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Unified Diff: third_party/freetype2/src/src/base/ftstroke.c

Issue 1524973002: Update freetype sources (2.6.2) in third party. (Closed) Base URL: https://github.com/domokit/mojo.git@master
Patch Set: Created 5 years ago
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Index: third_party/freetype2/src/src/base/ftstroke.c
diff --git a/third_party/freetype2/src/src/base/ftstroke.c b/third_party/freetype2/src/src/base/ftstroke.c
new file mode 100644
index 0000000000000000000000000000000000000000..fecb3cc25c0e14f25db68c41737aea47420a0f20
--- /dev/null
+++ b/third_party/freetype2/src/src/base/ftstroke.c
@@ -0,0 +1,2468 @@
+/***************************************************************************/
+/* */
+/* ftstroke.c */
+/* */
+/* FreeType path stroker (body). */
+/* */
+/* Copyright 2002-2015 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_STROKER_H
+#include FT_TRIGONOMETRY_H
+#include FT_OUTLINE_H
+#include FT_INTERNAL_MEMORY_H
+#include FT_INTERNAL_DEBUG_H
+#include FT_INTERNAL_OBJECTS_H
+
+#include "basepic.h"
+
+
+ /* declare an extern to access `ft_outline_glyph_class' globally */
+ /* allocated in `ftglyph.c', and use the FT_OUTLINE_GLYPH_CLASS_GET */
+ /* macro to access it when FT_CONFIG_OPTION_PIC is defined */
+#ifndef FT_CONFIG_OPTION_PIC
+ FT_CALLBACK_TABLE const FT_Glyph_Class ft_outline_glyph_class;
+#endif
+
+
+ /* 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;
+ b = base[1].x;
+ a = base[3].x = ( base[2].x + b ) / 2;
+ b = base[1].x = ( base[0].x + b ) / 2;
+ base[2].x = ( a + b ) / 2;
+
+ base[4].y = base[2].y;
+ b = base[1].y;
+ a = base[3].y = ( base[2].y + b ) / 2;
+ b = base[1].y = ( base[0].y + b ) / 2;
+ base[2].y = ( a + b ) / 2;
+ }
+
+
+ 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, d;
+
+
+ base[6].x = base[3].x;
+ c = base[1].x;
+ d = base[2].x;
+ base[1].x = a = ( base[0].x + c ) / 2;
+ base[5].x = b = ( base[3].x + d ) / 2;
+ c = ( c + d ) / 2;
+ base[2].x = a = ( a + c ) / 2;
+ base[4].x = b = ( b + c ) / 2;
+ base[3].x = ( a + b ) / 2;
+
+ base[6].y = base[3].y;
+ c = base[1].y;
+ d = base[2].y;
+ base[1].y = a = ( base[0].y + c ) / 2;
+ base[5].y = b = ( base[3].y + d ) / 2;
+ c = ( c + d ) / 2;
+ base[2].y = a = ( a + c ) / 2;
+ base[4].y = b = ( b + c ) / 2;
+ base[3].y = ( a + b ) / 2;
+ }
+
+
+ /* 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];
+
+ 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 */
+ if ( border->num_points > 0 &&
+ 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_Angle total, angle, step, rotate, next, theta;
+ FT_Vector a, b, a2, b2;
+ FT_Fixed length;
+ FT_Error error = FT_Err_Ok;
+
+
+ /* compute start point */
+ FT_Vector_From_Polar( &a, radius, angle_start );
+ a.x += center->x;
+ a.y += center->y;
+
+ total = angle_diff;
+ angle = angle_start;
+ rotate = ( angle_diff >= 0 ) ? FT_ANGLE_PI2 : -FT_ANGLE_PI2;
+
+ while ( total != 0 )
+ {
+ step = total;
+ if ( step > FT_ARC_CUBIC_ANGLE )
+ step = FT_ARC_CUBIC_ANGLE;
+
+ else if ( step < -FT_ARC_CUBIC_ANGLE )
+ step = -FT_ARC_CUBIC_ANGLE;
+
+ next = angle + step;
+ theta = step;
+ if ( theta < 0 )
+ theta = -theta;
+
+ theta >>= 1;
+
+ /* compute end point */
+ FT_Vector_From_Polar( &b, radius, next );
+ b.x += center->x;
+ b.y += center->y;
+
+ /* compute first and second control points */
+ length = FT_MulDiv( radius, FT_Sin( theta ) * 4,
+ ( 0x10000L + FT_Cos( theta ) ) * 3 );
+
+ FT_Vector_From_Polar( &a2, length, angle + rotate );
+ a2.x += a.x;
+ a2.y += a.y;
+
+ FT_Vector_From_Polar( &b2, length, next - rotate );
+ b2.x += b.x;
+ b2.y += b.y;
+
+ /* add cubic arc */
+ error = ft_stroke_border_cubicto( border, &a2, &b2, &b );
+ if ( error )
+ break;
+
+ /* process the rest of the arc ?? */
+ a = b;
+ total -= step;
+ angle = next;
+ }
+
+ 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 */
+ 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 if ( stroker->line_cap == FT_STROKER_LINECAP_SQUARE )
+ {
+ /* add a square cap */
+ FT_Vector delta, delta2;
+ FT_Angle rotate = FT_SIDE_TO_ROTATE( side );
+ FT_Fixed radius = stroker->radius;
+ FT_StrokeBorder border = stroker->borders + side;
+
+
+ FT_Vector_From_Polar( &delta2, radius, angle + rotate );
+ FT_Vector_From_Polar( &delta, radius, angle );
+
+ delta.x += stroker->center.x + delta2.x;
+ delta.y += stroker->center.y + delta2.y;
+
+ error = ft_stroke_border_lineto( border, &delta, FALSE );
+ if ( error )
+ goto Exit;
+
+ FT_Vector_From_Polar( &delta2, radius, angle - rotate );
+ FT_Vector_From_Polar( &delta, radius, angle );
+
+ delta.x += delta2.x + stroker->center.x;
+ delta.y += delta2.y + stroker->center.y;
+
+ error = ft_stroke_border_lineto( border, &delta, FALSE );
+ }
+ else if ( stroker->line_cap == FT_STROKER_LINECAP_BUTT )
+ {
+ /* add a butt ending */
+ FT_Vector delta;
+ FT_Angle rotate = FT_SIDE_TO_ROTATE( side );
+ FT_Fixed radius = stroker->radius;
+ FT_StrokeBorder border = stroker->borders + side;
+
+
+ FT_Vector_From_Polar( &delta, radius, angle + rotate );
+
+ delta.x += stroker->center.x;
+ delta.y += stroker->center.y;
+
+ error = ft_stroke_border_lineto( border, &delta, FALSE );
+ if ( error )
+ goto Exit;
+
+ FT_Vector_From_Polar( &delta, radius, angle - rotate );
+
+ delta.x += stroker->center.x;
+ delta.y += stroker->center.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, thcos;
+ 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_pos_abs( FT_MulFix( stroker->radius,
+ FT_Tan( theta ) ) );
+
+
+ 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;
+
+ thcos = FT_Cos( theta );
+
+ length = FT_DivFix( stroker->radius, thcos );
+
+ FT_Vector_From_Polar( &delta, length, phi + rotate );
+ 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 sigma = 0, radius = stroker->radius;
+ FT_Angle theta = 0, phi = 0;
+ FT_Fixed thcos = 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 );
+
+ if ( !bevel )
+ {
+ theta = FT_Angle_Diff( stroker->angle_in, stroker->angle_out );
+
+ if ( theta == FT_ANGLE_PI )
+ {
+ theta = rotate;
+ phi = stroker->angle_in;
+ }
+ else
+ {
+ theta /= 2;
+ phi = stroker->angle_in + theta + rotate;
+ }
+
+ thcos = FT_Cos( theta );
+ sigma = FT_MulFix( stroker->miter_limit, thcos );
+
+ /* is miter limit exceeded? */
+ if ( sigma < 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 */
+ {
+ /* the miter is truncated */
+ FT_Vector middle, delta;
+ FT_Fixed length;
+
+
+ /* compute middle point */
+ FT_Vector_From_Polar( &middle,
+ FT_MulFix( radius, stroker->miter_limit ),
+ phi );
+ middle.x += stroker->center.x;
+ middle.y += stroker->center.y;
+
+ /* compute first angle point */
+ length = FT_MulDiv( radius, 0x10000L - sigma,
+ ft_pos_abs( FT_Sin( theta ) ) );
+
+ FT_Vector_From_Polar( &delta, length, phi + rotate );
+ delta.x += middle.x;
+ delta.y += middle.y;
+
+ error = ft_stroke_border_lineto( border, &delta, FALSE );
+ if ( error )
+ goto Exit;
+
+ /* compute second angle point */
+ FT_Vector_From_Polar( &delta, length, phi - rotate );
+ delta.x += middle.x;
+ 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_DivFix( stroker->radius, thcos );
+
+ 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;
+
+ 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;
+
+ 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
+ {
+ FT_Angle turn;
+ FT_Int inside_side;
+
+
+ /* close the path if needed */
+ if ( stroker->center.x != stroker->subpath_start.x ||
+ 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;
+ turn = FT_Angle_Diff( stroker->angle_in,
+ stroker->angle_out );
+
+ /* no specific corner processing is required if the turn is 0 */
+ if ( turn != 0 )
+ {
+ /* when we turn to the right, the inside side is 0 */
+ /* otherwise, the inside side is 1 */
+ inside_side = ( turn < 0 );
+
+ error = ft_stroker_inside( stroker,
+ inside_side,
+ stroker->subpath_line_length );
+ if ( error )
+ goto Exit;
+
+ /* process the outside side */
+ error = ft_stroker_outside( stroker,
+ !inside_side,
+ 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;
+
+ /* for FT_OUTLINE_GLYPH_CLASS_GET (in PIC mode) */
+ FT_Library library = stroker->library;
+
+ FT_UNUSED( library );
+
+
+ if ( !pglyph )
+ goto Exit;
+
+ glyph = *pglyph;
+ if ( !glyph || glyph->clazz != FT_OUTLINE_GLYPH_CLASS_GET )
+ goto Exit;
+
+ {
+ FT_Glyph copy;
+
+
+ error = FT_Glyph_Copy( glyph, &copy );
+ 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;
+
+ /* for FT_OUTLINE_GLYPH_CLASS_GET (in PIC mode) */
+ FT_Library library = stroker->library;
+
+ FT_UNUSED( library );
+
+
+ if ( !pglyph )
+ goto Exit;
+
+ glyph = *pglyph;
+ if ( !glyph || glyph->clazz != FT_OUTLINE_GLYPH_CLASS_GET )
+ goto Exit;
+
+ {
+ FT_Glyph copy;
+
+
+ error = FT_Glyph_Copy( glyph, &copy );
+ 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 */
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