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      1 /*
      2  * Copyright (C) 2006, 2007, 2008, 2009 Apple Inc. All rights reserved.
      3  *
      4  * Redistribution and use in source and binary forms, with or without
      5  * modification, are permitted provided that the following conditions
      6  * are met:
      7  * 1. Redistributions of source code must retain the above copyright
      8  *    notice, this list of conditions and the following disclaimer.
      9  * 2. Redistributions in binary form must reproduce the above copyright
     10  *    notice, this list of conditions and the following disclaimer in the
     11  *    documentation and/or other materials provided with the distribution.
     12  *
     13  * THIS SOFTWARE IS PROVIDED BY APPLE INC. AND ITS CONTRIBUTORS ``AS IS'' AND ANY
     14  * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
     15  * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
     16  * DISCLAIMED. IN NO EVENT SHALL APPLE INC. OR ITS CONTRIBUTORS BE LIABLE FOR ANY
     17  * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
     18  * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
     19  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
     20  * ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
     21  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
     22  * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
     23  */
     24 
     25 #include "config.h"
     26 #include "core/platform/graphics/Font.h"
     27 
     28 #include "core/platform/graphics/FontFallbackList.h"
     29 #include "core/platform/graphics/GlyphBuffer.h"
     30 #include "core/platform/graphics/GraphicsContext.h"
     31 #include "core/platform/graphics/IntRect.h"
     32 #include "core/platform/graphics/SimpleFontData.h"
     33 #include "core/platform/graphics/TextRun.h"
     34 #include "core/platform/graphics/mac/ComplexTextController.h"
     35 #include "wtf/MathExtras.h"
     36 
     37 #include "core/platform/graphics/harfbuzz/HarfBuzzShaper.h"
     38 
     39 using namespace std;
     40 
     41 namespace WebCore {
     42 
     43 static bool preferHarfBuzz(const Font* font)
     44 {
     45     const FontDescription& description = font->fontDescription();
     46     return description.featureSettings() && description.featureSettings()->size() > 0;
     47 }
     48 
     49 FloatRect Font::selectionRectForComplexText(const TextRun& run, const FloatPoint& point, int h,
     50                                             int from, int to) const
     51 {
     52     if (preferHarfBuzz(this)) {
     53         HarfBuzzShaper shaper(this, run);
     54         if (shaper.shape())
     55             return shaper.selectionRect(point, h, from, to);
     56     }
     57     ComplexTextController controller(this, run);
     58     controller.advance(from);
     59     float beforeWidth = controller.runWidthSoFar();
     60     controller.advance(to);
     61     float afterWidth = controller.runWidthSoFar();
     62 
     63     // Using roundf() rather than ceilf() for the right edge as a compromise to ensure correct caret positioning
     64     if (run.rtl()) {
     65         float totalWidth = controller.totalWidth();
     66         return FloatRect(floorf(point.x() + totalWidth - afterWidth), point.y(), roundf(point.x() + totalWidth - beforeWidth) - floorf(point.x() + totalWidth - afterWidth), h);
     67     }
     68 
     69     return FloatRect(floorf(point.x() + beforeWidth), point.y(), roundf(point.x() + afterWidth) - floorf(point.x() + beforeWidth), h);
     70 }
     71 
     72 float Font::getGlyphsAndAdvancesForComplexText(const TextRun& run, int from, int to, GlyphBuffer& glyphBuffer, ForTextEmphasisOrNot forTextEmphasis) const
     73 {
     74     float initialAdvance;
     75 
     76     ComplexTextController controller(this, run, false, 0, forTextEmphasis);
     77     controller.advance(from);
     78     float beforeWidth = controller.runWidthSoFar();
     79     controller.advance(to, &glyphBuffer);
     80 
     81     if (glyphBuffer.isEmpty())
     82         return 0;
     83 
     84     float afterWidth = controller.runWidthSoFar();
     85 
     86     if (run.rtl()) {
     87         initialAdvance = controller.totalWidth() + controller.finalRoundingWidth() - afterWidth;
     88         glyphBuffer.reverse(0, glyphBuffer.size());
     89     } else
     90         initialAdvance = beforeWidth;
     91 
     92     return initialAdvance;
     93 }
     94 
     95 void Font::drawComplexText(GraphicsContext* context, const TextRunPaintInfo& runInfo, const FloatPoint& point) const
     96 {
     97     if (preferHarfBuzz(this)) {
     98         GlyphBuffer glyphBuffer;
     99         HarfBuzzShaper shaper(this, runInfo.run);
    100         shaper.setDrawRange(runInfo.from, runInfo.to);
    101         if (shaper.shape(&glyphBuffer)) {
    102             drawGlyphBuffer(context, runInfo, glyphBuffer, point);
    103             return;
    104         }
    105     }
    106     // This glyph buffer holds our glyphs + advances + font data for each glyph.
    107     GlyphBuffer glyphBuffer;
    108 
    109     float startX = point.x() + getGlyphsAndAdvancesForComplexText(runInfo.run, runInfo.from, runInfo.to, glyphBuffer);
    110 
    111     // We couldn't generate any glyphs for the run.  Give up.
    112     if (glyphBuffer.isEmpty())
    113         return;
    114 
    115     // Draw the glyph buffer now at the starting point returned in startX.
    116     FloatPoint startPoint(startX, point.y());
    117     drawGlyphBuffer(context, runInfo, glyphBuffer, startPoint);
    118 }
    119 
    120 void Font::drawEmphasisMarksForComplexText(GraphicsContext* context, const TextRunPaintInfo& runInfo, const AtomicString& mark, const FloatPoint& point) const
    121 {
    122     GlyphBuffer glyphBuffer;
    123     float initialAdvance = getGlyphsAndAdvancesForComplexText(runInfo.run, runInfo.from, runInfo.to, glyphBuffer, ForTextEmphasis);
    124 
    125     if (glyphBuffer.isEmpty())
    126         return;
    127 
    128     drawEmphasisMarks(context, runInfo, glyphBuffer, mark, FloatPoint(point.x() + initialAdvance, point.y()));
    129 }
    130 
    131 float Font::floatWidthForComplexText(const TextRun& run, HashSet<const SimpleFontData*>* fallbackFonts, GlyphOverflow* glyphOverflow) const
    132 {
    133     if (preferHarfBuzz(this)) {
    134         HarfBuzzShaper shaper(this, run);
    135         if (shaper.shape())
    136             return shaper.totalWidth();
    137     }
    138     ComplexTextController controller(this, run, true, fallbackFonts);
    139     if (glyphOverflow) {
    140         glyphOverflow->top = max<int>(glyphOverflow->top, ceilf(-controller.minGlyphBoundingBoxY()) - (glyphOverflow->computeBounds ? 0 : fontMetrics().ascent()));
    141         glyphOverflow->bottom = max<int>(glyphOverflow->bottom, ceilf(controller.maxGlyphBoundingBoxY()) - (glyphOverflow->computeBounds ? 0 : fontMetrics().descent()));
    142         glyphOverflow->left = max<int>(0, ceilf(-controller.minGlyphBoundingBoxX()));
    143         glyphOverflow->right = max<int>(0, ceilf(controller.maxGlyphBoundingBoxX() - controller.totalWidth()));
    144     }
    145     return controller.totalWidth();
    146 }
    147 
    148 int Font::offsetForPositionForComplexText(const TextRun& run, float x, bool includePartialGlyphs) const
    149 {
    150     if (preferHarfBuzz(this)) {
    151         HarfBuzzShaper shaper(this, run);
    152         if (shaper.shape())
    153             return shaper.offsetForPosition(x);
    154     }
    155     ComplexTextController controller(this, run);
    156     return controller.offsetForPosition(x, includePartialGlyphs);
    157 }
    158 
    159 const SimpleFontData* Font::fontDataForCombiningCharacterSequence(const UChar* characters, size_t length, FontDataVariant variant) const
    160 {
    161     UChar32 baseCharacter;
    162     size_t baseCharacterLength = 0;
    163     U16_NEXT(characters, baseCharacterLength, length, baseCharacter);
    164 
    165     GlyphData baseCharacterGlyphData = glyphDataForCharacter(baseCharacter, false, variant);
    166 
    167     if (!baseCharacterGlyphData.glyph)
    168         return 0;
    169 
    170     if (length == baseCharacterLength)
    171         return baseCharacterGlyphData.fontData;
    172 
    173     bool triedBaseCharacterFontData = false;
    174 
    175     unsigned i = 0;
    176     for (const FontData* fontData = fontDataAt(0); fontData; fontData = fontDataAt(++i)) {
    177         const SimpleFontData* simpleFontData = fontData->fontDataForCharacter(baseCharacter);
    178         if (variant == NormalVariant) {
    179             if (simpleFontData->platformData().orientation() == Vertical) {
    180                 if (isCJKIdeographOrSymbol(baseCharacter) && !simpleFontData->hasVerticalGlyphs()) {
    181                     variant = BrokenIdeographVariant;
    182                     simpleFontData = simpleFontData->brokenIdeographFontData().get();
    183                 } else if (m_fontDescription.nonCJKGlyphOrientation() == NonCJKGlyphOrientationVerticalRight) {
    184                     SimpleFontData* verticalRightFontData = simpleFontData->verticalRightOrientationFontData().get();
    185                     Glyph verticalRightGlyph = verticalRightFontData->glyphForCharacter(baseCharacter);
    186                     if (verticalRightGlyph == baseCharacterGlyphData.glyph)
    187                         simpleFontData = verticalRightFontData;
    188                 } else {
    189                     SimpleFontData* uprightFontData = simpleFontData->uprightOrientationFontData().get();
    190                     Glyph uprightGlyph = uprightFontData->glyphForCharacter(baseCharacter);
    191                     if (uprightGlyph != baseCharacterGlyphData.glyph)
    192                         simpleFontData = uprightFontData;
    193                 }
    194             }
    195         } else {
    196             if (const SimpleFontData* variantFontData = simpleFontData->variantFontData(m_fontDescription, variant).get())
    197                 simpleFontData = variantFontData;
    198         }
    199 
    200         if (simpleFontData == baseCharacterGlyphData.fontData)
    201             triedBaseCharacterFontData = true;
    202 
    203         if (simpleFontData->canRenderCombiningCharacterSequence(characters, length))
    204             return simpleFontData;
    205     }
    206 
    207     if (!triedBaseCharacterFontData && baseCharacterGlyphData.fontData && baseCharacterGlyphData.fontData->canRenderCombiningCharacterSequence(characters, length))
    208         return baseCharacterGlyphData.fontData;
    209 
    210     return SimpleFontData::systemFallback();
    211 }
    212 
    213 } // namespace WebCore
    214