#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_FAST_ALLOCATED;
public:
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;
GlyphMetricsPage() = default;
explicit 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);
}
private:
void setMetricsForIndex(unsigned index, const T& metrics)
{
m_metrics[index] = metrics;
}
std::array<T, size> m_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 { false };
GlyphMetricsPage m_primaryPage; 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& page = m_pages->ensure(pageNumber, [] {
return std::make_unique<GlyphMetricsPage>(unknownMetrics());
}).iterator->value;
return *page;
}
}
#endif