ftgrays.c

qt-embedded-2.3.8.tar.gz源码

      p     = fx1 * ( y2 - y1 );
      first = 0;
      incr  = -1;
      dx    = -dx;
    }

    delta = p / dx;
    mod   = p % dx;
    if ( mod < 0 )
    {
      delta--;
      mod += dx;
    }

    ras.area  += ( fx1 + first ) * delta;
    ras.cover += delta;

    ex1 += incr;
    if ( set_cell( RAS_VAR_ ex1, ey ) )
      goto Error;
    y1  += delta;

    if ( ex1 != ex2 )
    {
      p     = ONE_PIXEL * ( y2 - y1 );
      lift  = p / dx;
      rem   = p % dx;
      if ( rem < 0 )
      {
        lift--;
        rem += dx;
      }

      mod -= dx;

      while ( ex1 != ex2 )
      {
        delta = lift;
        mod  += rem;
        if ( mod >= 0 )
        {
          mod -= dx;
          delta++;
        }

        ras.area  += ONE_PIXEL * delta;
        ras.cover += delta;
        y1        += delta;
        ex1       += incr;
        if ( set_cell( RAS_VAR_ ex1, ey ) )
          goto Error;
      }
    }

    delta      = y2 - y1;
    ras.area  += ( fx2 + ONE_PIXEL - first ) * delta;
    ras.cover += delta;

    return 0;

  Error:
    return 1;
  }


  /*************************************************************************/
  /*                                                                       */
  /* Render a given line as a series of scanlines.                         */
  /*                                                                       */
  static
  int  render_line( RAS_ARG_ TPos  to_x,
                             TPos  to_y )
  {
    TScan  ey1, ey2, fy1, fy2;
    TPos   dx, dy, x, x2;
    int    p, rem, mod, lift, delta, first, incr;


    ey1 = TRUNC( ras.last_ey );
    ey2 = TRUNC( to_y ); /* if (ey2 >= ras.max_ey) ey2 = ras.max_ey-1; */
    fy1 = ras.y - ras.last_ey;
    fy2 = to_y - SUBPIXELS( ey2 );

    dx = to_x - ras.x;
    dy = to_y - ras.y;

    /* XXX: we should do something about the trivial case where dx == 0, */
    /*      as it happens very often!                                    */

    /* perform vertical clipping */
    {
      TScan  min, max;


      min = ey1;
      max = ey2;
      if ( ey1 > ey2 )
      {
        min = ey2;
        max = ey1;
      }
      if ( min >= ras.max_ey || max < ras.min_ey )
        goto End;
    }

    /* everything is on a single scanline */
    if ( ey1 == ey2 )
    {
      if ( render_scanline( RAS_VAR_ ey1, ras.x, fy1, to_x, fy2 ) )
        goto Error;
      goto End;
    }

    /* ok, we have to render several scanlines */
    p     = ( ONE_PIXEL - fy1 ) * dx;
    first = ONE_PIXEL;
    incr  = 1;

    if ( dy < 0 )
    {
      p     = fy1 * dx;
      first = 0;
      incr  = -1;
      dy    = -dy;
    }

    delta = p / dy;
    mod   = p % dy;
    if ( mod < 0 )
    {
      delta--;
      mod += dy;
    }

    x = ras.x + delta;
    if ( render_scanline( RAS_VAR_ ey1, ras.x, fy1, x, first ) )
      goto Error;

    ey1 += incr;
    if ( set_cell( RAS_VAR_ TRUNC( x ), ey1 ) )
      goto Error;

    if ( ey1 != ey2 )
    {
      p     = ONE_PIXEL * dx;
      lift  = p / dy;
      rem   = p % dy;
      if ( rem < 0 )
      {
        lift--;
        rem += dy;
      }
      mod -= dy;

      while ( ey1 != ey2 )
      {
        delta = lift;
        mod  += rem;
        if ( mod >= 0 )
        {
          mod -= dy;
          delta++;
        }

        x2 = x + delta;
        if ( render_scanline( RAS_VAR_ ey1,
                              x, ONE_PIXEL - first, x2, first ) )
          goto Error;
        x = x2;
        ey1 += incr;
        if ( set_cell( RAS_VAR_ TRUNC( x ), ey1 ) )
          goto Error;
      }
    }

    if ( render_scanline( RAS_VAR_ ey1,
                          x, ONE_PIXEL - first, to_x, fy2 ) )
      goto Error;

  End:
    ras.x       = to_x;
    ras.y       = to_y;
    ras.last_ey = SUBPIXELS( ey2 );

    return 0;

  Error:
    return 1;
  }


  static
  void  split_conic( FT_Vector*  base )
  {
    TPos  a, b;


    base[4].x = base[2].x;
    b = base[1].x;
    a = base[3].x = ( base[2].x + b ) / 2;
    b = base[1].x = ( base[0].x + b ) / 2;
    base[2].x = ( a + b ) / 2;

    base[4].y = base[2].y;
    b = base[1].y;
    a = base[3].y = ( base[2].y + b ) / 2;
    b = base[1].y = ( base[0].y + b ) / 2;
    base[2].y = ( a + b ) / 2;
  }


  static
  int  render_conic( RAS_ARG_ FT_Vector*  control,
                              FT_Vector*  to )
  {
    TPos        dx, dy;
    int         top, level;
    int*        levels;
    FT_Vector*  arc;


    dx = DOWNSCALE( ras.x ) + to->x - ( control->x << 1 );
    if ( dx < 0 )
      dx = -dx;
    dy = DOWNSCALE( ras.y ) + to->y - ( control->y << 1 );
    if ( dy < 0 )
      dy = -dy;
    if ( dx < dy )
      dx = dy;

    level = 1;
    dx = dx / ras.conic_level;
    while ( dx > 0 )
    {
      dx >>= 2;
      level++;
    }

    /* a shortcut to speed things up */
    if ( level <= 1 )
    {
      /* we compute the mid-point directly in order to avoid */
      /* calling split_conic()                               */
      TPos   to_x, to_y, mid_x, mid_y;


      to_x  = UPSCALE( to->x );
      to_y  = UPSCALE( to->y );
      mid_x = ( ras.x + to_x + 2 * UPSCALE( control->x ) ) / 4;
      mid_y = ( ras.y + to_y + 2 * UPSCALE( control->y ) ) / 4;

      return render_line( RAS_VAR_ mid_x, mid_y ) ||
             render_line( RAS_VAR_ to_x, to_y );
    }

    arc       = ras.bez_stack;
    levels    = ras.lev_stack;
    top       = 0;
    levels[0] = level;

    arc[0].x = UPSCALE( to->x );
    arc[0].y = UPSCALE( to->y );
    arc[1].x = UPSCALE( control->x );
    arc[1].y = UPSCALE( control->y );
    arc[2].x = ras.x;
    arc[2].y = ras.y;

    while ( top >= 0 )
    {
      level = levels[top];
      if ( level > 1 )
      {
        /* check that the arc crosses the current band */
        TPos  min, max, y;


        min = max = arc[0].y;

        y = arc[1].y;
        if ( y < min ) min = y;
        if ( y > max ) max = y;

        y = arc[2].y;
        if ( y < min ) min = y;
        if ( y > max ) max = y;

        if ( TRUNC( min ) >= ras.max_ey || TRUNC( max ) < 0 )
          goto Draw;

        split_conic( arc );
        arc += 2;
        top++;
        levels[top] = levels[top - 1] = level - 1;
        continue;
      }

    Draw:
      {
        TPos  to_x, to_y, mid_x, mid_y;


        to_x  = arc[0].x;
        to_y  = arc[0].y;
        mid_x = ( ras.x + to_x + 2 * arc[1].x ) / 4;
        mid_y = ( ras.y + to_y + 2 * arc[1].y ) / 4;

        if ( render_line( RAS_VAR_ mid_x, mid_y ) ||
             render_line( RAS_VAR_ to_x, to_y )   )
          return 1;

        top--;
        arc -= 2;
      }
    }
    return 0;
  }


  static
  void  split_cubic( FT_Vector*  base )
  {
    TPos  a, b, c, d;


    base[6].x = base[3].x;
    c = base[1].x;
    d = base[2].x;
    base[1].x = a = ( base[0].x + c ) / 2;
    base[5].x = b = ( base[3].x + d ) / 2;
    c = ( c + d ) / 2;
    base[2].x = a = ( a + c ) / 2;
    base[4].x = b = ( b + c ) / 2;
    base[3].x = ( a + b ) / 2;

    base[6].y = base[3].y;
    c = base[1].y;
    d = base[2].y;
    base[1].y = a = ( base[0].y + c ) / 2;
    base[5].y = b = ( base[3].y + d ) / 2;
    c = ( c + d ) / 2;
    base[2].y = a = ( a + c ) / 2;
    base[4].y = b = ( b + c ) / 2;
    base[3].y = ( a + b ) / 2;
  }


  static
  int  render_cubic( RAS_ARG_ FT_Vector*  control1,
                              FT_Vector*  control2,
                              FT_Vector*  to )
  {
    TPos        dx, dy, da, db;
    int         top, level;
    int*        levels;
    FT_Vector*  arc;


    dx = DOWNSCALE( ras.x ) + to->x - ( control1->x << 1 );
    if ( dx < 0 )
      dx = -dx;
    dy = DOWNSCALE( ras.y ) + to->y - ( control1->y << 1 );
    if ( dy < 0 )
      dy = -dy;
    if ( dx < dy )
      dx = dy;
    da = dx;

    dx = DOWNSCALE( ras.x ) + to->x - 3 * ( control1->x + control2->x );
    if ( dx < 0 )
      dx = -dx;
    dy = DOWNSCALE( ras.y ) + to->y - 3 * ( control1->x + control2->y );
    if ( dy < 0 )
      dy = -dy;
    if ( dx < dy )
      dx = dy;
    db = dx;

    level = 1;
    da    = da / ras.cubic_level;
    db    = db / ras.conic_level;
    while ( da > 0 || db > 0 )
    {
      da >>= 2;
      db >>= 3;
      level++;
    }

    if ( level <= 1 )
    {
      TPos   to_x, to_y, mid_x, mid_y;


      to_x  = UPSCALE( to->x );
      to_y  = UPSCALE( to->y );
      mid_x = ( ras.x + to_x +
                3 * UPSCALE( control1->x + control2->x ) ) / 8;
      mid_y = ( ras.y + to_y +
                3 * UPSCALE( control1->y + control2->y ) ) / 8;

      return render_line( RAS_VAR_ mid_x, mid_y ) ||
             render_line( RAS_VAR_ to_x, to_y );
    }

    arc      = ras.bez_stack;
    arc[0].x = UPSCALE( to->x );
    arc[0].y = UPSCALE( to->y );
    arc[1].x = UPSCALE( control2->x );
    arc[1].y = UPSCALE( control2->y );
    arc[2].x = UPSCALE( control1->x );
    arc[2].y = UPSCALE( control1->y );
    arc[3].x = ras.x;
    arc[3].y = ras.y;

    levels    = ras.lev_stack;
    top       = 0;
    levels[0] = level;

    while ( top >= 0 )
    {
      level = levels[top];
      if ( level > 1 )
      {
        /* check that the arc crosses the current band */
        TPos  min, max, y;


        min = max = arc[0].y;
        y = arc[1].y;
        if ( y < min ) min = y;
        if ( y > max ) max = y;
        y = arc[2].y;
        if ( y < min ) min = y;
        if ( y > max ) max = y;
        y = arc[3].y;
        if ( y < min ) min = y;
        if ( y > max ) max = y;
        if ( TRUNC( min ) >= ras.max_ey || TRUNC( max ) < 0 )
          goto Draw;
        split_cubic( arc );
        arc += 3;
        top ++;
        levels[top] = levels[top - 1] = level - 1;
        continue;
      }

    Draw:
      {
        TPos  to_x, to_y, mid_x, mid_y;


        to_x  = arc[0].x;
        to_y  = arc[0].y;
        mid_x = ( ras.x + to_x + 3 * ( arc[1].x + arc[2].x ) ) / 8;
        mid_y = ( ras.y + to_y + 3 * ( arc[1].y + arc[2].y ) ) / 8;

        if ( render_line( RAS_VAR_ mid_x, mid_y ) ||
             render_line( RAS_VAR_ to_x, to_y )   )
          return 1;
        top --;
        arc -= 3;
      }
    }
    return 0;
  }


  /* a macro comparing two cell pointers.  Returns true if a <= b. */
#if 1

#define PACK( a )          ( ( (long)(a)->y << 16 ) + (a)->x )
#define LESS_THAN( a, b )  ( PACK( a ) < PACK( b ) )

#else /* 1 */

#define LESS_THAN( a, b )  ( (a)->y < (b)->y || \
                             ( (a)->y == (b)->y && (a)->x < (b)->x ) )

#endif /* 1 */

#define SWAP_CELLS( a, b, temp )  do             \
                                  {              \
                                    temp = *(a); \
                                    *(a) = *(b); \
                                    *(b) = temp; \
                                  } while ( 0 )
#define DEBUG_SORT
#define QUICK_SORT

#ifdef SHELL_SORT

  /* a simple shell sort algorithm that works directly on our */
  /* cells table                                              */
  static
  void  shell_sort ( PCell  cells,