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      1 /*
      2  * Copyright (c) 2006, 2007, 2008, Google 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 are
      6  * met:
      7  *
      8  *     * Redistributions of source code must retain the above copyright
      9  * notice, this list of conditions and the following disclaimer.
     10  *     * Redistributions in binary form must reproduce the above
     11  * copyright notice, this list of conditions and the following disclaimer
     12  * in the documentation and/or other materials provided with the
     13  * distribution.
     14  *     * Neither the name of Google Inc. nor the names of its
     15  * contributors may be used to endorse or promote products derived from
     16  * this software without specific prior written permission.
     17  *
     18  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
     19  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
     20  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
     21  * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
     22  * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
     23  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
     24  * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
     25  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
     26  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
     27  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
     28  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
     29  */
     30 
     31 #include "config.h"
     32 #include "public/platform/Platform.h"
     33 
     34 #include "SkTypeface.h"
     35 #include "platform/LayoutTestSupport.h"
     36 #include "platform/RuntimeEnabledFeatures.h"
     37 #include "platform/fonts/FontPlatformData.h"
     38 #include "platform/graphics/GraphicsContext.h"
     39 #include "public/platform/linux/WebFontRenderStyle.h"
     40 #include "public/platform/linux/WebSandboxSupport.h"
     41 
     42 namespace blink {
     43 
     44 static SkPaint::Hinting skiaHinting = SkPaint::kNormal_Hinting;
     45 static bool useSkiaAutoHint = true;
     46 static bool useSkiaBitmaps = true;
     47 static bool useSkiaAntiAlias = true;
     48 static bool useSkiaSubpixelRendering = false;
     49 
     50 void FontPlatformData::setHinting(SkPaint::Hinting hinting)
     51 {
     52     skiaHinting = hinting;
     53 }
     54 
     55 void FontPlatformData::setAutoHint(bool useAutoHint)
     56 {
     57     useSkiaAutoHint = useAutoHint;
     58 }
     59 
     60 void FontPlatformData::setUseBitmaps(bool useBitmaps)
     61 {
     62     useSkiaBitmaps = useBitmaps;
     63 }
     64 
     65 void FontPlatformData::setAntiAlias(bool useAntiAlias)
     66 {
     67     useSkiaAntiAlias = useAntiAlias;
     68 }
     69 
     70 void FontPlatformData::setSubpixelRendering(bool useSubpixelRendering)
     71 {
     72     useSkiaSubpixelRendering = useSubpixelRendering;
     73 }
     74 
     75 void FontPlatformData::setupPaint(SkPaint* paint, GraphicsContext* context)
     76     const
     77 {
     78     paint->setAntiAlias(m_style.useAntiAlias);
     79     paint->setHinting(static_cast<SkPaint::Hinting>(m_style.hintStyle));
     80     paint->setEmbeddedBitmapText(m_style.useBitmaps);
     81     paint->setAutohinted(m_style.useAutoHint);
     82     if (m_style.useAntiAlias)
     83         paint->setLCDRenderText(m_style.useSubpixelRendering);
     84 
     85     // Do not enable subpixel text on low-dpi if full hinting is requested.
     86     bool useSubpixelText = RuntimeEnabledFeatures::subpixelFontScalingEnabled()
     87         && (paint->getHinting() != SkPaint::kFull_Hinting
     88             || (context && context->deviceScaleFactor() > 1.0f));
     89 
     90     // TestRunner specifically toggles the subpixel positioning flag.
     91     if (useSubpixelText && !LayoutTestSupport::isRunningLayoutTest())
     92         paint->setSubpixelText(true);
     93     else
     94         paint->setSubpixelText(m_style.useSubpixelPositioning);
     95 
     96     const float ts = m_textSize >= 0 ? m_textSize : 12;
     97     paint->setTextSize(SkFloatToScalar(ts));
     98     paint->setTypeface(m_typeface.get());
     99     paint->setFakeBoldText(m_syntheticBold);
    100     paint->setTextSkewX(m_syntheticItalic ? -SK_Scalar1 / 4 : 0);
    101 }
    102 
    103 void FontPlatformData::querySystemForRenderStyle(bool useSkiaSubpixelPositioning)
    104 {
    105     WebFontRenderStyle style;
    106 #if OS(ANDROID)
    107     style.setDefaults();
    108 #else
    109     // If the font name is missing (i.e. probably a web font) or the sandbox is disabled, use the system defaults.
    110     if (!m_family.length() || !Platform::current()->sandboxSupport()) {
    111         style.setDefaults();
    112     } else {
    113         const int sizeAndStyle = (((int)m_textSize) << 2) | (m_typeface->style() & 3);
    114         Platform::current()->sandboxSupport()->getRenderStyleForStrike(m_family.data(), sizeAndStyle, &style);
    115     }
    116 #endif
    117     style.toFontRenderStyle(&m_style);
    118 
    119     // Fix FontRenderStyle::NoPreference to actual styles.
    120     if (m_style.useAntiAlias == FontRenderStyle::NoPreference)
    121         m_style.useAntiAlias = useSkiaAntiAlias;
    122 
    123     if (!m_style.useHinting)
    124         m_style.hintStyle = SkPaint::kNo_Hinting;
    125     else if (m_style.useHinting == FontRenderStyle::NoPreference)
    126         m_style.hintStyle = skiaHinting;
    127 
    128     if (m_style.useBitmaps == FontRenderStyle::NoPreference)
    129         m_style.useBitmaps = useSkiaBitmaps;
    130     if (m_style.useAutoHint == FontRenderStyle::NoPreference)
    131         m_style.useAutoHint = useSkiaAutoHint;
    132     if (m_style.useAntiAlias == FontRenderStyle::NoPreference)
    133         m_style.useAntiAlias = useSkiaAntiAlias;
    134     if (m_style.useSubpixelRendering == FontRenderStyle::NoPreference)
    135         m_style.useSubpixelRendering = useSkiaSubpixelRendering;
    136 
    137     // TestRunner specifically toggles the subpixel positioning flag.
    138     if (m_style.useSubpixelPositioning == FontRenderStyle::NoPreference
    139         || LayoutTestSupport::isRunningLayoutTest())
    140         m_style.useSubpixelPositioning = useSkiaSubpixelPositioning;
    141 }
    142 
    143 bool FontPlatformData::defaultUseSubpixelPositioning()
    144 {
    145     return FontDescription::subpixelPositioning();
    146 }
    147 
    148 } // namespace blink
    149