static void
BBox_Cubic_Check( FT_Pos p1,
FT_Pos p2,
FT_Pos p3,
FT_Pos p4,
FT_Pos* min,
FT_Pos* max )
{
FT_Pos nmin, nmax;
FT_Int shift;
/* This function is only called when a control off-point is outside */
/* the bbox that contains all on-points. It finds a local extremum */
/* within the segment using iterative bisection of the segment. */
/* The fixed-point arithmetic of bisection is inherently stable */
/* but may loose accuracy in the two lowest bits. To compensate, */
/* we upscale the segment if there is room. Large values may need */
/* to be downscaled to avoid overflows during bisection. */
/* The control off-point outside the bbox is likely to have the top */
/* absolute value among arguments. */
shift = 27 - FT_MSB( FT_ABS( p2 ) | FT_ABS( p3 ) );
if ( shift > 0 )
{
/* upscaling too much just wastes time */
if ( shift > 2 )
shift = 2;
p1 <<= shift;
p2 <<= shift;
p3 <<= shift;
p4 <<= shift;
nmin = *min << shift;
nmax = *max << shift;
}
else
{
p1 >>= -shift;
p2 >>= -shift;
p3 >>= -shift;
p4 >>= -shift;
nmin = *min >> -shift;
nmax = *max >> -shift;
}
nmax = update_cubic_max( p1, p2, p3, p4, nmax );
/* now flip the signs to update the minimum */
nmin = -update_cubic_max( -p1, -p2, -p3, -p4, -nmin );
if ( shift > 0 )
{
nmin >>= shift;
nmax >>= shift;
}
pfr_face_get_kerning( FT_Face pfrface, /* PFR_Face */
FT_UInt glyph1,
FT_UInt glyph2,
FT_Vector* kerning )
{
PFR_Face face = (PFR_Face)pfrface;
FT_Error error = FT_Err_Ok;
PFR_PhyFont phy_font = &face->phy_font;
FT_UInt32 code1, code2, pair;
kerning->x = 0;
kerning->y = 0;
if ( glyph1 > 0 )
glyph1--;
if ( glyph2 > 0 )
glyph2--;
/* convert glyph indices to character codes */
if ( glyph1 > phy_font->num_chars ||
glyph2 > phy_font->num_chars )
goto Exit;
code1 = phy_font->chars[glyph1].char_code;
code2 = phy_font->chars[glyph2].char_code;
pair = PFR_KERN_INDEX( code1, code2 );
/* now search the list of kerning items */
{
PFR_KernItem item = phy_font->kern_items;
FT_Stream stream = pfrface->stream;
for ( ; item; item = item->next )
{
if ( pair >= item->pair1 && pair <= item->pair2 )
goto FoundPair;
}
goto Exit;
FoundPair: /* we found an item, now parse it and find the value if any */
if ( FT_STREAM_SEEK( item->offset ) ||
FT_FRAME_ENTER( item->pair_count * item->pair_size ) )
goto Exit;
{
FT_UInt count = item->pair_count;
FT_UInt size = item->pair_size;
FT_UInt power = 1 << FT_MSB( count );
FT_UInt probe = power * size;
FT_UInt extra = count - power;
FT_Byte* base = stream->cursor;
FT_Bool twobytes = FT_BOOL( item->flags & 1 );
FT_Bool twobyte_adj = FT_BOOL( item->flags & 2 );
FT_Byte* p;
FT_UInt32 cpair;
if ( extra > 0 )
{
p = base + extra * size;
if ( twobytes )
cpair = FT_NEXT_ULONG( p );
else
cpair = PFR_NEXT_KPAIR( p );
if ( cpair == pair )
goto Found;
if ( cpair < pair )
{
if ( twobyte_adj )
p += 2;
else
p++;
base = p;
}
}
while ( probe > size )
{
probe >>= 1;
p = base + probe;
if ( twobytes )
cpair = FT_NEXT_ULONG( p );
else
cpair = PFR_NEXT_KPAIR( p );
if ( cpair == pair )
goto Found;
if ( cpair < pair )
base += probe;
}
p = base;
if ( twobytes )
cpair = FT_NEXT_ULONG( p );
else
cpair = PFR_NEXT_KPAIR( p );
if ( cpair == pair )
{
FT_Int value;
Found:
if ( twobyte_adj )
value = FT_PEEK_SHORT( p );
else
value = p[0];
kerning->x = item->base_adj + value;
}
}
FT_FRAME_EXIT();
}
Exit:
return error;
}
static void
BBox_Cubic_Check( FT_Pos y1,
FT_Pos y2,
FT_Pos y3,
FT_Pos y4,
FT_Pos* min,
FT_Pos* max )
{
/* always compare first and last points */
if ( y1 < *min ) *min = y1;
else if ( y1 > *max ) *max = y1;
if ( y4 < *min ) *min = y4;
else if ( y4 > *max ) *max = y4;
/* now, try to see if there are split points here */
if ( y1 <= y4 )
{
/* flat or ascending arc test */
if ( y1 <= y2 && y2 <= y4 && y1 <= y3 && y3 <= y4 )
return;
}
else /* y1 > y4 */
{
/* descending arc test */
if ( y1 >= y2 && y2 >= y4 && y1 >= y3 && y3 >= y4 )
return;
}
/* There are some split points. Find them. */
/* We already made sure that a, b, and c below cannot be all zero. */
{
FT_Pos a = y4 - 3*y3 + 3*y2 - y1;
FT_Pos b = y3 - 2*y2 + y1;
FT_Pos c = y2 - y1;
FT_Pos d;
FT_Fixed t;
FT_Int shift;
/* We need to solve `ax^2+2bx+c' here, without floating points! */
/* The trick is to normalize to a different representation in order */
/* to use our 16.16 fixed-point routines. */
/* */
/* We compute FT_MulFix(b,b) and FT_MulFix(a,c) after normalization. */
/* These values must fit into a single 16.16 value. */
/* */
/* We normalize a, b, and c to `8.16' fixed-point values to ensure */
/* that their product is held in a `16.16' value including the sign. */
/* Necessarily, we need to shift `a', `b', and `c' so that the most */
/* significant bit of their absolute values is at position 22. */
/* */
/* This also means that we are using 23 bits of precision to compute */
/* the zeros, independently of the range of the original polynomial */
/* coefficients. */
/* */
/* This algorithm should ensure reasonably accurate values for the */
/* zeros. Note that they are only expressed with 16 bits when */
/* computing the extrema (the zeros need to be in 0..1 exclusive */
/* to be considered part of the arc). */
shift = FT_MSB( FT_ABS( a ) | FT_ABS( b ) | FT_ABS( c ) );
if ( shift > 22 )
{
shift -= 22;
/* this loses some bits of precision, but we use 23 of them */
/* for the computation anyway */
a >>= shift;
b >>= shift;
c >>= shift;
}
else
{
af_loader_compute_darkening( AF_Loader loader,
FT_Face face,
FT_Pos standard_width )
{
AF_Module module = loader->globals->module;
FT_UShort units_per_EM;
FT_Fixed ppem, em_ratio;
FT_Fixed stem_width, stem_width_per_1000, scaled_stem, darken_amount;
FT_Int log_base_2;
FT_Int x1, y1, x2, y2, x3, y3, x4, y4;
ppem = FT_MAX( af_intToFixed( 4 ),
af_intToFixed( face->size->metrics.x_ppem ) );
units_per_EM = face->units_per_EM;
em_ratio = FT_DivFix( af_intToFixed( 1000 ),
af_intToFixed ( units_per_EM ) );
if ( em_ratio < af_floatToFixed( .01 ) )
{
/* If something goes wrong, don't embolden. */
return 0;
}
x1 = module->darken_params[0];
y1 = module->darken_params[1];
x2 = module->darken_params[2];
y2 = module->darken_params[3];
x3 = module->darken_params[4];
y3 = module->darken_params[5];
x4 = module->darken_params[6];
y4 = module->darken_params[7];
if ( standard_width <= 0 )
{
stem_width = af_intToFixed( 75 ); /* taken from cf2font.c */
stem_width_per_1000 = stem_width;
}
else
{
stem_width = af_intToFixed( standard_width );
stem_width_per_1000 = FT_MulFix( stem_width, em_ratio );
}
log_base_2 = FT_MSB( (FT_UInt32)stem_width_per_1000 ) +
FT_MSB( (FT_UInt32)ppem );
if ( log_base_2 >= 46 )
{
/* possible overflow */
scaled_stem = af_intToFixed( x4 );
}
else
scaled_stem = FT_MulFix( stem_width_per_1000, ppem );
/* now apply the darkening parameters */
if ( scaled_stem < af_intToFixed( x1 ) )
darken_amount = FT_DivFix( af_intToFixed( y1 ), ppem );
else if ( scaled_stem < af_intToFixed( x2 ) )
{
FT_Int xdelta = x2 - x1;
FT_Int ydelta = y2 - y1;
FT_Int x = stem_width_per_1000 -
FT_DivFix( af_intToFixed( x1 ), ppem );
if ( !xdelta )
goto Try_x3;
darken_amount = FT_MulDiv( x, ydelta, xdelta ) +
FT_DivFix( af_intToFixed( y1 ), ppem );
}
else if ( scaled_stem < af_intToFixed( x3 ) )
{
Try_x3:
{
FT_Int xdelta = x3 - x2;
FT_Int ydelta = y3 - y2;
FT_Int x = stem_width_per_1000 -
FT_DivFix( af_intToFixed( x2 ), ppem );
if ( !xdelta )
goto Try_x4;
darken_amount = FT_MulDiv( x, ydelta, xdelta ) +
FT_DivFix( af_intToFixed( y2 ), ppem );
}
}
else if ( scaled_stem < af_intToFixed( x4 ) )
{
Try_x4:
{
FT_Int xdelta = x4 - x3;
FT_Int ydelta = y4 - y3;
FT_Int x = stem_width_per_1000 -
FT_DivFix( af_intToFixed( x3 ), ppem );
if ( !xdelta )
goto Use_y4;
darken_amount = FT_MulDiv( x, ydelta, xdelta ) +
FT_DivFix( af_intToFixed( y3 ), ppem );
}
}
else
{
Use_y4:
darken_amount = FT_DivFix( af_intToFixed( y4 ), ppem );
}
/* Convert darken_amount from per 1000 em to true character space. */
return af_fixedToInt( FT_DivFix( darken_amount, em_ratio ) );
}
FT_Outline_Get_Orientation( FT_Outline* outline )
{
FT_BBox cbox;
FT_Int xshift, yshift;
FT_Vector* points;
FT_Vector v_prev, v_cur;
FT_Int c, n, first;
FT_Pos area = 0;
if ( !outline || outline->n_points <= 0 )
return FT_ORIENTATION_TRUETYPE;
/* We use the nonzero winding rule to find the orientation. */
/* Since glyph outlines behave much more `regular' than arbitrary */
/* cubic or quadratic curves, this test deals with the polygon */
/* only that is spanned up by the control points. */
FT_Outline_Get_CBox( outline, &cbox );
/* Handle collapsed outlines to avoid undefined FT_MSB. */
if ( cbox.xMin == cbox.xMax || cbox.yMin == cbox.yMax )
return FT_ORIENTATION_NONE;
xshift = FT_MSB( (FT_UInt32)( FT_ABS( cbox.xMax ) |
FT_ABS( cbox.xMin ) ) ) - 14;
xshift = FT_MAX( xshift, 0 );
yshift = FT_MSB( (FT_UInt32)( cbox.yMax - cbox.yMin ) ) - 14;
yshift = FT_MAX( yshift, 0 );
points = outline->points;
first = 0;
for ( c = 0; c < outline->n_contours; c++ )
{
FT_Int last = outline->contours[c];
v_prev.x = points[last].x >> xshift;
v_prev.y = points[last].y >> yshift;
for ( n = first; n <= last; n++ )
{
v_cur.x = points[n].x >> xshift;
v_cur.y = points[n].y >> yshift;
area = ADD_LONG( area,
( v_cur.y - v_prev.y ) * ( v_cur.x + v_prev.x ) );
v_prev = v_cur;
}
first = last + 1;
}
if ( area > 0 )
return FT_ORIENTATION_POSTSCRIPT;
else if ( area < 0 )
return FT_ORIENTATION_TRUETYPE;
else
return FT_ORIENTATION_NONE;
}
/* Compute a stem darkening amount in character space. */
static void
cf2_computeDarkening( CF2_Fixed emRatio,
CF2_Fixed ppem,
CF2_Fixed stemWidth,
CF2_Fixed* darkenAmount,
CF2_Fixed boldenAmount,
FT_Bool stemDarkened,
FT_Int* darkenParams )
{
/*
* Total darkening amount is computed in 1000 unit character space
* using the modified 5 part curve as Adobe's Avalon rasterizer.
* The darkening amount is smaller for thicker stems.
* It becomes zero when the stem is thicker than 2.333 pixels.
*
* By default, we use
*
* darkenAmount = 0.4 pixels if scaledStem <= 0.5 pixels,
* darkenAmount = 0.275 pixels if 1 <= scaledStem <= 1.667 pixels,
* darkenAmount = 0 pixel if scaledStem >= 2.333 pixels,
*
* and piecewise linear in-between:
*
*
* darkening
* ^
* |
* | (x1,y1)
* |--------+
* | \
* | \
* | \ (x3,y3)
* | +----------+
* | (x2,y2) \
* | \
* | \
* | +-----------------
* | (x4,y4)
* +---------------------------------------------> stem
* thickness
*
*
* This corresponds to the following values for the
* `darkening-parameters' property:
*
* (x1, y1) = (500, 400)
* (x2, y2) = (1000, 275)
* (x3, y3) = (1667, 275)
* (x4, y4) = (2333, 0)
*
*/
/* Internal calculations are done in units per thousand for */
/* convenience. The x axis is scaled stem width in */
/* thousandths of a pixel. That is, 1000 is 1 pixel. */
/* The y axis is darkening amount in thousandths of a pixel.*/
/* In the code, below, dividing by ppem and */
/* adjusting for emRatio converts darkenAmount to character */
/* space (font units). */
CF2_Fixed stemWidthPer1000, scaledStem;
FT_Int logBase2;
*darkenAmount = 0;
if ( boldenAmount == 0 && !stemDarkened )
return;
/* protect against range problems and divide by zero */
if ( emRatio < cf2_floatToFixed( .01 ) )
return;
if ( stemDarkened )
{
FT_Int x1 = darkenParams[0];
FT_Int y1 = darkenParams[1];
FT_Int x2 = darkenParams[2];
FT_Int y2 = darkenParams[3];
FT_Int x3 = darkenParams[4];
FT_Int y3 = darkenParams[5];
FT_Int x4 = darkenParams[6];
FT_Int y4 = darkenParams[7];
/* convert from true character space to 1000 unit character space; */
/* add synthetic emboldening effect */
/* `stemWidthPer1000' will not overflow for a legitimate font */
stemWidthPer1000 = FT_MulFix( stemWidth + boldenAmount, emRatio );
/* `scaledStem' can easily overflow, so we must clamp its maximum */
/* value; the test doesn't need to be precise, but must be */
/* conservative. The clamp value (default 2333) where */
/* `darkenAmount' is zero is well below the overflow value of */
/* 32767. */
/* */
/* FT_MSB computes the integer part of the base 2 logarithm. The */
/* number of bits for the product is 1 or 2 more than the sum of */
/* logarithms; remembering that the 16 lowest bits of the fraction */
/* are dropped this is correct to within a factor of almost 4. */
/* For example, 0x80.0000 * 0x80.0000 = 0x4000.0000 is 23+23 and */
/* is flagged as possible overflow because 0xFF.FFFF * 0xFF.FFFF = */
/* 0xFFFF.FE00 is also 23+23. */
logBase2 = FT_MSB( (FT_UInt32)stemWidthPer1000 ) +
FT_MSB( (FT_UInt32)ppem );
if ( logBase2 >= 46 )
/* possible overflow */
scaledStem = cf2_intToFixed( x4 );
else
scaledStem = FT_MulFix( stemWidthPer1000, ppem );
/* now apply the darkening parameters */
if ( scaledStem < cf2_intToFixed( x1 ) )
*darkenAmount = FT_DivFix( cf2_intToFixed( y1 ), ppem );
else if ( scaledStem < cf2_intToFixed( x2 ) )
{
FT_Int xdelta = x2 - x1;
FT_Int ydelta = y2 - y1;
FT_Int x = stemWidthPer1000 -
FT_DivFix( cf2_intToFixed( x1 ), ppem );
if ( !xdelta )
goto Try_x3;
*darkenAmount = FT_MulDiv( x, ydelta, xdelta ) +
FT_DivFix( cf2_intToFixed( y1 ), ppem );
}
else if ( scaledStem < cf2_intToFixed( x3 ) )
{
Try_x3:
{
FT_Int xdelta = x3 - x2;
FT_Int ydelta = y3 - y2;
FT_Int x = stemWidthPer1000 -
FT_DivFix( cf2_intToFixed( x2 ), ppem );
if ( !xdelta )
goto Try_x4;
*darkenAmount = FT_MulDiv( x, ydelta, xdelta ) +
FT_DivFix( cf2_intToFixed( y2 ), ppem );
}
}
else if ( scaledStem < cf2_intToFixed( x4 ) )
{
Try_x4:
{
FT_Int xdelta = x4 - x3;
FT_Int ydelta = y4 - y3;
FT_Int x = stemWidthPer1000 -
FT_DivFix( cf2_intToFixed( x3 ), ppem );
if ( !xdelta )
goto Use_y4;
*darkenAmount = FT_MulDiv( x, ydelta, xdelta ) +
FT_DivFix( cf2_intToFixed( y3 ), ppem );
}
}
else
{
Use_y4:
*darkenAmount = FT_DivFix( cf2_intToFixed( y4 ), ppem );
}
/* use half the amount on each side and convert back to true */
/* character space */
*darkenAmount = FT_DivFix( *darkenAmount, 2 * emRatio );
}
/* add synthetic emboldening effect in character space */
*darkenAmount += boldenAmount / 2;
}
