ref: 600bbfe4aaa9ad0f73d8d73eef1b7670e5f7d3a3
dir: /libfreetype/pshglob.c/
/***************************************************************************/
/* */
/* pshglob.c */
/* */
/* PostScript hinter global hinting management (body). */
/* Inspired by the new auto-hinter module. */
/* */
/* 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_FREETYPE_H
#include FT_INTERNAL_OBJECTS_H
#include "pshglob.h"
#ifdef DEBUG_HINTER
PSH_Globals ps_debug_globals = 0;
#endif
/*************************************************************************/
/*************************************************************************/
/***** *****/
/***** STANDARD WIDTHS *****/
/***** *****/
/*************************************************************************/
/*************************************************************************/
/* scale the widths/heights table */
static void
psh_globals_scale_widths( PSH_Globals globals,
FT_UInt direction )
{
PSH_Dimension dim = &globals->dimension[direction];
PSH_Widths stdw = &dim->stdw;
FT_UInt count = stdw->count;
PSH_Width width = stdw->widths;
PSH_Width stand = width; /* standard width/height */
FT_Fixed scale = dim->scale_mult;
if ( count > 0 )
{
width->cur = FT_MulFix( width->org, scale );
width->fit = FT_RoundFix( width->cur );
width++;
count--;
for ( ; count > 0; count--, width++ )
{
FT_Pos w, dist;
w = FT_MulFix( width->org, scale );
dist = w - stand->cur;
if ( dist < 0 )
dist = -dist;
if ( dist < 128 )
w = stand->cur;
width->cur = w;
width->fit = FT_RoundFix( w );
}
}
}
/* org_width is is font units, result in device pixels, 26.6 format */
FT_LOCAL_DEF( FT_Pos )
psh_dimension_snap_width( PSH_Dimension dimension,
FT_Int org_width )
{
FT_UInt n;
FT_Pos width = FT_MulFix( org_width, dimension->scale_mult );
FT_Pos best = 64 + 32 + 2;
FT_Pos reference = width;
for ( n = 0; n < dimension->stdw.count; n++ )
{
FT_Pos w;
FT_Pos dist;
w = dimension->stdw.widths[n].cur;
dist = width - w;
if ( dist < 0 )
dist = -dist;
if ( dist < best )
{
best = dist;
reference = w;
}
}
if ( width >= reference )
{
width -= 0x21;
if ( width < reference )
width = reference;
}
else
{
width += 0x21;
if ( width > reference )
width = reference;
}
return width;
}
/*************************************************************************/
/*************************************************************************/
/***** *****/
/***** BLUE ZONES *****/
/***** *****/
/*************************************************************************/
/*************************************************************************/
static void
psh_blues_set_zones_0( PSH_Blues target,
FT_Bool is_others,
FT_UInt read_count,
FT_Short* read,
PSH_Blue_Table top_table,
PSH_Blue_Table bot_table )
{
FT_UInt count_top = top_table->count;
FT_UInt count_bot = bot_table->count;
FT_Bool first = 1;
FT_UNUSED( target );
for ( ; read_count > 0; read_count -= 2 )
{
FT_Int reference, delta;
FT_UInt count;
PSH_Blue_Zone zones, zone;
FT_Bool top;
/* read blue zone entry, and select target top/bottom zone */
top = 0;
if ( first || is_others )
{
reference = read[1];
delta = read[0] - reference;
zones = bot_table->zones;
count = count_bot;
first = 0;
}
else
{
reference = read[0];
delta = read[1] - reference;
zones = top_table->zones;
count = count_top;
top = 1;
}
/* insert into sorted table */
zone = zones;
for ( ; count > 0; count--, zone++ )
{
if ( reference < zone->org_ref )
break;
if ( reference == zone->org_ref )
{
FT_Int delta0 = zone->org_delta;
/* we have two zones on the same reference position -- */
/* only keep the largest one */
if ( delta < 0 )
{
if ( delta < delta0 )
zone->org_delta = delta;
}
else
{
if ( delta > delta0 )
zone->org_delta = delta;
}
goto Skip;
}
}
for ( ; count > 0; count-- )
zone[count] = zone[count-1];
zone->org_ref = reference;
zone->org_delta = delta;
if ( top )
count_top++;
else
count_bot++;
Skip:
read += 2;
}
top_table->count = count_top;
bot_table->count = count_bot;
}
/* Re-read blue zones from the original fonts and store them into out */
/* private structure. This function re-orders, sanitizes and */
/* fuzz-expands the zones as well. */
static void
psh_blues_set_zones( PSH_Blues target,
FT_UInt count,
FT_Short* blues,
FT_UInt count_others,
FT_Short* other_blues,
FT_Int fuzz,
FT_Int family )
{
PSH_Blue_Table top_table, bot_table;
FT_Int count_top, count_bot;
if ( family )
{
top_table = &target->family_top;
bot_table = &target->family_bottom;
}
else
{
top_table = &target->normal_top;
bot_table = &target->normal_bottom;
}
/* read the input blue zones, and build two sorted tables */
/* (one for the top zones, the other for the bottom zones) */
top_table->count = 0;
bot_table->count = 0;
/* first, the blues */
psh_blues_set_zones_0( target, 0,
count, blues, top_table, bot_table );
psh_blues_set_zones_0( target, 1,
count_others, other_blues, top_table, bot_table );
count_top = top_table->count;
count_bot = bot_table->count;
/* sanitize top table */
if ( count_top > 0 )
{
PSH_Blue_Zone zone = top_table->zones;
for ( count = count_top; count > 0; count--, zone++ )
{
FT_Int delta;
if ( count > 1 )
{
delta = zone[1].org_ref - zone[0].org_ref;
if ( zone->org_delta > delta )
zone->org_delta = delta;
}
zone->org_bottom = zone->org_ref;
zone->org_top = zone->org_delta + zone->org_ref;
}
}
/* sanitize bottom table */
if ( count_bot > 0 )
{
PSH_Blue_Zone zone = bot_table->zones;
for ( count = count_bot; count > 0; count--, zone++ )
{
FT_Int delta;
if ( count > 1 )
{
delta = zone[0].org_ref - zone[1].org_ref;
if ( zone->org_delta < delta )
zone->org_delta = delta;
}
zone->org_top = zone->org_ref;
zone->org_bottom = zone->org_delta + zone->org_ref;
}
}
/* expand top and bottom tables with blue fuzz */
{
FT_Int dim, top, bot, delta;
PSH_Blue_Zone zone;
zone = top_table->zones;
count = count_top;
for ( dim = 1; dim >= 0; dim-- )
{
if ( count > 0 )
{
/* expand the bottom of the lowest zone normally */
zone->org_bottom -= fuzz;
/* expand the top and bottom of intermediate zones; */
/* checking that the interval is smaller than the fuzz */
top = zone->org_top;
for ( count--; count > 0; count-- )
{
bot = zone[1].org_bottom;
delta = bot - top;
if ( delta < 2 * fuzz )
zone[0].org_top = zone[1].org_bottom = top + delta / 2;
else
{
zone[0].org_top = top + fuzz;
zone[1].org_bottom = bot - fuzz;
}
zone++;
top = zone->org_top;
}
/* expand the top of the highest zone normally */
zone->org_top = top + fuzz;
}
zone = bot_table->zones;
count = count_bot;
}
}
}
/* reset the blues table when the device transform changes */
static void
psh_blues_scale_zones( PSH_Blues blues,
FT_Fixed scale,
FT_Pos delta )
{
FT_UInt count;
FT_UInt num;
PSH_Blue_Table table = 0;
/* */
/* Determine whether we need to suppress overshoots or */
/* not. We simply need to compare the vertical scale */
/* parameter to the raw bluescale value. Here is why: */
/* */
/* We need to suppress overshoots for all pointsizes. */
/* At 300dpi that satisfy: */
/* */
/* pointsize < 240*bluescale + 0.49 */
/* */
/* This corresponds to: */
/* */
/* pixelsize < 1000*bluescale + 49/24 */
/* */
/* scale*EM_Size < 1000*bluescale + 49/24 */
/* */
/* However, for normal Type 1 fonts, EM_Size is 1000! */
/* We thus only check: */
/* */
/* scale < bluescale + 49/24000 */
/* */
/* which we shorten to */
/* */
/* "scale < bluescale" */
/* */
blues->no_overshoots = FT_BOOL( scale < blues->blue_scale );
/* */
/* The blue threshold is the font units distance under */
/* which overshoots are suppressed due to the BlueShift */
/* even if the scale is greater than BlueScale. */
/* */
/* It is the smallest distance such that */
/* */
/* dist <= BlueShift && dist*scale <= 0.5 pixels */
/* */
{
FT_Int threshold = blues->blue_shift;
while ( threshold > 0 && FT_MulFix( threshold, scale ) > 32 )
threshold --;
blues->blue_threshold = threshold;
}
for ( num = 0; num < 4; num++ )
{
PSH_Blue_Zone zone;
switch ( num )
{
case 0:
table = &blues->normal_top;
break;
case 1:
table = &blues->normal_bottom;
break;
case 2:
table = &blues->family_top;
break;
default:
table = &blues->family_bottom;
break;
}
zone = table->zones;
count = table->count;
for ( ; count > 0; count--, zone++ )
{
zone->cur_top = FT_MulFix( zone->org_top, scale ) + delta;
zone->cur_bottom = FT_MulFix( zone->org_bottom, scale ) + delta;
zone->cur_ref = FT_MulFix( zone->org_ref, scale ) + delta;
zone->cur_delta = FT_MulFix( zone->org_delta, scale );
/* round scaled reference position */
zone->cur_ref = ( zone->cur_ref + 32 ) & -64;
#if 0
if ( zone->cur_ref > zone->cur_top )
zone->cur_ref -= 64;
else if ( zone->cur_ref < zone->cur_bottom )
zone->cur_ref += 64;
#endif
}
}
/* process the families now */
for ( num = 0; num < 2; num++ )
{
PSH_Blue_Zone zone1, zone2;
FT_UInt count1, count2;
PSH_Blue_Table normal, family;
switch ( num )
{
case 0:
normal = &blues->normal_top;
family = &blues->family_top;
break;
default:
normal = &blues->normal_bottom;
family = &blues->family_bottom;
}
zone1 = normal->zones;
count1 = normal->count;
for ( ; count1 > 0; count1--, zone1++ )
{
/* try to find a family zone whose reference position is less */
/* than 1 pixel far from the current zone */
zone2 = family->zones;
count2 = family->count;
for ( ; count2 > 0; count2--, zone2++ )
{
FT_Pos Delta;
Delta = zone1->org_ref - zone2->org_ref;
if ( Delta < 0 )
Delta = -Delta;
if ( FT_MulFix( Delta, scale ) < 64 )
{
zone1->cur_top = zone2->cur_top;
zone1->cur_bottom = zone2->cur_bottom;
zone1->cur_ref = zone2->cur_ref;
zone1->cur_delta = zone2->cur_delta;
break;
}
}
}
}
}
FT_LOCAL_DEF( void )
psh_blues_snap_stem( PSH_Blues blues,
FT_Int stem_top,
FT_Int stem_bot,
PSH_Alignment alignment )
{
PSH_Blue_Table table;
FT_UInt count;
FT_Pos delta;
PSH_Blue_Zone zone;
FT_Int no_shoots;
alignment->align = PSH_BLUE_ALIGN_NONE;
no_shoots = blues->no_overshoots;
/* lookup stem top in top zones table */
table = &blues->normal_top;
count = table->count;
zone = table->zones;
for ( ; count > 0; count--, zone++ )
{
delta = stem_top - zone->org_bottom;
if ( delta < -blues->blue_fuzz )
break;
if ( stem_top <= zone->org_top + blues->blue_fuzz )
{
if ( no_shoots || delta <= blues->blue_threshold )
{
alignment->align |= PSH_BLUE_ALIGN_TOP;
alignment->align_top = zone->cur_ref;
}
break;
}
}
/* look up stem bottom in bottom zones table */
table = &blues->normal_bottom;
count = table->count;
zone = table->zones + count-1;
for ( ; count > 0; count--, zone-- )
{
delta = zone->org_top - stem_bot;
if ( delta < -blues->blue_fuzz )
break;
if ( stem_bot >= zone->org_bottom - blues->blue_fuzz )
{
if ( no_shoots || delta < blues->blue_shift )
{
alignment->align |= PSH_BLUE_ALIGN_BOT;
alignment->align_bot = zone->cur_ref;
}
break;
}
}
}
/*************************************************************************/
/*************************************************************************/
/***** *****/
/***** GLOBAL HINTS *****/
/***** *****/
/*************************************************************************/
/*************************************************************************/
static void
psh_globals_destroy( PSH_Globals globals )
{
if ( globals )
{
FT_Memory memory;
memory = globals->memory;
globals->dimension[0].stdw.count = 0;
globals->dimension[1].stdw.count = 0;
globals->blues.normal_top.count = 0;
globals->blues.normal_bottom.count = 0;
globals->blues.family_top.count = 0;
globals->blues.family_bottom.count = 0;
FT_FREE( globals );
#ifdef DEBUG_HINTER
ps_debug_globals = 0;
#endif
}
}
static FT_Error
psh_globals_new( FT_Memory memory,
T1_Private* priv,
PSH_Globals *aglobals )
{
PSH_Globals globals;
FT_Error error;
if ( !FT_NEW( globals ) )
{
FT_UInt count;
FT_Short* read;
globals->memory = memory;
/* copy standard widths */
{
PSH_Dimension dim = &globals->dimension[1];
PSH_Width write = dim->stdw.widths;
write->org = priv->standard_width[0];
write++;
read = priv->snap_widths;
for ( count = priv->num_snap_widths; count > 0; count-- )
{
write->org = *read;
write++;
read++;
}
dim->stdw.count = write - dim->stdw.widths;
}
/* copy standard heights */
{
PSH_Dimension dim = &globals->dimension[0];
PSH_Width write = dim->stdw.widths;
write->org = priv->standard_height[0];
write++;
read = priv->snap_heights;
for ( count = priv->num_snap_heights; count > 0; count-- )
{
write->org = *read;
write++;
read++;
}
dim->stdw.count = write - dim->stdw.widths;
}
/* copy blue zones */
psh_blues_set_zones( &globals->blues, priv->num_blue_values,
priv->blue_values, priv->num_other_blues,
priv->other_blues, priv->blue_fuzz, 0 );
psh_blues_set_zones( &globals->blues, priv->num_family_blues,
priv->family_blues, priv->num_family_other_blues,
priv->family_other_blues, priv->blue_fuzz, 1 );
globals->blues.blue_scale = priv->blue_scale
? priv->blue_scale
: 0x28937L; /* 0.039625 * 0x400000L */
globals->blues.blue_shift = priv->blue_shift
? priv->blue_shift
: 7;
globals->blues.blue_fuzz = priv->blue_fuzz;
globals->dimension[0].scale_mult = 0;
globals->dimension[0].scale_delta = 0;
globals->dimension[1].scale_mult = 0;
globals->dimension[1].scale_delta = 0;
#ifdef DEBUG_HINTER
ps_debug_globals = globals;
#endif
}
*aglobals = globals;
return error;
}
static FT_Error
psh_globals_set_scale( PSH_Globals globals,
FT_Fixed x_scale,
FT_Fixed y_scale,
FT_Fixed x_delta,
FT_Fixed y_delta )
{
PSH_Dimension dim = &globals->dimension[0];
dim = &globals->dimension[0];
if ( x_scale != dim->scale_mult ||
x_delta != dim->scale_delta )
{
dim->scale_mult = x_scale;
dim->scale_delta = x_delta;
psh_globals_scale_widths( globals, 0 );
}
dim = &globals->dimension[1];
if ( y_scale != dim->scale_mult ||
y_delta != dim->scale_delta )
{
dim->scale_mult = y_scale;
dim->scale_delta = y_delta;
psh_globals_scale_widths( globals, 1 );
psh_blues_scale_zones( &globals->blues, y_scale, y_delta );
}
return 0;
}
FT_LOCAL_DEF( void )
psh_globals_funcs_init( PSH_Globals_FuncsRec* funcs )
{
funcs->create = psh_globals_new;
funcs->set_scale = psh_globals_set_scale;
funcs->destroy = psh_globals_destroy;
}
/* END */