misc/libfreetype/include/freetype/internal/ftcalc.h
changeset 5172 88f2e05288ba
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/misc/libfreetype/include/freetype/internal/ftcalc.h	Mon Apr 25 01:46:54 2011 +0200
@@ -0,0 +1,179 @@
+/***************************************************************************/
+/*                                                                         */
+/*  ftcalc.h                                                               */
+/*                                                                         */
+/*    Arithmetic computations (specification).                             */
+/*                                                                         */
+/*  Copyright 1996-2001, 2002, 2003, 2004, 2005, 2006, 2008, 2009 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 FIXED_TO_INT( x )      ( FT_RoundFix( x ) >> 16 )
+
+#define ROUND_F26DOT6( x )     ( x >= 0 ? (    ( (x) + 32 ) & -64 )     \
+                                        : ( -( ( 32 - (x) ) & -64 ) ) )
+
+
+FT_END_HEADER
+
+#endif /* __FTCALC_H__ */
+
+
+/* END */