1 /* 2 * Copyright (C) Research In Motion Limited 2010-2011. All rights reserved. 3 * 4 * This library is free software; you can redistribute it and/or 5 * modify it under the terms of the GNU Library General Public 6 * License as published by the Free Software Foundation; either 7 * version 2 of the License, or (at your option) any later version. 8 * 9 * This library is distributed in the hope that it will be useful, 10 * but WITHOUT ANY WARRANTY; without even the implied warranty of 11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 12 * Library General Public License for more details. 13 * 14 * You should have received a copy of the GNU Library General Public License 15 * along with this library; see the file COPYING.LIB. If not, write to 16 * the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, 17 * Boston, MA 02110-1301, USA. 18 */ 19 20 #ifndef FontMetrics_h 21 #define FontMetrics_h 22 23 #include <wtf/MathExtras.h> 24 25 namespace WebCore { 26 27 const unsigned gDefaultUnitsPerEm = 1000; 28 29 class FontMetrics { 30 public: 31 FontMetrics() 32 : m_unitsPerEm(gDefaultUnitsPerEm) 33 , m_ascent(0) 34 , m_descent(0) 35 , m_lineGap(0) 36 , m_lineSpacing(0) 37 , m_xHeight(0) 38 { 39 } 40 41 unsigned unitsPerEm() const { return m_unitsPerEm; } 42 void setUnitsPerEm(unsigned unitsPerEm) { m_unitsPerEm = unitsPerEm; } 43 44 float floatAscent(FontBaseline baselineType = AlphabeticBaseline) const 45 { 46 if (baselineType == AlphabeticBaseline) 47 return m_ascent; 48 return floatHeight() / 2; 49 } 50 51 void setAscent(float ascent) { m_ascent = ascent; } 52 53 float floatDescent(FontBaseline baselineType = AlphabeticBaseline) const 54 { 55 if (baselineType == AlphabeticBaseline) 56 return m_descent; 57 return floatHeight() / 2; 58 } 59 60 void setDescent(float descent) { m_descent = descent; } 61 62 float floatHeight(FontBaseline baselineType = AlphabeticBaseline) const 63 { 64 return floatAscent(baselineType) + floatDescent(baselineType); 65 } 66 67 float floatLineGap() const { return m_lineGap; } 68 void setLineGap(float lineGap) { m_lineGap = lineGap; } 69 70 float floatLineSpacing() const { return m_lineSpacing; } 71 void setLineSpacing(float lineSpacing) { m_lineSpacing = lineSpacing; } 72 73 float xHeight() const { return m_xHeight; } 74 void setXHeight(float xHeight) { m_xHeight = xHeight; } 75 76 // Integer variants of certain metrics, used for HTML rendering. 77 int ascent(FontBaseline baselineType = AlphabeticBaseline) const 78 { 79 if (baselineType == AlphabeticBaseline) 80 return lroundf(m_ascent); 81 return height() - height() / 2; 82 } 83 84 int descent(FontBaseline baselineType = AlphabeticBaseline) const 85 { 86 if (baselineType == AlphabeticBaseline) 87 return lroundf(m_descent); 88 return height() / 2; 89 } 90 91 int height(FontBaseline baselineType = AlphabeticBaseline) const 92 { 93 return ascent(baselineType) + descent(baselineType); 94 } 95 96 int lineGap() const { return lroundf(m_lineGap); } 97 int lineSpacing() const { return lroundf(m_lineSpacing); } 98 99 bool hasIdenticalAscentDescentAndLineGap(const FontMetrics& other) const 100 { 101 return ascent() == other.ascent() && descent() == other.descent() && lineGap() == other.lineGap(); 102 } 103 104 private: 105 friend class SimpleFontData; 106 107 void reset() 108 { 109 m_unitsPerEm = gDefaultUnitsPerEm; 110 m_ascent = 0; 111 m_descent = 0; 112 m_lineGap = 0; 113 m_lineSpacing = 0; 114 m_xHeight = 0; 115 } 116 117 unsigned m_unitsPerEm; 118 float m_ascent; 119 float m_descent; 120 float m_lineGap; 121 float m_lineSpacing; 122 float m_xHeight; 123 }; 124 125 } // namespace WebCore 126 127 #endif // FontMetrics_h 128
