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/*
* Copyright (C) 2006, 2009 Apple Inc. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. Neither the name of Apple Inc. ("Apple") nor the names of
* its contributors may be used to endorse or promote products derived
* from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY APPLE AND ITS CONTRIBUTORS "AS IS" AND ANY
* EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
* WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
* DISCLAIMED. IN NO EVENT SHALL APPLE OR ITS CONTRIBUTORS BE LIABLE FOR ANY
* DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
* (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
* LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
* ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#ifndef GlyphMetricsMap_h
#define GlyphMetricsMap_h
#include "Glyph.h"
#include <array>
#include <wtf/HashMap.h>
namespace WebCore {
const float cGlyphSizeUnknown = -1;
template<class T> class GlyphMetricsMap {
WTF_MAKE_NONCOPYABLE(GlyphMetricsMap); WTF_MAKE_FAST_ALLOCATED;
public:
GlyphMetricsMap() : m_filledPrimaryPage(false) { }
T metricsForGlyph(Glyph glyph)
{
return locatePage(glyph / GlyphMetricsPage::size).metricsForGlyph(glyph);
}
void setMetricsForGlyph(Glyph glyph, const T& metrics)
{
locatePage(glyph / GlyphMetricsPage::size).setMetricsForGlyph(glyph, metrics);
}
private:
class GlyphMetricsPage {
WTF_MAKE_FAST_ALLOCATED;
public:
static const size_t size = 256; // Usually covers Latin-1 in a single page.
std::array<T, size> m_metrics;
GlyphMetricsPage() = default;
GlyphMetricsPage(const T& initialValue)
{
fill(initialValue);
}
void fill(const T& value)
{
m_metrics.fill(value);
}
T metricsForGlyph(Glyph glyph) const { return m_metrics[glyph % size]; }
void setMetricsForGlyph(Glyph glyph, const T& metrics)
{
setMetricsForIndex(glyph % size, metrics);
}
void setMetricsForIndex(unsigned index, const T& metrics)
{
m_metrics[index] = metrics;
}
};
GlyphMetricsPage& locatePage(unsigned pageNumber)
{
if (!pageNumber && m_filledPrimaryPage)
return m_primaryPage;
return locatePageSlowCase(pageNumber);
}
GlyphMetricsPage& locatePageSlowCase(unsigned pageNumber);
static T unknownMetrics();
bool m_filledPrimaryPage;
GlyphMetricsPage m_primaryPage; // We optimize for the page that contains glyph indices 0-255.
std::unique_ptr<HashMap<int, std::unique_ptr<GlyphMetricsPage>>> m_pages;
};
template<> inline float GlyphMetricsMap<float>::unknownMetrics()
{
return cGlyphSizeUnknown;
}
template<> inline FloatRect GlyphMetricsMap<FloatRect>::unknownMetrics()
{
return FloatRect(0, 0, cGlyphSizeUnknown, cGlyphSizeUnknown);
}
template<class T> typename GlyphMetricsMap<T>::GlyphMetricsPage& GlyphMetricsMap<T>::locatePageSlowCase(unsigned pageNumber)
{
if (!pageNumber) {
ASSERT(!m_filledPrimaryPage);
m_primaryPage.fill(unknownMetrics());
m_filledPrimaryPage = true;
return m_primaryPage;
}
if (!m_pages)
m_pages = std::make_unique<HashMap<int, std::unique_ptr<GlyphMetricsPage>>>();
auto& pageInMap = m_pages->add(pageNumber, nullptr).iterator->value;
if (!pageInMap)
pageInMap = std::make_unique<GlyphMetricsPage>(unknownMetrics());
return *pageInMap;
}
} // namespace WebCore
#endif
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