src/third_party/WebKit/Source/platform/fonts/FontDescription.cpp

   1 /*
   2  * Copyright (C) 2007 Nicholas Shanks <contact@nickshanks.com>
   3  * Copyright (C) 2008 Apple Inc. All rights reserved.
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that the following conditions
   7  * are met:
   8  *
   9  * 1.  Redistributions of source code must retain the above copyright
  10  *     notice, this list of conditions and the following disclaimer.
  11  * 2.  Redistributions in binary form must reproduce the above copyright
  12  *     notice, this list of conditions and the following disclaimer in the
  13  *     documentation and/or other materials provided with the distribution.
  14  * 3.  Neither the name of Apple Computer, Inc. ("Apple") nor the names of
  15  *     its contributors may be used to endorse or promote products derived
  16  *     from this software without specific prior written permission.
  17  *
  18  * THIS SOFTWARE IS PROVIDED BY APPLE AND ITS CONTRIBUTORS "AS IS" AND ANY
  19  * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
  20  * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
  21  * DISCLAIMED. IN NO EVENT SHALL APPLE OR ITS CONTRIBUTORS BE LIABLE FOR ANY
  22  * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
  23  * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
  24  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
  25  * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  26  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
  27  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  28  */
  29
  30 #include "config.h"
  31 #include "platform/fonts/FontDescription.h"
  32
  33 #include "RuntimeEnabledFeatures.h"
  34 #include "wtf/text/AtomicStringHash.h"
  35 #include "wtf/text/StringHash.h"
  36
  37 namespace WebCore {
  38
  39 struct SameSizeAsFontDescription {
  40     FontFamily familyList;
  41     RefPtr<FontFeatureSettings> m_featureSettings;
  42     float sizes[4];
  43     // FXIME: Make them fit into one word.
  44     uint32_t bitfields;
  45     uint32_t bitfields2 : 8;
  46 };
  47
  48 COMPILE_ASSERT(sizeof(FontDescription) == sizeof(SameSizeAsFontDescription), FontDescription_should_stay_small);
  49
  50 TypesettingFeatures FontDescription::s_defaultTypesettingFeatures = 0;
  51
  52 bool FontDescription::s_useSubpixelTextPositioning = false;
  53
  54 FontWeight FontDescription::lighterWeight(void) const
  55 {
  56     switch (m_weight) {
  57         case FontWeight100:
  58         case FontWeight200:
  59         case FontWeight300:
  60         case FontWeight400:
  61         case FontWeight500:
  62             return FontWeight100;
  63
  64         case FontWeight600:
  65         case FontWeight700:
  66             return FontWeight400;
  67
  68         case FontWeight800:
  69         case FontWeight900:
  70             return FontWeight700;
  71     }
  72     ASSERT_NOT_REACHED();
  73     return FontWeightNormal;
  74 }
  75
  76 FontWeight FontDescription::bolderWeight(void) const
  77 {
  78     switch (m_weight) {
  79         case FontWeight100:
  80         case FontWeight200:
  81         case FontWeight300:
  82             return FontWeight400;
  83
  84         case FontWeight400:
  85         case FontWeight500:
  86             return FontWeight700;
  87
  88         case FontWeight600:
  89         case FontWeight700:
  90         case FontWeight800:
  91         case FontWeight900:
  92             return FontWeight900;
  93     }
  94     ASSERT_NOT_REACHED();
  95     return FontWeightNormal;
  96 }
  97
  98 FontTraitsMask FontDescription::traitsMask() const
  99 {
 100     return static_cast<FontTraitsMask>((m_italic ? FontStyleItalicMask : FontStyleNormalMask)
 101             | (m_smallCaps ? FontVariantSmallCapsMask : FontVariantNormalMask)
 102             | (FontWeight100Mask << (m_weight - FontWeight100)));
 103
 104 }
 105
 106 void FontDescription::setTraitsMask(FontTraitsMask traitsMask)
 107 {
 108     switch (traitsMask & FontWeightMask) {
 109     case FontWeight100Mask:
 110         setWeight(FontWeight100);
 111         break;
 112     case FontWeight200Mask:
 113         setWeight(FontWeight200);
 114         break;
 115     case FontWeight300Mask:
 116         setWeight(FontWeight300);
 117         break;
 118     case FontWeight400Mask:
 119         setWeight(FontWeight400);
 120         break;
 121     case FontWeight500Mask:
 122         setWeight(FontWeight500);
 123         break;
 124     case FontWeight600Mask:
 125         setWeight(FontWeight600);
 126         break;
 127     case FontWeight700Mask:
 128         setWeight(FontWeight700);
 129         break;
 130     case FontWeight800Mask:
 131         setWeight(FontWeight800);
 132         break;
 133     case FontWeight900Mask:
 134         setWeight(FontWeight900);
 135         break;
 136     default:
 137         ASSERT_NOT_REACHED();
 138     }
 139     setItalic((traitsMask & FontStyleItalicMask) ? FontItalicOn : FontItalicOff);
 140     setSmallCaps((traitsMask & FontVariantSmallCapsMask) ? FontSmallCapsOn : FontSmallCapsOff);
 141 }
 142
 143 FontDescription FontDescription::makeNormalFeatureSettings() const
 144 {
 145     FontDescription normalDescription(*this);
 146     normalDescription.setFeatureSettings(0);
 147     return normalDescription;
 148 }
 149
 150 float FontDescription::effectiveFontSize() const
 151 {
 152     float size = (RuntimeEnabledFeatures::subpixelFontScalingEnabled())
 153         ? computedSize()
 154         : computedPixelSize();
 155
 156     // Ensure that the effective precision matches the font-cache precision.
 157     // This guarantees that the same precision is used regardless of cache status.
 158     return floorf(size * FontCacheKey::precisionMultiplier()) / FontCacheKey::precisionMultiplier();
 159 }
 160
 161 FontCacheKey FontDescription::cacheKey(const AtomicString& familyName, FontTraitsMask desiredTraits) const
 162 {
 163     FontTraitsMask traits = desiredTraits
 164         ? desiredTraits
 165         : traitsMask();
 166
 167     unsigned options =
 168         static_cast<unsigned>(m_syntheticItalic) << 8 | // bit 9
 169         static_cast<unsigned>(m_syntheticBold) << 7 | // bit 8
 170         static_cast<unsigned>(m_fontSmoothing) << 5 | // bits 6-7
 171         static_cast<unsigned>(m_textRendering) << 3 | // bits 4-5
 172         static_cast<unsigned>(m_orientation) << 2 | // bit 3
 173         static_cast<unsigned>(m_usePrinterFont) << 1 | // bit 2
 174         static_cast<unsigned>(m_subpixelTextPosition); // bit 1
 175
 176     return FontCacheKey(familyName, effectiveFontSize(), options | traits << 9);
 177 }
 178
 179
 180 void FontDescription::setDefaultTypesettingFeatures(TypesettingFeatures typesettingFeatures)
 181 {
 182     s_defaultTypesettingFeatures = typesettingFeatures;
 183 }
 184
 185 TypesettingFeatures FontDescription::defaultTypesettingFeatures()
 186 {
 187     return s_defaultTypesettingFeatures;
 188 }
 189
 190 void FontDescription::updateTypesettingFeatures() const
 191 {
 192     m_typesettingFeatures = s_defaultTypesettingFeatures;
 193
 194     switch (textRenderingMode()) {
 195     case AutoTextRendering:
 196         break;
 197     case OptimizeSpeed:
 198         m_typesettingFeatures &= ~(WebCore::Kerning | Ligatures);
 199         break;
 200     case GeometricPrecision:
 201     case OptimizeLegibility:
 202         m_typesettingFeatures |= WebCore::Kerning | Ligatures;
 203         break;
 204     }
 205
 206     switch (kerning()) {
 207     case FontDescription::NoneKerning:
 208         m_typesettingFeatures &= ~WebCore::Kerning;
 209         break;
 210     case FontDescription::NormalKerning:
 211         m_typesettingFeatures |= WebCore::Kerning;
 212         break;
 213     case FontDescription::AutoKerning:
 214         break;
 215     }
 216
 217     switch (commonLigaturesState()) {
 218     case FontDescription::DisabledLigaturesState:
 219         m_typesettingFeatures &= ~Ligatures;
 220         break;
 221     case FontDescription::EnabledLigaturesState:
 222         m_typesettingFeatures |= Ligatures;
 223         break;
 224     case FontDescription::NormalLigaturesState:
 225         break;
 226     }
 227 }
 228
 229 } // namespace WebCore