin.x(), m_glyphOrigin.y());
+        m_minGlyphBoundingBoxX = min(m_minGlyphBoundingBoxX, glyphBounds.x());
+        m_maxGlyphBoundingBoxX = max(m_maxGlyphBoundingBoxX, glyphBounds.right());
+        m_minGlyphBoundingBoxY = min(m_minGlyphBoundingBoxY, glyphBounds.y());
+        m_maxGlyphBoundingBoxY = max(m_maxGlyphBoundingBoxY, glyphBounds.bottom());
+        m_glyphOrigin.move(advance + offsetX, -offsetY);
+
+        // Mutate the glyph array to contain our altered advances.
+        if (m_computingOffsetPosition)
+            advances[k] = advance;
+    }
+
+    while (m_computingOffsetPosition && m_offsetX >= leftEdge && m_offsetX < m_runWidthSoFar) {
+        // The position is somewhere inside this run.
+        int trailing = 0;
+        ScriptXtoCP(m_offsetX - leftEdge, clusters.size(), glyphs.size(), clusters.data(), visualAttributes.data(),
+                    advances.data(), &item.a, &m_offsetPosition, &trailing);
+        if (trailing && m_includePartialGlyphs && m_offsetPosition < len - 1) {
+            m_offsetPosition += m_currentCharacter + m_items[i].iCharPos;
+            m_offsetX += m_run.rtl() ? -trailing : trailing;
+        } else {
+            m_computingOffsetPosition = false;
+            m_offsetPosition += m_currentCharacter + m_items[i].iCharPos;
+            if (trailing && m_includePartialGlyphs)
+               m_offsetPosition++;
+            return false;
+        }
+    }
+
+    return true;
+}
+
+bool UniscribeController::shape(const UChar* str, int len, SCRIPT_ITEM item, const SimpleFontData* fontData,
+                                Vector<WORD>& glyphs, Vector<WORD>& clusters,
+                                Vector<SCRIPT_VISATTR>& visualAttributes)
+{
+    HDC hdc = 0;
+    HFONT oldFont = 0;
+    HRESULT shapeResult = E_PENDING;
+    int glyphCount = 0;
+    do {
+        shapeResult = ScriptShape(hdc, fontData->scriptCache(), str, len, glyphs.size(), &item.a,
+                                  glyphs.data(), clusters.data(), visualAttributes.data(), &glyphCount);
+        if (shapeResult == E_PENDING) {
+            // The script cache isn't primed with enough info yet.  We need to select our HFONT into
+            // a DC and pass the DC in to ScriptShape.
+            ASSERT(!hdc);
+            hdc = GetDC(0);
+            HFONT hfont = fontData->platformData().hfont();
+            oldFont = (HFONT)SelectObject(hdc, hfont);
+        } else if (shapeResult == E_OUTOFMEMORY) {
+            // Need to resize our buffers.
+            glyphs.resize(glyphs.size() * 2);
+            visualAttributes.resize(glyphs.size());
+        }
+    } while (shapeResult == E_PENDING || shapeResult == E_OUTOFMEMORY);
+
+    if (hdc) {
+        SelectObject(hdc, oldFont);
+        ReleaseDC(0, hdc);
+    }
+
+    if (FAILED(shapeResult))
+        return false;
+
+    glyphs.shrink(glyphCount);
+    visualAttributes.shrink(glyphCount);
+
+    return true;
+}
+
+}