ref: da95af6cf67c65bd453fc19908a3f14ac2a8c0c5
dir: /src/pshinter/pshalgo.c/
/***************************************************************************/
/* */
/* pshalgo.c */
/* */
/* PostScript hinting algorithm (body). */
/* */
/* Copyright 2001, 2002, 2003, 2004, 2005 by */
/* David Turner, Robert Wilhelm, and Werner Lemberg. */
/* */
/* This file is part of the FreeType project, and may only be used */
/* modified and distributed under the terms of the FreeType project */
/* license, LICENSE.TXT. By continuing to use, modify, or distribute */
/* this file you indicate that you have read the license and */
/* understand and accept it fully. */
/* */
/***************************************************************************/
#include <ft2build.h>
#include FT_INTERNAL_OBJECTS_H
#include FT_INTERNAL_DEBUG_H
#include "pshalgo.h"
#include "pshnterr.h"
#undef FT_COMPONENT
#define FT_COMPONENT trace_pshalgo2
#ifdef DEBUG_HINTER
PSH_Hint_Table ps_debug_hint_table = 0;
PSH_HintFunc ps_debug_hint_func = 0;
PSH_Glyph ps_debug_glyph = 0;
#endif
#define COMPUTE_INFLEXS /* compute inflection points to optimize `S' */
/* and similar glyphs */
#define STRONGER /* slightly increase the contrast of smooth */
/* hinting */
/*************************************************************************/
/*************************************************************************/
/***** *****/
/***** BASIC HINTS RECORDINGS *****/
/***** *****/
/*************************************************************************/
/*************************************************************************/
/* return true if two stem hints overlap */
static FT_Int
psh_hint_overlap( PSH_Hint hint1,
PSH_Hint hint2 )
{
return hint1->org_pos + hint1->org_len >= hint2->org_pos &&
hint2->org_pos + hint2->org_len >= hint1->org_pos;
}
/* destroy hints table */
static void
psh_hint_table_done( PSH_Hint_Table table,
FT_Memory memory )
{
FT_FREE( table->zones );
table->num_zones = 0;
table->zone = 0;
FT_FREE( table->sort );
FT_FREE( table->hints );
table->num_hints = 0;
table->max_hints = 0;
table->sort_global = 0;
}
/* deactivate all hints in a table */
static void
psh_hint_table_deactivate( PSH_Hint_Table table )
{
FT_UInt count = table->max_hints;
PSH_Hint hint = table->hints;
for ( ; count > 0; count--, hint++ )
{
psh_hint_deactivate( hint );
hint->order = -1;
}
}
/* internal function to record a new hint */
static void
psh_hint_table_record( PSH_Hint_Table table,
FT_UInt idx )
{
PSH_Hint hint = table->hints + idx;
if ( idx >= table->max_hints )
{
FT_ERROR(( "psh_hint_table_record: invalid hint index %d\n", idx ));
return;
}
/* ignore active hints */
if ( psh_hint_is_active( hint ) )
return;
psh_hint_activate( hint );
/* now scan the current active hint set to check */
/* whether `hint' overlaps with another hint */
{
PSH_Hint* sorted = table->sort_global;
FT_UInt count = table->num_hints;
PSH_Hint hint2;
hint->parent = 0;
for ( ; count > 0; count--, sorted++ )
{
hint2 = sorted[0];
if ( psh_hint_overlap( hint, hint2 ) )
{
hint->parent = hint2;
break;
}
}
}
if ( table->num_hints < table->max_hints )
table->sort_global[table->num_hints++] = hint;
else
FT_ERROR(( "psh_hint_table_record: too many sorted hints! BUG!\n" ));
}
static void
psh_hint_table_record_mask( PSH_Hint_Table table,
PS_Mask hint_mask )
{
FT_Int mask = 0, val = 0;
FT_Byte* cursor = hint_mask->bytes;
FT_UInt idx, limit;
limit = hint_mask->num_bits;
for ( idx = 0; idx < limit; idx++ )
{
if ( mask == 0 )
{
val = *cursor++;
mask = 0x80;
}
if ( val & mask )
psh_hint_table_record( table, idx );
mask >>= 1;
}
}
/* create hints table */
static FT_Error
psh_hint_table_init( PSH_Hint_Table table,
PS_Hint_Table hints,
PS_Mask_Table hint_masks,
PS_Mask_Table counter_masks,
FT_Memory memory )
{
FT_UInt count;
FT_Error error;
FT_UNUSED( counter_masks );
count = hints->num_hints;
/* allocate our tables */
if ( FT_NEW_ARRAY( table->sort, 2 * count ) ||
FT_NEW_ARRAY( table->hints, count ) ||
FT_NEW_ARRAY( table->zones, 2 * count + 1 ) )
goto Exit;
table->max_hints = count;
table->sort_global = table->sort + count;
table->num_hints = 0;
table->num_zones = 0;
table->zone = 0;
/* initialize the `table->hints' array */
{
PSH_Hint write = table->hints;
PS_Hint read = hints->hints;
for ( ; count > 0; count--, write++, read++ )
{
write->org_pos = read->pos;
write->org_len = read->len;
write->flags = read->flags;
}
}
/* we now need to determine the initial `parent' stems; first */
/* activate the hints that are given by the initial hint masks */
if ( hint_masks )
{
PS_Mask mask = hint_masks->masks;
count = hint_masks->num_masks;
table->hint_masks = hint_masks;
for ( ; count > 0; count--, mask++ )
psh_hint_table_record_mask( table, mask );
}
/* finally, do a linear parse in case some hints were left alone */
if ( table->num_hints != table->max_hints )
{
FT_UInt idx;
FT_ERROR(( "psh_hint_table_init: missing/incorrect hint masks!\n" ));
count = table->max_hints;
for ( idx = 0; idx < count; idx++ )
psh_hint_table_record( table, idx );
}
Exit:
return error;
}
static void
psh_hint_table_activate_mask( PSH_Hint_Table table,
PS_Mask hint_mask )
{
FT_Int mask = 0, val = 0;
FT_Byte* cursor = hint_mask->bytes;
FT_UInt idx, limit, count;
limit = hint_mask->num_bits;
count = 0;
psh_hint_table_deactivate( table );
for ( idx = 0; idx < limit; idx++ )
{
if ( mask == 0 )
{
val = *cursor++;
mask = 0x80;
}
if ( val & mask )
{
PSH_Hint hint = &table->hints[idx];
if ( !psh_hint_is_active( hint ) )
{
FT_UInt count2;
#if 0
PSH_Hint* sort = table->sort;
PSH_Hint hint2;
for ( count2 = count; count2 > 0; count2--, sort++ )
{
hint2 = sort[0];
if ( psh_hint_overlap( hint, hint2 ) )
FT_ERROR(( "psh_hint_table_activate_mask:"
" found overlapping hints\n" ))
}
#else
count2 = 0;
#endif
if ( count2 == 0 )
{
psh_hint_activate( hint );
if ( count < table->max_hints )
table->sort[count++] = hint;
else
FT_ERROR(( "psh_hint_tableactivate_mask:"
" too many active hints\n" ));
}
}
}
mask >>= 1;
}
table->num_hints = count;
/* now, sort the hints; they are guaranteed to not overlap */
/* so we can compare their "org_pos" field directly */
{
FT_Int i1, i2;
PSH_Hint hint1, hint2;
PSH_Hint* sort = table->sort;
/* a simple bubble sort will do, since in 99% of cases, the hints */
/* will be already sorted -- and the sort will be linear */
for ( i1 = 1; i1 < (FT_Int)count; i1++ )
{
hint1 = sort[i1];
for ( i2 = i1 - 1; i2 >= 0; i2-- )
{
hint2 = sort[i2];
if ( hint2->org_pos < hint1->org_pos )
break;
sort[i2 + 1] = hint2;
sort[i2] = hint1;
}
}
}
}
/*************************************************************************/
/*************************************************************************/
/***** *****/
/***** HINTS GRID-FITTING AND OPTIMIZATION *****/
/***** *****/
/*************************************************************************/
/*************************************************************************/
#if 1
static FT_Pos
psh_dimension_quantize_len( PSH_Dimension dim,
FT_Pos len,
FT_Bool do_snapping )
{
if ( len <= 64 )
len = 64;
else
{
FT_Pos delta = len - dim->stdw.widths[0].cur;
if ( delta < 0 )
delta = -delta;
if ( delta < 40 )
{
len = dim->stdw.widths[0].cur;
if ( len < 48 )
len = 48;
}
if ( len < 3 * 64 )
{
delta = ( len & 63 );
len &= -64;
if ( delta < 10 )
len += delta;
else if ( delta < 32 )
len += 10;
else if ( delta < 54 )
len += 54;
else
len += delta;
}
else
len = FT_PIX_ROUND( len );
}
if ( do_snapping )
len = FT_PIX_ROUND( len );
return len;
}
#endif /* 0 */
#ifdef DEBUG_HINTER
static void
ps_simple_scale( PSH_Hint_Table table,
FT_Fixed scale,
FT_Fixed delta,
FT_Int dimension )
{
PSH_Hint hint;
FT_UInt count;
for ( count = 0; count < table->max_hints; count++ )
{
hint = table->hints + count;
hint->cur_pos = FT_MulFix( hint->org_pos, scale ) + delta;
hint->cur_len = FT_MulFix( hint->org_len, scale );
if ( ps_debug_hint_func )
ps_debug_hint_func( hint, dimension );
}
}
#endif /* DEBUG_HINTER */
static FT_Fixed
psh_hint_snap_stem_side_delta( FT_Fixed pos,
FT_Fixed len )
{
FT_Fixed delta1 = FT_PIX_ROUND( pos ) - pos;
FT_Fixed delta2 = FT_PIX_ROUND( pos + len ) - pos - len;
if ( FT_ABS( delta1 ) <= FT_ABS( delta2 ) )
return delta1;
else
return delta2;
}
static void
psh_hint_align( PSH_Hint hint,
PSH_Globals globals,
FT_Int dimension,
PSH_Glyph glyph )
{
PSH_Dimension dim = &globals->dimension[dimension];
FT_Fixed scale = dim->scale_mult;
FT_Fixed delta = dim->scale_delta;
if ( !psh_hint_is_fitted( hint ) )
{
FT_Pos pos = FT_MulFix( hint->org_pos, scale ) + delta;
FT_Pos len = FT_MulFix( hint->org_len, scale );
FT_Int do_snapping;
FT_Pos fit_len;
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 ) )
{
hint->cur_pos = pos;
hint->cur_len = len;
psh_hint_set_fitted( hint );
return;
}
/* 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 );
hint->cur_len = fit_len = len;
/* check blue zones for horizontal stems */
align.align = PSH_BLUE_ALIGN_NONE;
align.align_bot = align.align_top = 0;
if ( dimension == 1 )
psh_blues_snap_stem( &globals->blues,
hint->org_pos + hint->org_len,
hint->org_pos,
&align );
switch ( align.align )
{
case PSH_BLUE_ALIGN_TOP:
/* the top of the stem is aligned against a blue zone */
hint->cur_pos = align.align_top - fit_len;
break;
case PSH_BLUE_ALIGN_BOT:
/* the bottom of the stem is aligned against a blue zone */
hint->cur_pos = align.align_bot;
break;
case PSH_BLUE_ALIGN_TOP | PSH_BLUE_ALIGN_BOT:
/* both edges of the stem are aligned against blue zones */
hint->cur_pos = align.align_bot;
hint->cur_len = align.align_top - align.align_bot;
break;
default:
{
PSH_Hint parent = hint->parent;
if ( parent )
{
FT_Pos par_org_center, par_cur_center;
FT_Pos cur_org_center, cur_delta;
/* ensure that parent is already fitted */
if ( !psh_hint_is_fitted( parent ) )
psh_hint_align( parent, globals, dimension, glyph );
/* keep original relation between hints, this is, use the */
/* scaled distance between the centers of the hints to */
/* compute the new position */
par_org_center = parent->org_pos + ( parent->org_len >> 1 );
par_cur_center = parent->cur_pos + ( parent->cur_len >> 1 );
cur_org_center = hint->org_pos + ( hint->org_len >> 1 );
cur_delta = FT_MulFix( cur_org_center - par_org_center, scale );
pos = par_cur_center + cur_delta - ( len >> 1 );
}
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.
*/
if ( glyph->do_stem_adjust )
{
if ( len <= 64 )
{
/* the stem is less than one pixel; we will center it
* around the nearest pixel center
*/
#if 1
pos = FT_PIX_FLOOR( pos + ( len >> 1 ) );
#else
/* this seems to be a bug! */
pos = pos + FT_PIX_FLOOR( len >> 1 );
#endif
len = 64;
}
else
{
len = psh_dimension_quantize_len( dim, len, 0 );
}
}
/* now that we have a good hinted stem width, try to position */
/* the stem along a pixel grid integer coordinate */
hint->cur_pos = pos + psh_hint_snap_stem_side_delta( pos, len );
hint->cur_len = len;
}
}
if ( do_snapping )
{
pos = hint->cur_pos;
len = hint->cur_len;
if ( len < 64 )
len = 64;
else
len = FT_PIX_ROUND( len );
switch ( align.align )
{
case PSH_BLUE_ALIGN_TOP:
hint->cur_pos = align.align_top - len;
hint->cur_len = len;
break;
case PSH_BLUE_ALIGN_BOT:
hint->cur_len = len;
break;
case PSH_BLUE_ALIGN_BOT | PSH_BLUE_ALIGN_TOP:
/* don't touch */
break;
default:
hint->cur_len = len;
if ( len & 64 )
pos = FT_PIX_FLOOR( pos + ( len >> 1 ) ) + 32;
else
pos = FT_PIX_ROUND( pos + ( len >> 1 ) );
hint->cur_pos = pos - ( len >> 1 );
hint->cur_len = len;
}
}
psh_hint_set_fitted( hint );
#ifdef DEBUG_HINTER
if ( ps_debug_hint_func )
ps_debug_hint_func( hint, dimension );
#endif
}
}
#if 0 /* not used for now, experimental */
/*
* A variant to perform "light" hinting (i.e. FT_RENDER_MODE_LIGHT)
* of stems
*/
static void
psh_hint_align_light( PSH_Hint hint,
PSH_Globals globals,
FT_Int dimension,
PSH_Glyph glyph )
{
PSH_Dimension dim = &globals->dimension[dimension];
FT_Fixed scale = dim->scale_mult;
FT_Fixed delta = dim->scale_delta;
if ( !psh_hint_is_fitted( hint ) )
{
FT_Pos pos = FT_MulFix( hint->org_pos, scale ) + delta;
FT_Pos len = FT_MulFix( hint->org_len, scale );
FT_Pos fit_len;
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 ) )
{
hint->cur_pos = pos;
hint->cur_len = len;
psh_hint_set_fitted( hint );
return;
}
fit_len = len;
hint->cur_len = fit_len;
/* check blue zones for horizontal stems */
align.align = PSH_BLUE_ALIGN_NONE;
align.align_bot = align.align_top = 0;
if ( dimension == 1 )
psh_blues_snap_stem( &globals->blues,
hint->org_pos + hint->org_len,
hint->org_pos,
&align );
switch ( align.align )
{
case PSH_BLUE_ALIGN_TOP:
/* the top of the stem is aligned against a blue zone */
hint->cur_pos = align.align_top - fit_len;
break;
case PSH_BLUE_ALIGN_BOT:
/* the bottom of the stem is aligned against a blue zone */
hint->cur_pos = align.align_bot;
break;
case PSH_BLUE_ALIGN_TOP | PSH_BLUE_ALIGN_BOT:
/* both edges of the stem are aligned against blue zones */
hint->cur_pos = align.align_bot;
hint->cur_len = align.align_top - align.align_bot;
break;
default:
{
PSH_Hint parent = hint->parent;
if ( parent )
{
FT_Pos par_org_center, par_cur_center;
FT_Pos cur_org_center, cur_delta;
/* ensure that parent is already fitted */
if ( !psh_hint_is_fitted( parent ) )
psh_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 );
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 )
{
if ( ( pos + len + 63 ) / 64 != pos / 64 + 1 )
pos += psh_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.
*/
else /* len > 64 */
{
FT_Fixed frac_len = len & 63;
FT_Fixed center = pos + ( len >> 1 );
FT_Fixed delta_a, delta_b;
if ( ( len / 64 ) & 1 )
{
delta_a = FT_PIX_FLOOR( center ) + 32 - center;
delta_b = FT_PIX_ROUND( center ) - center;
}
else
{
delta_a = FT_PIX_ROUND( center ) - center;
delta_b = FT_PIX_FLOOR( center ) + 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 )
{
pos += psh_hint_snap_stem_side_delta ( pos, len );
}
else if ( frac_len < 48 )
{
FT_Fixed side_delta = psh_hint_snap_stem_side_delta ( pos,
len );
if ( FT_ABS( side_delta ) < FT_ABS( delta_b ) )
pos += side_delta;
else
pos += delta_b;
}
else
{
pos += delta_b;
}
}
hint->cur_pos = pos;
}
} /* switch */
psh_hint_set_fitted( hint );
#ifdef DEBUG_HINTER
if ( ps_debug_hint_func )
ps_debug_hint_func( hint, dimension );
#endif
}
}
#endif /* 0 */
static void
psh_hint_table_align_hints( PSH_Hint_Table table,
PSH_Globals globals,
FT_Int dimension,
PSH_Glyph glyph )
{
PSH_Hint hint;
FT_UInt count;
#ifdef DEBUG_HINTER
PSH_Dimension dim = &globals->dimension[dimension];
FT_Fixed scale = dim->scale_mult;
FT_Fixed delta = dim->scale_delta;
if ( ps_debug_no_vert_hints && dimension == 0 )
{
ps_simple_scale( table, scale, delta, dimension );
return;
}
if ( ps_debug_no_horz_hints && dimension == 1 )
{
ps_simple_scale( table, scale, delta, dimension );
return;
}
#endif /* DEBUG_HINTER*/
hint = table->hints;
count = table->max_hints;
for ( ; count > 0; count--, hint++ )
psh_hint_align( hint, globals, dimension, glyph );
}
/*************************************************************************/
/*************************************************************************/
/***** *****/
/***** POINTS INTERPOLATION ROUTINES *****/
/***** *****/
/*************************************************************************/
/*************************************************************************/
#define PSH_ZONE_MIN -3200000L
#define PSH_ZONE_MAX +3200000L
#define xxDEBUG_ZONES
#ifdef DEBUG_ZONES
#include <stdio.h>
static void
psh_print_zone( PSH_Zone zone )
{
printf( "zone [scale,delta,min,max] = [%.3f,%.3f,%d,%d]\n",
zone->scale / 65536.0,
zone->delta / 64.0,
zone->min,
zone->max );
}
#else
#define psh_print_zone( x ) do { } while ( 0 )
#endif /* DEBUG_ZONES */
/*************************************************************************/
/*************************************************************************/
/***** *****/
/***** HINTER GLYPH MANAGEMENT *****/
/***** *****/
/*************************************************************************/
/*************************************************************************/
#ifdef COMPUTE_INFLEXS
/* compute all inflex points in a given glyph */
static void
psh_glyph_compute_inflections( PSH_Glyph glyph )
{
FT_UInt n;
for ( n = 0; n < glyph->num_contours; n++ )
{
PSH_Point first, start, end, before, after;
FT_Angle angle_in, angle_seg, angle_out;
FT_Angle diff_in, diff_out;
FT_Int finished = 0;
/* we need at least 4 points to create an inflection point */
if ( glyph->contours[n].count < 4 )
continue;
/* compute first segment in contour */
first = glyph->contours[n].start;
start = end = first;
do
{
end = end->next;
if ( end == first )
goto Skip;
} while ( PSH_POINT_EQUAL_ORG( end, first ) );
angle_seg = PSH_POINT_ANGLE( start, end );
/* extend the segment start whenever possible */
before = start;
do
{
do
{
start = before;
before = before->prev;
if ( before == first )
goto Skip;
} while ( PSH_POINT_EQUAL_ORG( before, start ) );
angle_in = PSH_POINT_ANGLE( before, start );
} while ( angle_in == angle_seg );
first = start;
diff_in = FT_Angle_Diff( angle_in, angle_seg );
/* now, process all segments in the contour */
do
{
/* first, extend current segment's end whenever possible */
after = end;
do
{
do
{
end = after;
after = after->next;
if ( after == first )
finished = 1;
} while ( PSH_POINT_EQUAL_ORG( end, after ) );
angle_out = PSH_POINT_ANGLE( end, after );
} while ( angle_out == angle_seg );
diff_out = FT_Angle_Diff( angle_seg, angle_out );
if ( ( diff_in ^ diff_out ) < 0 )
{
/* diff_in and diff_out have different signs, we have */
/* inflection points here... */
do
{
psh_point_set_inflex( start );
start = start->next;
}
while ( start != end );
psh_point_set_inflex( start );
}
start = end;
end = after;
angle_seg = angle_out;
diff_in = diff_out;
} while ( !finished );
Skip:
;
}
}
#endif /* COMPUTE_INFLEXS */
static void
psh_glyph_done( PSH_Glyph glyph )
{
FT_Memory memory = glyph->memory;
psh_hint_table_done( &glyph->hint_tables[1], memory );
psh_hint_table_done( &glyph->hint_tables[0], memory );
FT_FREE( glyph->points );
FT_FREE( glyph->contours );
glyph->num_points = 0;
glyph->num_contours = 0;
glyph->memory = 0;
}
static int
psh_compute_dir( FT_Pos dx,
FT_Pos dy )
{
FT_Pos ax, ay;
int result = PSH_DIR_NONE;
ax = ( dx >= 0 ) ? dx : -dx;
ay = ( dy >= 0 ) ? dy : -dy;
if ( ay * 12 < ax )
{
/* |dy| <<< |dx| means a near-horizontal segment */
result = ( dx >= 0 ) ? PSH_DIR_RIGHT : PSH_DIR_LEFT;
}
else if ( ax * 12 < ay )
{
/* |dx| <<< |dy| means a near-vertical segment */
result = ( dy >= 0 ) ? PSH_DIR_UP : PSH_DIR_DOWN;
}
return result;
}
/* load outline point coordinates into hinter glyph */
static void
psh_glyph_load_points( PSH_Glyph glyph,
FT_Int dimension )
{
FT_Vector* vec = glyph->outline->points;
PSH_Point point = glyph->points;
FT_UInt count = glyph->num_points;
for ( ; count > 0; count--, point++, vec++ )
{
point->flags2 = 0;
point->hint = NULL;
if ( dimension == 0 )
{
point->org_u = vec->x;
point->org_v = vec->y;
}
else
{
point->org_u = vec->y;
point->org_v = vec->x;
}
#ifdef DEBUG_HINTER
point->org_x = vec->x;
point->org_y = vec->y;
#endif
}
}
/* save hinted point coordinates back to outline */
static void
psh_glyph_save_points( PSH_Glyph glyph,
FT_Int dimension )
{
FT_UInt n;
PSH_Point point = glyph->points;
FT_Vector* vec = glyph->outline->points;
char* tags = glyph->outline->tags;
for ( n = 0; n < glyph->num_points; n++ )
{
if ( dimension == 0 )
vec[n].x = point->cur_u;
else
vec[n].y = point->cur_u;
if ( psh_point_is_strong( point ) )
tags[n] |= (char)( ( dimension == 0 ) ? 32 : 64 );
#ifdef DEBUG_HINTER
if ( dimension == 0 )
{
point->cur_x = point->cur_u;
point->flags_x = point->flags2 | point->flags;
}
else
{
point->cur_y = point->cur_u;
point->flags_y = point->flags2 | point->flags;
}
#endif
point++;
}
}
static FT_Error
psh_glyph_init( PSH_Glyph glyph,
FT_Outline* outline,
PS_Hints ps_hints,
PSH_Globals globals )
{
FT_Error error;
FT_Memory memory;
/* clear all fields */
FT_MEM_ZERO( glyph, sizeof ( *glyph ) );
memory = glyph->memory = globals->memory;
/* allocate and setup points + contours arrays */
if ( FT_NEW_ARRAY( glyph->points, outline->n_points ) ||
FT_NEW_ARRAY( glyph->contours, outline->n_contours ) )
goto Exit;
glyph->num_points = outline->n_points;
glyph->num_contours = outline->n_contours;
{
FT_UInt first = 0, next, n;
PSH_Point points = glyph->points;
PSH_Contour contour = glyph->contours;
for ( n = 0; n < glyph->num_contours; n++ )
{
FT_Int count;
PSH_Point point;
next = outline->contours[n] + 1;
count = next - first;
contour->start = points + first;
contour->count = (FT_UInt)count;
if ( count > 0 )
{
point = points + first;
point->prev = points + next - 1;
point->contour = contour;
for ( ; count > 1; count-- )
{
point[0].next = point + 1;
point[1].prev = point;
point++;
point->contour = contour;
}
point->next = points + first;
}
contour++;
first = next;
}
}
{
PSH_Point points = glyph->points;
PSH_Point point = points;
FT_Vector* vec = outline->points;
FT_UInt n;
for ( n = 0; n < glyph->num_points; n++, point++ )
{
FT_Int n_prev = (FT_Int)( point->prev - points );
FT_Int n_next = (FT_Int)( point->next - points );
FT_Pos dxi, dyi, dxo, dyo;
if ( !( outline->tags[n] & FT_CURVE_TAG_ON ) )
point->flags = PSH_POINT_OFF;
dxi = vec[n].x - vec[n_prev].x;
dyi = vec[n].y - vec[n_prev].y;
point->dir_in = (FT_Char)psh_compute_dir( dxi, dyi );
dxo = vec[n_next].x - vec[n].x;
dyo = vec[n_next].y - vec[n].y;
point->dir_out = (FT_Char)psh_compute_dir( dxo, dyo );
/* detect smooth points */
if ( point->flags & PSH_POINT_OFF )
point->flags |= PSH_POINT_SMOOTH;
else if ( point->dir_in != PSH_DIR_NONE ||
point->dir_out != PSH_DIR_NONE )
{
if ( point->dir_in == point->dir_out )
point->flags |= PSH_POINT_SMOOTH;
}
else
{
FT_Angle angle_in, angle_out, diff;
angle_in = FT_Atan2( dxi, dyi );
angle_out = FT_Atan2( dxo, dyo );
diff = angle_in - angle_out;
if ( diff < 0 )
diff = -diff;
if ( diff > FT_ANGLE_PI )
diff = FT_ANGLE_2PI - diff;
if ( diff < FT_ANGLE_PI / 16 )
point->flags |= PSH_POINT_SMOOTH;
}
}
}
glyph->outline = outline;
glyph->globals = globals;
#ifdef COMPUTE_INFLEXS
psh_glyph_load_points( glyph, 0 );
psh_glyph_compute_inflections( glyph );
#endif /* COMPUTE_INFLEXS */
/* now deal with hints tables */
error = psh_hint_table_init( &glyph->hint_tables [0],
&ps_hints->dimension[0].hints,
&ps_hints->dimension[0].masks,
&ps_hints->dimension[0].counters,
memory );
if ( error )
goto Exit;
error = psh_hint_table_init( &glyph->hint_tables [1],
&ps_hints->dimension[1].hints,
&ps_hints->dimension[1].masks,
&ps_hints->dimension[1].counters,
memory );
if ( error )
goto Exit;
Exit:
return error;
}
/* compute all extrema in a glyph for a given dimension */
static void
psh_glyph_compute_extrema( PSH_Glyph glyph )
{
FT_UInt n;
/* first of all, compute all local extrema */
for ( n = 0; n < glyph->num_contours; n++ )
{
PSH_Point first = glyph->contours[n].start;
PSH_Point point, before, after;
if ( glyph->contours[n].count == 0 )
continue;
point = first;
before = point;
after = point;
do
{
before = before->prev;
if ( before == first )
goto Skip;
} while ( before->org_u == point->org_u );
first = point = before->next;
for (;;)
{
after = point;
do
{
after = after->next;
if ( after == first )
goto Next;
} while ( after->org_u == point->org_u );
if ( before->org_u < point->org_u )
{
if ( after->org_u < point->org_u )
{
/* local maximum */
goto Extremum;
}
}
else /* before->org_u > point->org_u */
{
if ( after->org_u > point->org_u )
{
/* local minimum */
Extremum:
do
{
psh_point_set_extremum( point );
point = point->next;
} while ( point != after );
}
}
before = after->prev;
point = after;
} /* for */
Next:
;
}
/* for each extremum, determine its direction along the */
/* orthogonal axis */
for ( n = 0; n < glyph->num_points; n++ )
{
PSH_Point point, before, after;
point = &glyph->points[n];
before = point;
after = point;
if ( psh_point_is_extremum( point ) )
{
do
{
before = before->prev;
if ( before == point )
goto Skip;
} while ( before->org_v == point->org_v );
do
{
after = after->next;
if ( after == point )
goto Skip;
} while ( after->org_v == point->org_v );
}
if ( before->org_v < point->org_v &&
after->org_v > point->org_v )
{
psh_point_set_positive( point );
}
else if ( before->org_v > point->org_v &&
after->org_v < point->org_v )
{
psh_point_set_negative( point );
}
Skip:
;
}
}
/* major_dir is the direction for points on the bottom/left of the stem; */
/* Points on the top/right of the stem will have a direction of */
/* -major_dir. */
static void
psh_hint_table_find_strong_point( PSH_Hint_Table table,
PSH_Point point,
FT_Int threshold,
FT_Int major_dir )
{
PSH_Hint* sort = table->sort;
FT_UInt num_hints = table->num_hints;
FT_Int point_dir = 0;
if ( PSH_DIR_COMPARE( point->dir_in, major_dir ) )
point_dir = point->dir_in;
else if ( PSH_DIR_COMPARE( point->dir_out, major_dir ) )
point_dir = point->dir_out;
if ( point_dir )
{
FT_UInt flag;
for ( ; num_hints > 0; num_hints--, sort++ )
{
PSH_Hint hint = sort[0];
FT_Pos d;
if ( point_dir == major_dir )
{
flag = PSH_POINT_EDGE_MIN;
d = point->org_u - hint->org_pos;
if ( FT_ABS( d ) < threshold )
{
Is_Strong:
psh_point_set_strong( point );
point->flags2 |= flag;
point->hint = hint;
break;
}
}
else if ( point_dir == -major_dir )
{
flag = PSH_POINT_EDGE_MAX;
d = point->org_u - hint->org_pos - hint->org_len;
if ( FT_ABS( d ) < threshold )
goto Is_Strong;
}
}
}
#if 1
else if ( psh_point_is_extremum( point ) )
{
/* treat extrema as special cases for stem edge alignment */
FT_UInt min_flag, max_flag;
if ( major_dir == PSH_DIR_HORIZONTAL )
{
min_flag = PSH_POINT_POSITIVE;
max_flag = PSH_POINT_NEGATIVE;
}
else
{
min_flag = PSH_POINT_NEGATIVE;
max_flag = PSH_POINT_POSITIVE;
}
for ( ; num_hints > 0; num_hints--, sort++ )
{
PSH_Hint hint = sort[0];
FT_Pos d;
FT_Int flag;
if ( point->flags2 & min_flag )
{
flag = PSH_POINT_EDGE_MIN;
d = point->org_u - hint->org_pos;
if ( FT_ABS( d ) < threshold )
{
Is_Strong2:
point->flags2 |= flag;
point->hint = hint;
psh_point_set_strong( point );
break;
}
}
else if ( point->flags2 & max_flag )
{
flag = PSH_POINT_EDGE_MAX;
d = point->org_u - hint->org_pos - hint->org_len;
if ( FT_ABS( d ) < threshold )
goto Is_Strong2;
}
if ( point->org_u >= hint->org_pos &&
point->org_u <= hint->org_pos + hint->org_len )
{
point->hint = hint;
}
}
}
#endif /* 1 */
}
/* the accepted shift for strong points in fractional pixels */
#define PSH_STRONG_THRESHOLD 32
/* the maximum shift value in font units */
#define PSH_STRONG_THRESHOLD_MAXIMUM 30
/* find strong points in a glyph */
static void
psh_glyph_find_strong_points( PSH_Glyph glyph,
FT_Int dimension )
{
/* a point is `strong' if it is located on a stem edge and */
/* has an `in' or `out' tangent parallel to the hint's direction */
PSH_Hint_Table table = &glyph->hint_tables[dimension];
PS_Mask mask = table->hint_masks->masks;
FT_UInt num_masks = table->hint_masks->num_masks;
FT_UInt first = 0;
FT_Int major_dir = dimension == 0 ? PSH_DIR_VERTICAL
: PSH_DIR_HORIZONTAL;
PSH_Dimension dim = &glyph->globals->dimension[dimension];
FT_Fixed scale = dim->scale_mult;
FT_Int threshold;
threshold = (FT_Int)FT_DivFix( PSH_STRONG_THRESHOLD, scale );
if ( threshold > PSH_STRONG_THRESHOLD_MAXIMUM )
threshold = PSH_STRONG_THRESHOLD_MAXIMUM;
/* process secondary hints to `selected' points */
if ( num_masks > 1 && glyph->num_points > 0 )
{
first = mask->end_point;
mask++;
for ( ; num_masks > 1; num_masks--, mask++ )
{
FT_UInt next;
FT_Int count;
next = mask->end_point;
count = next - first;
if ( count > 0 )
{
PSH_Point point = glyph->points + first;
psh_hint_table_activate_mask( table, mask );
for ( ; count > 0; count--, point++ )
psh_hint_table_find_strong_point( table, point,
threshold, major_dir );
}
first = next;
}
}
/* process primary hints for all points */
if ( num_masks == 1 )
{
FT_UInt count = glyph->num_points;
PSH_Point point = glyph->points;
psh_hint_table_activate_mask( table, table->hint_masks->masks );
for ( ; count > 0; count--, point++ )
{
if ( !psh_point_is_strong( point ) )
psh_hint_table_find_strong_point( table, point,
threshold, major_dir );
}
}
/* now, certain points may have been attached to a hint and */
/* not marked as strong; update their flags then */
{
FT_UInt count = glyph->num_points;
PSH_Point point = glyph->points;
for ( ; count > 0; count--, point++ )
if ( point->hint && !psh_point_is_strong( point ) )
psh_point_set_strong( point );
}
}
/* find points in a glyph which are in a blue zone and have `in' or */
/* `out' tangents parallel to the horizontal axis */
static void
psh_glyph_find_blue_points( PSH_Blues blues,
PSH_Glyph glyph )
{
PSH_Blue_Table table;
PSH_Blue_Zone zone;
FT_UInt glyph_count = glyph->num_points;
FT_UInt blue_count;
PSH_Point point = glyph->points;
for ( ; glyph_count > 0; glyph_count--, point++ )
{
FT_Pos y;
/* check tangents */
if ( !PSH_DIR_COMPARE( point->dir_in, PSH_DIR_HORIZONTAL ) &&
!PSH_DIR_COMPARE( point->dir_out, PSH_DIR_HORIZONTAL ) )
continue;
/* skip strong points */
if ( psh_point_is_strong( point ) )
continue;
y = point->org_u;
/* look up top zones */
table = &blues->normal_top;
blue_count = table->count;
zone = table->zones;
for ( ; blue_count > 0; blue_count--, zone++ )
{
FT_Pos delta = y - zone->org_bottom;
if ( delta < -blues->blue_fuzz )
break;
if ( y <= zone->org_top + blues->blue_fuzz )
if ( blues->no_overshoots || delta <= blues->blue_threshold )
{
point->cur_u = zone->cur_bottom;
psh_point_set_strong( point );
psh_point_set_fitted( point );
}
}
/* look up bottom zones */
table = &blues->normal_bottom;
blue_count = table->count;
zone = table->zones + blue_count - 1;
for ( ; blue_count > 0; blue_count--, zone-- )
{
FT_Pos delta = zone->org_top - y;
if ( delta < -blues->blue_fuzz )
break;
if ( y >= zone->org_bottom - blues->blue_fuzz )
if ( blues->no_overshoots || delta < blues->blue_threshold )
{
point->cur_u = zone->cur_top;
psh_point_set_strong( point );
psh_point_set_fitted( point );
}
}
}
}
/* interpolate strong points with the help of hinted coordinates */
static void
psh_glyph_interpolate_strong_points( PSH_Glyph glyph,
FT_Int dimension )
{
PSH_Dimension dim = &glyph->globals->dimension[dimension];
FT_Fixed scale = dim->scale_mult;
FT_UInt count = glyph->num_points;
PSH_Point point = glyph->points;
for ( ; count > 0; count--, point++ )
{
PSH_Hint hint = point->hint;
if ( hint )
{
FT_Pos delta;
if ( psh_point_is_edge_min( point ) )
point->cur_u = hint->cur_pos;
else if ( psh_point_is_edge_max( point ) )
point->cur_u = hint->cur_pos + hint->cur_len;
else
{
delta = point->org_u - hint->org_pos;
if ( delta <= 0 )
point->cur_u = hint->cur_pos + FT_MulFix( delta, scale );
else if ( delta >= hint->org_len )
point->cur_u = hint->cur_pos + hint->cur_len +
FT_MulFix( delta - hint->org_len, scale );
else if ( hint->org_len > 0 )
point->cur_u = hint->cur_pos +
FT_MulDiv( delta, hint->cur_len,
hint->org_len );
else
point->cur_u = hint->cur_pos;
}
psh_point_set_fitted( point );
}
}
}
static void
psh_glyph_interpolate_normal_points( PSH_Glyph glyph,
FT_Int dimension )
{
#if 1
/* first technique: a point is strong if it is a local extremum */
PSH_Dimension dim = &glyph->globals->dimension[dimension];
FT_Fixed scale = dim->scale_mult;
FT_UInt count = glyph->num_points;
PSH_Point point = glyph->points;
for ( ; count > 0; count--, point++ )
{
if ( psh_point_is_strong( point ) )
continue;
/* sometimes, some local extrema are smooth points */
if ( psh_point_is_smooth( point ) )
{
if ( point->dir_in == PSH_DIR_NONE ||
point->dir_in != point->dir_out )
continue;
if ( !psh_point_is_extremum( point ) &&
!psh_point_is_inflex( point ) )
continue;
point->flags &= ~PSH_POINT_SMOOTH;
}
/* find best enclosing point coordinates */
{
PSH_Point before = 0;
PSH_Point after = 0;
FT_Pos diff_before = -32000;
FT_Pos diff_after = 32000;
FT_Pos u = point->org_u;
FT_Int count2 = glyph->num_points;
PSH_Point cur = glyph->points;
for ( ; count2 > 0; count2--, cur++ )
{
if ( psh_point_is_strong( cur ) )
{
FT_Pos diff = cur->org_u - u;
if ( diff <= 0 )
{
if ( diff > diff_before )
{
diff_before = diff;
before = cur;
}
}
else if ( diff >= 0 )
{
if ( diff < diff_after )
{
diff_after = diff;
after = cur;
}
}
}
}
if ( !before )
{
if ( !after )
continue;
/* we are before the first strong point coordinate; */
/* simply translate the point */
point->cur_u = after->cur_u +
FT_MulFix( point->org_u - after->org_u, scale );
}
else if ( !after )
{
/* we are after the last strong point coordinate; */
/* simply translate the point */
point->cur_u = before->cur_u +
FT_MulFix( point->org_u - before->org_u, scale );
}
else
{
if ( diff_before == 0 )
point->cur_u = before->cur_u;
else if ( diff_after == 0 )
point->cur_u = after->cur_u;
else
point->cur_u = before->cur_u +
FT_MulDiv( u - before->org_u,
after->cur_u - before->cur_u,
after->org_u - before->org_u );
}
psh_point_set_fitted( point );
}
}
#endif /* 1 */
}
/* interpolate other points */
static void
psh_glyph_interpolate_other_points( PSH_Glyph glyph,
FT_Int dimension )
{
PSH_Dimension dim = &glyph->globals->dimension[dimension];
FT_Fixed scale = dim->scale_mult;
FT_Fixed delta = dim->scale_delta;
PSH_Contour contour = glyph->contours;
FT_UInt num_contours = glyph->num_contours;
for ( ; num_contours > 0; num_contours--, contour++ )
{
PSH_Point start = contour->start;
PSH_Point first, next, point;
FT_UInt fit_count;
/* count the number of strong points in this contour */
next = start + contour->count;
fit_count = 0;
first = 0;
for ( point = start; point < next; point++ )
if ( psh_point_is_fitted( point ) )
{
if ( !first )
first = point;
fit_count++;
}
/* if there are less than 2 fitted points in the contour, we */
/* simply scale and eventually translate the contour points */
if ( fit_count < 2 )
{
if ( fit_count == 1 )
delta = first->cur_u - FT_MulFix( first->org_u, scale );
for ( point = start; point < next; point++ )
if ( point != first )
point->cur_u = FT_MulFix( point->org_u, scale ) + delta;
goto Next_Contour;
}
/* there are more than 2 strong points in this contour; we */
/* need to interpolate weak points between them */
start = first;
do
{
point = first;
/* skip consecutive fitted points */
for (;;)
{
next = first->next;
if ( next == start )
goto Next_Contour;
if ( !psh_point_is_fitted( next ) )
break;
first = next;
}
/* find next fitted point after unfitted one */
for (;;)
{
next = next->next;
if ( psh_point_is_fitted( next ) )
break;
}
/* now interpolate between them */
{
FT_Pos org_a, org_ab, cur_a, cur_ab;
FT_Pos org_c, org_ac, cur_c;
FT_Fixed scale_ab;
if ( first->org_u <= next->org_u )
{
org_a = first->org_u;
cur_a = first->cur_u;
org_ab = next->org_u - org_a;
cur_ab = next->cur_u - cur_a;
}
else
{
org_a = next->org_u;
cur_a = next->cur_u;
org_ab = first->org_u - org_a;
cur_ab = first->cur_u - cur_a;
}
scale_ab = 0x10000L;
if ( org_ab > 0 )
scale_ab = FT_DivFix( cur_ab, org_ab );
point = first->next;
do
{
org_c = point->org_u;
org_ac = org_c - org_a;
if ( org_ac <= 0 )
{
/* on the left of the interpolation zone */
cur_c = cur_a + FT_MulFix( org_ac, scale );
}
else if ( org_ac >= org_ab )
{
/* on the right on the interpolation zone */
cur_c = cur_a + cur_ab + FT_MulFix( org_ac - org_ab, scale );
}
else
{
/* within the interpolation zone */
cur_c = cur_a + FT_MulFix( org_ac, scale_ab );
}
point->cur_u = cur_c;
point = point->next;
} while ( point != next );
}
/* keep going until all points in the contours have been processed */
first = next;
} while ( first != start );
Next_Contour:
;
}
}
/*************************************************************************/
/*************************************************************************/
/***** *****/
/***** HIGH-LEVEL INTERFACE *****/
/***** *****/
/*************************************************************************/
/*************************************************************************/
FT_Error
ps_hints_apply( PS_Hints ps_hints,
FT_Outline* outline,
PSH_Globals globals,
FT_Render_Mode hint_mode )
{
PSH_GlyphRec glyphrec;
PSH_Glyph glyph = &glyphrec;
FT_Error error;
#ifdef DEBUG_HINTER
FT_Memory memory;
#endif
FT_Int dimension;
/* something to do? */
if ( outline->n_points == 0 || outline->n_contours == 0 )
return PSH_Err_Ok;
#ifdef DEBUG_HINTER
memory = globals->memory;
if ( ps_debug_glyph )
{
psh_glyph_done( ps_debug_glyph );
FT_FREE( ps_debug_glyph );
}
if ( FT_NEW( glyph ) )
return error;
ps_debug_glyph = glyph;
#endif /* DEBUG_HINTER */
error = psh_glyph_init( glyph, outline, ps_hints, globals );
if ( error )
goto Exit;
/* try to optimize the y_scale so that the top of non-capital letters
* is aligned on a pixel boundary whenever possible
*/
{
PSH_Dimension dim_x = &glyph->globals->dimension[0];
PSH_Dimension dim_y = &glyph->globals->dimension[1];
FT_Fixed x_scale = dim_x->scale_mult;
FT_Fixed y_scale = dim_y->scale_mult;
FT_Fixed scaled;
FT_Fixed fitted;
scaled = FT_MulFix( globals->blues.normal_top.zones->org_ref, y_scale );
fitted = FT_PIX_ROUND( scaled );
if ( fitted != 0 && scaled != fitted )
{
y_scale = FT_MulDiv( y_scale, fitted, scaled );
if ( fitted < scaled )
x_scale -= x_scale / 50;
psh_globals_set_scale( glyph->globals, x_scale, y_scale, 0, 0 );
}
}
glyph->do_horz_hints = 1;
glyph->do_vert_hints = 1;
glyph->do_horz_snapping = FT_BOOL( hint_mode == FT_RENDER_MODE_MONO ||
hint_mode == FT_RENDER_MODE_LCD );
glyph->do_vert_snapping = FT_BOOL( hint_mode == FT_RENDER_MODE_MONO ||
hint_mode == FT_RENDER_MODE_LCD_V );
glyph->do_stem_adjust = FT_BOOL( hint_mode != FT_RENDER_MODE_LIGHT );
for ( dimension = 0; dimension < 2; dimension++ )
{
/* load outline coordinates into glyph */
psh_glyph_load_points( glyph, dimension );
/* compute local extrema */
psh_glyph_compute_extrema( glyph );
/* compute aligned stem/hints positions */
psh_hint_table_align_hints( &glyph->hint_tables[dimension],
glyph->globals,
dimension,
glyph );
/* find strong points, align them, then interpolate others */
psh_glyph_find_strong_points( glyph, dimension );
if ( dimension == 1 )
psh_glyph_find_blue_points( &globals->blues, glyph );
psh_glyph_interpolate_strong_points( glyph, dimension );
psh_glyph_interpolate_normal_points( glyph, dimension );
psh_glyph_interpolate_other_points( glyph, dimension );
/* save hinted coordinates back to outline */
psh_glyph_save_points( glyph, dimension );
}
Exit:
#ifndef DEBUG_HINTER
psh_glyph_done( glyph );
#endif
return error;
}
/* END */