kc3-lang/freetype/src/autofit/afangles.c

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• Hash : 332da87d
  Author :
  Date : 2011-01-23T12:42:23
  

  [autofit] Some formatting and clean-ups.
  

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• src/autofit/afangles.c

• /***************************************************************************/
  /*                                                                         */
  /*  afangles.c                                                             */
  /*                                                                         */
  /*    Routines used to compute vector angles with limited accuracy         */
  /*    and very high speed.  It also contains sorting routines (body).      */
  /*                                                                         */
  /*  Copyright 2003-2006, 2011 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.                                        */
  /*                                                                         */
  /***************************************************************************/
  
  
  #include "aftypes.h"
  
  
  #if 0
  
    FT_LOCAL_DEF( FT_Int )
    af_corner_is_flat( FT_Pos  x_in,
                       FT_Pos  y_in,
                       FT_Pos  x_out,
                       FT_Pos  y_out )
    {
      FT_Pos  ax = x_in;
      FT_Pos  ay = y_in;
  
      FT_Pos  d_in, d_out, d_corner;
  
  
      if ( ax < 0 )
        ax = -ax;
      if ( ay < 0 )
        ay = -ay;
      d_in = ax + ay;
  
      ax = x_out;
      if ( ax < 0 )
        ax = -ax;
      ay = y_out;
      if ( ay < 0 )
        ay = -ay;
      d_out = ax + ay;
  
      ax = x_out + x_in;
      if ( ax < 0 )
        ax = -ax;
      ay = y_out + y_in;
      if ( ay < 0 )
        ay = -ay;
      d_corner = ax + ay;
  
      return ( d_in + d_out - d_corner ) < ( d_corner >> 4 );
    }
  
  
    FT_LOCAL_DEF( FT_Int )
    af_corner_orientation( FT_Pos  x_in,
                           FT_Pos  y_in,
                           FT_Pos  x_out,
                           FT_Pos  y_out )
    {
      FT_Pos  delta;
  
  
      delta = x_in * y_out - y_in * x_out;
  
      if ( delta == 0 )
        return 0;
      else
        return 1 - 2 * ( delta < 0 );
    }
  
  #endif /* 0 */
  
  
    /*
     *  We are not using `af_angle_atan' anymore, but we keep the source
     *  code below just in case...
     */
  
  
  #if 0
  
  
    /*
     *  The trick here is to realize that we don't need a very accurate angle
     *  approximation.  We are going to use the result of `af_angle_atan' to
     *  only compare the sign of angle differences, or check whether its
     *  magnitude is very small.
     *
     *  The approximation
     *
     *    dy * PI / (|dx|+|dy|)
     *
     *  should be enough, and much faster to compute.
     */
    FT_LOCAL_DEF( AF_Angle )
    af_angle_atan( FT_Fixed  dx,
                   FT_Fixed  dy )
    {
      AF_Angle  angle;
      FT_Fixed  ax = dx;
      FT_Fixed  ay = dy;
  
  
      if ( ax < 0 )
        ax = -ax;
      if ( ay < 0 )
        ay = -ay;
  
      ax += ay;
  
      if ( ax == 0 )
        angle = 0;
      else
      {
        angle = ( AF_ANGLE_PI2 * dy ) / ( ax + ay );
        if ( dx < 0 )
        {
          if ( angle >= 0 )
            angle = AF_ANGLE_PI - angle;
          else
            angle = -AF_ANGLE_PI - angle;
        }
      }
  
      return angle;
    }
  
  
  #elif 0
  
  
    /* the following table has been automatically generated with */
    /* the `mather.py' Python script                             */
  
  #define AF_ATAN_BITS  8
  
    static const FT_Byte  af_arctan[1L << AF_ATAN_BITS] =
    {
       0,  0,  1,  1,  1,  2,  2,  2,
       3,  3,  3,  3,  4,  4,  4,  5,
       5,  5,  6,  6,  6,  7,  7,  7,
       8,  8,  8,  9,  9,  9, 10, 10,
      10, 10, 11, 11, 11, 12, 12, 12,
      13, 13, 13, 14, 14, 14, 14, 15,
      15, 15, 16, 16, 16, 17, 17, 17,
      18, 18, 18, 18, 19, 19, 19, 20,
      20, 20, 21, 21, 21, 21, 22, 22,
      22, 23, 23, 23, 24, 24, 24, 24,
      25, 25, 25, 26, 26, 26, 26, 27,
      27, 27, 28, 28, 28, 28, 29, 29,
      29, 30, 30, 30, 30, 31, 31, 31,
      31, 32, 32, 32, 33, 33, 33, 33,
      34, 34, 34, 34, 35, 35, 35, 35,
      36, 36, 36, 36, 37, 37, 37, 38,
      38, 38, 38, 39, 39, 39, 39, 40,
      40, 40, 40, 41, 41, 41, 41, 42,
      42, 42, 42, 42, 43, 43, 43, 43,
      44, 44, 44, 44, 45, 45, 45, 45,
      46, 46, 46, 46, 46, 47, 47, 47,
      47, 48, 48, 48, 48, 48, 49, 49,
      49, 49, 50, 50, 50, 50, 50, 51,
      51, 51, 51, 51, 52, 52, 52, 52,
      52, 53, 53, 53, 53, 53, 54, 54,
      54, 54, 54, 55, 55, 55, 55, 55,
      56, 56, 56, 56, 56, 57, 57, 57,
      57, 57, 57, 58, 58, 58, 58, 58,
      59, 59, 59, 59, 59, 59, 60, 60,
      60, 60, 60, 61, 61, 61, 61, 61,
      61, 62, 62, 62, 62, 62, 62, 63,
      63, 63, 63, 63, 63, 64, 64, 64
    };
  
  
    FT_LOCAL_DEF( AF_Angle )
    af_angle_atan( FT_Fixed  dx,
                   FT_Fixed  dy )
    {
      AF_Angle  angle;
  
  
      /* check trivial cases */
      if ( dy == 0 )
      {
        angle = 0;
        if ( dx < 0 )
          angle = AF_ANGLE_PI;
        return angle;
      }
      else if ( dx == 0 )
      {
        angle = AF_ANGLE_PI2;
        if ( dy < 0 )
          angle = -AF_ANGLE_PI2;
        return angle;
      }
  
      angle = 0;
      if ( dx < 0 )
      {
        dx = -dx;
        dy = -dy;
        angle = AF_ANGLE_PI;
      }
  
      if ( dy < 0 )
      {
        FT_Pos  tmp;
  
  
        tmp = dx;
        dx  = -dy;
        dy  = tmp;
        angle -= AF_ANGLE_PI2;
      }
  
      if ( dx == 0 && dy == 0 )
        return 0;
  
      if ( dx == dy )
        angle += AF_ANGLE_PI4;
      else if ( dx > dy )
        angle += af_arctan[FT_DivFix( dy, dx ) >> ( 16 - AF_ATAN_BITS )];
      else
        angle += AF_ANGLE_PI2 -
                 af_arctan[FT_DivFix( dx, dy ) >> ( 16 - AF_ATAN_BITS )];
  
      if ( angle > AF_ANGLE_PI )
        angle -= AF_ANGLE_2PI;
  
      return angle;
    }
  
  
  #endif /* 0 */
  
  
    FT_LOCAL_DEF( void )
    af_sort_pos( FT_UInt  count,
                 FT_Pos*  table )
    {
      FT_UInt  i, j;
      FT_Pos   swap;
  
  
      for ( i = 1; i < count; i++ )
      {
        for ( j = i; j > 0; j-- )
        {
          if ( table[j] > table[j - 1] )
            break;
  
          swap         = table[j];
          table[j]     = table[j - 1];
          table[j - 1] = swap;
        }
      }
    }
  
  
    FT_LOCAL_DEF( void )
    af_sort_widths( FT_UInt   count,
                    AF_Width  table )
    {
      FT_UInt      i, j;
      AF_WidthRec  swap;
  
  
      for ( i = 1; i < count; i++ )
      {
        for ( j = i; j > 0; j-- )
        {
          if ( table[j].org > table[j - 1].org )
            break;
  
          swap         = table[j];
          table[j]     = table[j - 1];
          table[j - 1] = swap;
        }
      }
    }
  
  
  /* END */
  

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