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

Branch : - branch - master v2.13 - tag -

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  Commit

• Author : David Turner
  Date : 2003-12-24 18:42:04
  Hash : cf2c49c8
  Message : * fixed compilation problems in the cache sub-system * partial updates to src/autofit

• src/autofit/afangles.c

• #include "aftypes.h"
  
    /* this table was generated for AF_ANGLE_PI = 256 */
  #define AF_ANGLE_MAX_ITERS  8
  #define AF_TRIG_MAX_ITERS   9
  
    static const FT_Fixed
    af_angle_arctan_table[9] =
    {
      90, 64, 38, 20, 10, 5, 3, 1, 1
    };
  
  
    static FT_Int
    af_angle_prenorm( FT_Vector*  vec )
    {
      FT_Fixed  x, y, z;
      FT_Int    shift;
  
  
      x = vec->x;
      y = vec->y;
  
      z     = ( ( x >= 0 ) ? x : - x ) | ( (y >= 0) ? y : -y );
      shift = 0;
  
      if ( z < ( 1L << 27 ) )
      {
        do
        {
          shift++;
          z <<= 1;
        } while ( z < ( 1L << 27 ) );
  
        vec->x = x << shift;
        vec->y = y << shift;
      }
      else if ( z > ( 1L << 28 ) )
      {
        do
        {
          shift++;
          z >>= 1;
        } while ( z > ( 1L << 28 ) );
  
        vec->x = x >> shift;
        vec->y = y >> shift;
        shift  = -shift;
      }
      return shift;
    }
  
  
    static void
    af_angle_pseudo_polarize( FT_Vector*  vec )
    {
      FT_Fixed         theta;
      FT_Fixed         yi, i;
      FT_Fixed         x, y;
      const FT_Fixed  *arctanptr;
  
  
      x = vec->x;
      y = vec->y;
  
      /* Get the vector into the right half plane */
      theta = 0;
      if ( x < 0 )
      {
        x = -x;
        y = -y;
        theta = 2 * AF_ANGLE_PI2;
      }
  
      if ( y > 0 )
        theta = - theta;
  
      arctanptr = af_angle_arctan_table;
  
      if ( y < 0 )
      {
        /* Rotate positive */
        yi     = y + ( x << 1 );
        x      = x - ( y << 1 );
        y      = yi;
        theta -= *arctanptr++;  /* Subtract angle */
      }
      else
      {
        /* Rotate negative */
        yi     = y - ( x << 1 );
        x      = x + ( y << 1 );
        y      = yi;
        theta += *arctanptr++;  /* Add angle */
      }
  
      i = 0;
      do
      {
        if ( y < 0 )
        {
          /* Rotate positive */
          yi     = y + ( x >> i );
          x      = x - ( y >> i );
          y      = yi;
          theta -= *arctanptr++;
        }
        else
        {
          /* Rotate negative */
          yi     = y - ( x >> i );
          x      = x + ( y >> i );
          y      = yi;
          theta += *arctanptr++;
        }
      } while ( ++i < AF_TRIG_MAX_ITERS );
  
      /* round theta */
      if ( theta >= 0 )
        theta = FT_PAD_ROUND( theta, 4 );
      else
        theta = - FT_PAD_ROUND( theta, 4 );
  
      vec->x = x;
      vec->y = theta;
    }
  
  
    /* documentation is in fttrigon.h */
  
    FT_LOCAL_DEF( AF_Angle )
    af_angle_atan( FT_Fixed  dx,
                   FT_Fixed  dy )
    {
      FT_Vector  v;
  
  
      if ( dx == 0 && dy == 0 )
        return 0;
  
      v.x = dx;
      v.y = dy;
      af_angle_prenorm( &v );
      af_angle_pseudo_polarize( &v );
  
      return v.y;
    }
  
  
  
    FT_LOCAL_DEF( AF_Angle )
    af_angle_diff( AF_Angle  angle1,
                   AF_Angle  angle2 )
    {
      AF_Angle  delta = angle2 - angle1;
  
      delta %= AF_ANGLE_2PI;
      if ( delta < 0 )
        delta += AF_ANGLE_2PI;
  
      if ( delta > AF_ANGLE_PI )
        delta -= AF_ANGLE_2PI;
  
      return delta;
    }
  
  
   /* well, this needs to be somewhere, right :-)
    */
  
    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;
        }
      }
    }