ref: 09d11c64e5014a64dbc7b807899b3dd2581fe26f
dir: /libfreetype/pshalgo1.c/
/***************************************************************************/
/* */
/* pshalgo1.c */
/* */
/* PostScript hinting algorithm 1 (body). */
/* */
/* Copyright 2001, 2002 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 "pshalgo1.h"
#undef FT_COMPONENT
#define FT_COMPONENT trace_pshalgo1
#ifdef DEBUG_HINTER
PSH1_Hint_Table ps1_debug_hint_table = 0;
PSH1_HintFunc ps1_debug_hint_func = 0;
#endif
/************************************************************************/
/************************************************************************/
/***** *****/
/***** BASIC HINTS RECORDINGS *****/
/***** *****/
/************************************************************************/
/************************************************************************/
/* return true iff two stem hints overlap */
static FT_Int
psh1_hint_overlap( PSH1_Hint hint1,
PSH1_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
psh1_hint_table_done( PSH1_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
psh1_hint_table_deactivate( PSH1_Hint_Table table )
{
FT_UInt count = table->max_hints;
PSH1_Hint hint = table->hints;
for ( ; count > 0; count--, hint++ )
{
psh1_hint_deactivate( hint );
hint->order = -1;
}
}
/* internal function used to record a new hint */
static void
psh1_hint_table_record( PSH1_Hint_Table table,
FT_UInt idx )
{
PSH1_Hint hint = table->hints + idx;
if ( idx >= table->max_hints )
{
FT_ERROR(( "%s.activate: invalid hint index %d\n", idx ));
return;
}
/* ignore active hints */
if ( psh1_hint_is_active( hint ) )
return;
psh1_hint_activate( hint );
/* now scan the current active hint set in order to determine */
/* if we are overlapping with another segment */
{
PSH1_Hint* sorted = table->sort_global;
FT_UInt count = table->num_hints;
PSH1_Hint hint2;
hint->parent = 0;
for ( ; count > 0; count--, sorted++ )
{
hint2 = sorted[0];
if ( psh1_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(( "%s.activate: too many sorted hints! BUG!\n",
"ps.fitter" ));
}
static void
psh1_hint_table_record_mask( PSH1_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;
if ( limit != table->max_hints )
FT_ERROR(( "%s.activate_mask: invalid bit count (%d instead of %d)\n",
"ps.fitter", hint_mask->num_bits, table->max_hints ));
for ( idx = 0; idx < limit; idx++ )
{
if ( mask == 0 )
{
val = *cursor++;
mask = 0x80;
}
if ( val & mask )
psh1_hint_table_record( table, idx );
mask >>= 1;
}
}
/* create hints table */
static FT_Error
psh1_hint_table_init( PSH1_Hint_Table table,
PS_Hint_Table hints,
PS_Mask_Table hint_masks,
PS_Mask_Table counter_masks,
FT_Memory memory )
{
FT_UInt count = hints->num_hints;
FT_Error error;
FT_UNUSED( counter_masks );
/* 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;
/* now, initialize the "hints" array */
{
PSH1_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 )
{
FT_UInt Count = hint_masks->num_masks;
PS_Mask Mask = hint_masks->masks;
table->hint_masks = hint_masks;
for ( ; Count > 0; Count--, Mask++ )
psh1_hint_table_record_mask( table, Mask );
}
/* now, do a linear parse in case some hints were left alone */
if ( table->num_hints != table->max_hints )
{
FT_UInt Index, Count;
FT_ERROR(( "%s.init: missing/incorrect hint masks!\n" ));
Count = table->max_hints;
for ( Index = 0; Index < Count; Index++ )
psh1_hint_table_record( table, Index );
}
Exit:
return error;
}
static void
psh1_hint_table_activate_mask( PSH1_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;
psh1_hint_table_deactivate( table );
for ( idx = 0; idx < limit; idx++ )
{
if ( mask == 0 )
{
val = *cursor++;
mask = 0x80;
}
if ( val & mask )
{
PSH1_Hint hint = &table->hints[idx];
if ( !psh1_hint_is_active( hint ) )
{
PSH1_Hint* sort = table->sort;
FT_UInt count2;
PSH1_Hint hint2;
for ( count2 = count; count2 > 0; count2--, sort++ )
{
hint2 = sort[0];
if ( psh1_hint_overlap( hint, hint2 ) )
{
FT_ERROR(( "%s.activate_mask: found overlapping hints\n",
"psf.hint" ));
break;
}
}
if ( count2 == 0 )
{
psh1_hint_activate( hint );
if ( count < table->max_hints )
table->sort[count++] = hint;
else
FT_ERROR(( "%s.activate_mask: too many active hints\n",
"psf.hint" ));
}
}
}
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;
PSH1_Hint hint1, hint2;
PSH1_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 *****/
/***** *****/
/*************************************************************************/
/*************************************************************************/
#ifdef DEBUG_HINTER
void
ps_simple_scale( PSH1_Hint_Table table,
FT_Fixed scale,
FT_Fixed delta,
FT_Int vertical )
{
PSH1_Hint hint;
FT_UInt count;
for ( count = 0; count < table->num_hints; count++ )
{
hint = table->sort[count];
if ( psh1_hint_is_active( hint ) )
{
hint->cur_pos = FT_MulFix( hint->org_pos, scale ) + delta;
hint->cur_len = FT_MulFix( hint->org_len, scale );
if ( ps1_debug_hint_func )
ps1_debug_hint_func( hint, vertical );
}
}
}
#endif
FT_LOCAL_DEF( FT_Error )
psh1_hint_table_optimize( PSH1_Hint_Table table,
PSH_Globals globals,
FT_Outline* outline,
FT_Int vertical )
{
PSH_Dimension dim = &globals->dimension[vertical];
FT_Fixed scale = dim->scale_mult;
FT_Fixed delta = dim->scale_delta;
FT_UNUSED( outline );
#ifdef DEBUG_HINTER
if ( ps_debug_no_vert_hints && vertical )
{
ps_simple_scale( table, scale, delta, vertical );
return 0;
}
if ( ps_debug_no_horz_hints && !vertical )
{
ps_simple_scale( table, scale, delta, vertical );
return 0;
}
#endif
/* XXXX: for now, we only scale the hints to test all other aspects */
/* of the PostScript hinter */
{
PSH1_Hint hint;
FT_UInt count;
for ( count = 0; count < table->num_hints; count++ )
{
hint = table->sort[count];
if ( psh1_hint_is_active( hint ) )
{
#if 1
FT_Pos pos = FT_MulFix( hint->org_pos, scale ) + delta;
FT_Pos len = FT_MulFix( hint->org_len, scale );
FT_Pos fit_center;
FT_Pos fit_len;
PSH_AlignmentRec align;
/* compute fitted width/height */
fit_len = psh_dimension_snap_width( dim, hint->org_len );
if ( fit_len < 64 )
fit_len = 64;
else
fit_len = ( fit_len + 32 ) & -64;
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 ( !vertical )
{
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:
/* normal processing */
if ( ( fit_len / 64 ) & 1 )
{
/* odd number of pixels */
fit_center = ( ( pos + ( len >> 1 ) ) & -64 ) + 32;
}
else
{
/* even number of pixels */
fit_center = ( pos + ( len >> 1 ) + 32 ) & -64;
}
hint->cur_pos = fit_center - ( fit_len >> 1 );
}
# else
hint->cur_pos = ( FT_MulFix( hint->org_pos, scale ) + delta + 32 )
& -64;
hint->cur_len = FT_MulFix( hint->org_len, scale );
# endif
#ifdef DEBUG_HINTER
if ( ps1_debug_hint_func )
ps1_debug_hint_func( hint, vertical );
#endif
}
}
}
return 0;
}
/*************************************************************************/
/*************************************************************************/
/***** *****/
/***** POINTS INTERPOLATION ROUTINES *****/
/***** *****/
/*************************************************************************/
/*************************************************************************/
#define PSH1_ZONE_MIN -3200000
#define PSH1_ZONE_MAX +3200000
#define xxDEBUG_ZONES
#ifdef DEBUG_ZONES
#include <stdio.h>
static void
psh1_print_zone( PSH1_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 psh1_print_zone( x ) do { } while ( 0 )
#endif
/* setup interpolation zones once the hints have been grid-fitted */
/* by the optimizer */
static void
psh1_hint_table_setup_zones( PSH1_Hint_Table table,
FT_Fixed scale,
FT_Fixed delta )
{
FT_UInt count;
PSH1_Zone zone;
PSH1_Hint *sort, hint, hint2;
zone = table->zones;
/* special case, no hints defined */
if ( table->num_hints == 0 )
{
zone->scale = scale;
zone->delta = delta;
zone->min = PSH1_ZONE_MIN;
zone->max = PSH1_ZONE_MAX;
table->num_zones = 1;
table->zone = zone;
return;
}
/* the first zone is before the first hint */
/* x' = (x-x0)*s + x0' = x*s + ( x0' - x0*s ) */
sort = table->sort;
hint = sort[0];
zone->scale = scale;
zone->delta = hint->cur_pos - FT_MulFix( hint->org_pos, scale );
zone->min = PSH1_ZONE_MIN;
zone->max = hint->org_pos;
psh1_print_zone( zone );
zone++;
for ( count = table->num_hints; count > 0; count-- )
{
FT_Fixed scale2;
if ( hint->org_len > 0 )
{
/* setup a zone for inner-stem interpolation */
/* (x' - x0') = (x - x0)*(x1'-x0')/(x1-x0) */
/* x' = x*s2 + x0' - x0*s2 */
scale2 = FT_DivFix( hint->cur_len, hint->org_len );
zone->scale = scale2;
zone->min = hint->org_pos;
zone->max = hint->org_pos + hint->org_len;
zone->delta = hint->cur_pos - FT_MulFix( zone->min, scale2 );
psh1_print_zone( zone );
zone++;
}
if ( count == 1 )
break;
sort++;
hint2 = sort[0];
/* setup zone for inter-stem interpolation */
/* (x'-x1') = (x-x1)*(x2'-x1')/(x2-x1) */
/* x' = x*s3 + x1' - x1*s3 */
scale2 = FT_DivFix( hint2->cur_pos - (hint->cur_pos + hint->cur_len),
hint2->org_pos - (hint->org_pos + hint->org_len) );
zone->scale = scale2;
zone->min = hint->org_pos + hint->org_len;
zone->max = hint2->org_pos;
zone->delta = hint->cur_pos + hint->cur_len -
FT_MulFix( zone->min, scale2 );
psh1_print_zone( zone );
zone++;
hint = hint2;
}
/* the last zone */
zone->scale = scale;
zone->min = hint->org_pos + hint->org_len;
zone->max = PSH1_ZONE_MAX;
zone->delta = hint->cur_pos + hint->cur_len -
FT_MulFix( zone->min, scale );
psh1_print_zone( zone );
zone++;
table->num_zones = zone - table->zones;
table->zone = table->zones;
}
/* tune a single coordinate with the current interpolation zones */
static FT_Pos
psh1_hint_table_tune_coord( PSH1_Hint_Table table,
FT_Int coord )
{
PSH1_Zone zone;
zone = table->zone;
if ( coord < zone->min )
{
do
{
if ( zone == table->zones )
break;
zone--;
} while ( coord < zone->min );
table->zone = zone;
}
else if ( coord > zone->max )
{
do
{
if ( zone == table->zones + table->num_zones - 1 )
break;
zone++;
} while ( coord > zone->max );
table->zone = zone;
}
return FT_MulFix( coord, zone->scale ) + zone->delta;
}
/* tune a given outline with current interpolation zones. */
/* The function only works in a single dimension. */
static void
psh1_hint_table_tune_outline( PSH1_Hint_Table table,
FT_Outline* outline,
PSH_Globals globals,
FT_Int vertical )
{
FT_UInt count, first, last;
PS_Mask_Table hint_masks = table->hint_masks;
PS_Mask mask;
PSH_Dimension dim = &globals->dimension[vertical];
FT_Fixed scale = dim->scale_mult;
FT_Fixed delta = dim->scale_delta;
if ( hint_masks && hint_masks->num_masks > 0 )
{
first = 0;
mask = hint_masks->masks;
count = hint_masks->num_masks;
for ( ; count > 0; count--, mask++ )
{
last = mask->end_point;
if ( last > first )
{
FT_Vector* vec;
FT_Int count2;
psh1_hint_table_activate_mask( table, mask );
psh1_hint_table_optimize( table, globals, outline, vertical );
psh1_hint_table_setup_zones( table, scale, delta );
last = mask->end_point;
vec = outline->points + first;
count2 = last - first;
for ( ; count2 > 0; count2--, vec++ )
{
FT_Pos x, *px;
px = vertical ? &vec->x : &vec->y;
x = *px;
*px = psh1_hint_table_tune_coord( table, (FT_Int)x );
}
}
first = last;
}
}
else /* no hints in this glyph, simply scale the outline */
{
FT_Vector* vec;
vec = outline->points;
count = outline->n_points;
if ( vertical )
{
for ( ; count > 0; count--, vec++ )
vec->x = FT_MulFix( vec->x, scale ) + delta;
}
else
{
for ( ; count > 0; count--, vec++ )
vec->y = FT_MulFix( vec->y, scale ) + delta;
}
}
}
/*************************************************************************/
/*************************************************************************/
/***** *****/
/***** HIGH-LEVEL INTERFACE *****/
/***** *****/
/*************************************************************************/
/*************************************************************************/
FT_Error
ps1_hints_apply( PS_Hints ps_hints,
FT_Outline* outline,
PSH_Globals globals,
FT_Render_Mode hint_mode )
{
PSH1_Hint_TableRec hints;
FT_Error error = 0;
FT_Int dimension;
FT_UNUSED( hint_mode );
for ( dimension = 1; dimension >= 0; dimension-- )
{
PS_Dimension dim = &ps_hints->dimension[dimension];
/* initialize hints table */
FT_MEM_ZERO( &hints, sizeof ( hints ) );
error = psh1_hint_table_init( &hints,
&dim->hints,
&dim->masks,
&dim->counters,
ps_hints->memory );
if ( error )
goto Exit;
psh1_hint_table_tune_outline( &hints,
outline,
globals,
dimension );
psh1_hint_table_done( &hints, ps_hints->memory );
}
Exit:
return error;
}
/* END */