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[ft-devel] [Patch] CJK autofit/autohint blue zones
|
From: |
JustFillBug |
|
Subject: |
[ft-devel] [Patch] CJK autofit/autohint blue zones |
|
Date: |
Sat, 8 Jan 2011 05:13:29 +0000 (UTC) |
|
User-agent: |
slrn/pre1.0.0-18 (Linux) |
The CJK autofit module in freetype2 does not do blue zone management.
Therefore CJK glyphs always have uneven bottom at small point size.
Since I always use 16pt or larger font, it won't bother me. But there
are complains about the mis-aligned glyph bottom in small point size
from time to time.
I took a look at the problem lately and ported the latin blue zone
routines to the CJK module.
The CJK blue zone code was turned off in the indic module as the code
made use of some CJK specific characters.
What specific to CJK is that many CJK fonts use glyphs with similiar
width too. So the blue zone concept also applys horizontally.
In addition, the overshoot of round edge in latin became undershoot of
flat stroke against the end of vertical stroke in CJK. (like T vs. L)
So 4 set of top/bottom/left/right blue zones are detected. Each set has
both fill and unfill character lists to reflect normal and undershoot
characters.
Issues:
=======
The way the edges are detected in CJK autofitter is different from Latin
autofitter. As can be seem using fontforge autofit function.
In Latin code, there are 'single' edges which do not pair with any other
edges. While in CJK fitter, the 'single' edges are lost. So the bottom
edge on stroke like Y will not be detected by the CJK fitter.
As a result, the termnial edges of stems cannot be aligned since the
edge is not detected. There are no problem to aligned along the stem
directions, i.e. the bottom edge of lower horizontal stem are aligned
properly.
Data:
=====
The character used to calculate blue zones are some high freqeuncy
Chinese characters which reflect the needed feature.
Maybe some frequently used Japanese and Korean Hanzi should be added
too.
The characters picked are:
top:
address@hidden
军同已愿既星是景民照现�F理用置要��那配里�_雷露面顾
bottom:
个为人他以们你������到和大对��就我时�r有来�橐��f说
主些因它想意理生��看着置者自著�e过还进�M�^道��里面
left:
address@hidden
即吗吧听呢品响�崾���收断�嗝餮坶g间际陈限除��随�H�S
right:
事前�W将�⑶橄牖蛘�斯新样�用��]没然特现�F球第��谁起
例�e别制动�勇��嵩鲋该鞒�期构物确种�{调�M费那都�g间
To view debug log, you need to define AF_DEBUG and turn on _af_debug in
autofit/afmodule.c
src/autofit/afcjk.c | 698 ++++++++++++++++++++++++++++++++++++++++++++++--
src/autofit/afcjk.h | 78 +++++-
src/autofit/afindic.c | 35 ++-
3 files changed, 779 insertions(+), 32 deletions(-)
diff --git a/builds/unix/install-sh b/builds/unix/install-sh
old mode 100644
new mode 100755
diff --git a/src/autofit/afcjk.c b/src/autofit/afcjk.c
index f3b1067..466c769 100644
--- a/src/autofit/afcjk.c
+++ b/src/autofit/afcjk.c
@@ -45,8 +45,456 @@
/*************************************************************************/
/*************************************************************************/
+ /* Basically the Latin version with AF_CJKMetrics to replace AF_LatinMetrics
*/
+ FT_LOCAL_DEF( void )
+ af_cjk_metrics_init_widths( AF_CJKMetrics metrics,
+ FT_Face face,
+ FT_ULong charcode )
+ {
+ /* scan the array of segments in each direction */
+ AF_GlyphHintsRec hints[1];
+
+
+ af_glyph_hints_init( hints, face->memory );
+
+ metrics->axis[AF_DIMENSION_HORZ].width_count = 0;
+ metrics->axis[AF_DIMENSION_VERT].width_count = 0;
+
+ {
+ FT_Error error;
+ FT_UInt glyph_index;
+ int dim;
+ AF_CJKMetricsRec dummy[1];
+ AF_Scaler scaler = &dummy->root.scaler;
+
+
+ glyph_index = FT_Get_Char_Index( face, charcode );
+ if ( glyph_index == 0 )
+ goto Exit;
+
+ error = FT_Load_Glyph( face, glyph_index, FT_LOAD_NO_SCALE );
+ if ( error || face->glyph->outline.n_points <= 0 )
+ goto Exit;
+
+ FT_ZERO( dummy );
+
+ dummy->units_per_em = metrics->units_per_em;
+ scaler->x_scale = scaler->y_scale = 0x10000L;
+ scaler->x_delta = scaler->y_delta = 0;
+ scaler->face = face;
+ scaler->render_mode = FT_RENDER_MODE_NORMAL;
+ scaler->flags = 0;
+
+ af_glyph_hints_rescale( hints, (AF_ScriptMetrics)dummy );
+
+ error = af_glyph_hints_reload( hints, &face->glyph->outline );
+ if ( error )
+ goto Exit;
+
+ for ( dim = 0; dim < AF_DIMENSION_MAX; dim++ )
+ {
+ AF_CJKAxis axis = &metrics->axis[dim];
+ AF_AxisHints axhints = &hints->axis[dim];
+ AF_Segment seg, limit, link;
+ FT_UInt num_widths = 0;
+
+
+ error = af_latin_hints_compute_segments( hints,
+ (AF_Dimension)dim );
+ if ( error )
+ goto Exit;
+
+ af_latin_hints_link_segments( hints,
+ (AF_Dimension)dim );
+
+ seg = axhints->segments;
+ limit = seg + axhints->num_segments;
+
+ for ( ; seg < limit; seg++ )
+ {
+ link = seg->link;
+
+ /* we only consider stem segments there! */
+ if ( link && link->link == seg && link > seg )
+ {
+ FT_Pos dist;
+
+
+ dist = seg->pos - link->pos;
+ if ( dist < 0 )
+ dist = -dist;
+
+ if ( num_widths < AF_CJK_MAX_WIDTHS )
+ axis->widths[ num_widths++ ].org = dist;
+ }
+ }
+
+ af_sort_widths( num_widths, axis->widths );
+ axis->width_count = num_widths;
+ }
+
+ Exit:
+ for ( dim = 0; dim < AF_DIMENSION_MAX; dim++ )
+ {
+ AF_CJKAxis axis = &metrics->axis[dim];
+ FT_Pos stdw;
+
+
+ stdw = ( axis->width_count > 0 )
+ ? axis->widths[0].org
+ : AF_LATIN_CONSTANT( metrics, 50 );
+
+ /* let's try 20% of the smallest width */
+ axis->edge_distance_threshold = stdw / 5;
+ axis->standard_width = stdw;
+ axis->extra_light = 0;
+ }
+ }
+
+ af_glyph_hints_done( hints );
+ }
+
+
+
+#define AF_CJK_MAX_TEST_CHARACTERS 32
+
+
+ /* Every blue zone has 2 types of fill and unfill,
+ * Which means fill the entire square or not.
+ * */
+ enum
+ {
+ AF_CJK_BLUE_TYPE_FILL,
+ AF_CJK_BLUE_TYPE_UNFILL,
+ AF_CJK_BLUE_TYPE_MAX
+ };
+
+ /* Put some common and representative CJK characters here. */
+ static const FT_ULong af_cjk_blue_chars[AF_CJK_BLUE_MAX]
+ [AF_CJK_BLUE_TYPE_MAX]
+ [AF_CJK_MAX_TEST_CHARACTERS] =
+ {
+ {
+ {
+ 0X4ED6, 0X4EEC, 0X4F60, 0X4F86, 0X5011, 0X5230, 0X548C, 0X5730,
+ 0X5BF9, 0X5C0D, 0X5C31, 0X5E2D, 0X6211, 0X65F6, 0X6642, 0X6703,
+ 0X6765, 0X70BA, 0X80FD, 0X8230, 0X8AAA, 0X8BF4, 0X8FD9, 0X9019,
+ 0X9F4A /* top fill */
+ },
+ {
+ 0X519B, 0X540C, 0X5DF2, 0X613F, 0X65E2, 0X661F, 0X662F, 0X666F,
+ 0X6C11, 0X7167, 0X73B0, 0X73FE, 0X7406, 0X7528, 0X7F6E, 0X8981,
+ 0X8ECD, 0X90A3, 0X914D, 0X91CC, 0X958B, 0X96F7, 0X9732, 0X9762,
+ 0X987E /* top unfill */
+ }
+ },
+ {
+ {
+ 0X4E2A, 0X4E3A, 0X4EBA, 0X4ED6, 0X4EE5, 0X4EEC, 0X4F60, 0X4F86,
+ 0X500B, 0X5011, 0X5230, 0X548C, 0X5927, 0X5BF9, 0X5C0D, 0X5C31,
+ 0X6211, 0X65F6, 0X6642, 0X6709, 0X6765, 0X70BA, 0X8981, 0X8AAA,
+ 0X8BF4 /* bottom fill */
+ },
+ {
+ 0X4E3B, 0X4E9B, 0X56E0, 0X5B83, 0X60F3, 0X610F, 0X7406, 0X751F,
+ 0X7576, 0X770B, 0X7740, 0X7F6E, 0X8005, 0X81EA, 0X8457, 0X88E1,
+ 0X8FC7, 0X8FD8, 0X8FDB, 0X9032, 0X904E, 0X9053, 0X9084, 0X91CC,
+ 0X9762 /* bottom unfill */
+ }
+ },
+ {
+ {
+ 0X4E9B, 0X4EEC, 0X4F60, 0X4F86, 0X5011, 0X5230, 0X548C, 0X5730,
+ 0X5979, 0X5C06, 0X5C07, 0X5C31, 0X5E74, 0X5F97, 0X60C5, 0X6700,
+ 0X6837, 0X6A23, 0X7406, 0X80FD, 0X8AAA, 0X8BF4, 0X8FD9, 0X9019,
+ 0X90A /* left fill */
+ },
+ {
+ 0X5373, 0X5417, 0X5427, 0X542C, 0X5462, 0X54C1, 0X54CD, 0X55CE,
+ 0X5E08, 0X5E2B, 0X6536, 0X65AD, 0X65B7, 0X660E, 0X773C, 0X9593,
+ 0X95F4, 0X9645, 0X9648, 0X9650, 0X9664, 0X9673, 0X968F, 0X969B,
+ 0X96A8 /* left unfill */
+ }
+ },
+ {
+ {
+ 0X4E8B, 0X524D, 0X5B78, 0X5C06, 0X5C07, 0X60C5, 0X60F3, 0X6216,
+ 0X653F, 0X65AF, 0X65B0, 0X6837, 0X6A23, 0X6C11, 0X6C92, 0X6CA1,
+ 0X7136, 0X7279, 0X73B0, 0X73FE, 0X7403, 0X7B2C, 0X7D93, 0X8C01,
+ 0X8D77 /* right fill */
+ },
+ {
+ 0X4F8B, 0X5225, 0X522B, 0X5236, 0X52A8, 0X52D5, 0X5417, 0X55CE,
+ 0X589E, 0X6307, 0X660E, 0X671D, 0X671F, 0X6784, 0X7269, 0X786E,
+ 0X79CD, 0X8ABF, 0X8C03, 0X8CBB, 0X8D39, 0X90A3, 0X90FD, 0X9593,
+ 0X95F4 /* right unfill */
+ }
+ }
+ };
+
+
+ /* Calculate blue zones for all the CJK_BLUE_XXX's */
+ static void
+ af_cjk_metrics_init_blues( AF_CJKMetrics metrics,
+ FT_Face face,
+ const FT_ULong blue_chars[AF_CJK_BLUE_MAX]
+ [AF_CJK_BLUE_TYPE_MAX]
+ [AF_CJK_MAX_TEST_CHARACTERS] )
+ {
+ FT_Pos fills[AF_CJK_MAX_TEST_CHARACTERS];
+ FT_Pos flats [AF_CJK_MAX_TEST_CHARACTERS];
+ FT_Int num_fills;
+ FT_Int num_flats;
+ FT_Int bb;
+ AF_CJKBlue blue;
+ FT_Error error;
+ AF_CJKAxis axis;
+ FT_GlyphSlot glyph = face->glyph;
+
+ /* we compute the blues simply by loading each character from the */
+ /* 'blue_chars[blues]' string, then compute its extreme */
+ /* points (depending blue zone type etc.) */
+
+ AF_LOG(( "cjk blue zones computation\n" ));
+ AF_LOG(( "------------------------------------------------\n" ));
+
+ for ( bb = 0; bb < AF_CJK_BLUE_MAX; bb++ )
+ {
+ FT_Int fill_type;
+ FT_Pos* blue_ref;
+ FT_Pos* blue_shoot;
+
+
+ num_fills = 0;
+ num_flats = 0;
+ for ( fill_type = 0 ; fill_type < AF_CJK_BLUE_TYPE_MAX; fill_type++)
+ {
+ const FT_ULong* p = blue_chars[bb][fill_type];
+ const FT_ULong* limit = p + AF_CJK_MAX_TEST_CHARACTERS;
+ FT_Bool fill = ( fill_type == AF_CJK_BLUE_TYPE_FILL );
+
+
+ AF_LOG(( "cjk blue %3d/%d: ", bb, fill_type ));
+
+
+ for ( ; p < limit && *p; p++ )
+ {
+ FT_UInt glyph_index;
+ FT_Pos best_pos; /* same as points.y */
+ FT_Int best_point, best_first, best_last;
+ FT_Vector* points;
+
+ AF_LOG(( "0X%lX", *p ));
+
+ /* load the character in the face -- skip unknown or empty ones */
+ glyph_index = FT_Get_Char_Index( face, *p );
+ if ( glyph_index == 0 )
+ continue;
+
+ error = FT_Load_Glyph( face, glyph_index, FT_LOAD_NO_SCALE );
+ if ( error || glyph->outline.n_points <= 0 )
+ continue;
+
+ /* now compute min or max point indices and coordinates */
+ points = glyph->outline.points;
+ best_point = -1;
+ best_pos = 0; /* make compiler happy */
+ best_first = 0; /* ditto */
+ best_last = 0; /* ditto */
+
+ {
+ FT_Int nn;
+ FT_Int first = 0;
+ FT_Int last = -1;
+
+
+ for ( nn = 0; nn < glyph->outline.n_contours; first = last+1, nn++ )
+ {
+ FT_Int old_best_point = best_point;
+ FT_Int pp;
+
+
+ last = glyph->outline.contours[nn];
+
+ /* Avoid single-point contours since they are never rasterized. */
+ /* In some fonts, they correspond to mark attachment points */
+ /* which are way outside of the glyph's real outline. */
+ if ( last <= first )
+ continue;
+
+ switch (bb)
+ {
+ case AF_CJK_BLUE_TOP:
+ for ( pp = first; pp <= last; pp++ )
+ if ( best_point < 0 || points[pp].y > best_pos )
+ {
+ best_point = pp;
+ best_pos = points[pp].y;
+ }
+ break;
+ case AF_CJK_BLUE_BOTTOM:
+ for ( pp = first; pp <= last; pp++ )
+ if ( best_point < 0 || points[pp].y < best_pos )
+ {
+ best_point = pp;
+ best_pos = points[pp].y;
+ }
+ break;
+ case AF_CJK_BLUE_LEFT:
+ for ( pp = first; pp <= last; pp++ )
+ if ( best_point < 0 || points[pp].x < best_pos )
+ {
+ best_point = pp;
+ best_pos = points[pp].x;
+ }
+ break;
+ case AF_CJK_BLUE_RIGHT:
+ for ( pp = first; pp <= last; pp++ )
+ if ( best_point < 0 || points[pp].x > best_pos )
+ {
+ best_point = pp;
+ best_pos = points[pp].x;
+ }
+ break;
+ default:
+ ;
+ }
+
+ if ( best_point != old_best_point )
+ {
+ best_first = first;
+ best_last = last;
+ }
+ }
+ AF_LOG(( "%5ld, ", best_pos ));
+ }
+
+ if (fill)
+ fills[num_fills++] = best_pos;
+ else
+ flats[num_flats++] = best_pos;
+ }
+
+ AF_LOG(( "\n" ));
+ }
+
+ if ( num_flats == 0 && num_fills == 0)
+ {
+ /*
+ * we couldn't find a single glyph to compute this blue zone,
+ * we will simply ignore it then
+ */
+ AF_LOG(( "empty\n" ));
+ continue;
+ }
+
+ /* we have computed the contents of the `fill' and `flats' tables, */
+ /* now determine the reference position of the blue -- */
+ /* we simply take the median value after a simple sort */
+ af_sort_pos( num_flats, flats );
+ af_sort_pos( num_fills, fills );
+
+ if ( AF_CJK_BLUE_TOP == bb || AF_CJK_BLUE_BOTTOM == bb )
+ axis = &metrics->axis[AF_DIMENSION_VERT];
+ else
+ axis = &metrics->axis[AF_DIMENSION_HORZ];
+
+ blue = & axis->blues[axis->blue_count];
+ blue_ref = & blue->ref.org;
+ blue_shoot = & blue->shoot.org;
+
+ axis->blue_count++;
+ if ( num_flats == 0 )
+ {
+ *blue_ref =
+ *blue_shoot = fills[num_fills/2];
+ }
+ else if ( num_fills == 0 )
+ {
+ *blue_ref =
+ *blue_shoot = flats[num_flats/2];
+ }
+ else
+ {
+ *blue_ref = fills[num_fills / 2];
+ *blue_shoot = flats[num_flats / 2];
+ }
+
+ /* make sure blue_ref >= blue_shoot for top/right or
+ * vis vesa for bottom/left. */
+ if ( *blue_shoot != *blue_ref )
+ {
+ FT_Pos ref = *blue_ref;
+ FT_Pos shoot = *blue_shoot;
+ FT_Bool under_ref = FT_BOOL( shoot < ref );
+
+
+ if ( (AF_CJK_BLUE_TOP == bb || AF_CJK_BLUE_RIGHT == bb ) ^
+ under_ref )
+ *blue_shoot = *blue_ref = ( shoot + ref ) / 2;
+ }
+
+ blue->flags = 0;
+ if ( AF_CJK_BLUE_TOP == bb )
+ blue->flags |= AF_CJK_BLUE_IS_TOP;
+ else if ( AF_CJK_BLUE_RIGHT == bb )
+ blue->flags |= AF_CJK_BLUE_IS_RIGHT;
+
+ AF_LOG(( "-- cjk ref = %ld shoot = %ld\n", *blue_ref, *blue_shoot ));
+ }
+ return;
+ }
+
+
+ /* Basically the Latin version with type AF_CJKMetrics for metrics. */
+ FT_LOCAL_DEF( void )
+ af_cjk_metrics_check_digits( AF_CJKMetrics metrics,
+ FT_Face face )
+ {
+ FT_UInt i;
+ FT_Bool started = 0, same_width = 1;
+ FT_Fixed advance, old_advance = 0;
+
+
+ /* check whether all ASCII digits have the same advance width; */
+ /* digit `0' is 0x30 in all supported charmaps */
+ for ( i = 0x30; i <= 0x39; i++ )
+ {
+ FT_UInt glyph_index;
+
+
+ glyph_index = FT_Get_Char_Index( face, i );
+ if ( glyph_index == 0 )
+ continue;
+
+ if ( FT_Get_Advance( face, glyph_index,
+ FT_LOAD_NO_SCALE |
+ FT_LOAD_NO_HINTING |
+ FT_LOAD_IGNORE_TRANSFORM,
+ &advance ) )
+ continue;
+
+ if ( started )
+ {
+ if ( advance != old_advance )
+ {
+ same_width = 0;
+ break;
+ }
+ }
+ else
+ {
+ old_advance = advance;
+ started = 1;
+ }
+ }
+
+ metrics->root.digits_have_same_width = same_width;
+ }
+
+
FT_LOCAL_DEF( FT_Error )
- af_cjk_metrics_init( AF_LatinMetrics metrics,
+ af_cjk_metrics_init( AF_CJKMetrics metrics,
FT_Face face )
{
FT_CharMap oldmap = face->charmap;
@@ -54,15 +502,13 @@
metrics->units_per_em = face->units_per_EM;
- /* TODO are there blues? */
-
if ( FT_Select_Charmap( face, FT_ENCODING_UNICODE ) )
face->charmap = NULL;
else
{
- /* latin's version would suffice */
- af_latin_metrics_init_widths( metrics, face, 0x7530 );
- af_latin_metrics_check_digits( metrics, face );
+ af_cjk_metrics_init_widths( metrics, face, 0x7530 );
+ af_cjk_metrics_init_blues( metrics, face, af_cjk_blue_chars );
+ af_cjk_metrics_check_digits( metrics, face );
}
FT_Set_Charmap( face, oldmap );
@@ -72,30 +518,92 @@
static void
- af_cjk_metrics_scale_dim( AF_LatinMetrics metrics,
+ af_cjk_metrics_scale_dim( AF_CJKMetrics metrics,
AF_Scaler scaler,
AF_Dimension dim )
{
- AF_LatinAxis axis;
+ FT_Fixed scale;
+ FT_Pos delta;
+ AF_CJKAxis axis;
+ FT_UInt nn;
axis = &metrics->axis[dim];
if ( dim == AF_DIMENSION_HORZ )
{
- axis->scale = scaler->x_scale;
- axis->delta = scaler->x_delta;
+ scale = scaler->x_scale;
+ delta = scaler->x_delta;
}
else
{
- axis->scale = scaler->y_scale;
- axis->delta = scaler->y_delta;
+ scale = scaler->y_scale;
+ delta = scaler->y_delta;
+ }
+
+ if ( axis->org_scale == scale && axis->org_delta == delta )
+ return;
+
+ axis->org_scale = scale;
+ axis->org_delta = delta;
+
+ axis->scale = scale;
+ axis->delta = delta;
+
+ /* scale the blue zones */
+ for ( nn = 0; nn < axis->blue_count; nn++ )
+ {
+ AF_CJKBlue blue = &axis->blues[nn];
+ FT_Pos dist;
+
+
+ blue->ref.cur = FT_MulFix( blue->ref.org, scale ) + delta;
+ blue->ref.fit = blue->ref.cur;
+ blue->shoot.cur = FT_MulFix( blue->shoot.org, scale ) + delta;
+ blue->shoot.fit = blue->shoot.cur;
+ blue->flags &= ~AF_CJK_BLUE_ACTIVE;
+
+ /* a blue zone is only active if it is less than 3/4 pixels tall */
+ dist = FT_MulFix( blue->ref.org - blue->shoot.org, scale );
+ if ( dist <= 48 && dist >= -48 )
+ {
+ FT_Pos delta1, delta2;
+
+ delta1 = blue->shoot.org - blue->ref.org;
+ delta2 = delta1;
+ if ( delta1 < 0 )
+ delta2 = -delta2;
+
+ delta2 = FT_MulFix( delta2, scale );
+
+ if ( delta2 < 32 )
+ delta2 = 0;
+ else if ( delta2 < 64 )
+ delta2 = 32 + ( ( ( delta2 - 32 ) + 16 ) & ~31 );
+ else
+ delta2 = FT_PIX_ROUND( delta2 );
+
+ if ( delta1 < 0 )
+ delta2 = -delta2;
+
+ blue->ref.fit = FT_PIX_ROUND( blue->ref.cur );
+ blue->shoot.fit = blue->ref.fit + delta2;
+
+ AF_LOG(( ">> active cjk blue zone %c%d[%ld/%ld]: "
+ "ref: cur=%.2g fit=%.2g shoot: cur=%.2g fit=%.2g\n",
+ ( dim == AF_DIMENSION_HORZ ) ? 'H':'V',
+ nn, blue->ref.org, blue->shoot.org,
+ blue->ref.cur/64.0, blue->ref.fit/64.0,
+ blue->shoot.cur/64.0, blue->shoot.fit/64.0 ));
+
+ blue->flags |= AF_CJK_BLUE_ACTIVE;
+ }
}
}
FT_LOCAL_DEF( void )
- af_cjk_metrics_scale( AF_LatinMetrics metrics,
+ af_cjk_metrics_scale( AF_CJKMetrics metrics,
AF_Scaler scaler )
{
metrics->root.scaler = *scaler;
@@ -329,7 +837,7 @@
AF_AxisHints axis = &hints->axis[dim];
FT_Error error = AF_Err_Ok;
FT_Memory memory = hints->memory;
- AF_LatinAxis laxis = &((AF_LatinMetrics)hints->metrics)->axis[dim];
+ AF_CJKAxis laxis = &((AF_CJKMetrics)hints->metrics)->axis[dim];
AF_Segment segments = axis->segments;
AF_Segment segment_limit = segments + axis->num_segments;
@@ -601,9 +1109,94 @@
}
+ FT_LOCAL_DEF( void )
+ af_cjk_hints_compute_blue_edges( AF_GlyphHints hints,
+ AF_CJKMetrics metrics,
+ AF_Dimension dim )
+ {
+ AF_AxisHints axis = &hints->axis[ dim ];
+ AF_Edge edge = axis->edges;
+ AF_Edge edge_limit = edge + axis->num_edges;
+ AF_CJKAxis cjk = &metrics->axis[ dim ];
+ FT_Fixed scale = cjk->scale;
+ FT_Pos best_dist0; /* initial threshold */
+
+
+ /* compute the initial threshold as a fraction of the EM size */
+ best_dist0 = FT_MulFix( metrics->units_per_em / 40, scale );
+
+ if ( best_dist0 > 64 / 2 ) /* Maximum 1/2 pixel */
+ best_dist0 = 64 / 2;
+
+ /* compute which blue zones are active, i.e. have their scaled */
+ /* size < 3/4 pixels */
+
+ /* If the distant between an edge and a blue zone is shorter than
+ * best_dist0, set the blue zone for the edge. Then earch for the blue zone
+ * with the smallest best_dist to the edge. */
+ for ( ; edge < edge_limit; edge++ )
+ {
+ FT_UInt bb;
+ AF_Width best_blue = NULL;
+ FT_Pos best_dist = best_dist0;
+
+
+ for ( bb = 0; bb < cjk->blue_count; bb++ )
+ {
+ AF_CJKBlue blue = cjk->blues + bb;
+ FT_Bool is_top_right_blue, is_major_dir;
+
+ /* skip inactive blue zones (i.e., those that are too small) */
+ if ( !( blue->flags & AF_CJK_BLUE_ACTIVE ) )
+ continue;
+
+ /* if it is a top zone, check for right edges -- if it is a bottom */
+ /* zone, check for left edges */
+ /* */
+ /* of course, that's for TrueType */
+ is_top_right_blue = FT_BOOL(
+ ( ( blue->flags & AF_CJK_BLUE_IS_TOP ) != 0 ) ||
+ ( ( blue->flags & AF_CJK_BLUE_IS_RIGHT ) != 0 ) );
+ is_major_dir = FT_BOOL( edge->dir == axis->major_dir );
+
+ /* if it is a top zone, the edge must be against the major */
+ /* direction; if it is a bottom zone, it must be in the major */
+ /* direction */
+ if ( is_top_right_blue ^ is_major_dir )
+ {
+ FT_Pos dist;
+ AF_Width compare;
+
+
+ /* Compare the edge to the closest blue zone type */
+ if ( FT_ABS( edge->fpos - blue->ref.org ) >
+ FT_ABS( edge->fpos - blue->shoot.org ) )
+ compare = &blue->shoot;
+ else
+ compare = &blue->ref;
+
+ dist = edge->fpos - compare->org;
+ if (dist < 0)
+ dist = -dist;
+
+ dist = FT_MulFix( dist, scale );
+ if ( dist < best_dist )
+ {
+ best_dist = dist;
+ best_blue = compare;
+ }
+ }
+ }
+
+ if ( best_blue )
+ edge->blue_edge = best_blue;
+ }
+ }
+
+
FT_LOCAL_DEF( FT_Error )
af_cjk_hints_init( AF_GlyphHints hints,
- AF_LatinMetrics metrics )
+ AF_CJKMetrics metrics )
{
FT_Render_Mode mode;
FT_UInt32 scaler_flags, other_flags;
@@ -728,8 +1321,8 @@
AF_Edge_Flags base_flags,
AF_Edge_Flags stem_flags )
{
- AF_LatinMetrics metrics = (AF_LatinMetrics) hints->metrics;
- AF_LatinAxis axis = & metrics->axis[dim];
+ AF_CJKMetrics metrics = (AF_CJKMetrics) hints->metrics;
+ AF_CJKAxis axis = & metrics->axis[dim];
FT_Pos dist = width;
FT_Int sign = 0;
FT_Int vertical = ( dim == AF_DIMENSION_VERT );
@@ -1027,6 +1620,58 @@
FT_Int skipped = 0;
+ /* we begin by aligning all stems relative to the blue zone */
+ AF_LOG(( "==== cjk hinting %s edges =====\n",
+ dim == AF_DIMENSION_HORZ ? "vertical" : "horizontal" ));
+
+ if ( AF_HINTS_DO_BLUES( hints ) )
+ {
+ for ( edge = edges; edge < edge_limit; edge++ )
+ {
+ AF_Width blue;
+ AF_Edge edge1, edge2;
+
+
+ if ( edge->flags & AF_EDGE_DONE )
+ continue;
+
+ blue = edge->blue_edge;
+ edge1 = NULL;
+ edge2 = edge->link;
+
+ if ( blue )
+ {
+ edge1 = edge;
+ }
+ else if ( edge2 && edge2->blue_edge )
+ {
+ blue = edge2->blue_edge;
+ edge1 = edge2;
+ edge2 = edge;
+ }
+
+ if ( !edge1 )
+ continue;
+
+ AF_LOG(( "CJKBLUE: edge %d @%d (opos=%.2f) snapped to (%.2f), "
+ "was (%.2f)\n",
+ edge1-edges, edge1->fpos, edge1->opos / 64.0, blue->fit /
64.0,
+ edge1->pos / 64.0 ));
+
+ edge1->pos = blue->fit;
+ edge1->flags |= AF_EDGE_DONE;
+
+ if ( edge2 && !edge2->blue_edge )
+ {
+ af_cjk_align_linked_edge( hints, dim, edge1, edge2 );
+ edge2->flags |= AF_EDGE_DONE;
+ }
+
+ if ( !anchor )
+ anchor = edge;
+ }
+ }
+
/* now we align all stem edges. */
for ( edge = edges; edge < edge_limit; edge++ )
{
@@ -1045,6 +1690,15 @@
}
/* now align the stem */
+ /* this should not happen, but it's better to be safe */
+ if ( edge2->blue_edge )
+ {
+ AF_LOG(( "ASSERTION FAILED for edge %d\n", edge2-edges ));
+
+ af_cjk_align_linked_edge( hints, dim, edge2, edge );
+ edge->flags |= AF_EDGE_DONE;
+ continue;
+ }
if ( edge2 < edge )
{
@@ -1363,7 +2017,7 @@
FT_LOCAL_DEF( FT_Error )
af_cjk_hints_apply( AF_GlyphHints hints,
FT_Outline* outline,
- AF_LatinMetrics metrics )
+ AF_CJKMetrics metrics )
{
FT_Error error;
int dim;
@@ -1381,6 +2035,8 @@
error = af_cjk_hints_detect_features( hints, AF_DIMENSION_HORZ );
if ( error )
goto Exit;
+
+ af_cjk_hints_compute_blue_edges( hints, metrics, AF_DIMENSION_HORZ );
}
if ( AF_HINTS_DO_VERTICAL( hints ) )
@@ -1388,6 +2044,8 @@
error = af_cjk_hints_detect_features( hints, AF_DIMENSION_VERT );
if ( error )
goto Exit;
+
+ af_cjk_hints_compute_blue_edges( hints, metrics, AF_DIMENSION_VERT );
}
/* grid-fit the outline */
@@ -1474,7 +2132,7 @@
AF_SCRIPT_CJK,
af_cjk_uniranges,
- sizeof( AF_LatinMetricsRec ),
+ sizeof( AF_CJKMetricsRec ),
(AF_Script_InitMetricsFunc) af_cjk_metrics_init,
(AF_Script_ScaleMetricsFunc)af_cjk_metrics_scale,
@@ -1496,7 +2154,7 @@
AF_SCRIPT_CJK,
af_cjk_uniranges,
- sizeof( AF_LatinMetricsRec ),
+ sizeof( AF_CJKMetricsRec ),
(AF_Script_InitMetricsFunc) NULL,
(AF_Script_ScaleMetricsFunc)NULL,
diff --git a/src/autofit/afcjk.h b/src/autofit/afcjk.h
index 0b20d4a..20b7f80 100644
--- a/src/autofit/afcjk.h
+++ b/src/autofit/afcjk.h
@@ -20,6 +20,7 @@
#define __AFCJK_H__
#include "afhints.h"
+#include "aflatin.h"
FT_BEGIN_HEADER
@@ -29,23 +30,92 @@ FT_BEGIN_HEADER
AF_DECLARE_SCRIPT_CLASS(af_cjk_script_class)
+ /* CJK (global) metrics management */
+
+ /*
+ * CJK glyphs tend to fill the square. So we have both verticle and
+ * horizontal blue zones. But some glyphs have flat bounding stroke that
+ * leave some space between neighbour glyphs.
+ */
+ enum
+ {
+ AF_CJK_BLUE_TOP,
+ AF_CJK_BLUE_BOTTOM,
+ AF_CJK_BLUE_LEFT,
+ AF_CJK_BLUE_RIGHT,
+
+ AF_CJK_BLUE_MAX
+ };
+
+
+#define AF_CJK_MAX_WIDTHS 16
+#define AF_CJK_MAX_BLUES AF_CJK_BLUE_MAX
+
+
+ enum
+ {
+ AF_CJK_BLUE_ACTIVE = 1 << 0,
+ AF_CJK_BLUE_IS_TOP = 1 << 1,
+ AF_CJK_BLUE_IS_RIGHT = 1 << 2,
+ AF_CJK_BLUE_ADJUSTMENT = 1 << 3, /* used for scale adjustment */
+ /* optimization */
+ AF_CJK_BLUE_FLAG_MAX
+ };
+
+ typedef struct AF_CJKBlueRec_
+ {
+ AF_WidthRec ref;
+ AF_WidthRec shoot; /* undershoot */
+ FT_UInt flags;
+
+ } AF_CJKBlueRec, *AF_CJKBlue;
+
+ typedef struct AF_CJKAxisRec_
+ {
+ FT_Fixed scale;
+ FT_Pos delta;
+
+ FT_UInt width_count;
+ AF_WidthRec widths[AF_CJK_MAX_WIDTHS];
+ FT_Pos edge_distance_threshold;
+ FT_Pos standard_width;
+ FT_Bool extra_light;
+
+ /* used for horizontal metrics too for CJK */
+ FT_Bool control_overshoot;
+ FT_UInt blue_count;
+ AF_CJKBlueRec blues[AF_CJK_BLUE_MAX];
+
+ FT_Fixed org_scale;
+ FT_Pos org_delta;
+
+ } AF_CJKAxisRec, *AF_CJKAxis;
+
+
+ typedef struct AF_CJKMetricsRec_
+ {
+ AF_ScriptMetricsRec root;
+ FT_UInt units_per_em;
+ AF_CJKAxisRec axis[AF_DIMENSION_MAX];
+
+ } AF_CJKMetricsRec, *AF_CJKMetrics;
FT_LOCAL( FT_Error )
- af_cjk_metrics_init( AF_LatinMetrics metrics,
+ af_cjk_metrics_init( AF_CJKMetrics metrics,
FT_Face face );
FT_LOCAL( void )
- af_cjk_metrics_scale( AF_LatinMetrics metrics,
+ af_cjk_metrics_scale( AF_CJKMetrics metrics,
AF_Scaler scaler );
FT_LOCAL( FT_Error )
af_cjk_hints_init( AF_GlyphHints hints,
- AF_LatinMetrics metrics );
+ AF_CJKMetrics metrics );
FT_LOCAL( FT_Error )
af_cjk_hints_apply( AF_GlyphHints hints,
FT_Outline* outline,
- AF_LatinMetrics metrics );
+ AF_CJKMetrics metrics );
/* */
diff --git a/src/autofit/afindic.c b/src/autofit/afindic.c
index 1d9e9ea..778aa06 100644
--- a/src/autofit/afindic.c
+++ b/src/autofit/afindic.c
@@ -33,16 +33,35 @@
static FT_Error
- af_indic_metrics_init( AF_LatinMetrics metrics,
+ af_indic_metrics_init( AF_CJKMetrics metrics,
FT_Face face )
{
- /* use CJK routines */
- return af_cjk_metrics_init( metrics, face );
+ /* skip blue zone init in CJK routines */
+ FT_CharMap oldmap = face->charmap;
+
+
+ metrics->units_per_em = face->units_per_EM;
+
+ if ( FT_Select_Charmap( face, FT_ENCODING_UNICODE ) )
+ face->charmap = NULL;
+ else
+ {
+ af_cjk_metrics_init_widths( metrics, face, 0x7530 );
+#if 0
+ /* either need indic specific blue_chars[] or just skip blue zones. */
+ af_cjk_metrics_init_blues( metrics, face, af_cjk_blue_chars );
+#endif
+ af_cjk_metrics_check_digits( metrics, face );
+ }
+
+ FT_Set_Charmap( face, oldmap );
+
+ return AF_Err_Ok;
}
static void
- af_indic_metrics_scale( AF_LatinMetrics metrics,
+ af_indic_metrics_scale( AF_CJKMetrics metrics,
AF_Scaler scaler )
{
/* use CJK routines */
@@ -52,7 +71,7 @@
static FT_Error
af_indic_hints_init( AF_GlyphHints hints,
- AF_LatinMetrics metrics )
+ AF_CJKMetrics metrics )
{
/* use CJK routines */
return af_cjk_hints_init( hints, metrics );
@@ -62,7 +81,7 @@
static FT_Error
af_indic_hints_apply( AF_GlyphHints hints,
FT_Outline* outline,
- AF_LatinMetrics metrics)
+ AF_CJKMetrics metrics)
{
/* use CJK routines */
return af_cjk_hints_apply( hints, outline, metrics );
@@ -92,7 +111,7 @@
AF_SCRIPT_INDIC,
af_indic_uniranges,
- sizeof( AF_LatinMetricsRec ),
+ sizeof( AF_CJKMetricsRec ),
(AF_Script_InitMetricsFunc) af_indic_metrics_init,
(AF_Script_ScaleMetricsFunc)af_indic_metrics_scale,
@@ -114,7 +133,7 @@
AF_SCRIPT_INDIC,
af_indic_uniranges,
- sizeof( AF_LatinMetricsRec ),
+ sizeof( AF_CJKMetricsRec ),
(AF_Script_InitMetricsFunc) NULL,
(AF_Script_ScaleMetricsFunc)NULL,
- [ft-devel] [Patch] CJK autofit/autohint blue zones,
JustFillBug <=
- Re: [ft-devel] [Patch] CJK autofit/autohint blue zones, mpsuzuki, 2011/01/08
- Re: [ft-devel] [Patch] CJK autofit/autohint blue zones, JustFillBug, 2011/01/08
- Re: [ft-devel] [Patch] CJK autofit/autohint blue zones, Werner LEMBERG, 2011/01/08
- Re: [ft-devel] [Patch] CJK autofit/autohint blue zones, JustFillBug, 2011/01/08
- Re: [ft-devel] [Patch] CJK autofit/autohint blue zones, mpsuzuki, 2011/01/10
- Re: [ft-devel] [Patch] CJK autofit/autohint blue zones, JustFillBug, 2011/01/10
- Re: [ft-devel] [Patch] CJK autofit/autohint blue zones, Miles Bader, 2011/01/12
- Re: [ft-devel] [Patch] CJK autofit/autohint blue zones, JustFillBug, 2011/01/14