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