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: import gnu.java.lang.CPStringBuilder;
  42: 
  43: /**
  44:  * A utility class for fixed-point arithmetics, where numbers are
  45:  * represented with 26 dot 6 digits. This representation is used by
  46:  * TrueType coordinates.
  47:  *
  48:  * <p>A good compiler will inline calls of methods in this class.
  49:  *
  50:  * @author Sascha Brawer (brawer@dandelis.ch)
  51:  */
  52: public final class Fixed
  53: {
  54:   public static final int ONE = 1<<6;
  55: 
  56: 
  57:   /**
  58:    * The constructor is private so nobody can use it.
  59:    */
  60:   private Fixed()
  61:   {
  62:   }
  63: 
  64: 
  65:   /**
  66:    * Multiplies two fixed-point numbers.
  67:    */
  68:   public static int mul(int a, int b)
  69:   {
  70:     return (int) ((((long) a) * b) >> 6);
  71:   }
  72: 
  73:   public static int mul16(int a, int b)
  74:   {
  75:     return (int) ((((long) a) * b) >> 16);
  76:   }
  77: 
  78:   public static int div(int a, int b)
  79:   {
  80:     return (int) ((((long) a) << 6) / b);
  81:   }
  82: 
  83:   public static int div16(int a, int b)
  84:   {
  85:     return (int) ((((long) a) << 16) / b);
  86:   }
  87: 
  88:   public static int ceil(int a)
  89:   {
  90:     return (a + 63) & -64;
  91:   }
  92: 
  93: 
  94:   public static int floor(int a)
  95:   {
  96:     return a & -64;
  97:   }
  98: 
  99: 
 100:   /**
 101:    * Calculates the length of a fixed-point vector.
 102:    */
 103:   public static int vectorLength(int x, int y)
 104:   {
 105:     int shift;
 106:     float fx, fy;
 107: 
 108:     if (x == 0)
 109:       return Math.abs(y);
 110:     else if (y == 0)
 111:       return Math.abs(x);
 112: 
 113:     /* Use the FPU. */
 114:     fx = ((float) x) / 64.0f;
 115:     fy = ((float) y) / 64.0f;
 116:     return (int) (Math.sqrt(fx * fx + fy * fy) * 64.0);
 117:   }
 118: 
 119: 
 120:   public static int intValue(int f)
 121:   {
 122:     return f >> 6;
 123:   }
 124: 
 125: 
 126:   public static float floatValue(int f)
 127:   {
 128:     return ((float) f) / 64;
 129:   }
 130:   public static float floatValue16(int f)
 131:   {
 132:     return ((float) f) / 65536;
 133:   }
 134: 
 135:   public static double doubleValue(int f)
 136:   {
 137:     return ((double) f) / 64;
 138:   }
 139: 
 140: 
 141:   public static int valueOf(float f)
 142:   {
 143:     return (int) (f * 64);
 144:   }
 145: 
 146: 
 147:   public static int valueOf(double d)
 148:   {
 149:     return (int) (d * 64);
 150:   }
 151: 
 152:   public static int valueOf16(double d)
 153:   {
 154:     return (int) (d * (1 << 16));
 155:   }
 156: 
 157:   /**
 158:    * Makes a string representation of a fixed-point number.
 159:    */
 160:   public static String toString(int f)
 161:   {
 162:     return String.valueOf(floatValue(f));
 163:   }
 164: 
 165: 
 166:   public static String toString(int x, int y)
 167:   {
 168:     CPStringBuilder sbuf = new CPStringBuilder(40);
 169:     sbuf.append('(');
 170:     sbuf.append(((float) x) / 64);
 171:     sbuf.append(", ");
 172:     sbuf.append(((float) y) / 64);
 173:     sbuf.append(')');
 174:     return sbuf.toString();
 175:   }
 176: }