ref: ef3d2c234736bdd7359d51e1ad522ae5dc6698c5
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 */