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/***************************************************************************/
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/* */
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/* ftcalc.h */
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/* */
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/* Arithmetic computations (specification). */
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/* */
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/* Copyright 1996-2001, 2002, 2003, 2004, 2005, 2006, 2008, 2009 by */
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/* David Turner, Robert Wilhelm, and Werner Lemberg. */
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/* */
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/* This file is part of the FreeType project, and may only be used, */
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/* modified, and distributed under the terms of the FreeType project */
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/* license, LICENSE.TXT. By continuing to use, modify, or distribute */
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/* this file you indicate that you have read the license and */
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/* understand and accept it fully. */
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/* */
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/***************************************************************************/
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#ifndef __FTCALC_H__
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#define __FTCALC_H__
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#include <ft2build.h>
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#include FT_FREETYPE_H
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FT_BEGIN_HEADER
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/*************************************************************************/
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/* */
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/* <Function> */
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/* FT_FixedSqrt */
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/* */
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/* <Description> */
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/* Computes the square root of a 16.16 fixed point value. */
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/* */
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/* <Input> */
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/* x :: The value to compute the root for. */
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/* */
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/* <Return> */
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/* The result of `sqrt(x)'. */
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/* */
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/* <Note> */
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/* This function is not very fast. */
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/* */
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FT_BASE( FT_Int32 )
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FT_SqrtFixed( FT_Int32 x );
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#ifdef FT_CONFIG_OPTION_OLD_INTERNALS
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/*************************************************************************/
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/* */
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/* <Function> */
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/* FT_Sqrt32 */
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/* */
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/* <Description> */
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/* Computes the square root of an Int32 integer (which will be */
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/* handled as an unsigned long value). */
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/* */
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/* <Input> */
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/* x :: The value to compute the root for. */
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/* */
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/* <Return> */
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/* The result of `sqrt(x)'. */
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/* */
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FT_EXPORT( FT_Int32 )
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FT_Sqrt32( FT_Int32 x );
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#endif /* FT_CONFIG_OPTION_OLD_INTERNALS */
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/*************************************************************************/
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/* */
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/* FT_MulDiv() and FT_MulFix() are declared in freetype.h. */
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/* */
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/*************************************************************************/
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#ifdef TT_USE_BYTECODE_INTERPRETER
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/*************************************************************************/
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/* */
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/* <Function> */
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/* FT_MulDiv_No_Round */
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/* */
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/* <Description> */
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/* A very simple function used to perform the computation `(a*b)/c' */
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/* (without rounding) with maximal accuracy (it uses a 64-bit */
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/* intermediate integer whenever necessary). */
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/* */
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/* This function isn't necessarily as fast as some processor specific */
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/* operations, but is at least completely portable. */
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/* */
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/* <Input> */
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/* a :: The first multiplier. */
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/* b :: The second multiplier. */
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/* c :: The divisor. */
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/* */
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/* <Return> */
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/* The result of `(a*b)/c'. This function never traps when trying to */
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/* divide by zero; it simply returns `MaxInt' or `MinInt' depending */
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/* on the signs of `a' and `b'. */
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/* */
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FT_BASE( FT_Long )
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FT_MulDiv_No_Round( FT_Long a,
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FT_Long b,
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FT_Long c );
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#endif /* TT_USE_BYTECODE_INTERPRETER */
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/*
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* A variant of FT_Matrix_Multiply which scales its result afterwards.
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* The idea is that both `a' and `b' are scaled by factors of 10 so that
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* the values are as precise as possible to get a correct result during
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* the 64bit multiplication. Let `sa' and `sb' be the scaling factors of
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* `a' and `b', respectively, then the scaling factor of the result is
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* `sa*sb'.
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*/
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FT_BASE( void )
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FT_Matrix_Multiply_Scaled( const FT_Matrix* a,
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FT_Matrix *b,
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FT_Long scaling );
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/*
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* A variant of FT_Vector_Transform. See comments for
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* FT_Matrix_Multiply_Scaled.
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*/
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FT_BASE( void )
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FT_Vector_Transform_Scaled( FT_Vector* vector,
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const FT_Matrix* matrix,
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FT_Long scaling );
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/*
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* Return -1, 0, or +1, depending on the orientation of a given corner.
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* We use the Cartesian coordinate system, with positive vertical values
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* going upwards. The function returns +1 if the corner turns to the
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* left, -1 to the right, and 0 for undecidable cases.
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*/
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FT_BASE( FT_Int )
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ft_corner_orientation( FT_Pos in_x,
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FT_Pos in_y,
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FT_Pos out_x,
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FT_Pos out_y );
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/*
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* Return TRUE if a corner is flat or nearly flat. This is equivalent to
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* saying that the angle difference between the `in' and `out' vectors is
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* very small.
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*/
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FT_BASE( FT_Int )
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ft_corner_is_flat( FT_Pos in_x,
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FT_Pos in_y,
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FT_Pos out_x,
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FT_Pos out_y );
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#define INT_TO_F26DOT6( x ) ( (FT_Long)(x) << 6 )
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#define INT_TO_F2DOT14( x ) ( (FT_Long)(x) << 14 )
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#define INT_TO_FIXED( x ) ( (FT_Long)(x) << 16 )
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#define F2DOT14_TO_FIXED( x ) ( (FT_Long)(x) << 2 )
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#define FLOAT_TO_FIXED( x ) ( (FT_Long)( x * 65536.0 ) )
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#define FIXED_TO_INT( x ) ( FT_RoundFix( x ) >> 16 )
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#define ROUND_F26DOT6( x ) ( x >= 0 ? ( ( (x) + 32 ) & -64 ) \
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: ( -( ( 32 - (x) ) & -64 ) ) )
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FT_END_HEADER
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#endif /* __FTCALC_H__ */
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/* END */
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