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-rw-r--r--src/autofit/afcjk.c1506
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+/***************************************************************************/
+/* */
+/* afcjk.c */
+/* */
+/* Auto-fitter hinting routines for CJK script (body). */
+/* */
+/* Copyright 2006, 2007 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. */
+/* */
+/***************************************************************************/
+
+ /*
+ * The algorithm is based on akito's autohint patch, available here:
+ *
+ * http://www.kde.gr.jp/~akito/patch/freetype2/
+ *
+ */
+
+#include "aftypes.h"
+#include "aflatin.h"
+
+
+#ifdef AF_CONFIG_OPTION_CJK
+
+#include "afcjk.h"
+#include "aferrors.h"
+
+
+#ifdef AF_USE_WARPER
+#include "afwarp.h"
+#endif
+
+
+ /*************************************************************************/
+ /*************************************************************************/
+ /***** *****/
+ /***** C J K G L O B A L M E T R I C S *****/
+ /***** *****/
+ /*************************************************************************/
+ /*************************************************************************/
+
+ static FT_Error
+ af_cjk_metrics_init( AF_LatinMetrics metrics,
+ FT_Face face )
+ {
+ FT_CharMap oldmap = face->charmap;
+
+
+ metrics->units_per_em = face->units_per_EM;
+
+ /* TODO are there blues? */
+
+ if ( FT_Select_Charmap( face, FT_ENCODING_UNICODE ) )
+ face->charmap = NULL;
+
+ /* latin's version would suffice */
+ af_latin_metrics_init_widths( metrics, face, 0x7530 );
+
+ FT_Set_Charmap( face, oldmap );
+
+ return AF_Err_Ok;
+ }
+
+
+ static void
+ af_cjk_metrics_scale_dim( AF_LatinMetrics metrics,
+ AF_Scaler scaler,
+ AF_Dimension dim )
+ {
+ AF_LatinAxis axis;
+
+
+ axis = &metrics->axis[dim];
+
+ if ( dim == AF_DIMENSION_HORZ )
+ {
+ axis->scale = scaler->x_scale;
+ axis->delta = scaler->x_delta;
+ }
+ else
+ {
+ axis->scale = scaler->y_scale;
+ axis->delta = scaler->y_delta;
+ }
+ }
+
+
+ static void
+ af_cjk_metrics_scale( AF_LatinMetrics metrics,
+ AF_Scaler scaler )
+ {
+ metrics->root.scaler = *scaler;
+
+ af_cjk_metrics_scale_dim( metrics, scaler, AF_DIMENSION_HORZ );
+ af_cjk_metrics_scale_dim( metrics, scaler, AF_DIMENSION_VERT );
+ }
+
+
+ /*************************************************************************/
+ /*************************************************************************/
+ /***** *****/
+ /***** C J K G L Y P H A N A L Y S I S *****/
+ /***** *****/
+ /*************************************************************************/
+ /*************************************************************************/
+
+ static FT_Error
+ af_cjk_hints_compute_segments( AF_GlyphHints hints,
+ AF_Dimension dim )
+ {
+ AF_AxisHints axis = &hints->axis[dim];
+ AF_Segment segments = axis->segments;
+ AF_Segment segment_limit = segments + axis->num_segments;
+ FT_Error error;
+ AF_Segment seg;
+
+
+ error = af_latin_hints_compute_segments( hints, dim );
+ if ( error )
+ return error;
+
+ /* a segment is round if it doesn't have successive */
+ /* on-curve points. */
+ for ( seg = segments; seg < segment_limit; seg++ )
+ {
+ AF_Point pt = seg->first;
+ AF_Point last = seg->last;
+ AF_Flags f0 = (AF_Flags)(pt->flags & AF_FLAG_CONTROL);
+ AF_Flags f1;
+
+
+ seg->flags &= ~AF_EDGE_ROUND;
+
+ for ( ; pt != last; f0 = f1 )
+ {
+ pt = pt->next;
+ f1 = (AF_Flags)(pt->flags & AF_FLAG_CONTROL);
+
+ if ( !f0 && !f1 )
+ break;
+
+ if ( pt == last )
+ seg->flags |= AF_EDGE_ROUND;
+ }
+ }
+
+ return AF_Err_Ok;
+ }
+
+
+ static void
+ af_cjk_hints_link_segments( AF_GlyphHints hints,
+ AF_Dimension dim )
+ {
+ AF_AxisHints axis = &hints->axis[dim];
+ AF_Segment segments = axis->segments;
+ AF_Segment segment_limit = segments + axis->num_segments;
+ AF_Direction major_dir = axis->major_dir;
+ AF_Segment seg1, seg2;
+ FT_Pos len_threshold;
+ FT_Pos dist_threshold;
+
+
+ len_threshold = AF_LATIN_CONSTANT( hints->metrics, 8 );
+
+ dist_threshold = ( dim == AF_DIMENSION_HORZ ) ? hints->x_scale
+ : hints->y_scale;
+ dist_threshold = FT_DivFix( 64 * 3, dist_threshold );
+
+ /* now compare each segment to the others */
+ for ( seg1 = segments; seg1 < segment_limit; seg1++ )
+ {
+ /* the fake segments are for metrics hinting only */
+ if ( seg1->first == seg1->last )
+ continue;
+
+ if ( seg1->dir != major_dir )
+ continue;
+
+ for ( seg2 = segments; seg2 < segment_limit; seg2++ )
+ if ( seg2 != seg1 && seg1->dir + seg2->dir == 0 )
+ {
+ FT_Pos dist = seg2->pos - seg1->pos;
+
+
+ if ( dist < 0 )
+ continue;
+
+ {
+ FT_Pos min = seg1->min_coord;
+ FT_Pos max = seg1->max_coord;
+ FT_Pos len;
+
+
+ if ( min < seg2->min_coord )
+ min = seg2->min_coord;
+
+ if ( max > seg2->max_coord )
+ max = seg2->max_coord;
+
+ len = max - min;
+ if ( len >= len_threshold )
+ {
+ if ( dist * 8 < seg1->score * 9 &&
+ ( dist * 8 < seg1->score * 7 || seg1->len < len ) )
+ {
+ seg1->score = dist;
+ seg1->len = len;
+ seg1->link = seg2;
+ }
+
+ if ( dist * 8 < seg2->score * 9 &&
+ ( dist * 8 < seg2->score * 7 || seg2->len < len ) )
+ {
+ seg2->score = dist;
+ seg2->len = len;
+ seg2->link = seg1;
+ }
+ }
+ }
+ }
+ }
+
+ /*
+ * now compute the `serif' segments
+ *
+ * In Hanzi, some strokes are wider on one or both of the ends.
+ * We either identify the stems on the ends as serifs or remove
+ * the linkage, depending on the length of the stems.
+ *
+ */
+
+ {
+ AF_Segment link1, link2;
+
+
+ for ( seg1 = segments; seg1 < segment_limit; seg1++ )
+ {
+ link1 = seg1->link;
+ if ( !link1 || link1->link != seg1 || link1->pos <= seg1->pos )
+ continue;
+
+ if ( seg1->score >= dist_threshold )
+ continue;
+
+ for ( seg2 = segments; seg2 < segment_limit; seg2++ )
+ {
+ if ( seg2->pos > seg1->pos || seg1 == seg2 )
+ continue;
+
+ link2 = seg2->link;
+ if ( !link2 || link2->link != seg2 || link2->pos < link1->pos )
+ continue;
+
+ if ( seg1->pos == seg2->pos && link1->pos == link2->pos )
+ continue;
+
+ if ( seg2->score <= seg1->score || seg1->score * 4 <= seg2->score )
+ continue;
+
+ /* seg2 < seg1 < link1 < link2 */
+
+ if ( seg1->len >= seg2->len * 3 )
+ {
+ AF_Segment seg;
+
+
+ for ( seg = segments; seg < segment_limit; seg++ )
+ {
+ AF_Segment link = seg->link;
+
+
+ if ( link == seg2 )
+ {
+ seg->link = 0;
+ seg->serif = link1;
+ }
+ else if ( link == link2 )
+ {
+ seg->link = 0;
+ seg->serif = seg1;
+ }
+ }
+ }
+ else
+ {
+ seg1->link = link1->link = 0;
+
+ break;
+ }
+ }
+ }
+ }
+
+ for ( seg1 = segments; seg1 < segment_limit; seg1++ )
+ {
+ seg2 = seg1->link;
+
+ if ( seg2 )
+ {
+ seg2->num_linked++;
+ if ( seg2->link != seg1 )
+ {
+ seg1->link = 0;
+
+ if ( seg2->score < dist_threshold || seg1->score < seg2->score * 4 )
+ seg1->serif = seg2->link;
+ else
+ seg2->num_linked--;
+ }
+ }
+ }
+ }
+
+
+ static FT_Error
+ af_cjk_hints_compute_edges( AF_GlyphHints hints,
+ AF_Dimension dim )
+ {
+ 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_Segment segments = axis->segments;
+ AF_Segment segment_limit = segments + axis->num_segments;
+ AF_Segment seg;
+
+ FT_Fixed scale;
+ FT_Pos edge_distance_threshold;
+
+
+ axis->num_edges = 0;
+
+ scale = ( dim == AF_DIMENSION_HORZ ) ? hints->x_scale
+ : hints->y_scale;
+
+ /*********************************************************************/
+ /* */
+ /* We begin by generating a sorted table of edges for the current */
+ /* direction. To do so, we simply scan each segment and try to find */
+ /* an edge in our table that corresponds to its position. */
+ /* */
+ /* If no edge is found, we create and insert a new edge in the */
+ /* sorted table. Otherwise, we simply add the segment to the edge's */
+ /* list which is then processed in the second step to compute the */
+ /* edge's properties. */
+ /* */
+ /* Note that the edges table is sorted along the segment/edge */
+ /* position. */
+ /* */
+ /*********************************************************************/
+
+ edge_distance_threshold = FT_MulFix( laxis->edge_distance_threshold,
+ scale );
+ if ( edge_distance_threshold > 64 / 4 )
+ edge_distance_threshold = FT_DivFix( 64 / 4, scale );
+ else
+ edge_distance_threshold = laxis->edge_distance_threshold;
+
+ for ( seg = segments; seg < segment_limit; seg++ )
+ {
+ AF_Edge found = 0;
+ FT_Pos best = 0xFFFFU;
+ FT_Int ee;
+
+
+ /* look for an edge corresponding to the segment */
+ for ( ee = 0; ee < axis->num_edges; ee++ )
+ {
+ AF_Edge edge = axis->edges + ee;
+ FT_Pos dist;
+
+
+ if ( edge->dir != seg->dir )
+ continue;
+
+ dist = seg->pos - edge->fpos;
+ if ( dist < 0 )
+ dist = -dist;
+
+ if ( dist < edge_distance_threshold && dist < best )
+ {
+ AF_Segment link = seg->link;
+
+
+ /* check whether all linked segments of the candidate edge */
+ /* can make a single edge. */
+ if ( link )
+ {
+ AF_Segment seg1 = edge->first;
+ AF_Segment link1;
+ FT_Pos dist2 = 0;
+
+
+ do
+ {
+ link1 = seg1->link;
+ if ( link1 )
+ {
+ dist2 = AF_SEGMENT_DIST( link, link1 );
+ if ( dist2 >= edge_distance_threshold )
+ break;
+ }
+
+ } while ( ( seg1 = seg1->edge_next ) != edge->first );
+
+ if ( dist2 >= edge_distance_threshold )
+ continue;
+ }
+
+ best = dist;
+ found = edge;
+ }
+ }
+
+ if ( !found )
+ {
+ AF_Edge edge;
+
+
+ /* insert a new edge in the list and */
+ /* sort according to the position */
+ error = af_axis_hints_new_edge( axis, seg->pos, seg->dir, memory, &edge );
+ if ( error )
+ goto Exit;
+
+ /* add the segment to the new edge's list */
+ FT_ZERO( edge );
+
+ edge->first = seg;
+ edge->last = seg;
+ edge->fpos = seg->pos;
+ edge->opos = edge->pos = FT_MulFix( seg->pos, scale );
+ seg->edge_next = seg;
+ edge->dir = seg->dir;
+ }
+ else
+ {
+ /* if an edge was found, simply add the segment to the edge's */
+ /* list */
+ seg->edge_next = found->first;
+ found->last->edge_next = seg;
+ found->last = seg;
+ }
+ }
+
+ /*********************************************************************/
+ /* */
+ /* Good, we now compute each edge's properties according to segments */
+ /* found on its position. Basically, these are as follows. */
+ /* */
+ /* - edge's main direction */
+ /* - stem edge, serif edge or both (which defaults to stem then) */
+ /* - rounded edge, straight or both (which defaults to straight) */
+ /* - link for edge */
+ /* */
+ /*********************************************************************/
+
+ /* first of all, set the `edge' field in each segment -- this is */
+ /* required in order to compute edge links */
+ /* */
+ /* Note that removing this loop and setting the `edge' field of each */
+ /* segment directly in the code above slows down execution speed for */
+ /* some reasons on platforms like the Sun. */
+
+ {
+ AF_Edge edges = axis->edges;
+ AF_Edge edge_limit = edges + axis->num_edges;
+ AF_Edge edge;
+
+
+ for ( edge = edges; edge < edge_limit; edge++ )
+ {
+ seg = edge->first;
+ if ( seg )
+ do
+ {
+ seg->edge = edge;
+ seg = seg->edge_next;
+
+ } while ( seg != edge->first );
+ }
+
+ /* now compute each edge properties */
+ for ( edge = edges; edge < edge_limit; edge++ )
+ {
+ FT_Int is_round = 0; /* does it contain round segments? */
+ FT_Int is_straight = 0; /* does it contain straight segments? */
+
+
+ seg = edge->first;
+
+ do
+ {
+ FT_Bool is_serif;
+
+
+ /* check for roundness of segment */
+ if ( seg->flags & AF_EDGE_ROUND )
+ is_round++;
+ else
+ is_straight++;
+
+ /* check for links -- if seg->serif is set, then seg->link must */
+ /* be ignored */
+ is_serif = (FT_Bool)( seg->serif && seg->serif->edge != edge );
+
+ if ( seg->link || is_serif )
+ {
+ AF_Edge edge2;
+ AF_Segment seg2;
+
+
+ edge2 = edge->link;
+ seg2 = seg->link;
+
+ if ( is_serif )
+ {
+ seg2 = seg->serif;
+ edge2 = edge->serif;
+ }
+
+ if ( edge2 )
+ {
+ FT_Pos edge_delta;
+ FT_Pos seg_delta;
+
+
+ edge_delta = edge->fpos - edge2->fpos;
+ if ( edge_delta < 0 )
+ edge_delta = -edge_delta;
+
+ seg_delta = AF_SEGMENT_DIST( seg, seg2 );
+
+ if ( seg_delta < edge_delta )
+ edge2 = seg2->edge;
+ }
+ else
+ edge2 = seg2->edge;
+
+ if ( is_serif )
+ {
+ edge->serif = edge2;
+ edge2->flags |= AF_EDGE_SERIF;
+ }
+ else
+ edge->link = edge2;
+ }
+
+ seg = seg->edge_next;
+
+ } while ( seg != edge->first );
+
+ /* set the round/straight flags */
+ edge->flags = AF_EDGE_NORMAL;
+
+ if ( is_round > 0 && is_round >= is_straight )
+ edge->flags |= AF_EDGE_ROUND;
+
+ /* get rid of serifs if link is set */
+ /* XXX: This gets rid of many unpleasant artefacts! */
+ /* Example: the `c' in cour.pfa at size 13 */
+
+ if ( edge->serif && edge->link )
+ edge->serif = 0;
+ }
+ }
+
+ Exit:
+ return error;
+ }
+
+
+ static FT_Error
+ af_cjk_hints_detect_features( AF_GlyphHints hints,
+ AF_Dimension dim )
+ {
+ FT_Error error;
+
+
+ error = af_cjk_hints_compute_segments( hints, dim );
+ if ( !error )
+ {
+ af_cjk_hints_link_segments( hints, dim );
+
+ error = af_cjk_hints_compute_edges( hints, dim );
+ }
+ return error;
+ }
+
+
+ static FT_Error
+ af_cjk_hints_init( AF_GlyphHints hints,
+ AF_LatinMetrics metrics )
+ {
+ FT_Render_Mode mode;
+ FT_UInt32 scaler_flags, other_flags;
+
+
+ af_glyph_hints_rescale( hints, (AF_ScriptMetrics)metrics );
+
+ /*
+ * correct x_scale and y_scale when needed, since they may have
+ * been modified af_cjk_scale_dim above
+ */
+ hints->x_scale = metrics->axis[AF_DIMENSION_HORZ].scale;
+ hints->x_delta = metrics->axis[AF_DIMENSION_HORZ].delta;
+ hints->y_scale = metrics->axis[AF_DIMENSION_VERT].scale;
+ hints->y_delta = metrics->axis[AF_DIMENSION_VERT].delta;
+
+ /* compute flags depending on render mode, etc. */
+ mode = metrics->root.scaler.render_mode;
+
+#ifdef AF_USE_WARPER
+ if ( mode == FT_RENDER_MODE_LCD || mode == FT_RENDER_MODE_LCD_V )
+ metrics->root.scaler.render_mode = mode = FT_RENDER_MODE_NORMAL;
+#endif
+
+ scaler_flags = hints->scaler_flags;
+ other_flags = 0;
+
+ /*
+ * We snap the width of vertical stems for the monochrome and
+ * horizontal LCD rendering targets only.
+ */
+ if ( mode == FT_RENDER_MODE_MONO || mode == FT_RENDER_MODE_LCD )
+ other_flags |= AF_LATIN_HINTS_HORZ_SNAP;
+
+ /*
+ * We snap the width of horizontal stems for the monochrome and
+ * vertical LCD rendering targets only.
+ */
+ if ( mode == FT_RENDER_MODE_MONO || mode == FT_RENDER_MODE_LCD_V )
+ other_flags |= AF_LATIN_HINTS_VERT_SNAP;
+
+ /*
+ * We adjust stems to full pixels only if we don't use the `light' mode.
+ */
+ if ( mode != FT_RENDER_MODE_LIGHT )
+ other_flags |= AF_LATIN_HINTS_STEM_ADJUST;
+
+ if ( mode == FT_RENDER_MODE_MONO )
+ other_flags |= AF_LATIN_HINTS_MONO;
+
+ scaler_flags |= AF_SCALER_FLAG_NO_ADVANCE;
+
+ hints->scaler_flags = scaler_flags;
+ hints->other_flags = other_flags;
+
+ return 0;
+ }
+
+
+ /*************************************************************************/
+ /*************************************************************************/
+ /***** *****/
+ /***** C J K G L Y P H G R I D - F I T T I N G *****/
+ /***** *****/
+ /*************************************************************************/
+ /*************************************************************************/
+
+ /* snap a given width in scaled coordinates to one of the */
+ /* current standard widths */
+
+ static FT_Pos
+ af_cjk_snap_width( AF_Width widths,
+ FT_Int count,
+ FT_Pos width )
+ {
+ int n;
+ FT_Pos best = 64 + 32 + 2;
+ FT_Pos reference = width;
+ FT_Pos scaled;
+
+
+ for ( n = 0; n < count; n++ )
+ {
+ FT_Pos w;
+ FT_Pos dist;
+
+
+ w = widths[n].cur;
+ dist = width - w;
+ if ( dist < 0 )
+ dist = -dist;
+ if ( dist < best )
+ {
+ best = dist;
+ reference = w;
+ }
+ }
+
+ scaled = FT_PIX_ROUND( reference );
+
+ if ( width >= reference )
+ {
+ if ( width < scaled + 48 )
+ width = reference;
+ }
+ else
+ {
+ if ( width > scaled - 48 )
+ width = reference;
+ }
+
+ return width;
+ }
+
+
+ /* compute the snapped width of a given stem */
+
+ static FT_Pos
+ af_cjk_compute_stem_width( AF_GlyphHints hints,
+ AF_Dimension dim,
+ FT_Pos width,
+ AF_Edge_Flags base_flags,
+ AF_Edge_Flags stem_flags )
+ {
+ AF_LatinMetrics metrics = (AF_LatinMetrics) hints->metrics;
+ AF_LatinAxis axis = & metrics->axis[dim];
+ FT_Pos dist = width;
+ FT_Int sign = 0;
+ FT_Int vertical = ( dim == AF_DIMENSION_VERT );
+
+ FT_UNUSED( base_flags );
+ FT_UNUSED( stem_flags );
+
+
+ if ( !AF_LATIN_HINTS_DO_STEM_ADJUST( hints ) )
+ return width;
+
+ if ( dist < 0 )
+ {
+ dist = -width;
+ sign = 1;
+ }
+
+ if ( ( vertical && !AF_LATIN_HINTS_DO_VERT_SNAP( hints ) ) ||
+ ( !vertical && !AF_LATIN_HINTS_DO_HORZ_SNAP( hints ) ) )
+ {
+ /* smooth hinting process: very lightly quantize the stem width */
+
+ if ( axis->width_count > 0 )
+ {
+ if ( FT_ABS( dist - axis->widths[0].cur ) < 40 )
+ {
+ dist = axis->widths[0].cur;
+ if ( dist < 48 )
+ dist = 48;
+
+ goto Done_Width;
+ }
+ }
+
+ if ( dist < 54 )
+ dist += ( 54 - dist ) / 2 ;
+ else if ( dist < 3 * 64 )
+ {
+ FT_Pos delta;
+
+
+ delta = dist & 63;
+ dist &= -64;
+
+ if ( delta < 10 )
+ dist += delta;
+ else if ( delta < 22 )
+ dist += 10;
+ else if ( delta < 42 )
+ dist += delta;
+ else if ( delta < 54 )
+ dist += 54;
+ else
+ dist += delta;
+ }
+ }
+ else
+ {
+ /* strong hinting process: snap the stem width to integer pixels */
+
+ dist = af_cjk_snap_width( axis->widths, axis->width_count, dist );
+
+ if ( vertical )
+ {
+ /* in the case of vertical hinting, always round */
+ /* the stem heights to integer pixels */
+
+ if ( dist >= 64 )
+ dist = ( dist + 16 ) & ~63;
+ else
+ dist = 64;
+ }
+ else
+ {
+ if ( AF_LATIN_HINTS_DO_MONO( hints ) )
+ {
+ /* monochrome horizontal hinting: snap widths to integer pixels */
+ /* with a different threshold */
+
+ if ( dist < 64 )
+ dist = 64;
+ else
+ dist = ( dist + 32 ) & ~63;
+ }
+ else
+ {
+ /* for horizontal anti-aliased hinting, we adopt a more subtle */
+ /* approach: we strengthen small stems, round stems whose size */
+ /* is between 1 and 2 pixels to an integer, otherwise nothing */
+
+ if ( dist < 48 )
+ dist = ( dist + 64 ) >> 1;
+
+ else if ( dist < 128 )
+ dist = ( dist + 22 ) & ~63;
+ else
+ /* round otherwise to prevent color fringes in LCD mode */
+ dist = ( dist + 32 ) & ~63;
+ }
+ }
+ }
+
+ Done_Width:
+ if ( sign )
+ dist = -dist;
+
+ return dist;
+ }
+
+
+ /* align one stem edge relative to the previous stem edge */
+
+ static void
+ af_cjk_align_linked_edge( AF_GlyphHints hints,
+ AF_Dimension dim,
+ AF_Edge base_edge,
+ AF_Edge stem_edge )
+ {
+ FT_Pos dist = stem_edge->opos - base_edge->opos;
+
+ FT_Pos fitted_width = af_cjk_compute_stem_width(
+ hints, dim, dist,
+ (AF_Edge_Flags)base_edge->flags,
+ (AF_Edge_Flags)stem_edge->flags );
+
+
+ stem_edge->pos = base_edge->pos + fitted_width;
+ }
+
+
+ static void
+ af_cjk_align_serif_edge( AF_GlyphHints hints,
+ AF_Edge base,
+ AF_Edge serif )
+ {
+ FT_UNUSED( hints );
+
+ serif->pos = base->pos + ( serif->opos - base->opos );
+ }
+
+
+ /*************************************************************************/
+ /*************************************************************************/
+ /*************************************************************************/
+ /**** ****/
+ /**** E D G E H I N T I N G ****/
+ /**** ****/
+ /*************************************************************************/
+ /*************************************************************************/
+ /*************************************************************************/
+
+
+#define AF_LIGHT_MODE_MAX_HORZ_GAP 9
+#define AF_LIGHT_MODE_MAX_VERT_GAP 15
+#define AF_LIGHT_MODE_MAX_DELTA_ABS 14
+
+
+ static FT_Pos
+ af_hint_normal_stem( AF_GlyphHints hints,
+ AF_Edge edge,
+ AF_Edge edge2,
+ FT_Pos anchor,
+ AF_Dimension dim )
+ {
+ FT_Pos org_len, cur_len, org_center;
+ FT_Pos cur_pos1, cur_pos2;
+ FT_Pos d_off1, u_off1, d_off2, u_off2, delta;
+ FT_Pos offset;
+ FT_Pos threshold = 64;
+
+
+ if ( !AF_LATIN_HINTS_DO_STEM_ADJUST( hints ) )
+ {
+ if ( ( edge->flags & AF_EDGE_ROUND ) &&
+ ( edge2->flags & AF_EDGE_ROUND ) )
+ {
+ if ( dim == AF_DIMENSION_VERT )
+ threshold = 64 - AF_LIGHT_MODE_MAX_HORZ_GAP;
+ else
+ threshold = 64 - AF_LIGHT_MODE_MAX_VERT_GAP;
+ }
+ else
+ {
+ if ( dim == AF_DIMENSION_VERT )
+ threshold = 64 - AF_LIGHT_MODE_MAX_HORZ_GAP / 3;
+ else
+ threshold = 64 - AF_LIGHT_MODE_MAX_VERT_GAP / 3;
+ }
+ }
+
+ org_len = edge2->opos - edge->opos;
+ cur_len = af_cjk_compute_stem_width( hints, dim, org_len,
+ (AF_Edge_Flags)edge->flags,
+ (AF_Edge_Flags)edge2->flags );
+
+ org_center = ( edge->opos + edge2->opos ) / 2 + anchor;
+ cur_pos1 = org_center - cur_len / 2;
+ cur_pos2 = cur_pos1 + cur_len;
+ d_off1 = cur_pos1 - FT_PIX_FLOOR( cur_pos1 );
+ d_off2 = cur_pos2 - FT_PIX_FLOOR( cur_pos2 );
+ u_off1 = 64 - d_off1;
+ u_off2 = 64 - d_off2;
+ delta = 0;
+
+
+ if ( d_off1 == 0 || d_off2 == 0 )
+ goto Exit;
+
+ if ( cur_len <= threshold )
+ {
+ if ( d_off2 < cur_len )
+ {
+ if ( u_off1 <= d_off2 )
+ delta = u_off1;
+ else
+ delta = -d_off2;
+ }
+
+ goto Exit;
+ }
+
+ if ( threshold < 64 )
+ {
+ if ( d_off1 >= threshold || u_off1 >= threshold ||
+ d_off2 >= threshold || u_off2 >= threshold )
+ goto Exit;
+ }
+
+ offset = cur_len % 64;
+
+ if ( offset < 32 )
+ {
+ if ( u_off1 <= offset || d_off2 <= offset )
+ goto Exit;
+ }
+ else
+ offset = 64 - threshold;
+
+ d_off1 = threshold - u_off1;
+ u_off1 = u_off1 - offset;
+ u_off2 = threshold - d_off2;
+ d_off2 = d_off2 - offset;
+
+ if ( d_off1 <= u_off1 )
+ u_off1 = -d_off1;
+
+ if ( d_off2 <= u_off2 )
+ u_off2 = -d_off2;
+
+ if ( FT_ABS( u_off1 ) <= FT_ABS( u_off2 ) )
+ delta = u_off1;
+ else
+ delta = u_off2;
+
+ Exit:
+
+#if 1
+ if ( !AF_LATIN_HINTS_DO_STEM_ADJUST( hints ) )
+ {
+ if ( delta > AF_LIGHT_MODE_MAX_DELTA_ABS )
+ delta = AF_LIGHT_MODE_MAX_DELTA_ABS;
+ else if ( delta < -AF_LIGHT_MODE_MAX_DELTA_ABS )
+ delta = -AF_LIGHT_MODE_MAX_DELTA_ABS;
+ }
+#endif
+
+ cur_pos1 += delta;
+
+ if ( edge->opos < edge2->opos )
+ {
+ edge->pos = cur_pos1;
+ edge2->pos = cur_pos1 + cur_len;
+ }
+ else
+ {
+ edge->pos = cur_pos1 + cur_len;
+ edge2->pos = cur_pos1;
+ }
+
+ return delta;
+ }
+
+
+ static void
+ af_cjk_hint_edges( AF_GlyphHints hints,
+ AF_Dimension dim )
+ {
+ AF_AxisHints axis = &hints->axis[dim];
+ AF_Edge edges = axis->edges;
+ AF_Edge edge_limit = edges + axis->num_edges;
+ FT_Int n_edges;
+ AF_Edge edge;
+ AF_Edge anchor = 0;
+ FT_Pos delta = 0;
+ FT_Int skipped = 0;
+
+
+ /* now we align all stem edges. */
+ for ( edge = edges; edge < edge_limit; edge++ )
+ {
+ AF_Edge edge2;
+
+
+ if ( edge->flags & AF_EDGE_DONE )
+ continue;
+
+ /* skip all non-stem edges */
+ edge2 = edge->link;
+ if ( !edge2 )
+ {
+ skipped++;
+ continue;
+ }
+
+ /* now align the stem */
+
+ if ( edge2 < edge )
+ {
+ af_cjk_align_linked_edge( hints, dim, edge2, edge );
+ edge->flags |= AF_EDGE_DONE;
+ continue;
+ }
+
+ if ( dim != AF_DIMENSION_VERT && !anchor )
+ {
+
+#if 0
+ if ( fixedpitch )
+ {
+ AF_Edge left = edge;
+ AF_Edge right = edge_limit - 1;
+ AF_EdgeRec left1, left2, right1, right2;
+ FT_Pos target, center1, center2;
+ FT_Pos delta1, delta2, d1, d2;
+
+
+ while ( right > left && !right->link )
+ right--;
+
+ left1 = *left;
+ left2 = *left->link;
+ right1 = *right->link;
+ right2 = *right;
+
+ delta = ( ( ( hinter->pp2.x + 32 ) & -64 ) - hinter->pp2.x ) / 2;
+ target = left->opos + ( right->opos - left->opos ) / 2 + delta - 16;
+
+ delta1 = delta;
+ delta1 += af_hint_normal_stem( hints, left, left->link,
+ delta1, 0 );
+
+ if ( left->link != right )
+ af_hint_normal_stem( hints, right->link, right, delta1, 0 );
+
+ center1 = left->pos + ( right->pos - left->pos ) / 2;
+
+ if ( center1 >= target )
+ delta2 = delta - 32;
+ else
+ delta2 = delta + 32;
+
+ delta2 += af_hint_normal_stem( hints, &left1, &left2, delta2, 0 );
+
+ if ( delta1 != delta2 )
+ {
+ if ( left->link != right )
+ af_hint_normal_stem( hints, &right1, &right2, delta2, 0 );
+
+ center2 = left1.pos + ( right2.pos - left1.pos ) / 2;
+
+ d1 = center1 - target;
+ d2 = center2 - target;
+
+ if ( FT_ABS( d2 ) < FT_ABS( d1 ) )
+ {
+ left->pos = left1.pos;
+ left->link->pos = left2.pos;
+
+ if ( left->link != right )
+ {
+ right->link->pos = right1.pos;
+ right->pos = right2.pos;
+ }
+
+ delta1 = delta2;
+ }
+ }
+
+ delta = delta1;
+ right->link->flags |= AF_EDGE_DONE;
+ right->flags |= AF_EDGE_DONE;
+ }
+ else
+
+#endif /* 0 */
+
+ delta = af_hint_normal_stem( hints, edge, edge2, 0,
+ AF_DIMENSION_HORZ );
+ }
+ else
+ af_hint_normal_stem( hints, edge, edge2, delta, dim );
+
+#if 0
+ printf( "stem (%d,%d) adjusted (%.1f,%.1f)\n",
+ edge - edges, edge2 - edges,
+ ( edge->pos - edge->opos ) / 64.0,
+ ( edge2->pos - edge2->opos ) / 64.0 );
+#endif
+
+ anchor = edge;
+ edge->flags |= AF_EDGE_DONE;
+ edge2->flags |= AF_EDGE_DONE;
+ }
+
+ /* make sure that lowercase m's maintain their symmetry */
+
+ /* In general, lowercase m's have six vertical edges if they are sans */
+ /* serif, or twelve if they are with serifs. This implementation is */
+ /* based on that assumption, and seems to work very well with most */
+ /* faces. However, if for a certain face this assumption is not */
+ /* true, the m is just rendered like before. In addition, any stem */
+ /* correction will only be applied to symmetrical glyphs (even if the */
+ /* glyph is not an m), so the potential for unwanted distortion is */
+ /* relatively low. */
+
+ /* We don't handle horizontal edges since we can't easily assure that */
+ /* the third (lowest) stem aligns with the base line; it might end up */
+ /* one pixel higher or lower. */
+
+ n_edges = edge_limit - edges;
+ if ( dim == AF_DIMENSION_HORZ && ( n_edges == 6 || n_edges == 12 ) )
+ {
+ AF_Edge edge1, edge2, edge3;
+ FT_Pos dist1, dist2, span;
+
+
+ if ( n_edges == 6 )
+ {
+ edge1 = edges;
+ edge2 = edges + 2;
+ edge3 = edges + 4;
+ }
+ else
+ {
+ edge1 = edges + 1;
+ edge2 = edges + 5;
+ edge3 = edges + 9;
+ }
+
+ dist1 = edge2->opos - edge1->opos;
+ dist2 = edge3->opos - edge2->opos;
+
+ span = dist1 - dist2;
+ if ( span < 0 )
+ span = -span;
+
+ if ( edge1->link == edge1 + 1 &&
+ edge2->link == edge2 + 1 &&
+ edge3->link == edge3 + 1 && span < 8 )
+ {
+ delta = edge3->pos - ( 2 * edge2->pos - edge1->pos );
+ edge3->pos -= delta;
+ if ( edge3->link )
+ edge3->link->pos -= delta;
+
+ /* move the serifs along with the stem */
+ if ( n_edges == 12 )
+ {
+ ( edges + 8 )->pos -= delta;
+ ( edges + 11 )->pos -= delta;
+ }
+
+ edge3->flags |= AF_EDGE_DONE;
+ if ( edge3->link )
+ edge3->link->flags |= AF_EDGE_DONE;
+ }
+ }
+
+ if ( !skipped )
+ return;
+
+ /*
+ * now hint the remaining edges (serifs and single) in order
+ * to complete our processing
+ */
+ for ( edge = edges; edge < edge_limit; edge++ )
+ {
+ if ( edge->flags & AF_EDGE_DONE )
+ continue;
+
+ if ( edge->serif )
+ {
+ af_cjk_align_serif_edge( hints, edge->serif, edge );
+ edge->flags |= AF_EDGE_DONE;
+ skipped--;
+ }
+ }
+
+ if ( !skipped )
+ return;
+
+ for ( edge = edges; edge < edge_limit; edge++ )
+ {
+ AF_Edge before, after;
+
+
+ if ( edge->flags & AF_EDGE_DONE )
+ continue;
+
+ before = after = edge;
+
+ while ( --before >= edges )
+ if ( before->flags & AF_EDGE_DONE )
+ break;
+
+ while ( ++after < edge_limit )
+ if ( after->flags & AF_EDGE_DONE )
+ break;
+
+ if ( before >= edges || after < edge_limit )
+ {
+ if ( before < edges )
+ af_cjk_align_serif_edge( hints, after, edge );
+ else if ( after >= edge_limit )
+ af_cjk_align_serif_edge( hints, before, edge );
+ else
+ edge->pos = before->pos +
+ FT_MulDiv( edge->fpos - before->fpos,
+ after->pos - before->pos,
+ after->fpos - before->fpos );
+ }
+ }
+ }
+
+
+ static void
+ af_cjk_align_edge_points( AF_GlyphHints hints,
+ AF_Dimension dim )
+ {
+ AF_AxisHints axis = & hints->axis[dim];
+ AF_Edge edges = axis->edges;
+ AF_Edge edge_limit = edges + axis->num_edges;
+ AF_Edge edge;
+ FT_Bool snapping;
+
+
+ snapping = FT_BOOL( ( dim == AF_DIMENSION_HORZ &&
+ AF_LATIN_HINTS_DO_HORZ_SNAP( hints ) ) ||
+ ( dim == AF_DIMENSION_VERT &&
+ AF_LATIN_HINTS_DO_VERT_SNAP( hints ) ) );
+
+ for ( edge = edges; edge < edge_limit; edge++ )
+ {
+ /* move the points of each segment */
+ /* in each edge to the edge's position */
+ AF_Segment seg = edge->first;
+
+
+ if ( snapping )
+ {
+ do
+ {
+ AF_Point point = seg->first;
+
+
+ for (;;)
+ {
+ if ( dim == AF_DIMENSION_HORZ )
+ {
+ point->x = edge->pos;
+ point->flags |= AF_FLAG_TOUCH_X;
+ }
+ else
+ {
+ point->y = edge->pos;
+ point->flags |= AF_FLAG_TOUCH_Y;
+ }
+
+ if ( point == seg->last )
+ break;
+
+ point = point->next;
+ }
+
+ seg = seg->edge_next;
+
+ } while ( seg != edge->first );
+ }
+ else
+ {
+ FT_Pos delta = edge->pos - edge->opos;
+
+
+ do
+ {
+ AF_Point point = seg->first;
+
+
+ for (;;)
+ {
+ if ( dim == AF_DIMENSION_HORZ )
+ {
+ point->x += delta;
+ point->flags |= AF_FLAG_TOUCH_X;
+ }
+ else
+ {
+ point->y += delta;
+ point->flags |= AF_FLAG_TOUCH_Y;
+ }
+
+ if ( point == seg->last )
+ break;
+
+ point = point->next;
+ }
+
+ seg = seg->edge_next;
+
+ } while ( seg != edge->first );
+ }
+ }
+ }
+
+
+ static FT_Error
+ af_cjk_hints_apply( AF_GlyphHints hints,
+ FT_Outline* outline,
+ AF_LatinMetrics metrics )
+ {
+ FT_Error error;
+ int dim;
+
+ FT_UNUSED( metrics );
+
+
+ error = af_glyph_hints_reload( hints, outline, 0 );
+ if ( error )
+ goto Exit;
+
+ /* analyze glyph outline */
+ if ( AF_HINTS_DO_HORIZONTAL( hints ) )
+ {
+ error = af_cjk_hints_detect_features( hints, AF_DIMENSION_HORZ );
+ if ( error )
+ goto Exit;
+ }
+
+ if ( AF_HINTS_DO_VERTICAL( hints ) )
+ {
+ error = af_cjk_hints_detect_features( hints, AF_DIMENSION_VERT );
+ if ( error )
+ goto Exit;
+ }
+
+ /* grid-fit the outline */
+ for ( dim = 0; dim < AF_DIMENSION_MAX; dim++ )
+ {
+ if ( ( dim == AF_DIMENSION_HORZ && AF_HINTS_DO_HORIZONTAL( hints ) ) ||
+ ( dim == AF_DIMENSION_VERT && AF_HINTS_DO_VERTICAL( hints ) ) )
+ {
+
+#ifdef AF_USE_WARPER
+ if ( dim == AF_DIMENSION_HORZ &&
+ metrics->root.scaler.render_mode == FT_RENDER_MODE_NORMAL )
+ {
+ AF_WarperRec warper;
+ FT_Fixed scale;
+ FT_Pos delta;
+
+
+ af_warper_compute( &warper, hints, dim, &scale, &delta );
+ af_glyph_hints_scale_dim( hints, dim, scale, delta );
+ continue;
+ }
+#endif /* AF_USE_WARPER */
+
+ af_cjk_hint_edges( hints, (AF_Dimension)dim );
+ af_cjk_align_edge_points( hints, (AF_Dimension)dim );
+ af_glyph_hints_align_strong_points( hints, (AF_Dimension)dim );
+ af_glyph_hints_align_weak_points( hints, (AF_Dimension)dim );
+ }
+ }
+
+#if 0
+ af_glyph_hints_dump_points( hints );
+ af_glyph_hints_dump_segments( hints );
+ af_glyph_hints_dump_edges( hints );
+#endif
+
+ af_glyph_hints_save( hints, outline );
+
+ Exit:
+ return error;
+ }
+
+
+ /*************************************************************************/
+ /*************************************************************************/
+ /***** *****/
+ /***** C J K S C R I P T C L A S S *****/
+ /***** *****/
+ /*************************************************************************/
+ /*************************************************************************/
+
+
+ static const AF_Script_UniRangeRec af_cjk_uniranges[] =
+ {
+#if 0
+ { 0x0100, 0xFFFF }, /* why this? */
+#endif
+ { 0x2E80, 0x2EFF }, /* CJK Radicals Supplement */
+ { 0x2F00, 0x2FDF }, /* Kangxi Radicals */
+ { 0x3000, 0x303F }, /* CJK Symbols and Punctuation */
+ { 0x3040, 0x309F }, /* Hiragana */
+ { 0x30A0, 0x30FF }, /* Katakana */
+ { 0x3100, 0x312F }, /* Bopomofo */
+ { 0x3130, 0x318F }, /* Hangul Compatibility Jamo */
+ { 0x31A0, 0x31BF }, /* Bopomofo Extended */
+ { 0x31C0, 0x31EF }, /* CJK Strokes */
+ { 0x31F0, 0x31FF }, /* Katakana Phonetic Extensions */
+ { 0x3200, 0x32FF }, /* Enclosed CJK Letters and Months */
+ { 0x3300, 0x33FF }, /* CJK Compatibility */
+ { 0x3400, 0x4DBF }, /* CJK Unified Ideographs Extension A */
+ { 0x4DC0, 0x4DFF }, /* Yijing Hexagram Symbols */
+ { 0x4E00, 0x9FFF }, /* CJK Unified Ideographs */
+ { 0xF900, 0xFAFF }, /* CJK Compatibility Ideographs */
+ { 0xFE30, 0xFE4F }, /* CJK Compatibility Forms */
+ { 0xFF00, 0xFFEF }, /* Halfwidth and Fullwidth Forms */
+ { 0x20000, 0x2A6DF }, /* CJK Unified Ideographs Extension B */
+ { 0x2F800, 0x2FA1F }, /* CJK Compatibility Ideographs Supplement */
+ { 0, 0 }
+ };
+
+
+ FT_CALLBACK_TABLE_DEF const AF_ScriptClassRec
+ af_cjk_script_class =
+ {
+ AF_SCRIPT_CJK,
+ af_cjk_uniranges,
+
+ sizeof( AF_LatinMetricsRec ),
+
+ (AF_Script_InitMetricsFunc) af_cjk_metrics_init,
+ (AF_Script_ScaleMetricsFunc)af_cjk_metrics_scale,
+ (AF_Script_DoneMetricsFunc) NULL,
+
+ (AF_Script_InitHintsFunc) af_cjk_hints_init,
+ (AF_Script_ApplyHintsFunc) af_cjk_hints_apply
+ };
+
+#else /* !AF_CONFIG_OPTION_CJK */
+
+ static const AF_Script_UniRangeRec af_cjk_uniranges[] =
+ {
+ { 0, 0 }
+ };
+
+
+ FT_CALLBACK_TABLE_DEF const AF_ScriptClassRec
+ af_cjk_script_class =
+ {
+ AF_SCRIPT_CJK,
+ af_cjk_uniranges,
+
+ sizeof( AF_LatinMetricsRec ),
+
+ (AF_Script_InitMetricsFunc) NULL,
+ (AF_Script_ScaleMetricsFunc)NULL,
+ (AF_Script_DoneMetricsFunc) NULL,
+
+ (AF_Script_InitHintsFunc) NULL,
+ (AF_Script_ApplyHintsFunc) NULL
+ };
+
+#endif /* !AF_CONFIG_OPTION_CJK */
+
+
+/* END */
generated by cgit v1.2.3 (git 2.25.1) at 2024-04-20 01:35:41 +0000