git.sesse.net Git - casparcg/blob - SFML-1.6/extlibs/headers/freetype/internal/ftcalc.h

   1 /***************************************************************************/
   2 /*                                                                         */
   3 /*  ftcalc.h                                                               */
   4 /*                                                                         */
   5 /*    Arithmetic computations (specification).                             */
   6 /*                                                                         */
   7 /*  Copyright 1996-2001, 2002, 2003, 2004 by                               */
   8 /*  David Turner, Robert Wilhelm, and Werner Lemberg.                      */
   9 /*                                                                         */
  10 /*  This file is part of the FreeType project, and may only be used,       */
  11 /*  modified, and distributed under the terms of the FreeType project      */
  12 /*  license, LICENSE.TXT.  By continuing to use, modify, or distribute     */
  13 /*  this file you indicate that you have read the license and              */
  14 /*  understand and accept it fully.                                        */
  15 /*                                                                         */
  16 /***************************************************************************/
  17
  18
  19 #ifndef __FTCALC_H__
  20 #define __FTCALC_H__
  21
  22
  23 #include <ft2build.h>
  24 #include FT_FREETYPE_H
  25
  26
  27 FT_BEGIN_HEADER
  28
  29
  30   /*************************************************************************/
  31   /*                                                                       */
  32   /* <Function>                                                            */
  33   /*    FT_FixedSqrt                                                       */
  34   /*                                                                       */
  35   /* <Description>                                                         */
  36   /*    Computes the square root of a 16.16 fixed point value.             */
  37   /*                                                                       */
  38   /* <Input>                                                               */
  39   /*    x :: The value to compute the root for.                            */
  40   /*                                                                       */
  41   /* <Return>                                                              */
  42   /*    The result of `sqrt(x)'.                                           */
  43   /*                                                                       */
  44   /* <Note>                                                                */
  45   /*    This function is not very fast.                                    */
  46   /*                                                                       */
  47   FT_EXPORT( FT_Int32 )
  48   FT_SqrtFixed( FT_Int32  x );
  49
  50
  51 #define SQRT_32( x )  FT_Sqrt32( x )
  52
  53
  54   /*************************************************************************/
  55   /*                                                                       */
  56   /* <Function>                                                            */
  57   /*    FT_Sqrt32                                                          */
  58   /*                                                                       */
  59   /* <Description>                                                         */
  60   /*    Computes the square root of an Int32 integer (which will be        */
  61   /*    handled as an unsigned long value).                                */
  62   /*                                                                       */
  63   /* <Input>                                                               */
  64   /*    x :: The value to compute the root for.                            */
  65   /*                                                                       */
  66   /* <Return>                                                              */
  67   /*    The result of `sqrt(x)'.                                           */
  68   /*                                                                       */
  69   FT_EXPORT( FT_Int32 )
  70   FT_Sqrt32( FT_Int32  x );
  71
  72
  73   /*************************************************************************/
  74   /*                                                                       */
  75   /* FT_MulDiv() and FT_MulFix() are declared in freetype.h.               */
  76   /*                                                                       */
  77   /*************************************************************************/
  78
  79
  80 #ifdef TT_CONFIG_OPTION_BYTECODE_INTERPRETER
  81
  82   /*************************************************************************/
  83   /*                                                                       */
  84   /* <Function>                                                            */
  85   /*    FT_MulDiv_No_Round                                                 */
  86   /*                                                                       */
  87   /* <Description>                                                         */
  88   /*    A very simple function used to perform the computation `(a*b)/c'   */
  89   /*    (without rounding) with maximal accuracy (it uses a 64-bit         */
  90   /*    intermediate integer whenever necessary).                          */
  91   /*                                                                       */
  92   /*    This function isn't necessarily as fast as some processor specific */
  93   /*    operations, but is at least completely portable.                   */
  94   /*                                                                       */
  95   /* <Input>                                                               */
  96   /*    a :: The first multiplier.                                         */
  97   /*    b :: The second multiplier.                                        */
  98   /*    c :: The divisor.                                                  */
  99   /*                                                                       */
 100   /* <Return>                                                              */
 101   /*    The result of `(a*b)/c'.  This function never traps when trying to */
 102   /*    divide by zero; it simply returns `MaxInt' or `MinInt' depending   */
 103   /*    on the signs of `a' and `b'.                                       */
 104   /*                                                                       */
 105   FT_BASE( FT_Long )
 106   FT_MulDiv_No_Round( FT_Long  a,
 107                       FT_Long  b,
 108                       FT_Long  c );
 109
 110 #endif /* TT_CONFIG_OPTION_BYTECODE_INTERPRETER */
 111
 112
 113 #define INT_TO_F26DOT6( x )    ( (FT_Long)(x) << 6  )
 114 #define INT_TO_F2DOT14( x )    ( (FT_Long)(x) << 14 )
 115 #define INT_TO_FIXED( x )      ( (FT_Long)(x) << 16 )
 116 #define F2DOT14_TO_FIXED( x )  ( (FT_Long)(x) << 2  )
 117 #define FLOAT_TO_FIXED( x )    ( (FT_Long)( x * 65536.0 ) )
 118
 119 #define ROUND_F26DOT6( x )     ( x >= 0 ? (    ( (x) + 32 ) & -64 )     \
 120                                         : ( -( ( 32 - (x) ) & -64 ) ) )
 121
 122
 123 FT_END_HEADER
 124
 125 #endif /* __FTCALC_H__ */
 126
 127
 128 /* END */