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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 {
const unsigned gDefaultUnitsPerEm = 1000;
class FontMetrics {
public:
FontMetrics()
: m_unitsPerEm(gDefaultUnitsPerEm)
, m_ascent(0)
, m_descent(0)
, m_lineGap(0)
, m_lineSpacing(0)
, m_xHeight(0)
, m_zeroWidth(0)
, m_hasXHeight(false)
, m_hasZeroWidth(false)
{
}
unsigned unitsPerEm() const { return m_unitsPerEm; }
void setUnitsPerEm(unsigned unitsPerEm) { m_unitsPerEm = unitsPerEm; }
float floatAscent(FontBaseline baselineType = AlphabeticBaseline) const
{
if (baselineType == AlphabeticBaseline)
return m_ascent;
return floatHeight() / 2;
}
void setAscent(float ascent) { m_ascent = ascent; }
float floatDescent(FontBaseline baselineType = AlphabeticBaseline) const
{
if (baselineType == AlphabeticBaseline)
return m_descent;
return floatHeight() / 2;
}
void setDescent(float descent) { m_descent = descent; }
float floatHeight(FontBaseline baselineType = AlphabeticBaseline) const
{
return floatAscent(baselineType) + floatDescent(baselineType);
}
float floatLineGap() const { return m_lineGap; }
void setLineGap(float lineGap) { m_lineGap = lineGap; }
float floatLineSpacing() const { return m_lineSpacing; }
void setLineSpacing(float lineSpacing) { m_lineSpacing = lineSpacing; }
float xHeight() const { return m_xHeight; }
void setXHeight(float xHeight)
{
m_xHeight = xHeight;
m_hasXHeight = true;
}
bool hasXHeight() const { return m_hasXHeight && m_xHeight > 0; }
void setHasXHeight(bool hasXHeight) { m_hasXHeight = hasXHeight; }
// Integer variants of certain metrics, used for HTML rendering.
int ascent(FontBaseline baselineType = AlphabeticBaseline) const
{
if (baselineType == AlphabeticBaseline)
return lroundf(m_ascent);
return height() - height() / 2;
}
int descent(FontBaseline baselineType = AlphabeticBaseline) const
{
if (baselineType == AlphabeticBaseline)
return lroundf(m_descent);
return height() / 2;
}
int height(FontBaseline baselineType = AlphabeticBaseline) const
{
return ascent(baselineType) + descent(baselineType);
}
int lineGap() const { return lroundf(m_lineGap); }
int lineSpacing() const { return lroundf(m_lineSpacing); }
bool hasIdenticalAscentDescentAndLineGap(const FontMetrics& other) const
{
return ascent() == other.ascent() && descent() == other.descent() && lineGap() == other.lineGap();
}
float zeroWidth() const { return m_zeroWidth; }
void setZeroWidth(float zeroWidth)
{
m_zeroWidth = zeroWidth;
m_hasZeroWidth = true;
}
bool hasZeroWidth() const { return m_hasZeroWidth; }
void setHasZeroWidth(bool hasZeroWidth) { m_hasZeroWidth = hasZeroWidth; }
private:
friend class SimpleFontData;
void reset()
{
m_unitsPerEm = gDefaultUnitsPerEm;
m_ascent = 0;
m_descent = 0;
m_lineGap = 0;
m_lineSpacing = 0;
m_xHeight = 0;
m_hasXHeight = false;
}
unsigned m_unitsPerEm;
float m_ascent;
float m_descent;
float m_lineGap;
float m_lineSpacing;
float m_xHeight;
float m_zeroWidth;
bool m_hasXHeight;
bool m_hasZeroWidth;
};
static inline float scaleEmToUnits(float x, unsigned unitsPerEm)
{
return unitsPerEm ? x / unitsPerEm : x;
}
} // namespace WebCore
#endif // FontMetrics_h
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