|
|
|
|
@ -4,7 +4,7 @@ |
|
|
|
|
/* */ |
|
|
|
|
/* PostScript hinting algorithm 3 (body). */ |
|
|
|
|
/* */ |
|
|
|
|
/* Copyright 2001, 2002 by */ |
|
|
|
|
/* Copyright 2001, 2002, 2003 by */ |
|
|
|
|
/* David Turner, Robert Wilhelm, and Werner Lemberg. */ |
|
|
|
|
/* */ |
|
|
|
|
/* This file is part of the FreeType project, and may only be used */ |
|
|
|
|
@ -458,9 +458,9 @@ |
|
|
|
|
return; |
|
|
|
|
} |
|
|
|
|
|
|
|
|
|
/* perform stem snapping when requested - this is necessary
|
|
|
|
|
* for monochrome and LCD hinting modes only |
|
|
|
|
*/ |
|
|
|
|
/* perform stem snapping when requested - this is necessary
|
|
|
|
|
* for monochrome and LCD hinting modes only |
|
|
|
|
*/ |
|
|
|
|
do_snapping = ( dimension == 0 && glyph->do_horz_snapping ) || |
|
|
|
|
( dimension == 1 && glyph->do_vert_snapping ); |
|
|
|
|
|
|
|
|
|
@ -520,22 +520,22 @@ |
|
|
|
|
hint->cur_pos = pos; |
|
|
|
|
hint->cur_len = fit_len; |
|
|
|
|
|
|
|
|
|
/* stem adjustment tries to snap stem widths to standard
|
|
|
|
|
* ones. this is important to prevent unpleasant rounding |
|
|
|
|
* artefacts... |
|
|
|
|
*/ |
|
|
|
|
/* Stem adjustment tries to snap stem widths to standard
|
|
|
|
|
* ones. This is important to prevent unpleasant rounding |
|
|
|
|
* artefacts. |
|
|
|
|
*/ |
|
|
|
|
if ( glyph->do_stem_adjust ) |
|
|
|
|
{ |
|
|
|
|
if ( len <= 64 ) |
|
|
|
|
{ |
|
|
|
|
/* the stem is less than one pixel, we will center it
|
|
|
|
|
* around the nearest pixel center |
|
|
|
|
*/ |
|
|
|
|
/* the stem is less than one pixel; we will center it
|
|
|
|
|
* around the nearest pixel center |
|
|
|
|
*/ |
|
|
|
|
#if 1 |
|
|
|
|
pos = ( pos + (len >> 1) ) & -64; |
|
|
|
|
pos = ( pos + ( len >> 1 ) ) & -64; |
|
|
|
|
#else |
|
|
|
|
/* this seems to be a bug !! */ |
|
|
|
|
pos = ( pos + ( (len >> 1) & -64 ) ); |
|
|
|
|
/* this seems to be a bug! */ |
|
|
|
|
pos = ( pos + ( ( len >> 1 ) & -64 ) ); |
|
|
|
|
#endif |
|
|
|
|
len = 64; |
|
|
|
|
} |
|
|
|
|
@ -626,6 +626,7 @@ |
|
|
|
|
|
|
|
|
|
PSH_AlignmentRec align; |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
/* ignore stem alignments when requested through the hint flags */ |
|
|
|
|
if ( ( dimension == 0 && !glyph->do_horz_hints ) || |
|
|
|
|
( dimension == 1 && !glyph->do_vert_hints ) ) |
|
|
|
|
@ -684,53 +685,55 @@ |
|
|
|
|
if ( !psh3_hint_is_fitted( parent ) ) |
|
|
|
|
psh3_hint_align_light( parent, globals, dimension, glyph ); |
|
|
|
|
|
|
|
|
|
par_org_center = parent->org_pos + ( parent->org_len / 2); |
|
|
|
|
par_cur_center = parent->cur_pos + ( parent->cur_len / 2); |
|
|
|
|
cur_org_center = hint->org_pos + ( hint->org_len / 2); |
|
|
|
|
par_org_center = parent->org_pos + ( parent->org_len / 2 ); |
|
|
|
|
par_cur_center = parent->cur_pos + ( parent->cur_len / 2 ); |
|
|
|
|
cur_org_center = hint->org_pos + ( hint->org_len / 2 ); |
|
|
|
|
|
|
|
|
|
cur_delta = FT_MulFix( cur_org_center - par_org_center, scale ); |
|
|
|
|
pos = par_cur_center + cur_delta - ( len >> 1 ); |
|
|
|
|
} |
|
|
|
|
|
|
|
|
|
/* Stems less than one pixel wide are easy - we want to
|
|
|
|
|
* make them as dark as possible, so they must fall within |
|
|
|
|
* one pixel. If the stem is split between two pixels |
|
|
|
|
* then snap the edge that is nearer to the pixel boundary |
|
|
|
|
* to the pixel boundary |
|
|
|
|
*/ |
|
|
|
|
if (len <= 64) |
|
|
|
|
/* Stems less than one pixel wide are easy -- we want to
|
|
|
|
|
* make them as dark as possible, so they must fall within |
|
|
|
|
* one pixel. If the stem is split between two pixels |
|
|
|
|
* then snap the edge that is nearer to the pixel boundary |
|
|
|
|
* to the pixel boundary. |
|
|
|
|
*/ |
|
|
|
|
if ( len <= 64 ) |
|
|
|
|
{ |
|
|
|
|
if ( ( pos + len + 63 ) / 64 != pos / 64 + 1 ) |
|
|
|
|
pos += psh3_hint_snap_stem_side_delta ( pos, len ); |
|
|
|
|
} |
|
|
|
|
/* Position stems other to minimize the amount of mid-grays.
|
|
|
|
|
* There are, in general, two positions that do this, |
|
|
|
|
* illustrated as A) and B) below. |
|
|
|
|
* |
|
|
|
|
* + + + + |
|
|
|
|
* |
|
|
|
|
* A) |--------------------------------| |
|
|
|
|
* B) |--------------------------------| |
|
|
|
|
* C) |--------------------------------| |
|
|
|
|
* |
|
|
|
|
* Position A) (split the excess stem equally) should be better |
|
|
|
|
* for stems of width N + f where f < 0.5 |
|
|
|
|
* |
|
|
|
|
* Position B) (split the deficiency equally) should be better |
|
|
|
|
* for stems of width N + f where f > 0.5 |
|
|
|
|
* |
|
|
|
|
* It turns out though that minimizing the total number of lit |
|
|
|
|
* pixels is also important, so position C), with one edge |
|
|
|
|
* aligned with a pixel boundary is actually preferable |
|
|
|
|
* to A). There are also more possibile positions for C) than |
|
|
|
|
* for A) or B), so it involves less distortion of the overall |
|
|
|
|
* character shape. |
|
|
|
|
*/ |
|
|
|
|
|
|
|
|
|
/* Position stems other to minimize the amount of mid-grays.
|
|
|
|
|
* There are, in general, two positions that do this, |
|
|
|
|
* illustrated as A) and B) below. |
|
|
|
|
* |
|
|
|
|
* + + + + |
|
|
|
|
* |
|
|
|
|
* A) |--------------------------------| |
|
|
|
|
* B) |--------------------------------| |
|
|
|
|
* C) |--------------------------------| |
|
|
|
|
* |
|
|
|
|
* Position A) (split the excess stem equally) should be better |
|
|
|
|
* for stems of width N + f where f < 0.5. |
|
|
|
|
* |
|
|
|
|
* Position B) (split the deficiency equally) should be better |
|
|
|
|
* for stems of width N + f where f > 0.5. |
|
|
|
|
* |
|
|
|
|
* It turns out though that minimizing the total number of lit |
|
|
|
|
* pixels is also important, so position C), with one edge |
|
|
|
|
* aligned with a pixel boundary is actually preferable |
|
|
|
|
* to A). There are also more possibile positions for C) than |
|
|
|
|
* for A) or B), so it involves less distortion of the overall |
|
|
|
|
* character shape. |
|
|
|
|
*/ |
|
|
|
|
else /* len > 64 */ |
|
|
|
|
{ |
|
|
|
|
FT_Fixed frac_len = len & 63; |
|
|
|
|
FT_Fixed center = pos + ( len >> 1 ); |
|
|
|
|
FT_Fixed delta_a, delta_b; |
|
|
|
|
FT_Fixed frac_len = len & 63; |
|
|
|
|
FT_Fixed center = pos + ( len >> 1 ); |
|
|
|
|
FT_Fixed delta_a, delta_b; |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
if ( ( len / 64 ) & 1 ) |
|
|
|
|
{ |
|
|
|
|
@ -743,18 +746,20 @@ |
|
|
|
|
delta_b = ( center & -64 ) + 32 - center; |
|
|
|
|
} |
|
|
|
|
|
|
|
|
|
/* We choose between B) and C) above based on the amount
|
|
|
|
|
* of fractinal stem width; for small amounts, choose |
|
|
|
|
* C) always, for large amounts, B) always, and inbetween, |
|
|
|
|
* pick whichever one involves less stem movement. |
|
|
|
|
*/ |
|
|
|
|
if (frac_len < 32) |
|
|
|
|
/* We choose between B) and C) above based on the amount
|
|
|
|
|
* of fractinal stem width; for small amounts, choose |
|
|
|
|
* C) always, for large amounts, B) always, and inbetween, |
|
|
|
|
* pick whichever one involves less stem movement. |
|
|
|
|
*/ |
|
|
|
|
if ( frac_len < 32 ) |
|
|
|
|
{ |
|
|
|
|
pos += psh3_hint_snap_stem_side_delta ( pos, len ); |
|
|
|
|
} |
|
|
|
|
else if (frac_len < 48) |
|
|
|
|
else if ( frac_len < 48 ) |
|
|
|
|
{ |
|
|
|
|
FT_Fixed side_delta = psh3_hint_snap_stem_side_delta ( pos, len ); |
|
|
|
|
FT_Fixed side_delta = psh3_hint_snap_stem_side_delta ( pos, |
|
|
|
|
len ); |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
if ( ABS( side_delta ) < ABS( delta_b ) ) |
|
|
|
|
pos += side_delta; |
|
|
|
|
|
Werner Lemberg
22 years ago