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/src/compiler/android-ndk/jni/freetype/include/freetype/internal/ftcalc.h

http://ftk.googlecode.com/
C++ Header | 179 lines | 45 code | 34 blank | 100 comment | 0 complexity | 8ab30315ba473d514d6c583df95fa6ca MD5 | raw file
  1/***************************************************************************/
  2/*                                                                         */
  3/*  ftcalc.h                                                               */
  4/*                                                                         */
  5/*    Arithmetic computations (specification).                             */
  6/*                                                                         */
  7/*  Copyright 1996-2001, 2002, 2003, 2004, 2005, 2006, 2008, 2009 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
 27FT_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_BASE( FT_Int32 )
 48  FT_SqrtFixed( FT_Int32  x );
 49
 50
 51#ifdef FT_CONFIG_OPTION_OLD_INTERNALS
 52
 53  /*************************************************************************/
 54  /*                                                                       */
 55  /* <Function>                                                            */
 56  /*    FT_Sqrt32                                                          */
 57  /*                                                                       */
 58  /* <Description>                                                         */
 59  /*    Computes the square root of an Int32 integer (which will be        */
 60  /*    handled as an unsigned long value).                                */
 61  /*                                                                       */
 62  /* <Input>                                                               */
 63  /*    x :: The value to compute the root for.                            */
 64  /*                                                                       */
 65  /* <Return>                                                              */
 66  /*    The result of `sqrt(x)'.                                           */
 67  /*                                                                       */
 68  FT_EXPORT( FT_Int32 )
 69  FT_Sqrt32( FT_Int32  x );
 70
 71#endif /* FT_CONFIG_OPTION_OLD_INTERNALS */
 72
 73
 74  /*************************************************************************/
 75  /*                                                                       */
 76  /* FT_MulDiv() and FT_MulFix() are declared in freetype.h.               */
 77  /*                                                                       */
 78  /*************************************************************************/
 79
 80
 81#ifdef TT_USE_BYTECODE_INTERPRETER
 82
 83  /*************************************************************************/
 84  /*                                                                       */
 85  /* <Function>                                                            */
 86  /*    FT_MulDiv_No_Round                                                 */
 87  /*                                                                       */
 88  /* <Description>                                                         */
 89  /*    A very simple function used to perform the computation `(a*b)/c'   */
 90  /*    (without rounding) with maximal accuracy (it uses a 64-bit         */
 91  /*    intermediate integer whenever necessary).                          */
 92  /*                                                                       */
 93  /*    This function isn't necessarily as fast as some processor specific */
 94  /*    operations, but is at least completely portable.                   */
 95  /*                                                                       */
 96  /* <Input>                                                               */
 97  /*    a :: The first multiplier.                                         */
 98  /*    b :: The second multiplier.                                        */
 99  /*    c :: The divisor.                                                  */
100  /*                                                                       */
101  /* <Return>                                                              */
102  /*    The result of `(a*b)/c'.  This function never traps when trying to */
103  /*    divide by zero; it simply returns `MaxInt' or `MinInt' depending   */
104  /*    on the signs of `a' and `b'.                                       */
105  /*                                                                       */
106  FT_BASE( FT_Long )
107  FT_MulDiv_No_Round( FT_Long  a,
108                      FT_Long  b,
109                      FT_Long  c );
110
111#endif /* TT_USE_BYTECODE_INTERPRETER */
112
113
114  /*
115   *  A variant of FT_Matrix_Multiply which scales its result afterwards.
116   *  The idea is that both `a' and `b' are scaled by factors of 10 so that
117   *  the values are as precise as possible to get a correct result during
118   *  the 64bit multiplication.  Let `sa' and `sb' be the scaling factors of
119   *  `a' and `b', respectively, then the scaling factor of the result is
120   *  `sa*sb'.
121   */
122  FT_BASE( void )
123  FT_Matrix_Multiply_Scaled( const FT_Matrix*  a,
124                             FT_Matrix        *b,
125                             FT_Long           scaling );
126
127
128  /*
129   *  A variant of FT_Vector_Transform.  See comments for
130   *  FT_Matrix_Multiply_Scaled.
131   */
132
133  FT_BASE( void )
134  FT_Vector_Transform_Scaled( FT_Vector*        vector,
135                              const FT_Matrix*  matrix,
136                              FT_Long           scaling );
137
138
139  /*
140   *  Return -1, 0, or +1, depending on the orientation of a given corner.
141   *  We use the Cartesian coordinate system, with positive vertical values
142   *  going upwards.  The function returns +1 if the corner turns to the
143   *  left, -1 to the right, and 0 for undecidable cases.
144   */
145  FT_BASE( FT_Int )
146  ft_corner_orientation( FT_Pos  in_x,
147                         FT_Pos  in_y,
148                         FT_Pos  out_x,
149                         FT_Pos  out_y );
150
151  /*
152   *  Return TRUE if a corner is flat or nearly flat.  This is equivalent to
153   *  saying that the angle difference between the `in' and `out' vectors is
154   *  very small.
155   */
156  FT_BASE( FT_Int )
157  ft_corner_is_flat( FT_Pos  in_x,
158                     FT_Pos  in_y,
159                     FT_Pos  out_x,
160                     FT_Pos  out_y );
161
162
163#define INT_TO_F26DOT6( x )    ( (FT_Long)(x) << 6  )
164#define INT_TO_F2DOT14( x )    ( (FT_Long)(x) << 14 )
165#define INT_TO_FIXED( x )      ( (FT_Long)(x) << 16 )
166#define F2DOT14_TO_FIXED( x )  ( (FT_Long)(x) << 2  )
167#define FLOAT_TO_FIXED( x )    ( (FT_Long)( x * 65536.0 ) )
168#define FIXED_TO_INT( x )      ( FT_RoundFix( x ) >> 16 )
169
170#define ROUND_F26DOT6( x )     ( x >= 0 ? (    ( (x) + 32 ) & -64 )     \
171                                        : ( -( ( 32 - (x) ) & -64 ) ) )
172
173
174FT_END_HEADER
175
176#endif /* __FTCALC_H__ */
177
178
179/* END */