/***************************************************************************/ | |
/* */ | |
/* ftcalc.h */ | |
/* */ | |
/* Arithmetic computations (specification). */ | |
/* */ | |
/* Copyright 1996-2001, 2002, 2003, 2004, 2005, 2006, 2008 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_USE_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_USE_BYTECODE_INTERPRETER */ | |
/* | |
* A variant of FT_Matrix_Multiply which scales its result afterwards. | |
* The idea is that both `a' and `b' are scaled by factors of 10 so that | |
* the values are as precise as possible to get a correct result during | |
* the 64bit multiplication. Let `sa' and `sb' be the scaling factors of | |
* `a' and `b', respectively, then the scaling factor of the result is | |
* `sa*sb'. | |
*/ | |
FT_BASE( void ) | |
FT_Matrix_Multiply_Scaled( const FT_Matrix* a, | |
FT_Matrix *b, | |
FT_Long scaling ); | |
/* | |
* A variant of FT_Vector_Transform. See comments for | |
* FT_Matrix_Multiply_Scaled. | |
*/ | |
FT_BASE( void ) | |
FT_Vector_Transform_Scaled( FT_Vector* vector, | |
const FT_Matrix* matrix, | |
FT_Long scaling ); | |
/* | |
* Return -1, 0, or +1, depending on the orientation of a given corner. | |
* We use the Cartesian coordinate system, with positive vertical values | |
* going upwards. The function returns +1 if the corner turns to the | |
* left, -1 to the right, and 0 for undecidable cases. | |
*/ | |
FT_BASE( FT_Int ) | |
ft_corner_orientation( FT_Pos in_x, | |
FT_Pos in_y, | |
FT_Pos out_x, | |
FT_Pos out_y ); | |
/* | |
* Return TRUE if a corner is flat or nearly flat. This is equivalent to | |
* saying that the angle difference between the `in' and `out' vectors is | |
* very small. | |
*/ | |
FT_BASE( FT_Int ) | |
ft_corner_is_flat( FT_Pos in_x, | |
FT_Pos in_y, | |
FT_Pos out_x, | |
FT_Pos out_y ); | |
#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 */ |