src/third_party/WebKit/Source/platform/fonts/mac/FontComplexTextMac.cpp

   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 "platform/fonts/Font.h"
  27
  28 #include "platform/fonts/Character.h"
  29 #include "platform/fonts/FontFallbackList.h"
  30 #include "platform/fonts/GlyphBuffer.h"
  31 #include "platform/fonts/SimpleFontData.h"
  32 #include "platform/fonts/harfbuzz/HarfBuzzShaper.h"
  33 #include "platform/fonts/mac/ComplexTextController.h"
  34 #include "platform/geometry/IntRect.h"
  35 #include "platform/graphics/GraphicsContext.h"
  36 #include "platform/text/TextRun.h"
  37 #include "wtf/MathExtras.h"
  38
  39 namespace blink {
  40
  41 static bool preferHarfBuzz(const Font* font)
  42 {
  43     const FontDescription& description = font->fontDescription();
  44     return description.featureSettings() && description.featureSettings()->size() > 0;
  45 }
  46
  47 FloatRect Font::selectionRectForComplexText(const TextRun& run, const FloatPoint& point, int h,
  48                                             int from, int to) const
  49 {
  50     if (preferHarfBuzz(this)) {
  51         HarfBuzzShaper shaper(this, run);
  52         if (shaper.shape())
  53             return shaper.selectionRect(point, h, from, to);
  54     }
  55     ComplexTextController controller(this, run);
  56     controller.advance(from);
  57     float beforeWidth = controller.runWidthSoFar();
  58     controller.advance(to);
  59     float afterWidth = controller.runWidthSoFar();
  60
  61     // Using roundf() rather than ceilf() for the right edge as a compromise to ensure correct caret positioning
  62     if (run.rtl()) {
  63         float totalWidth = controller.totalWidth();
  64         return FloatRect(floorf(point.x() + totalWidth - afterWidth), point.y(), roundf(point.x() + totalWidth - beforeWidth) - floorf(point.x() + totalWidth - afterWidth), h);
  65     }
  66
  67     return FloatRect(floorf(point.x() + beforeWidth), point.y(), roundf(point.x() + afterWidth) - floorf(point.x() + beforeWidth), h);
  68 }
  69
  70 float Font::getGlyphsAndAdvancesForComplexText(const TextRunPaintInfo& runInfo, GlyphBuffer& glyphBuffer, ForTextEmphasisOrNot forTextEmphasis) const
  71 {
  72     float initialAdvance;
  73
  74     ComplexTextController controller(this, runInfo.run, false, 0, forTextEmphasis);
  75     controller.advance(runInfo.from);
  76     float beforeWidth = controller.runWidthSoFar();
  77     controller.advance(runInfo.to, &glyphBuffer);
  78
  79     if (glyphBuffer.isEmpty())
  80         return 0;
  81
  82     float afterWidth = controller.runWidthSoFar();
  83
  84     if (runInfo.run.rtl()) {
  85         initialAdvance = controller.totalWidth() - afterWidth;
  86         glyphBuffer.reverse();
  87     } else
  88         initialAdvance = beforeWidth;
  89
  90     return initialAdvance;
  91 }
  92
  93 float Font::drawComplexText(GraphicsContext* context, const TextRunPaintInfo& runInfo, const FloatPoint& point) const
  94 {
  95     if (preferHarfBuzz(this)) {
  96         GlyphBuffer glyphBuffer;
  97         HarfBuzzShaper shaper(this, runInfo.run);
  98         shaper.setDrawRange(runInfo.from, runInfo.to);
  99         if (shaper.shape(&glyphBuffer)) {
 100             return drawGlyphBuffer(context, runInfo, glyphBuffer, point);
 101         }
 102     }
 103     // This glyph buffer holds our glyphs + advances + font data for each glyph.
 104     GlyphBuffer glyphBuffer;
 105
 106     float startX = point.x() + getGlyphsAndAdvancesForComplexText(runInfo, glyphBuffer);
 107
 108     // We couldn't generate any glyphs for the run.  Give up.
 109     if (glyphBuffer.isEmpty())
 110         return 0;
 111
 112     // Draw the glyph buffer now at the starting point returned in startX.
 113     FloatPoint startPoint(startX, point.y());
 114     return drawGlyphBuffer(context, runInfo, glyphBuffer, startPoint);
 115 }
 116
 117 void Font::drawEmphasisMarksForComplexText(GraphicsContext* context, const TextRunPaintInfo& runInfo, const AtomicString& mark, const FloatPoint& point) const
 118 {
 119     GlyphBuffer glyphBuffer;
 120     float initialAdvance = getGlyphsAndAdvancesForComplexText(runInfo, glyphBuffer, ForTextEmphasis);
 121
 122     if (glyphBuffer.isEmpty())
 123         return;
 124
 125     drawEmphasisMarks(context, runInfo, glyphBuffer, mark, FloatPoint(point.x() + initialAdvance, point.y()));
 126 }
 127
 128 float Font::floatWidthForComplexText(const TextRun& run, HashSet<const SimpleFontData*>* fallbackFonts, IntRectExtent* glyphBounds) const
 129 {
 130     if (preferHarfBuzz(this)) {
 131         HarfBuzzShaper shaper(this, run);
 132         if (shaper.shape())
 133             return shaper.totalWidth();
 134     }
 135     ComplexTextController controller(this, run, true, fallbackFonts);
 136     glyphBounds->setTop(floorf(-controller.minGlyphBoundingBoxY()));
 137     glyphBounds->setBottom(ceilf(controller.maxGlyphBoundingBoxY()));
 138     glyphBounds->setLeft(std::max<int>(0, floorf(-controller.minGlyphBoundingBoxX())));
 139     glyphBounds->setRight(std::max<int>(0, ceilf(controller.maxGlyphBoundingBoxX() - controller.totalWidth())));
 140
 141     return controller.totalWidth();
 142 }
 143
 144 int Font::offsetForPositionForComplexText(const TextRun& run, float x, bool includePartialGlyphs) const
 145 {
 146     if (preferHarfBuzz(this)) {
 147         HarfBuzzShaper shaper(this, run);
 148         if (shaper.shape())
 149             return shaper.offsetForPosition(x);
 150     }
 151     ComplexTextController controller(this, run);
 152     return controller.offsetForPosition(x, includePartialGlyphs);
 153 }
 154
 155 const SimpleFontData* Font::fontDataForCombiningCharacterSequence(const UChar* characters, size_t length, FontDataVariant variant) const
 156 {
 157     UChar32 baseCharacter;
 158     size_t baseCharacterLength = 0;
 159     U16_NEXT(characters, baseCharacterLength, length, baseCharacter);
 160
 161     GlyphData baseCharacterGlyphData = glyphDataForCharacter(baseCharacter, false, false, variant);
 162
 163     if (!baseCharacterGlyphData.glyph)
 164         return 0;
 165
 166     if (length == baseCharacterLength)
 167         return baseCharacterGlyphData.fontData;
 168
 169     bool triedBaseCharacterFontData = false;
 170
 171     unsigned i = 0;
 172     for (const FontData* fontData = fontDataAt(0); fontData; fontData = fontDataAt(++i)) {
 173         const SimpleFontData* simpleFontData = fontData->fontDataForCharacter(baseCharacter);
 174         if (variant == NormalVariant) {
 175             if (simpleFontData->platformData().orientation() == Vertical) {
 176                 if (Character::isCJKIdeographOrSymbol(baseCharacter) && !simpleFontData->hasVerticalGlyphs()) {
 177                     variant = BrokenIdeographVariant;
 178                     simpleFontData = simpleFontData->brokenIdeographFontData().get();
 179                 } else if (m_fontDescription.nonCJKGlyphOrientation() == NonCJKGlyphOrientationVerticalRight) {
 180                     SimpleFontData* verticalRightFontData = simpleFontData->verticalRightOrientationFontData().get();
 181                     Glyph verticalRightGlyph = verticalRightFontData->glyphForCharacter(baseCharacter);
 182                     if (verticalRightGlyph == baseCharacterGlyphData.glyph)
 183                         simpleFontData = verticalRightFontData;
 184                 } else {
 185                     SimpleFontData* uprightFontData = simpleFontData->uprightOrientationFontData().get();
 186                     Glyph uprightGlyph = uprightFontData->glyphForCharacter(baseCharacter);
 187                     if (uprightGlyph != baseCharacterGlyphData.glyph)
 188                         simpleFontData = uprightFontData;
 189                 }
 190             }
 191         } else {
 192             if (const SimpleFontData* variantFontData = simpleFontData->variantFontData(m_fontDescription, variant).get())
 193                 simpleFontData = variantFontData;
 194         }
 195
 196         if (simpleFontData == baseCharacterGlyphData.fontData)
 197             triedBaseCharacterFontData = true;
 198
 199         if (simpleFontData->canRenderCombiningCharacterSequence(characters, length))
 200             return simpleFontData;
 201     }
 202
 203     if (!triedBaseCharacterFontData && baseCharacterGlyphData.fontData && baseCharacterGlyphData.fontData->canRenderCombiningCharacterSequence(characters, length))
 204         return baseCharacterGlyphData.fontData;
 205
 206     return SimpleFontData::systemFallback();
 207 }
 208
 209 } // namespace blink