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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 Computer, 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 THIRD_PARTY_BLINK_RENDERER_PLATFORM_FONTS_GLYPH_METRICS_MAP_H_
#define THIRD_PARTY_BLINK_RENDERER_PLATFORM_FONTS_GLYPH_METRICS_MAP_H_
#include <memory>
#include "base/memory/ptr_util.h"
#include "third_party/blink/renderer/platform/fonts/glyph.h"
#include "third_party/blink/renderer/platform/geometry/float_rect.h"
#include "third_party/blink/renderer/platform/wtf/allocator/allocator.h"
#include "third_party/blink/renderer/platform/wtf/assertions.h"
#include "third_party/blink/renderer/platform/wtf/hash_map.h"
#include "third_party/blink/renderer/platform/wtf/text/unicode.h"
namespace blink {
const float kCGlyphSizeUnknown = -1;
template <class T>
class GlyphMetricsMap {
USING_FAST_MALLOC(GlyphMetricsMap);
public:
GlyphMetricsMap() : filled_primary_page_(false) {}
T MetricsForGlyph(Glyph glyph) {
return LocatePage(glyph / GlyphMetricsPage::kSize)->MetricsForGlyph(glyph);
}
void SetMetricsForGlyph(Glyph glyph, const T& metrics) {
LocatePage(glyph / GlyphMetricsPage::kSize)
->SetMetricsForGlyph(glyph, metrics);
}
private:
class GlyphMetricsPage {
USING_FAST_MALLOC(GlyphMetricsPage);
DISALLOW_COPY_AND_ASSIGN(GlyphMetricsPage);
public:
static const size_t kSize =
256; // Usually covers Latin-1 in a single page.
GlyphMetricsPage() {}
T MetricsForGlyph(Glyph glyph) const { return metrics_[glyph % kSize]; }
void SetMetricsForGlyph(Glyph glyph, const T& metrics) {
SetMetricsForIndex(glyph % kSize, metrics);
}
void SetMetricsForIndex(unsigned index, const T& metrics) {
SECURITY_DCHECK(index < kSize);
metrics_[index] = metrics;
}
private:
T metrics_[kSize];
};
GlyphMetricsPage* LocatePage(unsigned page_number) {
if (!page_number && filled_primary_page_)
return &primary_page_;
return LocatePageSlowCase(page_number);
}
GlyphMetricsPage* LocatePageSlowCase(unsigned page_number);
static T UnknownMetrics();
bool filled_primary_page_;
// We optimize for the page that contains glyph indices 0-255.
GlyphMetricsPage primary_page_;
std::unique_ptr<HashMap<int, std::unique_ptr<GlyphMetricsPage>>> pages_;
DISALLOW_COPY_AND_ASSIGN(GlyphMetricsMap);
};
template <>
inline float GlyphMetricsMap<float>::UnknownMetrics() {
return kCGlyphSizeUnknown;
}
template <>
inline FloatRect GlyphMetricsMap<FloatRect>::UnknownMetrics() {
return FloatRect(0, 0, kCGlyphSizeUnknown, kCGlyphSizeUnknown);
}
template <class T>
typename GlyphMetricsMap<T>::GlyphMetricsPage*
GlyphMetricsMap<T>::LocatePageSlowCase(unsigned page_number) {
GlyphMetricsPage* page;
if (!page_number) {
DCHECK(!filled_primary_page_);
page = &primary_page_;
filled_primary_page_ = true;
} else {
if (pages_) {
page = pages_->at(page_number);
if (page)
return page;
} else {
pages_ =
std::make_unique<HashMap<int, std::unique_ptr<GlyphMetricsPage>>>();
}
page = new GlyphMetricsPage;
pages_->Set(page_number, base::WrapUnique(page));
}
// Fill in the whole page with the unknown glyph information.
for (unsigned i = 0; i < GlyphMetricsPage::kSize; i++)
page->SetMetricsForIndex(i, UnknownMetrics());
return page;
}
} // namespace blink
#endif // THIRD_PARTY_BLINK_RENDERER_PLATFORM_FONTS_GLYPH_METRICS_MAP_H_
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