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/*
* Copyright (C) Research In Motion Limited 2010-2011. All rights reserved.
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Library General Public
* License as published by the Free Software Foundation; either
* version 2 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Library General Public License for more details.
*
* You should have received a copy of the GNU Library General Public License
* along with this library; see the file COPYING.LIB. If not, write to
* the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
* Boston, MA 02110-1301, USA.
*/
#ifndef FontMetrics_h
#define FontMetrics_h
#include "FontBaseline.h"
#include <wtf/MathExtras.h>
namespace WebCore {
class FontMetrics {
public:
static const unsigned defaultUnitsPerEm = 1000;
unsigned unitsPerEm() const { return m_unitsPerEm; }
void setUnitsPerEm(unsigned unitsPerEm) { m_unitsPerEm = unitsPerEm; }
float floatAscent(FontBaseline baselineType = AlphabeticBaseline) const
{
if (baselineType == AlphabeticBaseline)
return m_floatAscent;
return floatHeight() / 2;
}
void setAscent(float ascent)
{
m_floatAscent = ascent;
m_intAscent = std::max(static_cast<int>(lroundf(ascent)), 0);
}
float floatDescent(FontBaseline baselineType = AlphabeticBaseline) const
{
if (baselineType == AlphabeticBaseline)
return m_floatDescent;
return floatHeight() / 2;
}
void setDescent(float descent)
{
m_floatDescent = descent;
m_intDescent = lroundf(descent);
}
float floatHeight(FontBaseline baselineType = AlphabeticBaseline) const
{
return floatAscent(baselineType) + floatDescent(baselineType);
}
float floatLineGap() const { return m_floatLineGap; }
void setLineGap(float lineGap)
{
m_floatLineGap = lineGap;
m_intLineGap = lroundf(lineGap);
}
float floatLineSpacing() const { return m_floatLineSpacing; }
void setLineSpacing(float lineSpacing)
{
m_floatLineSpacing = lineSpacing;
m_intLineSpacing = lroundf(lineSpacing);
}
float xHeight() const { return m_xHeight; }
void setXHeight(float xHeight) { m_xHeight = xHeight; }
bool hasXHeight() const { return m_xHeight > 0; }
bool hasCapHeight() const { return m_floatCapHeight > 0; }
float floatCapHeight() const { return m_floatCapHeight; }
void setCapHeight(float capHeight)
{
m_floatCapHeight = capHeight;
m_intCapHeight = lroundf(capHeight);
}
// Integer variants of certain metrics, used for HTML rendering.
int ascent(FontBaseline baselineType = AlphabeticBaseline) const
{
if (baselineType == AlphabeticBaseline)
return m_intAscent;
return height() - height() / 2;
}
int descent(FontBaseline baselineType = AlphabeticBaseline) const
{
if (baselineType == AlphabeticBaseline)
return m_intDescent;
return height() / 2;
}
int height(FontBaseline baselineType = AlphabeticBaseline) const
{
return ascent(baselineType) + descent(baselineType);
}
int lineGap() const { return m_intLineGap; }
int lineSpacing() const { return m_intLineSpacing; }
int capHeight() const { return m_intCapHeight; }
bool hasIdenticalAscentDescentAndLineGap(const FontMetrics& other) const
{
return ascent() == other.ascent() && descent() == other.descent() && lineGap() == other.lineGap();
}
std::optional<float> zeroWidth() const { return m_zeroWidth; }
void setZeroWidth(float zeroWidth) { m_zeroWidth = zeroWidth; }
float ideogramWidth() const { return m_ideogramWidth; }
void setIdeogramWidth(float ideogramWidth) { m_ideogramWidth = ideogramWidth; }
float underlinePosition() const { return m_underlinePosition; }
void setUnderlinePosition(float underlinePosition) { m_underlinePosition = underlinePosition; }
float underlineThickness() const { return m_underlineThickness; }
void setUnderlineThickness(float underlineThickness) { m_underlineThickness = underlineThickness; }
private:
friend class Font;
void reset()
{
m_unitsPerEm = defaultUnitsPerEm;
m_floatAscent = 0;
m_floatDescent = 0;
m_floatLineGap = 0;
m_floatLineSpacing = 0;
m_floatCapHeight = 0;
m_intAscent = 0;
m_intDescent = 0;
m_intLineGap = 0;
m_intLineSpacing = 0;
m_intCapHeight = 0;
m_xHeight = 0;
m_zeroWidth = std::nullopt;
m_ideogramWidth = 0;
m_underlinePosition = 0;
m_underlineThickness = 0;
}
unsigned m_unitsPerEm { defaultUnitsPerEm };
float m_floatAscent { 0 };
float m_floatDescent { 0 };
float m_floatLineGap { 0 };
float m_floatLineSpacing { 0 };
float m_floatCapHeight { 0 };
// Also cached as integers for performance.
int m_intAscent { 0 };
int m_intDescent { 0 };
int m_intLineGap { 0 };
int m_intLineSpacing { 0 };
int m_intCapHeight { 0 };
std::optional<float> m_zeroWidth;
float m_ideogramWidth { 0 };
float m_xHeight { 0 };
float m_underlinePosition { 0 };
float m_underlineThickness { 0 };
};
static inline float scaleEmToUnits(float x, unsigned unitsPerEm)
{
return unitsPerEm ? x / unitsPerEm : x;
}
} // namespace WebCore
#endif // FontMetrics_h
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