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      1 /*
      2  * Copyright (C) 2007 Nicholas Shanks <contact (at) 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[2];
     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 bool FontDescription::s_useSubpixelTextPositioning = false;
     51 
     52 FontWeight FontDescription::lighterWeight(void) const
     53 {
     54     switch (m_weight) {
     55         case FontWeight100:
     56         case FontWeight200:
     57         case FontWeight300:
     58         case FontWeight400:
     59         case FontWeight500:
     60             return FontWeight100;
     61 
     62         case FontWeight600:
     63         case FontWeight700:
     64             return FontWeight400;
     65 
     66         case FontWeight800:
     67         case FontWeight900:
     68             return FontWeight700;
     69     }
     70     ASSERT_NOT_REACHED();
     71     return FontWeightNormal;
     72 }
     73 
     74 FontWeight FontDescription::bolderWeight(void) const
     75 {
     76     switch (m_weight) {
     77         case FontWeight100:
     78         case FontWeight200:
     79         case FontWeight300:
     80             return FontWeight400;
     81 
     82         case FontWeight400:
     83         case FontWeight500:
     84             return FontWeight700;
     85 
     86         case FontWeight600:
     87         case FontWeight700:
     88         case FontWeight800:
     89         case FontWeight900:
     90             return FontWeight900;
     91     }
     92     ASSERT_NOT_REACHED();
     93     return FontWeightNormal;
     94 }
     95 
     96 FontTraitsMask FontDescription::traitsMask() const
     97 {
     98     return static_cast<FontTraitsMask>((m_italic ? FontStyleItalicMask : FontStyleNormalMask)
     99             | (m_smallCaps ? FontVariantSmallCapsMask : FontVariantNormalMask)
    100             | (FontWeight100Mask << (m_weight - FontWeight100)));
    101 
    102 }
    103 
    104 void FontDescription::setTraitsMask(FontTraitsMask traitsMask)
    105 {
    106     switch (traitsMask & FontWeightMask) {
    107     case FontWeight100Mask:
    108         setWeight(FontWeight100);
    109         break;
    110     case FontWeight200Mask:
    111         setWeight(FontWeight200);
    112         break;
    113     case FontWeight300Mask:
    114         setWeight(FontWeight300);
    115         break;
    116     case FontWeight400Mask:
    117         setWeight(FontWeight400);
    118         break;
    119     case FontWeight500Mask:
    120         setWeight(FontWeight500);
    121         break;
    122     case FontWeight600Mask:
    123         setWeight(FontWeight600);
    124         break;
    125     case FontWeight700Mask:
    126         setWeight(FontWeight700);
    127         break;
    128     case FontWeight800Mask:
    129         setWeight(FontWeight800);
    130         break;
    131     case FontWeight900Mask:
    132         setWeight(FontWeight900);
    133         break;
    134     default:
    135         ASSERT_NOT_REACHED();
    136     }
    137     setItalic((traitsMask & FontStyleItalicMask) ? FontItalicOn : FontItalicOff);
    138     setSmallCaps((traitsMask & FontVariantSmallCapsMask) ? FontSmallCapsOn : FontSmallCapsOff);
    139 }
    140 
    141 FontDescription FontDescription::makeNormalFeatureSettings() const
    142 {
    143     FontDescription normalDescription(*this);
    144     normalDescription.setFeatureSettings(0);
    145     return normalDescription;
    146 }
    147 
    148 float FontDescription::effectiveFontSize() const
    149 {
    150     float size = (RuntimeEnabledFeatures::subpixelFontScalingEnabled())
    151         ? computedSize()
    152         : computedPixelSize();
    153 
    154     // Ensure that the effective precision matches the font-cache precision.
    155     // This guarantees that the same precision is used regardless of cache status.
    156     return floorf(size * FontCacheKey::precisionMultiplier()) / FontCacheKey::precisionMultiplier();
    157 }
    158 
    159 FontCacheKey FontDescription::cacheKey(const AtomicString& familyName, FontTraitsMask desiredTraits) const
    160 {
    161     FontTraitsMask traits = desiredTraits
    162         ? desiredTraits
    163         : traitsMask();
    164 
    165     unsigned options =
    166         static_cast<unsigned>(m_syntheticItalic) << 8 | // bit 9
    167         static_cast<unsigned>(m_syntheticBold) << 7 | // bit 8
    168         static_cast<unsigned>(m_fontSmoothing) << 5 | // bits 6-7
    169         static_cast<unsigned>(m_textRendering) << 3 | // bits 4-5
    170         static_cast<unsigned>(m_orientation) << 2 | // bit 3
    171         static_cast<unsigned>(m_usePrinterFont) << 1 | // bit 2
    172         static_cast<unsigned>(m_subpixelTextPosition); // bit 1
    173 
    174     return FontCacheKey(familyName, effectiveFontSize(), options | traits << 9);
    175 }
    176 
    177 } // namespace WebCore
    178