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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 19:33:14 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 19:33:14 +0000 |
commit | 36d22d82aa202bb199967e9512281e9a53db42c9 (patch) | |
tree | 105e8c98ddea1c1e4784a60a5a6410fa416be2de /modules/freetype2/src/base/ftstroke.c | |
parent | Initial commit. (diff) | |
download | firefox-esr-36d22d82aa202bb199967e9512281e9a53db42c9.tar.xz firefox-esr-36d22d82aa202bb199967e9512281e9a53db42c9.zip |
Adding upstream version 115.7.0esr.upstream/115.7.0esrupstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'modules/freetype2/src/base/ftstroke.c')
-rw-r--r-- | modules/freetype2/src/base/ftstroke.c | 2408 |
1 files changed, 2408 insertions, 0 deletions
diff --git a/modules/freetype2/src/base/ftstroke.c b/modules/freetype2/src/base/ftstroke.c new file mode 100644 index 0000000000..db358e772e --- /dev/null +++ b/modules/freetype2/src/base/ftstroke.c @@ -0,0 +1,2408 @@ +/**************************************************************************** + * + * ftstroke.c + * + * FreeType path stroker (body). + * + * Copyright (C) 2002-2023 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 <freetype/ftstroke.h> +#include <freetype/fttrigon.h> +#include <freetype/ftoutln.h> +#include <freetype/internal/ftmemory.h> +#include <freetype/internal/ftdebug.h> +#include <freetype/internal/ftobjs.h> + + + /* declare an extern to access `ft_outline_glyph_class' globally */ + /* allocated in `ftglyph.c' */ + FT_CALLBACK_TABLE const FT_Glyph_Class ft_outline_glyph_class; + + + /* documentation is in ftstroke.h */ + + FT_EXPORT_DEF( FT_StrokerBorder ) + FT_Outline_GetInsideBorder( FT_Outline* outline ) + { + FT_Orientation o = FT_Outline_Get_Orientation( outline ); + + + return o == FT_ORIENTATION_TRUETYPE ? FT_STROKER_BORDER_RIGHT + : FT_STROKER_BORDER_LEFT; + } + + + /* documentation is in ftstroke.h */ + + FT_EXPORT_DEF( FT_StrokerBorder ) + FT_Outline_GetOutsideBorder( FT_Outline* outline ) + { + FT_Orientation o = FT_Outline_Get_Orientation( outline ); + + + return o == FT_ORIENTATION_TRUETYPE ? FT_STROKER_BORDER_LEFT + : FT_STROKER_BORDER_RIGHT; + } + + + /*************************************************************************/ + /*************************************************************************/ + /***** *****/ + /***** BEZIER COMPUTATIONS *****/ + /***** *****/ + /*************************************************************************/ + /*************************************************************************/ + +#define FT_SMALL_CONIC_THRESHOLD ( FT_ANGLE_PI / 6 ) +#define FT_SMALL_CUBIC_THRESHOLD ( FT_ANGLE_PI / 8 ) + +#define FT_EPSILON 2 + +#define FT_IS_SMALL( x ) ( (x) > -FT_EPSILON && (x) < FT_EPSILON ) + + + static FT_Pos + ft_pos_abs( FT_Pos x ) + { + return x >= 0 ? x : -x; + } + + + static void + ft_conic_split( FT_Vector* base ) + { + FT_Pos a, b; + + + base[4].x = base[2].x; + a = base[0].x + base[1].x; + b = base[1].x + base[2].x; + base[3].x = b >> 1; + base[2].x = ( a + b ) >> 2; + base[1].x = a >> 1; + + base[4].y = base[2].y; + a = base[0].y + base[1].y; + b = base[1].y + base[2].y; + base[3].y = b >> 1; + base[2].y = ( a + b ) >> 2; + base[1].y = a >> 1; + } + + + static FT_Bool + ft_conic_is_small_enough( FT_Vector* base, + FT_Angle *angle_in, + FT_Angle *angle_out ) + { + FT_Vector d1, d2; + FT_Angle theta; + FT_Int close1, close2; + + + d1.x = base[1].x - base[2].x; + d1.y = base[1].y - base[2].y; + d2.x = base[0].x - base[1].x; + d2.y = base[0].y - base[1].y; + + close1 = FT_IS_SMALL( d1.x ) && FT_IS_SMALL( d1.y ); + close2 = FT_IS_SMALL( d2.x ) && FT_IS_SMALL( d2.y ); + + if ( close1 ) + { + if ( close2 ) + { + /* basically a point; */ + /* do nothing to retain original direction */ + } + else + { + *angle_in = + *angle_out = FT_Atan2( d2.x, d2.y ); + } + } + else /* !close1 */ + { + if ( close2 ) + { + *angle_in = + *angle_out = FT_Atan2( d1.x, d1.y ); + } + else + { + *angle_in = FT_Atan2( d1.x, d1.y ); + *angle_out = FT_Atan2( d2.x, d2.y ); + } + } + + theta = ft_pos_abs( FT_Angle_Diff( *angle_in, *angle_out ) ); + + return FT_BOOL( theta < FT_SMALL_CONIC_THRESHOLD ); + } + + + static void + ft_cubic_split( FT_Vector* base ) + { + FT_Pos a, b, c; + + + base[6].x = base[3].x; + a = base[0].x + base[1].x; + b = base[1].x + base[2].x; + c = base[2].x + base[3].x; + base[5].x = c >> 1; + c += b; + base[4].x = c >> 2; + base[1].x = a >> 1; + a += b; + base[2].x = a >> 2; + base[3].x = ( a + c ) >> 3; + + base[6].y = base[3].y; + a = base[0].y + base[1].y; + b = base[1].y + base[2].y; + c = base[2].y + base[3].y; + base[5].y = c >> 1; + c += b; + base[4].y = c >> 2; + base[1].y = a >> 1; + a += b; + base[2].y = a >> 2; + base[3].y = ( a + c ) >> 3; + } + + + /* Return the average of `angle1' and `angle2'. */ + /* This gives correct result even if `angle1' and `angle2' */ + /* have opposite signs. */ + static FT_Angle + ft_angle_mean( FT_Angle angle1, + FT_Angle angle2 ) + { + return angle1 + FT_Angle_Diff( angle1, angle2 ) / 2; + } + + + static FT_Bool + ft_cubic_is_small_enough( FT_Vector* base, + FT_Angle *angle_in, + FT_Angle *angle_mid, + FT_Angle *angle_out ) + { + FT_Vector d1, d2, d3; + FT_Angle theta1, theta2; + FT_Int close1, close2, close3; + + + d1.x = base[2].x - base[3].x; + d1.y = base[2].y - base[3].y; + d2.x = base[1].x - base[2].x; + d2.y = base[1].y - base[2].y; + d3.x = base[0].x - base[1].x; + d3.y = base[0].y - base[1].y; + + close1 = FT_IS_SMALL( d1.x ) && FT_IS_SMALL( d1.y ); + close2 = FT_IS_SMALL( d2.x ) && FT_IS_SMALL( d2.y ); + close3 = FT_IS_SMALL( d3.x ) && FT_IS_SMALL( d3.y ); + + if ( close1 ) + { + if ( close2 ) + { + if ( close3 ) + { + /* basically a point; */ + /* do nothing to retain original direction */ + } + else /* !close3 */ + { + *angle_in = + *angle_mid = + *angle_out = FT_Atan2( d3.x, d3.y ); + } + } + else /* !close2 */ + { + if ( close3 ) + { + *angle_in = + *angle_mid = + *angle_out = FT_Atan2( d2.x, d2.y ); + } + else /* !close3 */ + { + *angle_in = + *angle_mid = FT_Atan2( d2.x, d2.y ); + *angle_out = FT_Atan2( d3.x, d3.y ); + } + } + } + else /* !close1 */ + { + if ( close2 ) + { + if ( close3 ) + { + *angle_in = + *angle_mid = + *angle_out = FT_Atan2( d1.x, d1.y ); + } + else /* !close3 */ + { + *angle_in = FT_Atan2( d1.x, d1.y ); + *angle_out = FT_Atan2( d3.x, d3.y ); + *angle_mid = ft_angle_mean( *angle_in, *angle_out ); + } + } + else /* !close2 */ + { + if ( close3 ) + { + *angle_in = FT_Atan2( d1.x, d1.y ); + *angle_mid = + *angle_out = FT_Atan2( d2.x, d2.y ); + } + else /* !close3 */ + { + *angle_in = FT_Atan2( d1.x, d1.y ); + *angle_mid = FT_Atan2( d2.x, d2.y ); + *angle_out = FT_Atan2( d3.x, d3.y ); + } + } + } + + theta1 = ft_pos_abs( FT_Angle_Diff( *angle_in, *angle_mid ) ); + theta2 = ft_pos_abs( FT_Angle_Diff( *angle_mid, *angle_out ) ); + + return FT_BOOL( theta1 < FT_SMALL_CUBIC_THRESHOLD && + theta2 < FT_SMALL_CUBIC_THRESHOLD ); + } + + + /*************************************************************************/ + /*************************************************************************/ + /***** *****/ + /***** STROKE BORDERS *****/ + /***** *****/ + /*************************************************************************/ + /*************************************************************************/ + + typedef enum FT_StrokeTags_ + { + FT_STROKE_TAG_ON = 1, /* on-curve point */ + FT_STROKE_TAG_CUBIC = 2, /* cubic off-point */ + FT_STROKE_TAG_BEGIN = 4, /* sub-path start */ + FT_STROKE_TAG_END = 8 /* sub-path end */ + + } FT_StrokeTags; + +#define FT_STROKE_TAG_BEGIN_END ( FT_STROKE_TAG_BEGIN | FT_STROKE_TAG_END ) + + typedef struct FT_StrokeBorderRec_ + { + FT_UInt num_points; + FT_UInt max_points; + FT_Vector* points; + FT_Byte* tags; + FT_Bool movable; /* TRUE for ends of lineto borders */ + FT_Int start; /* index of current sub-path start point */ + FT_Memory memory; + FT_Bool valid; + + } FT_StrokeBorderRec, *FT_StrokeBorder; + + + static FT_Error + ft_stroke_border_grow( FT_StrokeBorder border, + FT_UInt new_points ) + { + FT_UInt old_max = border->max_points; + FT_UInt new_max = border->num_points + new_points; + FT_Error error = FT_Err_Ok; + + + if ( new_max > old_max ) + { + FT_UInt cur_max = old_max; + FT_Memory memory = border->memory; + + + while ( cur_max < new_max ) + cur_max += ( cur_max >> 1 ) + 16; + + if ( FT_RENEW_ARRAY( border->points, old_max, cur_max ) || + FT_RENEW_ARRAY( border->tags, old_max, cur_max ) ) + goto Exit; + + border->max_points = cur_max; + } + + Exit: + return error; + } + + + static void + ft_stroke_border_close( FT_StrokeBorder border, + FT_Bool reverse ) + { + FT_UInt start = (FT_UInt)border->start; + FT_UInt count = border->num_points; + + + FT_ASSERT( border->start >= 0 ); + + /* don't record empty paths! */ + if ( count <= start + 1U ) + border->num_points = start; + else + { + /* copy the last point to the start of this sub-path, since */ + /* it contains the `adjusted' starting coordinates */ + border->num_points = --count; + border->points[start] = border->points[count]; + border->tags[start] = border->tags[count]; + + if ( reverse ) + { + /* reverse the points */ + { + FT_Vector* vec1 = border->points + start + 1; + FT_Vector* vec2 = border->points + count - 1; + + + for ( ; vec1 < vec2; vec1++, vec2-- ) + { + FT_Vector tmp; + + + tmp = *vec1; + *vec1 = *vec2; + *vec2 = tmp; + } + } + + /* then the tags */ + { + FT_Byte* tag1 = border->tags + start + 1; + FT_Byte* tag2 = border->tags + count - 1; + + + for ( ; tag1 < tag2; tag1++, tag2-- ) + { + FT_Byte tmp; + + + tmp = *tag1; + *tag1 = *tag2; + *tag2 = tmp; + } + } + } + + border->tags[start ] |= FT_STROKE_TAG_BEGIN; + border->tags[count - 1] |= FT_STROKE_TAG_END; + } + + border->start = -1; + border->movable = FALSE; + } + + + static FT_Error + ft_stroke_border_lineto( FT_StrokeBorder border, + FT_Vector* to, + FT_Bool movable ) + { + FT_Error error = FT_Err_Ok; + + + FT_ASSERT( border->start >= 0 ); + + if ( border->movable ) + { + /* move last point */ + border->points[border->num_points - 1] = *to; + } + else + { + /* don't add zero-length lineto, but always add moveto */ + if ( border->num_points > (FT_UInt)border->start && + FT_IS_SMALL( border->points[border->num_points - 1].x - to->x ) && + FT_IS_SMALL( border->points[border->num_points - 1].y - to->y ) ) + return error; + + /* add one point */ + error = ft_stroke_border_grow( border, 1 ); + if ( !error ) + { + FT_Vector* vec = border->points + border->num_points; + FT_Byte* tag = border->tags + border->num_points; + + + vec[0] = *to; + tag[0] = FT_STROKE_TAG_ON; + + border->num_points += 1; + } + } + border->movable = movable; + return error; + } + + + static FT_Error + ft_stroke_border_conicto( FT_StrokeBorder border, + FT_Vector* control, + FT_Vector* to ) + { + FT_Error error; + + + FT_ASSERT( border->start >= 0 ); + + error = ft_stroke_border_grow( border, 2 ); + if ( !error ) + { + FT_Vector* vec = border->points + border->num_points; + FT_Byte* tag = border->tags + border->num_points; + + + vec[0] = *control; + vec[1] = *to; + + tag[0] = 0; + tag[1] = FT_STROKE_TAG_ON; + + border->num_points += 2; + } + + border->movable = FALSE; + + return error; + } + + + static FT_Error + ft_stroke_border_cubicto( FT_StrokeBorder border, + FT_Vector* control1, + FT_Vector* control2, + FT_Vector* to ) + { + FT_Error error; + + + FT_ASSERT( border->start >= 0 ); + + error = ft_stroke_border_grow( border, 3 ); + if ( !error ) + { + FT_Vector* vec = border->points + border->num_points; + FT_Byte* tag = border->tags + border->num_points; + + + vec[0] = *control1; + vec[1] = *control2; + vec[2] = *to; + + tag[0] = FT_STROKE_TAG_CUBIC; + tag[1] = FT_STROKE_TAG_CUBIC; + tag[2] = FT_STROKE_TAG_ON; + + border->num_points += 3; + } + + border->movable = FALSE; + + return error; + } + + +#define FT_ARC_CUBIC_ANGLE ( FT_ANGLE_PI / 2 ) + + + static FT_Error + ft_stroke_border_arcto( FT_StrokeBorder border, + FT_Vector* center, + FT_Fixed radius, + FT_Angle angle_start, + FT_Angle angle_diff ) + { + FT_Fixed coef; + FT_Vector a0, a1, a2, a3; + FT_Int i, arcs = 1; + FT_Error error = FT_Err_Ok; + + + /* number of cubic arcs to draw */ + while ( angle_diff > FT_ARC_CUBIC_ANGLE * arcs || + -angle_diff > FT_ARC_CUBIC_ANGLE * arcs ) + arcs++; + + /* control tangents */ + coef = FT_Tan( angle_diff / ( 4 * arcs ) ); + coef += coef / 3; + + /* compute start and first control point */ + FT_Vector_From_Polar( &a0, radius, angle_start ); + a1.x = FT_MulFix( -a0.y, coef ); + a1.y = FT_MulFix( a0.x, coef ); + + a0.x += center->x; + a0.y += center->y; + a1.x += a0.x; + a1.y += a0.y; + + for ( i = 1; i <= arcs; i++ ) + { + /* compute end and second control point */ + FT_Vector_From_Polar( &a3, radius, + angle_start + i * angle_diff / arcs ); + a2.x = FT_MulFix( a3.y, coef ); + a2.y = FT_MulFix( -a3.x, coef ); + + a3.x += center->x; + a3.y += center->y; + a2.x += a3.x; + a2.y += a3.y; + + /* add cubic arc */ + error = ft_stroke_border_cubicto( border, &a1, &a2, &a3 ); + if ( error ) + break; + + /* a0 = a3; */ + a1.x = a3.x - a2.x + a3.x; + a1.y = a3.y - a2.y + a3.y; + } + + return error; + } + + + static FT_Error + ft_stroke_border_moveto( FT_StrokeBorder border, + FT_Vector* to ) + { + /* close current open path if any ? */ + if ( border->start >= 0 ) + ft_stroke_border_close( border, FALSE ); + + border->start = (FT_Int)border->num_points; + border->movable = FALSE; + + return ft_stroke_border_lineto( border, to, FALSE ); + } + + + static void + ft_stroke_border_init( FT_StrokeBorder border, + FT_Memory memory ) + { + border->memory = memory; + border->points = NULL; + border->tags = NULL; + + border->num_points = 0; + border->max_points = 0; + border->start = -1; + border->valid = FALSE; + } + + + static void + ft_stroke_border_reset( FT_StrokeBorder border ) + { + border->num_points = 0; + border->start = -1; + border->valid = FALSE; + } + + + static void + ft_stroke_border_done( FT_StrokeBorder border ) + { + FT_Memory memory = border->memory; + + + FT_FREE( border->points ); + FT_FREE( border->tags ); + + border->num_points = 0; + border->max_points = 0; + border->start = -1; + border->valid = FALSE; + } + + + static FT_Error + ft_stroke_border_get_counts( FT_StrokeBorder border, + FT_UInt *anum_points, + FT_UInt *anum_contours ) + { + FT_Error error = FT_Err_Ok; + FT_UInt num_points = 0; + FT_UInt num_contours = 0; + + FT_UInt count = border->num_points; + FT_Vector* point = border->points; + FT_Byte* tags = border->tags; + FT_Int in_contour = 0; + + + for ( ; count > 0; count--, num_points++, point++, tags++ ) + { + if ( tags[0] & FT_STROKE_TAG_BEGIN ) + { + if ( in_contour != 0 ) + goto Fail; + + in_contour = 1; + } + else if ( in_contour == 0 ) + goto Fail; + + if ( tags[0] & FT_STROKE_TAG_END ) + { + in_contour = 0; + num_contours++; + } + } + + if ( in_contour != 0 ) + goto Fail; + + border->valid = TRUE; + + Exit: + *anum_points = num_points; + *anum_contours = num_contours; + return error; + + Fail: + num_points = 0; + num_contours = 0; + goto Exit; + } + + + static void + ft_stroke_border_export( FT_StrokeBorder border, + FT_Outline* outline ) + { + /* copy point locations */ + if ( border->num_points ) + FT_ARRAY_COPY( outline->points + outline->n_points, + border->points, + border->num_points ); + + /* copy tags */ + { + FT_UInt count = border->num_points; + FT_Byte* read = border->tags; + FT_Byte* write = (FT_Byte*)outline->tags + outline->n_points; + + + for ( ; count > 0; count--, read++, write++ ) + { + if ( *read & FT_STROKE_TAG_ON ) + *write = FT_CURVE_TAG_ON; + else if ( *read & FT_STROKE_TAG_CUBIC ) + *write = FT_CURVE_TAG_CUBIC; + else + *write = FT_CURVE_TAG_CONIC; + } + } + + /* copy contours */ + { + FT_UInt count = border->num_points; + FT_Byte* tags = border->tags; + FT_Short* write = outline->contours + outline->n_contours; + FT_Short idx = (FT_Short)outline->n_points; + + + for ( ; count > 0; count--, tags++, idx++ ) + { + if ( *tags & FT_STROKE_TAG_END ) + { + *write++ = idx; + outline->n_contours++; + } + } + } + + outline->n_points += (short)border->num_points; + + FT_ASSERT( FT_Outline_Check( outline ) == 0 ); + } + + + /*************************************************************************/ + /*************************************************************************/ + /***** *****/ + /***** STROKER *****/ + /***** *****/ + /*************************************************************************/ + /*************************************************************************/ + +#define FT_SIDE_TO_ROTATE( s ) ( FT_ANGLE_PI2 - (s) * FT_ANGLE_PI ) + + typedef struct FT_StrokerRec_ + { + FT_Angle angle_in; /* direction into curr join */ + FT_Angle angle_out; /* direction out of join */ + FT_Vector center; /* current position */ + FT_Fixed line_length; /* length of last lineto */ + FT_Bool first_point; /* is this the start? */ + FT_Bool subpath_open; /* is the subpath open? */ + FT_Angle subpath_angle; /* subpath start direction */ + FT_Vector subpath_start; /* subpath start position */ + FT_Fixed subpath_line_length; /* subpath start lineto len */ + FT_Bool handle_wide_strokes; /* use wide strokes logic? */ + + FT_Stroker_LineCap line_cap; + FT_Stroker_LineJoin line_join; + FT_Stroker_LineJoin line_join_saved; + FT_Fixed miter_limit; + FT_Fixed radius; + + FT_StrokeBorderRec borders[2]; + FT_Library library; + + } FT_StrokerRec; + + + /* documentation is in ftstroke.h */ + + FT_EXPORT_DEF( FT_Error ) + FT_Stroker_New( FT_Library library, + FT_Stroker *astroker ) + { + FT_Error error; /* assigned in FT_NEW */ + FT_Memory memory; + FT_Stroker stroker = NULL; + + + if ( !library ) + return FT_THROW( Invalid_Library_Handle ); + + if ( !astroker ) + return FT_THROW( Invalid_Argument ); + + memory = library->memory; + + if ( !FT_NEW( stroker ) ) + { + stroker->library = library; + + ft_stroke_border_init( &stroker->borders[0], memory ); + ft_stroke_border_init( &stroker->borders[1], memory ); + } + + *astroker = stroker; + + return error; + } + + + /* documentation is in ftstroke.h */ + + FT_EXPORT_DEF( void ) + FT_Stroker_Set( FT_Stroker stroker, + FT_Fixed radius, + FT_Stroker_LineCap line_cap, + FT_Stroker_LineJoin line_join, + FT_Fixed miter_limit ) + { + if ( !stroker ) + return; + + stroker->radius = radius; + stroker->line_cap = line_cap; + stroker->line_join = line_join; + stroker->miter_limit = miter_limit; + + /* ensure miter limit has sensible value */ + if ( stroker->miter_limit < 0x10000L ) + stroker->miter_limit = 0x10000L; + + /* save line join style: */ + /* line join style can be temporarily changed when stroking curves */ + stroker->line_join_saved = line_join; + + FT_Stroker_Rewind( stroker ); + } + + + /* documentation is in ftstroke.h */ + + FT_EXPORT_DEF( void ) + FT_Stroker_Rewind( FT_Stroker stroker ) + { + if ( stroker ) + { + ft_stroke_border_reset( &stroker->borders[0] ); + ft_stroke_border_reset( &stroker->borders[1] ); + } + } + + + /* documentation is in ftstroke.h */ + + FT_EXPORT_DEF( void ) + FT_Stroker_Done( FT_Stroker stroker ) + { + if ( stroker ) + { + FT_Memory memory = stroker->library->memory; + + + ft_stroke_border_done( &stroker->borders[0] ); + ft_stroke_border_done( &stroker->borders[1] ); + + stroker->library = NULL; + FT_FREE( stroker ); + } + } + + + /* create a circular arc at a corner or cap */ + static FT_Error + ft_stroker_arcto( FT_Stroker stroker, + FT_Int side ) + { + FT_Angle total, rotate; + FT_Fixed radius = stroker->radius; + FT_Error error = FT_Err_Ok; + FT_StrokeBorder border = stroker->borders + side; + + + rotate = FT_SIDE_TO_ROTATE( side ); + + total = FT_Angle_Diff( stroker->angle_in, stroker->angle_out ); + if ( total == FT_ANGLE_PI ) + total = -rotate * 2; + + error = ft_stroke_border_arcto( border, + &stroker->center, + radius, + stroker->angle_in + rotate, + total ); + border->movable = FALSE; + return error; + } + + + /* add a cap at the end of an opened path */ + static FT_Error + ft_stroker_cap( FT_Stroker stroker, + FT_Angle angle, + FT_Int side ) + { + FT_Error error = FT_Err_Ok; + + + if ( stroker->line_cap == FT_STROKER_LINECAP_ROUND ) + { + /* add a round cap */ + stroker->angle_in = angle; + stroker->angle_out = angle + FT_ANGLE_PI; + + error = ft_stroker_arcto( stroker, side ); + } + else + { + /* add a square or butt cap */ + FT_Vector middle, delta; + FT_Fixed radius = stroker->radius; + FT_StrokeBorder border = stroker->borders + side; + + + /* compute middle point and first angle point */ + FT_Vector_From_Polar( &middle, radius, angle ); + delta.x = side ? middle.y : -middle.y; + delta.y = side ? -middle.x : middle.x; + + if ( stroker->line_cap == FT_STROKER_LINECAP_SQUARE ) + { + middle.x += stroker->center.x; + middle.y += stroker->center.y; + } + else /* FT_STROKER_LINECAP_BUTT */ + { + middle.x = stroker->center.x; + middle.y = stroker->center.y; + } + + delta.x += middle.x; + delta.y += middle.y; + + error = ft_stroke_border_lineto( border, &delta, FALSE ); + if ( error ) + goto Exit; + + /* compute second angle point */ + delta.x = middle.x - delta.x + middle.x; + delta.y = middle.y - delta.y + middle.y; + + error = ft_stroke_border_lineto( border, &delta, FALSE ); + } + + Exit: + return error; + } + + + /* process an inside corner, i.e. compute intersection */ + static FT_Error + ft_stroker_inside( FT_Stroker stroker, + FT_Int side, + FT_Fixed line_length ) + { + FT_StrokeBorder border = stroker->borders + side; + FT_Angle phi, theta, rotate; + FT_Fixed length; + FT_Vector sigma = { 0, 0 }; + FT_Vector delta; + FT_Error error = FT_Err_Ok; + FT_Bool intersect; /* use intersection of lines? */ + + + rotate = FT_SIDE_TO_ROTATE( side ); + + theta = FT_Angle_Diff( stroker->angle_in, stroker->angle_out ) / 2; + + /* Only intersect borders if between two lineto's and both */ + /* lines are long enough (line_length is zero for curves). */ + /* Also avoid U-turns of nearly 180 degree. */ + if ( !border->movable || line_length == 0 || + theta > 0x59C000 || theta < -0x59C000 ) + intersect = FALSE; + else + { + /* compute minimum required length of lines */ + FT_Fixed min_length; + + + FT_Vector_Unit( &sigma, theta ); + min_length = + ft_pos_abs( FT_MulDiv( stroker->radius, sigma.y, sigma.x ) ); + + intersect = FT_BOOL( min_length && + stroker->line_length >= min_length && + line_length >= min_length ); + } + + if ( !intersect ) + { + FT_Vector_From_Polar( &delta, stroker->radius, + stroker->angle_out + rotate ); + delta.x += stroker->center.x; + delta.y += stroker->center.y; + + border->movable = FALSE; + } + else + { + /* compute median angle */ + phi = stroker->angle_in + theta + rotate; + + length = FT_DivFix( stroker->radius, sigma.x ); + + FT_Vector_From_Polar( &delta, length, phi ); + delta.x += stroker->center.x; + delta.y += stroker->center.y; + } + + error = ft_stroke_border_lineto( border, &delta, FALSE ); + + return error; + } + + + /* process an outside corner, i.e. compute bevel/miter/round */ + static FT_Error + ft_stroker_outside( FT_Stroker stroker, + FT_Int side, + FT_Fixed line_length ) + { + FT_StrokeBorder border = stroker->borders + side; + FT_Error error; + FT_Angle rotate; + + + if ( stroker->line_join == FT_STROKER_LINEJOIN_ROUND ) + error = ft_stroker_arcto( stroker, side ); + else + { + /* this is a mitered (pointed) or beveled (truncated) corner */ + FT_Fixed radius = stroker->radius; + FT_Vector sigma = { 0, 0 }; + FT_Angle theta = 0, phi = 0; + FT_Bool bevel, fixed_bevel; + + + rotate = FT_SIDE_TO_ROTATE( side ); + + bevel = + FT_BOOL( stroker->line_join == FT_STROKER_LINEJOIN_BEVEL ); + + fixed_bevel = + FT_BOOL( stroker->line_join != FT_STROKER_LINEJOIN_MITER_VARIABLE ); + + /* check miter limit first */ + if ( !bevel ) + { + theta = FT_Angle_Diff( stroker->angle_in, stroker->angle_out ) / 2; + + if ( theta == FT_ANGLE_PI2 ) + theta = -rotate; + + phi = stroker->angle_in + theta + rotate; + + FT_Vector_From_Polar( &sigma, stroker->miter_limit, theta ); + + /* is miter limit exceeded? */ + if ( sigma.x < 0x10000L ) + { + /* don't create variable bevels for very small deviations; */ + /* FT_Sin(x) = 0 for x <= 57 */ + if ( fixed_bevel || ft_pos_abs( theta ) > 57 ) + bevel = TRUE; + } + } + + if ( bevel ) /* this is a bevel (broken angle) */ + { + if ( fixed_bevel ) + { + /* the outer corners are simply joined together */ + FT_Vector delta; + + + /* add bevel */ + FT_Vector_From_Polar( &delta, + radius, + stroker->angle_out + rotate ); + delta.x += stroker->center.x; + delta.y += stroker->center.y; + + border->movable = FALSE; + error = ft_stroke_border_lineto( border, &delta, FALSE ); + } + else /* variable bevel or clipped miter */ + { + /* the miter is truncated */ + FT_Vector middle, delta; + FT_Fixed coef; + + + /* compute middle point and first angle point */ + FT_Vector_From_Polar( &middle, + FT_MulFix( radius, stroker->miter_limit ), + phi ); + + coef = FT_DivFix( 0x10000L - sigma.x, sigma.y ); + delta.x = FT_MulFix( middle.y, coef ); + delta.y = FT_MulFix( -middle.x, coef ); + + middle.x += stroker->center.x; + middle.y += stroker->center.y; + delta.x += middle.x; + delta.y += middle.y; + + error = ft_stroke_border_lineto( border, &delta, FALSE ); + if ( error ) + goto Exit; + + /* compute second angle point */ + delta.x = middle.x - delta.x + middle.x; + delta.y = middle.y - delta.y + middle.y; + + error = ft_stroke_border_lineto( border, &delta, FALSE ); + if ( error ) + goto Exit; + + /* finally, add an end point; only needed if not lineto */ + /* (line_length is zero for curves) */ + if ( line_length == 0 ) + { + FT_Vector_From_Polar( &delta, + radius, + stroker->angle_out + rotate ); + + delta.x += stroker->center.x; + delta.y += stroker->center.y; + + error = ft_stroke_border_lineto( border, &delta, FALSE ); + } + } + } + else /* this is a miter (intersection) */ + { + FT_Fixed length; + FT_Vector delta; + + + length = FT_MulDiv( stroker->radius, stroker->miter_limit, sigma.x ); + + FT_Vector_From_Polar( &delta, length, phi ); + delta.x += stroker->center.x; + delta.y += stroker->center.y; + + error = ft_stroke_border_lineto( border, &delta, FALSE ); + if ( error ) + goto Exit; + + /* now add an end point; only needed if not lineto */ + /* (line_length is zero for curves) */ + if ( line_length == 0 ) + { + FT_Vector_From_Polar( &delta, + stroker->radius, + stroker->angle_out + rotate ); + delta.x += stroker->center.x; + delta.y += stroker->center.y; + + error = ft_stroke_border_lineto( border, &delta, FALSE ); + } + } + } + + Exit: + return error; + } + + + static FT_Error + ft_stroker_process_corner( FT_Stroker stroker, + FT_Fixed line_length ) + { + FT_Error error = FT_Err_Ok; + FT_Angle turn; + FT_Int inside_side; + + + turn = FT_Angle_Diff( stroker->angle_in, stroker->angle_out ); + + /* no specific corner processing is required if the turn is 0 */ + if ( turn == 0 ) + goto Exit; + + /* when we turn to the right, the inside side is 0 */ + /* otherwise, the inside side is 1 */ + inside_side = ( turn < 0 ); + + /* process the inside side */ + error = ft_stroker_inside( stroker, inside_side, line_length ); + if ( error ) + goto Exit; + + /* process the outside side */ + error = ft_stroker_outside( stroker, !inside_side, line_length ); + + Exit: + return error; + } + + + /* add two points to the left and right borders corresponding to the */ + /* start of the subpath */ + static FT_Error + ft_stroker_subpath_start( FT_Stroker stroker, + FT_Angle start_angle, + FT_Fixed line_length ) + { + FT_Vector delta; + FT_Vector point; + FT_Error error; + FT_StrokeBorder border; + + + FT_Vector_From_Polar( &delta, stroker->radius, + start_angle + FT_ANGLE_PI2 ); + + point.x = stroker->center.x + delta.x; + point.y = stroker->center.y + delta.y; + + border = stroker->borders; + error = ft_stroke_border_moveto( border, &point ); + if ( error ) + goto Exit; + + point.x = stroker->center.x - delta.x; + point.y = stroker->center.y - delta.y; + + border++; + error = ft_stroke_border_moveto( border, &point ); + + /* save angle, position, and line length for last join */ + /* (line_length is zero for curves) */ + stroker->subpath_angle = start_angle; + stroker->first_point = FALSE; + stroker->subpath_line_length = line_length; + + Exit: + return error; + } + + + /* documentation is in ftstroke.h */ + + FT_EXPORT_DEF( FT_Error ) + FT_Stroker_LineTo( FT_Stroker stroker, + FT_Vector* to ) + { + FT_Error error = FT_Err_Ok; + FT_StrokeBorder border; + FT_Vector delta; + FT_Angle angle; + FT_Int side; + FT_Fixed line_length; + + + if ( !stroker || !to ) + return FT_THROW( Invalid_Argument ); + + delta.x = to->x - stroker->center.x; + delta.y = to->y - stroker->center.y; + + /* a zero-length lineto is a no-op; avoid creating a spurious corner */ + if ( delta.x == 0 && delta.y == 0 ) + goto Exit; + + /* compute length of line */ + line_length = FT_Vector_Length( &delta ); + + angle = FT_Atan2( delta.x, delta.y ); + FT_Vector_From_Polar( &delta, stroker->radius, angle + FT_ANGLE_PI2 ); + + /* process corner if necessary */ + if ( stroker->first_point ) + { + /* This is the first segment of a subpath. We need to */ + /* add a point to each border at their respective starting */ + /* point locations. */ + error = ft_stroker_subpath_start( stroker, angle, line_length ); + if ( error ) + goto Exit; + } + else + { + /* process the current corner */ + stroker->angle_out = angle; + error = ft_stroker_process_corner( stroker, line_length ); + if ( error ) + goto Exit; + } + + /* now add a line segment to both the `inside' and `outside' paths */ + for ( border = stroker->borders, side = 1; side >= 0; side--, border++ ) + { + FT_Vector point; + + + point.x = to->x + delta.x; + point.y = to->y + delta.y; + + /* the ends of lineto borders are movable */ + error = ft_stroke_border_lineto( border, &point, TRUE ); + if ( error ) + goto Exit; + + delta.x = -delta.x; + delta.y = -delta.y; + } + + stroker->angle_in = angle; + stroker->center = *to; + stroker->line_length = line_length; + + Exit: + return error; + } + + + /* documentation is in ftstroke.h */ + + FT_EXPORT_DEF( FT_Error ) + FT_Stroker_ConicTo( FT_Stroker stroker, + FT_Vector* control, + FT_Vector* to ) + { + FT_Error error = FT_Err_Ok; + FT_Vector bez_stack[34]; + FT_Vector* arc; + FT_Vector* limit = bez_stack + 30; + FT_Bool first_arc = TRUE; + + + if ( !stroker || !control || !to ) + { + error = FT_THROW( Invalid_Argument ); + goto Exit; + } + + /* if all control points are coincident, this is a no-op; */ + /* avoid creating a spurious corner */ + if ( FT_IS_SMALL( stroker->center.x - control->x ) && + FT_IS_SMALL( stroker->center.y - control->y ) && + FT_IS_SMALL( control->x - to->x ) && + FT_IS_SMALL( control->y - to->y ) ) + { + stroker->center = *to; + goto Exit; + } + + arc = bez_stack; + arc[0] = *to; + arc[1] = *control; + arc[2] = stroker->center; + + while ( arc >= bez_stack ) + { + FT_Angle angle_in, angle_out; + + + /* initialize with current direction */ + angle_in = angle_out = stroker->angle_in; + + if ( arc < limit && + !ft_conic_is_small_enough( arc, &angle_in, &angle_out ) ) + { + if ( stroker->first_point ) + stroker->angle_in = angle_in; + + ft_conic_split( arc ); + arc += 2; + continue; + } + + if ( first_arc ) + { + first_arc = FALSE; + + /* process corner if necessary */ + if ( stroker->first_point ) + error = ft_stroker_subpath_start( stroker, angle_in, 0 ); + else + { + stroker->angle_out = angle_in; + error = ft_stroker_process_corner( stroker, 0 ); + } + } + else if ( ft_pos_abs( FT_Angle_Diff( stroker->angle_in, angle_in ) ) > + FT_SMALL_CONIC_THRESHOLD / 4 ) + { + /* if the deviation from one arc to the next is too great, */ + /* add a round corner */ + stroker->center = arc[2]; + stroker->angle_out = angle_in; + stroker->line_join = FT_STROKER_LINEJOIN_ROUND; + + error = ft_stroker_process_corner( stroker, 0 ); + + /* reinstate line join style */ + stroker->line_join = stroker->line_join_saved; + } + + if ( error ) + goto Exit; + + /* the arc's angle is small enough; we can add it directly to each */ + /* border */ + { + FT_Vector ctrl, end; + FT_Angle theta, phi, rotate, alpha0 = 0; + FT_Fixed length; + FT_StrokeBorder border; + FT_Int side; + + + theta = FT_Angle_Diff( angle_in, angle_out ) / 2; + phi = angle_in + theta; + length = FT_DivFix( stroker->radius, FT_Cos( theta ) ); + + /* compute direction of original arc */ + if ( stroker->handle_wide_strokes ) + alpha0 = FT_Atan2( arc[0].x - arc[2].x, arc[0].y - arc[2].y ); + + for ( border = stroker->borders, side = 0; + side <= 1; + side++, border++ ) + { + rotate = FT_SIDE_TO_ROTATE( side ); + + /* compute control point */ + FT_Vector_From_Polar( &ctrl, length, phi + rotate ); + ctrl.x += arc[1].x; + ctrl.y += arc[1].y; + + /* compute end point */ + FT_Vector_From_Polar( &end, stroker->radius, angle_out + rotate ); + end.x += arc[0].x; + end.y += arc[0].y; + + if ( stroker->handle_wide_strokes ) + { + FT_Vector start; + FT_Angle alpha1; + + + /* determine whether the border radius is greater than the */ + /* radius of curvature of the original arc */ + start = border->points[border->num_points - 1]; + + alpha1 = FT_Atan2( end.x - start.x, end.y - start.y ); + + /* is the direction of the border arc opposite to */ + /* that of the original arc? */ + if ( ft_pos_abs( FT_Angle_Diff( alpha0, alpha1 ) ) > + FT_ANGLE_PI / 2 ) + { + FT_Angle beta, gamma; + FT_Vector bvec, delta; + FT_Fixed blen, sinA, sinB, alen; + + + /* use the sine rule to find the intersection point */ + beta = FT_Atan2( arc[2].x - start.x, arc[2].y - start.y ); + gamma = FT_Atan2( arc[0].x - end.x, arc[0].y - end.y ); + + bvec.x = end.x - start.x; + bvec.y = end.y - start.y; + + blen = FT_Vector_Length( &bvec ); + + sinA = ft_pos_abs( FT_Sin( alpha1 - gamma ) ); + sinB = ft_pos_abs( FT_Sin( beta - gamma ) ); + + alen = FT_MulDiv( blen, sinA, sinB ); + + FT_Vector_From_Polar( &delta, alen, beta ); + delta.x += start.x; + delta.y += start.y; + + /* circumnavigate the negative sector backwards */ + border->movable = FALSE; + error = ft_stroke_border_lineto( border, &delta, FALSE ); + if ( error ) + goto Exit; + error = ft_stroke_border_lineto( border, &end, FALSE ); + if ( error ) + goto Exit; + error = ft_stroke_border_conicto( border, &ctrl, &start ); + if ( error ) + goto Exit; + /* and then move to the endpoint */ + error = ft_stroke_border_lineto( border, &end, FALSE ); + if ( error ) + goto Exit; + + continue; + } + + /* else fall through */ + } + + /* simply add an arc */ + error = ft_stroke_border_conicto( border, &ctrl, &end ); + if ( error ) + goto Exit; + } + } + + arc -= 2; + + stroker->angle_in = angle_out; + } + + stroker->center = *to; + stroker->line_length = 0; + + Exit: + return error; + } + + + /* documentation is in ftstroke.h */ + + FT_EXPORT_DEF( FT_Error ) + FT_Stroker_CubicTo( FT_Stroker stroker, + FT_Vector* control1, + FT_Vector* control2, + FT_Vector* to ) + { + FT_Error error = FT_Err_Ok; + FT_Vector bez_stack[37]; + FT_Vector* arc; + FT_Vector* limit = bez_stack + 32; + FT_Bool first_arc = TRUE; + + + if ( !stroker || !control1 || !control2 || !to ) + { + error = FT_THROW( Invalid_Argument ); + goto Exit; + } + + /* if all control points are coincident, this is a no-op; */ + /* avoid creating a spurious corner */ + if ( FT_IS_SMALL( stroker->center.x - control1->x ) && + FT_IS_SMALL( stroker->center.y - control1->y ) && + FT_IS_SMALL( control1->x - control2->x ) && + FT_IS_SMALL( control1->y - control2->y ) && + FT_IS_SMALL( control2->x - to->x ) && + FT_IS_SMALL( control2->y - to->y ) ) + { + stroker->center = *to; + goto Exit; + } + + arc = bez_stack; + arc[0] = *to; + arc[1] = *control2; + arc[2] = *control1; + arc[3] = stroker->center; + + while ( arc >= bez_stack ) + { + FT_Angle angle_in, angle_mid, angle_out; + + + /* initialize with current direction */ + angle_in = angle_out = angle_mid = stroker->angle_in; + + if ( arc < limit && + !ft_cubic_is_small_enough( arc, &angle_in, + &angle_mid, &angle_out ) ) + { + if ( stroker->first_point ) + stroker->angle_in = angle_in; + + ft_cubic_split( arc ); + arc += 3; + continue; + } + + if ( first_arc ) + { + first_arc = FALSE; + + /* process corner if necessary */ + if ( stroker->first_point ) + error = ft_stroker_subpath_start( stroker, angle_in, 0 ); + else + { + stroker->angle_out = angle_in; + error = ft_stroker_process_corner( stroker, 0 ); + } + } + else if ( ft_pos_abs( FT_Angle_Diff( stroker->angle_in, angle_in ) ) > + FT_SMALL_CUBIC_THRESHOLD / 4 ) + { + /* if the deviation from one arc to the next is too great, */ + /* add a round corner */ + stroker->center = arc[3]; + stroker->angle_out = angle_in; + stroker->line_join = FT_STROKER_LINEJOIN_ROUND; + + error = ft_stroker_process_corner( stroker, 0 ); + + /* reinstate line join style */ + stroker->line_join = stroker->line_join_saved; + } + + if ( error ) + goto Exit; + + /* the arc's angle is small enough; we can add it directly to each */ + /* border */ + { + FT_Vector ctrl1, ctrl2, end; + FT_Angle theta1, phi1, theta2, phi2, rotate, alpha0 = 0; + FT_Fixed length1, length2; + FT_StrokeBorder border; + FT_Int side; + + + theta1 = FT_Angle_Diff( angle_in, angle_mid ) / 2; + theta2 = FT_Angle_Diff( angle_mid, angle_out ) / 2; + phi1 = ft_angle_mean( angle_in, angle_mid ); + phi2 = ft_angle_mean( angle_mid, angle_out ); + length1 = FT_DivFix( stroker->radius, FT_Cos( theta1 ) ); + length2 = FT_DivFix( stroker->radius, FT_Cos( theta2 ) ); + + /* compute direction of original arc */ + if ( stroker->handle_wide_strokes ) + alpha0 = FT_Atan2( arc[0].x - arc[3].x, arc[0].y - arc[3].y ); + + for ( border = stroker->borders, side = 0; + side <= 1; + side++, border++ ) + { + rotate = FT_SIDE_TO_ROTATE( side ); + + /* compute control points */ + FT_Vector_From_Polar( &ctrl1, length1, phi1 + rotate ); + ctrl1.x += arc[2].x; + ctrl1.y += arc[2].y; + + FT_Vector_From_Polar( &ctrl2, length2, phi2 + rotate ); + ctrl2.x += arc[1].x; + ctrl2.y += arc[1].y; + + /* compute end point */ + FT_Vector_From_Polar( &end, stroker->radius, angle_out + rotate ); + end.x += arc[0].x; + end.y += arc[0].y; + + if ( stroker->handle_wide_strokes ) + { + FT_Vector start; + FT_Angle alpha1; + + + /* determine whether the border radius is greater than the */ + /* radius of curvature of the original arc */ + start = border->points[border->num_points - 1]; + + alpha1 = FT_Atan2( end.x - start.x, end.y - start.y ); + + /* is the direction of the border arc opposite to */ + /* that of the original arc? */ + if ( ft_pos_abs( FT_Angle_Diff( alpha0, alpha1 ) ) > + FT_ANGLE_PI / 2 ) + { + FT_Angle beta, gamma; + FT_Vector bvec, delta; + FT_Fixed blen, sinA, sinB, alen; + + + /* use the sine rule to find the intersection point */ + beta = FT_Atan2( arc[3].x - start.x, arc[3].y - start.y ); + gamma = FT_Atan2( arc[0].x - end.x, arc[0].y - end.y ); + + bvec.x = end.x - start.x; + bvec.y = end.y - start.y; + + blen = FT_Vector_Length( &bvec ); + + sinA = ft_pos_abs( FT_Sin( alpha1 - gamma ) ); + sinB = ft_pos_abs( FT_Sin( beta - gamma ) ); + + alen = FT_MulDiv( blen, sinA, sinB ); + + FT_Vector_From_Polar( &delta, alen, beta ); + delta.x += start.x; + delta.y += start.y; + + /* circumnavigate the negative sector backwards */ + border->movable = FALSE; + error = ft_stroke_border_lineto( border, &delta, FALSE ); + if ( error ) + goto Exit; + error = ft_stroke_border_lineto( border, &end, FALSE ); + if ( error ) + goto Exit; + error = ft_stroke_border_cubicto( border, + &ctrl2, + &ctrl1, + &start ); + if ( error ) + goto Exit; + /* and then move to the endpoint */ + error = ft_stroke_border_lineto( border, &end, FALSE ); + if ( error ) + goto Exit; + + continue; + } + + /* else fall through */ + } + + /* simply add an arc */ + error = ft_stroke_border_cubicto( border, &ctrl1, &ctrl2, &end ); + if ( error ) + goto Exit; + } + } + + arc -= 3; + + stroker->angle_in = angle_out; + } + + stroker->center = *to; + stroker->line_length = 0; + + Exit: + return error; + } + + + /* documentation is in ftstroke.h */ + + FT_EXPORT_DEF( FT_Error ) + FT_Stroker_BeginSubPath( FT_Stroker stroker, + FT_Vector* to, + FT_Bool open ) + { + if ( !stroker || !to ) + return FT_THROW( Invalid_Argument ); + + /* We cannot process the first point, because there is not enough */ + /* information regarding its corner/cap. The latter will be processed */ + /* in the `FT_Stroker_EndSubPath' routine. */ + /* */ + stroker->first_point = TRUE; + stroker->center = *to; + stroker->subpath_open = open; + + /* Determine if we need to check whether the border radius is greater */ + /* than the radius of curvature of a curve, to handle this case */ + /* specially. This is only required if bevel joins or butt caps may */ + /* be created, because round & miter joins and round & square caps */ + /* cover the negative sector created with wide strokes. */ + stroker->handle_wide_strokes = + FT_BOOL( stroker->line_join != FT_STROKER_LINEJOIN_ROUND || + ( stroker->subpath_open && + stroker->line_cap == FT_STROKER_LINECAP_BUTT ) ); + + /* record the subpath start point for each border */ + stroker->subpath_start = *to; + + stroker->angle_in = 0; + + return FT_Err_Ok; + } + + + static FT_Error + ft_stroker_add_reverse_left( FT_Stroker stroker, + FT_Bool open ) + { + FT_StrokeBorder right = stroker->borders + 0; + FT_StrokeBorder left = stroker->borders + 1; + FT_Int new_points; + FT_Error error = FT_Err_Ok; + + + FT_ASSERT( left->start >= 0 ); + + new_points = (FT_Int)left->num_points - left->start; + if ( new_points > 0 ) + { + error = ft_stroke_border_grow( right, (FT_UInt)new_points ); + if ( error ) + goto Exit; + + { + FT_Vector* dst_point = right->points + right->num_points; + FT_Byte* dst_tag = right->tags + right->num_points; + FT_Vector* src_point = left->points + left->num_points - 1; + FT_Byte* src_tag = left->tags + left->num_points - 1; + + + while ( src_point >= left->points + left->start ) + { + *dst_point = *src_point; + *dst_tag = *src_tag; + + if ( open ) + dst_tag[0] &= ~FT_STROKE_TAG_BEGIN_END; + else + { + FT_Byte ttag = + (FT_Byte)( dst_tag[0] & FT_STROKE_TAG_BEGIN_END ); + + + /* switch begin/end tags if necessary */ + if ( ttag == FT_STROKE_TAG_BEGIN || + ttag == FT_STROKE_TAG_END ) + dst_tag[0] ^= FT_STROKE_TAG_BEGIN_END; + } + + src_point--; + src_tag--; + dst_point++; + dst_tag++; + } + } + + left->num_points = (FT_UInt)left->start; + right->num_points += (FT_UInt)new_points; + + right->movable = FALSE; + left->movable = FALSE; + } + + Exit: + return error; + } + + + /* documentation is in ftstroke.h */ + + /* there's a lot of magic in this function! */ + FT_EXPORT_DEF( FT_Error ) + FT_Stroker_EndSubPath( FT_Stroker stroker ) + { + FT_Error error = FT_Err_Ok; + + + if ( !stroker ) + { + error = FT_THROW( Invalid_Argument ); + goto Exit; + } + + if ( stroker->subpath_open ) + { + FT_StrokeBorder right = stroker->borders; + + + /* All right, this is an opened path, we need to add a cap between */ + /* right & left, add the reverse of left, then add a final cap */ + /* between left & right. */ + error = ft_stroker_cap( stroker, stroker->angle_in, 0 ); + if ( error ) + goto Exit; + + /* add reversed points from `left' to `right' */ + error = ft_stroker_add_reverse_left( stroker, TRUE ); + if ( error ) + goto Exit; + + /* now add the final cap */ + stroker->center = stroker->subpath_start; + error = ft_stroker_cap( stroker, + stroker->subpath_angle + FT_ANGLE_PI, 0 ); + if ( error ) + goto Exit; + + /* Now end the right subpath accordingly. The left one is */ + /* rewind and doesn't need further processing. */ + ft_stroke_border_close( right, FALSE ); + } + else + { + /* close the path if needed */ + if ( !FT_IS_SMALL( stroker->center.x - stroker->subpath_start.x ) || + !FT_IS_SMALL( stroker->center.y - stroker->subpath_start.y ) ) + { + error = FT_Stroker_LineTo( stroker, &stroker->subpath_start ); + if ( error ) + goto Exit; + } + + /* process the corner */ + stroker->angle_out = stroker->subpath_angle; + + error = ft_stroker_process_corner( stroker, + stroker->subpath_line_length ); + if ( error ) + goto Exit; + + /* then end our two subpaths */ + ft_stroke_border_close( stroker->borders + 0, FALSE ); + ft_stroke_border_close( stroker->borders + 1, TRUE ); + } + + Exit: + return error; + } + + + /* documentation is in ftstroke.h */ + + FT_EXPORT_DEF( FT_Error ) + FT_Stroker_GetBorderCounts( FT_Stroker stroker, + FT_StrokerBorder border, + FT_UInt *anum_points, + FT_UInt *anum_contours ) + { + FT_UInt num_points = 0, num_contours = 0; + FT_Error error; + + + if ( !stroker || border > 1 ) + { + error = FT_THROW( Invalid_Argument ); + goto Exit; + } + + error = ft_stroke_border_get_counts( stroker->borders + border, + &num_points, &num_contours ); + Exit: + if ( anum_points ) + *anum_points = num_points; + + if ( anum_contours ) + *anum_contours = num_contours; + + return error; + } + + + /* documentation is in ftstroke.h */ + + FT_EXPORT_DEF( FT_Error ) + FT_Stroker_GetCounts( FT_Stroker stroker, + FT_UInt *anum_points, + FT_UInt *anum_contours ) + { + FT_UInt count1, count2, num_points = 0; + FT_UInt count3, count4, num_contours = 0; + FT_Error error; + + + if ( !stroker ) + { + error = FT_THROW( Invalid_Argument ); + goto Exit; + } + + error = ft_stroke_border_get_counts( stroker->borders + 0, + &count1, &count2 ); + if ( error ) + goto Exit; + + error = ft_stroke_border_get_counts( stroker->borders + 1, + &count3, &count4 ); + if ( error ) + goto Exit; + + num_points = count1 + count3; + num_contours = count2 + count4; + + Exit: + if ( anum_points ) + *anum_points = num_points; + + if ( anum_contours ) + *anum_contours = num_contours; + + return error; + } + + + /* documentation is in ftstroke.h */ + + FT_EXPORT_DEF( void ) + FT_Stroker_ExportBorder( FT_Stroker stroker, + FT_StrokerBorder border, + FT_Outline* outline ) + { + if ( !stroker || !outline ) + return; + + if ( border == FT_STROKER_BORDER_LEFT || + border == FT_STROKER_BORDER_RIGHT ) + { + FT_StrokeBorder sborder = & stroker->borders[border]; + + + if ( sborder->valid ) + ft_stroke_border_export( sborder, outline ); + } + } + + + /* documentation is in ftstroke.h */ + + FT_EXPORT_DEF( void ) + FT_Stroker_Export( FT_Stroker stroker, + FT_Outline* outline ) + { + FT_Stroker_ExportBorder( stroker, FT_STROKER_BORDER_LEFT, outline ); + FT_Stroker_ExportBorder( stroker, FT_STROKER_BORDER_RIGHT, outline ); + } + + + /* documentation is in ftstroke.h */ + + /* + * The following is very similar to FT_Outline_Decompose, except + * that we do support opened paths, and do not scale the outline. + */ + FT_EXPORT_DEF( FT_Error ) + FT_Stroker_ParseOutline( FT_Stroker stroker, + FT_Outline* outline, + FT_Bool opened ) + { + FT_Vector v_last; + FT_Vector v_control; + FT_Vector v_start; + + FT_Vector* point; + FT_Vector* limit; + char* tags; + + FT_Error error; + + FT_Int n; /* index of contour in outline */ + FT_UInt first; /* index of first point in contour */ + FT_Int tag; /* current point's state */ + + + if ( !outline ) + return FT_THROW( Invalid_Outline ); + + if ( !stroker ) + return FT_THROW( Invalid_Argument ); + + FT_Stroker_Rewind( stroker ); + + first = 0; + + for ( n = 0; n < outline->n_contours; n++ ) + { + FT_UInt last; /* index of last point in contour */ + + + last = (FT_UInt)outline->contours[n]; + limit = outline->points + last; + + /* skip empty points; we don't stroke these */ + if ( last <= first ) + { + first = last + 1; + continue; + } + + v_start = outline->points[first]; + v_last = outline->points[last]; + + v_control = v_start; + + point = outline->points + first; + tags = outline->tags + first; + tag = FT_CURVE_TAG( tags[0] ); + + /* A contour cannot start with a cubic control point! */ + if ( tag == FT_CURVE_TAG_CUBIC ) + goto Invalid_Outline; + + /* check first point to determine origin */ + if ( tag == FT_CURVE_TAG_CONIC ) + { + /* First point is conic control. Yes, this happens. */ + if ( FT_CURVE_TAG( outline->tags[last] ) == FT_CURVE_TAG_ON ) + { + /* start at last point if it is on the curve */ + v_start = v_last; + limit--; + } + else + { + /* if both first and last points are conic, */ + /* start at their middle */ + v_start.x = ( v_start.x + v_last.x ) / 2; + v_start.y = ( v_start.y + v_last.y ) / 2; + } + point--; + tags--; + } + + error = FT_Stroker_BeginSubPath( stroker, &v_start, opened ); + if ( error ) + goto Exit; + + while ( point < limit ) + { + point++; + tags++; + + tag = FT_CURVE_TAG( tags[0] ); + switch ( tag ) + { + case FT_CURVE_TAG_ON: /* emit a single line_to */ + { + FT_Vector vec; + + + vec.x = point->x; + vec.y = point->y; + + error = FT_Stroker_LineTo( stroker, &vec ); + if ( error ) + goto Exit; + continue; + } + + case FT_CURVE_TAG_CONIC: /* consume conic arcs */ + v_control.x = point->x; + v_control.y = point->y; + + Do_Conic: + if ( point < limit ) + { + FT_Vector vec; + FT_Vector v_middle; + + + point++; + tags++; + tag = FT_CURVE_TAG( tags[0] ); + + vec = point[0]; + + if ( tag == FT_CURVE_TAG_ON ) + { + error = FT_Stroker_ConicTo( stroker, &v_control, &vec ); + if ( error ) + goto Exit; + continue; + } + + if ( tag != FT_CURVE_TAG_CONIC ) + goto Invalid_Outline; + + v_middle.x = ( v_control.x + vec.x ) / 2; + v_middle.y = ( v_control.y + vec.y ) / 2; + + error = FT_Stroker_ConicTo( stroker, &v_control, &v_middle ); + if ( error ) + goto Exit; + + v_control = vec; + goto Do_Conic; + } + + error = FT_Stroker_ConicTo( stroker, &v_control, &v_start ); + goto Close; + + default: /* FT_CURVE_TAG_CUBIC */ + { + FT_Vector vec1, vec2; + + + if ( point + 1 > limit || + FT_CURVE_TAG( tags[1] ) != FT_CURVE_TAG_CUBIC ) + goto Invalid_Outline; + + point += 2; + tags += 2; + + vec1 = point[-2]; + vec2 = point[-1]; + + if ( point <= limit ) + { + FT_Vector vec; + + + vec = point[0]; + + error = FT_Stroker_CubicTo( stroker, &vec1, &vec2, &vec ); + if ( error ) + goto Exit; + continue; + } + + error = FT_Stroker_CubicTo( stroker, &vec1, &vec2, &v_start ); + goto Close; + } + } + } + + Close: + if ( error ) + goto Exit; + + /* don't try to end the path if no segments have been generated */ + if ( !stroker->first_point ) + { + error = FT_Stroker_EndSubPath( stroker ); + if ( error ) + goto Exit; + } + + first = last + 1; + } + + return FT_Err_Ok; + + Exit: + return error; + + Invalid_Outline: + return FT_THROW( Invalid_Outline ); + } + + + /* documentation is in ftstroke.h */ + + FT_EXPORT_DEF( FT_Error ) + FT_Glyph_Stroke( FT_Glyph *pglyph, + FT_Stroker stroker, + FT_Bool destroy ) + { + FT_Error error = FT_ERR( Invalid_Argument ); + FT_Glyph glyph = NULL; + + + if ( !pglyph ) + goto Exit; + + glyph = *pglyph; + if ( !glyph || glyph->clazz != &ft_outline_glyph_class ) + goto Exit; + + { + FT_Glyph copy; + + + error = FT_Glyph_Copy( glyph, © ); + if ( error ) + goto Exit; + + glyph = copy; + } + + { + FT_OutlineGlyph oglyph = (FT_OutlineGlyph)glyph; + FT_Outline* outline = &oglyph->outline; + FT_UInt num_points, num_contours; + + + error = FT_Stroker_ParseOutline( stroker, outline, FALSE ); + if ( error ) + goto Fail; + + FT_Stroker_GetCounts( stroker, &num_points, &num_contours ); + + FT_Outline_Done( glyph->library, outline ); + + error = FT_Outline_New( glyph->library, + num_points, + (FT_Int)num_contours, + outline ); + if ( error ) + goto Fail; + + outline->n_points = 0; + outline->n_contours = 0; + + FT_Stroker_Export( stroker, outline ); + } + + if ( destroy ) + FT_Done_Glyph( *pglyph ); + + *pglyph = glyph; + goto Exit; + + Fail: + FT_Done_Glyph( glyph ); + glyph = NULL; + + if ( !destroy ) + *pglyph = NULL; + + Exit: + return error; + } + + + /* documentation is in ftstroke.h */ + + FT_EXPORT_DEF( FT_Error ) + FT_Glyph_StrokeBorder( FT_Glyph *pglyph, + FT_Stroker stroker, + FT_Bool inside, + FT_Bool destroy ) + { + FT_Error error = FT_ERR( Invalid_Argument ); + FT_Glyph glyph = NULL; + + + if ( !pglyph ) + goto Exit; + + glyph = *pglyph; + if ( !glyph || glyph->clazz != &ft_outline_glyph_class ) + goto Exit; + + { + FT_Glyph copy; + + + error = FT_Glyph_Copy( glyph, © ); + if ( error ) + goto Exit; + + glyph = copy; + } + + { + FT_OutlineGlyph oglyph = (FT_OutlineGlyph)glyph; + FT_StrokerBorder border; + FT_Outline* outline = &oglyph->outline; + FT_UInt num_points, num_contours; + + + border = FT_Outline_GetOutsideBorder( outline ); + if ( inside ) + { + if ( border == FT_STROKER_BORDER_LEFT ) + border = FT_STROKER_BORDER_RIGHT; + else + border = FT_STROKER_BORDER_LEFT; + } + + error = FT_Stroker_ParseOutline( stroker, outline, FALSE ); + if ( error ) + goto Fail; + + FT_Stroker_GetBorderCounts( stroker, border, + &num_points, &num_contours ); + + FT_Outline_Done( glyph->library, outline ); + + error = FT_Outline_New( glyph->library, + num_points, + (FT_Int)num_contours, + outline ); + if ( error ) + goto Fail; + + outline->n_points = 0; + outline->n_contours = 0; + + FT_Stroker_ExportBorder( stroker, border, outline ); + } + + if ( destroy ) + FT_Done_Glyph( *pglyph ); + + *pglyph = glyph; + goto Exit; + + Fail: + FT_Done_Glyph( glyph ); + glyph = NULL; + + if ( !destroy ) + *pglyph = NULL; + + Exit: + return error; + } + + +/* END */ |