| /***************************************************************************/ |
| /* */ |
| /* ftcalc.h */ |
| /* */ |
| /* Arithmetic computations (specification). */ |
| /* */ |
| /* Copyright 1996-2001, 2002, 2003, 2004, 2005, 2006 by */ |
| /* David Turner, Robert Wilhelm, and Werner Lemberg. */ |
| /* */ |
| /* This file is part of the FreeType project, and may only be used, */ |
| /* modified, and distributed under the terms of the FreeType project */ |
| /* license, LICENSE.TXT. By continuing to use, modify, or distribute */ |
| /* this file you indicate that you have read the license and */ |
| /* understand and accept it fully. */ |
| /* */ |
| /***************************************************************************/ |
| |
| |
| #ifndef __FTCALC_H__ |
| #define __FTCALC_H__ |
| |
| |
| #include <ft2build.h> |
| #include FT_FREETYPE_H |
| |
| |
| FT_BEGIN_HEADER |
| |
| |
| /*************************************************************************/ |
| /* */ |
| /* <Function> */ |
| /* FT_FixedSqrt */ |
| /* */ |
| /* <Description> */ |
| /* Computes the square root of a 16.16 fixed point value. */ |
| /* */ |
| /* <Input> */ |
| /* x :: The value to compute the root for. */ |
| /* */ |
| /* <Return> */ |
| /* The result of `sqrt(x)'. */ |
| /* */ |
| /* <Note> */ |
| /* This function is not very fast. */ |
| /* */ |
| FT_BASE( FT_Int32 ) |
| FT_SqrtFixed( FT_Int32 x ); |
| |
| |
| #ifdef FT_CONFIG_OPTION_OLD_INTERNALS |
| |
| /*************************************************************************/ |
| /* */ |
| /* <Function> */ |
| /* FT_Sqrt32 */ |
| /* */ |
| /* <Description> */ |
| /* Computes the square root of an Int32 integer (which will be */ |
| /* handled as an unsigned long value). */ |
| /* */ |
| /* <Input> */ |
| /* x :: The value to compute the root for. */ |
| /* */ |
| /* <Return> */ |
| /* The result of `sqrt(x)'. */ |
| /* */ |
| FT_EXPORT( FT_Int32 ) |
| FT_Sqrt32( FT_Int32 x ); |
| |
| #endif /* FT_CONFIG_OPTION_OLD_INTERNALS */ |
| |
| |
| /*************************************************************************/ |
| /* */ |
| /* FT_MulDiv() and FT_MulFix() are declared in freetype.h. */ |
| /* */ |
| /*************************************************************************/ |
| |
| |
| #ifdef TT_CONFIG_OPTION_BYTECODE_INTERPRETER |
| |
| /*************************************************************************/ |
| /* */ |
| /* <Function> */ |
| /* FT_MulDiv_No_Round */ |
| /* */ |
| /* <Description> */ |
| /* A very simple function used to perform the computation `(a*b)/c' */ |
| /* (without rounding) with maximal accuracy (it uses a 64-bit */ |
| /* intermediate integer whenever necessary). */ |
| /* */ |
| /* This function isn't necessarily as fast as some processor specific */ |
| /* operations, but is at least completely portable. */ |
| /* */ |
| /* <Input> */ |
| /* a :: The first multiplier. */ |
| /* b :: The second multiplier. */ |
| /* c :: The divisor. */ |
| /* */ |
| /* <Return> */ |
| /* The result of `(a*b)/c'. This function never traps when trying to */ |
| /* divide by zero; it simply returns `MaxInt' or `MinInt' depending */ |
| /* on the signs of `a' and `b'. */ |
| /* */ |
| FT_BASE( FT_Long ) |
| FT_MulDiv_No_Round( FT_Long a, |
| FT_Long b, |
| FT_Long c ); |
| |
| #endif /* TT_CONFIG_OPTION_BYTECODE_INTERPRETER */ |
| |
| |
| #define INT_TO_F26DOT6( x ) ( (FT_Long)(x) << 6 ) |
| #define INT_TO_F2DOT14( x ) ( (FT_Long)(x) << 14 ) |
| #define INT_TO_FIXED( x ) ( (FT_Long)(x) << 16 ) |
| #define F2DOT14_TO_FIXED( x ) ( (FT_Long)(x) << 2 ) |
| #define FLOAT_TO_FIXED( x ) ( (FT_Long)( x * 65536.0 ) ) |
| |
| #define ROUND_F26DOT6( x ) ( x >= 0 ? ( ( (x) + 32 ) & -64 ) \ |
| : ( -( ( 32 - (x) ) & -64 ) ) ) |
| |
| |
| FT_END_HEADER |
| |
| #endif /* __FTCALC_H__ */ |
| |
| |
| /* END */ |