Source for gnu.java.awt.font.opentype.truetype.Fixed

   1: /* Fixed.java -- Fixed-point arithmetics for TrueType coordinates.
   2:    Copyright (C) 2006 Free Software Foundation, Inc.
   3: 
   4: This file is part of GNU Classpath.
   5: 
   6: GNU Classpath is free software; you can redistribute it and/or modify
   7: it under the terms of the GNU General Public License as published by
   8: the Free Software Foundation; either version 2, or (at your option)
   9: any later version.
  10: 
  11: GNU Classpath is distributed in the hope that it will be useful, but
  12: WITHOUT ANY WARRANTY; without even the implied warranty of
  13: MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14: General Public License for more details.
  15: 
  16: You should have received a copy of the GNU General Public License
  17: along with GNU Classpath; see the file COPYING.  If not, write to the
  18: Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
  19: 02110-1301 USA.
  20: 
  21: Linking this library statically or dynamically with other modules is
  22: making a combined work based on this library.  Thus, the terms and
  23: conditions of the GNU General Public License cover the whole
  24: combination.
  25: 
  26: As a special exception, the copyright holders of this library give you
  27: permission to link this library with independent modules to produce an
  28: executable, regardless of the license terms of these independent
  29: modules, and to copy and distribute the resulting executable under
  30: terms of your choice, provided that you also meet, for each linked
  31: independent module, the terms and conditions of the license of that
  32: module.  An independent module is a module which is not derived from
  33: or based on this library.  If you modify this library, you may extend
  34: this exception to your version of the library, but you are not
  35: obligated to do so.  If you do not wish to do so, delete this
  36: exception statement from your version. */
  37: 
  38: 
  39: package gnu.java.awt.font.opentype.truetype;
  40: 
  41: 
  42: /**
  43:  * A utility class for fixed-point arithmetics, where numbers are
  44:  * represented with 26 dot 6 digits. This representation is used by
  45:  * TrueType coordinates.
  46:  *
  47:  * <p>A good compiler will inline calls of methods in this class.
  48:  *
  49:  * @author Sascha Brawer (brawer@dandelis.ch)
  50:  */
  51: public final class Fixed
  52: {
  53:   public static final int ONE = 1<<6;
  54: 
  55: 
  56:   /**
  57:    * The constructor is private so nobody can use it.
  58:    */
  59:   private Fixed()
  60:   {
  61:   }
  62: 
  63: 
  64:   /**
  65:    * Multiplies two fixed-point numbers.
  66:    */
  67:   public static int mul(int a, int b)
  68:   {
  69:     return (int) ((((long) a) * b) >> 6);
  70:   }
  71: 
  72:   public static int mul16(int a, int b)
  73:   {
  74:     return (int) ((((long) a) * b) >> 16);
  75:   }
  76: 
  77:   public static int div(int a, int b)
  78:   {
  79:     return (int) ((((long) a) << 6) / b);
  80:   }
  81: 
  82:   public static int div16(int a, int b)
  83:   {
  84:     return (int) ((((long) a) << 16) / b);
  85:   }
  86: 
  87:   public static int ceil(int a)
  88:   {
  89:     return (a + 63) & -64;
  90:   }
  91: 
  92: 
  93:   public static int floor(int a)
  94:   {
  95:     return a & -64;
  96:   }
  97: 
  98: 
  99:   /**
 100:    * Calculates the length of a fixed-point vector.
 101:    */
 102:   public static int vectorLength(int x, int y)
 103:   {
 104:     int shift;
 105:     float fx, fy;
 106: 
 107:     if (x == 0)
 108:       return Math.abs(y);
 109:     else if (y == 0)
 110:       return Math.abs(x);
 111: 
 112:     /* Use the FPU. */
 113:     fx = ((float) x) / 64.0f;
 114:     fy = ((float) y) / 64.0f;
 115:     return (int) (Math.sqrt(fx * fx + fy * fy) * 64.0);
 116:   }
 117: 
 118: 
 119:   public static int intValue(int f)
 120:   {
 121:     return f >> 6;
 122:   }
 123: 
 124: 
 125:   public static float floatValue(int f)
 126:   {
 127:     return ((float) f) / 64;
 128:   }
 129:   public static float floatValue16(int f)
 130:   {
 131:     return ((float) f) / 65536;
 132:   }
 133: 
 134:   public static double doubleValue(int f)
 135:   {
 136:     return ((double) f) / 64;
 137:   }
 138: 
 139: 
 140:   public static int valueOf(float f)
 141:   {
 142:     return (int) (f * 64);
 143:   }
 144: 
 145: 
 146:   public static int valueOf(double d)
 147:   {
 148:     return (int) (d * 64);
 149:   }
 150: 
 151:   public static int valueOf16(double d)
 152:   {
 153:     return (int) (d * (1 << 16));
 154:   }
 155: 
 156:   /**
 157:    * Makes a string representation of a fixed-point number.
 158:    */
 159:   public static String toString(int f)
 160:   {
 161:     return String.valueOf(floatValue(f));
 162:   }
 163: 
 164: 
 165:   public static String toString(int x, int y)
 166:   {
 167:     StringBuffer sbuf = new StringBuffer(40);
 168:     sbuf.append('(');
 169:     sbuf.append(((float) x) / 64);
 170:     sbuf.append(", ");
 171:     sbuf.append(((float) y) / 64);
 172:     sbuf.append(')');
 173:     return sbuf.toString();
 174:   }
 175: }