okular/generators/dvi/length.h

   1 // -*- Mode: C++; c-basic-offset: 2; indent-tabs-mode: nil; c-brace-offset: 0; -*-
   2 //
   3 // Class: length
   4 //
   5 // Part of KVIEWSHELL
   6 //
   7 // (C) 2005 Stefan Kebekus
   8 // (C) 2006 Wilfried Huss
   9 //
  10 // Distributed under the GPL.
  11
  12 #ifndef _length_h_
  13 #define _length_h_
  14
  15 #include <cmath>
  16 #include <math.h>
  17
  18 class QString;
  19
  20 #define mm_per_cm 10.0
  21 #define mm_per_m 1000.0
  22 #define mm_per_inch 25.4
  23 #define mm_per_TeXPoint (2540.0/7227.0)
  24 #define mm_per_bigPoint (25.4/72.0)
  25 #define mm_per_pica (25.4/6.0)
  26 #define mm_per_didot (25.4*0.0148)
  27 #define mm_per_cicero (25.4*0.178)
  28 #define mm_per_scaledPoint (25.4/(72.27 * 65536.0))
  29
  30
  31 /** @short Represents a phyical length
  32
  33     This class is used to represent a physical length. Its main purpose
  34     it to help in the conversion of units, and to avoid confusion
  35     about units. To avoid misunderstandings, there is no default
  36     constructor so that this class needs to be explicitly initialized
  37     with one of the functions below.
  38
  39     @warning Lengths are stored internally in mm. If you convert to
  40     or from any other unit, expect floating point round-off errors.
  41
  42     @author Stefan Kebekus <kebekus@kde.org>
  43     @version 1.0.0
  44 */
  45
  46 class Length
  47 {
  48  public:
  49   /** constructs a 'length = 0mm' object */
  50   Length() {length_in_mm = 0;}
  51
  52   /** sets the length in millimeters */
  53   void setLength_in_mm(double l)  {length_in_mm = l;}
  54
  55   /** sets the length in centimeters */
  56   void setLength_in_cm(double l)  {length_in_mm = l*mm_per_cm;}
  57
  58   /** sets the length in meters */
  59   void setLength_in_m(double l)  {length_in_mm = l*mm_per_m;}
  60
  61   /** sets the length in inches */
  62   void setLength_in_inch(double l)  {length_in_mm = l*mm_per_inch;}
  63
  64   /** sets the length in TeX points */
  65   void setLength_in_TeXPoints(double l)  {length_in_mm = l*mm_per_TeXPoint;}
  66
  67   /** sets the length in big points (1/72 of an inch) */
  68   void setLength_in_bigPoints(double l)  {length_in_mm = l*mm_per_bigPoint;}
  69
  70   /** sets the length in picas (1/6 of an inch) */
  71   void setLength_in_pica(double l)  {length_in_mm = l*mm_per_pica;}
  72
  73   /** sets the length in didots (0.0148 inches) */
  74   void setLength_in_didot(double l)  {length_in_mm = l*mm_per_didot;}
  75
  76   /** sets the length in ciceros (0.178 inches) */
  77   void setLength_in_cicero(double l)  {length_in_mm = l*mm_per_cicero;}
  78
  79   /** sets the length in scaled points (1 scaled point = 65536 TeX points) */
  80   void setLength_in_scaledPoints(double l) {length_in_mm = l*mm_per_scaledPoint;}
  81
  82   /** sets the length in pixel. The parameter @param res is the resolution of the
  83       used device in DPI. */
  84   void setLength_in_pixel(int l, double res) { setLength_in_inch(l / res); }
  85
  86   /** @returns the length in millimeters */
  87   double getLength_in_mm() const {return length_in_mm;}
  88
  89   /** @returns the length in centimeters */
  90   double getLength_in_cm() const {return length_in_mm/mm_per_cm;}
  91
  92   /** @returns the length in meters */
  93   double getLength_in_m() const {return length_in_mm/mm_per_m;}
  94
  95   /** @returns the length in inches */
  96   double getLength_in_inch() const {return length_in_mm/mm_per_inch;}
  97
  98   /** @returns the length in TeX points */
  99   double getLength_in_TeXPoints() const {return length_in_mm/mm_per_TeXPoint;}
 100
 101   /** @returns the length in big points (1/72 of an inch) */
 102   double getLength_in_bigPoints() const {return length_in_mm/mm_per_bigPoint;}
 103
 104   /** @returns the length in picas (1/6 of an inch) */
 105   double getLength_in_pica() const {return length_in_mm/mm_per_pica;}
 106
 107   /** @returns the length in didots (0.0148 inches) */
 108   double getLength_in_didot() const {return length_in_mm/mm_per_didot;}
 109
 110   /** @returns the length in ciceros (0.178 inches) */
 111   double getLength_in_cicero() const {return length_in_mm/mm_per_cicero;}
 112
 113   /** @returns the length in scaled points (1 scaled point = 65536 TeX points) */
 114   double getLength_in_scaledPoints() const {return length_in_mm/mm_per_scaledPoint;}
 115
 116   /** @returns the length in pixel. The parameter @param res is the resolution of the
 117       used device in DPI. */
 118   int getLength_in_pixel(double res) const { return int(getLength_in_inch() * res); }
 119
 120   /** @returns true is lengths differ by no more than 2mm */
 121   bool isNearlyEqual(const Length &o) const {return fabs(length_in_mm-o.getLength_in_mm()) <= 2.0;}
 122
 123   /** Comparison of two lengthes */
 124   bool operator > (const Length &o) const {return (length_in_mm > o.getLength_in_mm());}
 125   bool operator < (const Length &o) const {return (length_in_mm < o.getLength_in_mm());}
 126
 127   /** Comparison of two lengthes */
 128   bool operator >= (const Length &o) const {return (length_in_mm >= o.getLength_in_mm());}
 129   bool operator <= (const Length &o) const {return (length_in_mm <= o.getLength_in_mm());}
 130
 131   /** Ratio of two lengthes
 132
 133   @warning There is no safeguared to prevent you from division by
 134   zero. If the length in the denominator is near 0.0, a floating point
 135   exception may occur.
 136
 137   @returns the ratio of the two lengthes as a double
 138   */
 139   double operator / (const Length &o) const {return (length_in_mm/o.getLength_in_mm());}
 140
 141   /** Sum of two lengthes
 142
 143   @returns the sum of the lengthes as a Length
 144   */
 145   Length operator + (const Length &o) const {Length r; r.length_in_mm = length_in_mm + o.length_in_mm; return r; }
 146
 147   /** Difference of two lengthes
 148
 149   @returns the difference of the lengthes as a Length
 150   */
 151   Length operator - (const Length &o) const {Length r; r.length_in_mm = length_in_mm - o.length_in_mm; return r; }
 152
 153   /** Division of a length
 154
 155   @warning There is no safeguared to prevent you from division by
 156   zero. If the number in the denominator is near 0.0, a floating point
 157   exception may occur.
 158
 159   @returns a fraction of the original length as a Length
 160   */
 161   Length operator / (const double l) const {Length r; r.length_in_mm = length_in_mm/l; return r; }
 162
 163   /** Multiplication of a length
 164
 165   @returns a multiplied length as a Length
 166   */
 167   Length operator * (const double l) const {Length r; r.length_in_mm = length_in_mm*l; return r; }
 168
 169   /** This method converts a string that gives a distance in one of the
 170   commonly used units, such as "12.3mm", "12 inch" or "15 didot" to
 171   millimeters. For a complete list of supported units, see the
 172   static lists that are hardcoded in "units.cpp".
 173
 174   If the conversion is not possible *ok is set to "false" and an
 175   undefined value is returned. If the unit could not be recognized,
 176   an error message is printed via kdError(). Otherwise, *ok is set
 177   to true.
 178
 179   It is possible in rare circumstances that ok is set to true
 180   although the string is malformed.
 181
 182   It is fine to set ok to 0. */
 183   static float convertToMM(const QString &distance, bool *ok=0);
 184
 185  private:
 186   /** Length in millimeters */
 187   double length_in_mm;
 188 };
 189
 190 #undef mm_per_cm
 191 #undef mm_per_m
 192 #undef mm_per_inch
 193 #undef mm_per_TeXPoint
 194 #undef mm_per_bigPoint
 195 #undef mm_per_pica
 196 #undef mm_per_didot
 197 #undef mm_per_cicero
 198 #undef mm_per_scaledPoint
 199
 200 #endif