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- #include <ft2build.h>
- #include FT_STROKER_H
- #include FT_TRIGONOMETRY_H
- #include FT_INTERNAL_MEMORY_H
- #include FT_INTERNAL_DEBUG_H
- /***************************************************************************/
- /***************************************************************************/
- /***** *****/
- /***** BEZIER COMPUTATIONS *****/
- /***** *****/
- /***************************************************************************/
- /***************************************************************************/
- #define FT_SMALL_CONIC_THRESHOLD (FT_ANGLE_PI/6)
- #define FT_SMALL_CUBIC_THRESHOLD (FT_ANGLE_PI/6)
- #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)
- *angle_in = *angle_out = 0;
- else
- *angle_in = *angle_out = FT_Atan2( d2.x, d2.y );
- }
- else 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;
- }
- 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 || close3)
- {
- if (close2)
- {
- /* basically a point */
- *angle_in = *angle_out = *angle_mid = 0;
- }
- else if (close1)
- {
- *angle_in = *angle_mid = FT_Atan2( d2.x, d2.y );
- *angle_out = FT_Atan2( d3.x, d3.y );
- }
- else /* close2 */
- {
- *angle_in = FT_Atan2( d1.x, d1.y );
- *angle_mid = *angle_out = FT_Atan2( d2.x, d2.y );
- }
- }
- else if (close2)
- {
- *angle_in = *angle_mid = FT_Atan2( d1.x, d1.y );
- *angle_out = FT_Atan2( d3.x, d3.y );
- }
- else
- {
- *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_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;
- typedef struct FT_StrokeBorderRec_
- {
- FT_UInt num_points;
- FT_UInt max_points;
- FT_Vector* points;
- FT_Byte* tags;
- FT_Bool movable;
- FT_Int start; /* index of current sub-path start point */
- FT_Memory memory;
- } 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 = 0;
- 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_ASSERT( border->start >= 0 );
- border->tags[ border->start ] |= FT_STROKE_TAG_BEGIN;
- border->tags[ border->num_points-1 ] |= FT_STROKE_TAG_END;
- border->start = -1;
- border->movable = 0;
- }
- static FT_Error
- ft_stroke_border_lineto( FT_StrokeBorder border,
- FT_Vector* to,
- FT_Bool movable )
- {
- FT_Error error = 0;
- FT_ASSERT( border->start >= 0 );
- if ( border->movable )
- {
- /* move last point */
- border->points[ border->num_points-1 ] = *to;
- }
- else
- {
- /* 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 = 0;
- 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 = 0;
- 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 = 0;
- /* 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 );
- border->start = border->num_points;
- border->movable = 0;
- return ft_stroke_border_lineto( border, to, 0 );
- }
- 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;
- }
- static void
- ft_stroke_border_reset( FT_StrokeBorder border )
- {
- border->num_points = 0;
- border->start = -1;
- }
- 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;
- }
- static FT_Error
- ft_stroke_border_get_counts( FT_StrokeBorder border,
- FT_UInt *anum_points,
- FT_UInt *anum_contours )
- {
- FT_Error error = 0;
- 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--, 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 )
- {
- if ( in_contour == 0 )
- goto Fail;
- in_contour = 0;
- num_contours++;
- }
- }
- if ( in_contour != 0 )
- goto Fail;
- 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_MEM_COPY( outline->points + outline->n_points,
- border->points,
- border->num_points * sizeof(FT_Vector) );
- /* 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 index = (FT_Short) outline->n_points;
- for ( ; count > 0; count--, tags++, write++, index++ )
- {
- if ( *tags & FT_STROKE_TAG_END )
- {
- *write++ = index;
- outline->n_contours++;
- }
- }
- }
- outline->n_points = (short)( outline->n_points + 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;
- FT_Angle angle_out;
- FT_Vector center;
- FT_Bool first_point;
- FT_Bool subpath_open;
- FT_Angle subpath_angle;
- FT_Vector subpath_start;
- FT_Stroker_LineCap line_cap;
- FT_Stroker_LineJoin line_join;
- FT_Fixed miter_limit;
- FT_Fixed radius;
- FT_Bool valid;
- FT_StrokeBorderRec borders[2];
- FT_Memory memory;
- } FT_StrokerRec;
- FT_EXPORT_DEF( FT_Error )
- FT_Stroker_New( FT_Memory memory,
- FT_Stroker *astroker )
- {
- FT_Error error;
- FT_Stroker stroker;
- if ( !FT_NEW( stroker ) )
- {
- stroker->memory = memory;
- ft_stroke_border_init( &stroker->borders[0], memory );
- ft_stroke_border_init( &stroker->borders[1], memory );
- }
- *astroker = stroker;
- return error;
- }
- 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 )
- {
- stroker->radius = radius;
- stroker->line_cap = line_cap;
- stroker->line_join = line_join;
- stroker->miter_limit = miter_limit;
- stroker->valid = 0;
- ft_stroke_border_reset( &stroker->borders[0] );
- ft_stroke_border_reset( &stroker->borders[1] );
- }
- FT_EXPORT_DEF( void )
- FT_Stroker_Done( FT_Stroker stroker )
- {
- if ( stroker )
- {
- FT_Memory memory = stroker->memory;
- ft_stroke_border_done( &stroker->borders[0] );
- ft_stroke_border_done( &stroker->borders[1] );
- stroker->memory = NULL;
- FT_FREE( stroker );
- }
- }
- /* creates 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 = 0;
- 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 = 0;
- return error;
- }
- /* adds 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 = 0;
- 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, 0 );
- 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, 0 );
- }
- Exit:
- return error;
- }
- /* process an inside corner, i.e. compute intersection */
- static FT_Error
- ft_stroker_inside( FT_Stroker stroker,
- FT_Int side)
- {
- FT_StrokeBorder border = stroker->borders + side;
- FT_Angle phi, theta, rotate;
- FT_Fixed length, thcos, sigma;
- FT_Vector delta;
- FT_Error error = 0;
- rotate = FT_SIDE_TO_ROTATE(side);
- /* compute median angle */
- theta = FT_Angle_Diff( stroker->angle_in, stroker->angle_out );
- if ( theta == FT_ANGLE_PI )
- theta = rotate;
- else
- theta = theta/2;
- phi = stroker->angle_in + theta;
- thcos = FT_Cos( theta );
- sigma = FT_MulFix( stroker->miter_limit, thcos );
- if ( sigma < 0x10000L )
- {
- FT_Vector_From_Polar( &delta, stroker->radius, stroker->angle_out + rotate );
- delta.x += stroker->center.x;
- delta.y += stroker->center.y;
- border->movable = 0;
- }
- else
- {
- 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, 0 );
- 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_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 or beveled corner */
- FT_Fixed sigma, radius = stroker->radius;
- FT_Angle theta, phi;
- FT_Fixed thcos;
- FT_Bool miter;
- rotate = FT_SIDE_TO_ROTATE(side);
- miter = FT_BOOL( stroker->line_join == FT_STROKER_LINEJOIN_MITER );
- theta = FT_Angle_Diff( stroker->angle_in, stroker->angle_out );
- if (theta == FT_ANGLE_PI)
- theta = rotate;
- else
- theta = theta/2;
- thcos = FT_Cos( theta );
- sigma = FT_MulFix( stroker->miter_limit, thcos );
- if ( sigma >= 0x10000L )
- miter = 0;
- phi = stroker->angle_in + theta + rotate;
- if (miter) /* this is a miter (broken angle) */
- {
- 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_MulFix( radius, FT_DivFix( 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, 0 );
- 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, 0 );
- if (error) goto Exit;
- /* finally, add a movable end point */
- 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, 1 );
- }
- else /* this is a bevel (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, 0 );
- if (error) goto Exit;
- /* now add end point */
- 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, 1 );
- }
- }
- Exit:
- return error;
- }
- static FT_Error
- ft_stroker_process_corner( FT_Stroker stroker )
- {
- FT_Error error = 0;
- 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 */
- inside_side = 0;
- /* otherwise, the inside side is 1 */
- if (turn < 0)
- inside_side = 1;
- /* process the inside side */
- error = ft_stroker_inside( stroker, inside_side );
- if (error) goto Exit;
- /* process the outside side */
- error = ft_stroker_outside( stroker, 1-inside_side );
- 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_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 for last cap */
- stroker->subpath_angle = start_angle;
- stroker->first_point = 0;
- Exit:
- return error;
- }
- FT_EXPORT_DEF( FT_Error )
- FT_Stroker_LineTo( FT_Stroker stroker,
- FT_Vector* to )
- {
- FT_Error error = 0;
- FT_StrokeBorder border;
- FT_Vector delta;
- FT_Angle angle;
- FT_Int side;
- delta.x = to->x - stroker->center.x;
- delta.y = to->y - stroker->center.y;
- 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 );
- if (error) goto Exit;
- }
- else
- {
- /* process the current corner */
- stroker->angle_out = angle;
- error = ft_stroker_process_corner( stroker );
- 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;
- error = ft_stroke_border_lineto( border, &point, 1 );
- if (error) goto Exit;
- delta.x = -delta.x;
- delta.y = -delta.y;
- }
- stroker->angle_in = angle;
- stroker->center = *to;
- Exit:
- return error;
- }
- FT_EXPORT_DEF( FT_Error )
- FT_Stroker_ConicTo( FT_Stroker stroker,
- FT_Vector* control,
- FT_Vector* to )
- {
- FT_Error error = 0;
- FT_Vector bez_stack[34];
- FT_Vector* arc;
- FT_Vector* limit = bez_stack + 30;
- FT_Angle start_angle;
- FT_Bool first_arc = 1;
- arc = bez_stack;
- arc[0] = *to;
- arc[1] = *control;
- arc[2] = stroker->center;
- while ( arc >= bez_stack )
- {
- FT_Angle angle_in, angle_out;
- angle_in = angle_out = 0; /* remove compiler warnings */
- if ( arc < limit &&
- !ft_conic_is_small_enough( arc, &angle_in, &angle_out ) )
- {
- ft_conic_split( arc );
- arc += 2;
- continue;
- }
- if ( first_arc )
- {
- first_arc = 0;
- start_angle = angle_in;
- /* process corner if necessary */
- if ( stroker->first_point )
- error = ft_stroker_subpath_start( stroker, start_angle );
- else
- {
- stroker->angle_out = start_angle;
- error = ft_stroker_process_corner( stroker );
- }
- }
- /* the arc's angle is small enough, we can add it directly to each */
- /* border.. */
- {
- FT_Vector ctrl, end;
- FT_Angle theta, phi, rotate;
- FT_Fixed length;
- FT_Int side;
- theta = FT_Angle_Diff( angle_in, angle_out )/2;
- phi = angle_in + theta;
- length = FT_DivFix( stroker->radius, FT_Cos(theta) );
- for ( side = 0; side <= 1; side++ )
- {
- 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;
- error = ft_stroke_border_conicto( stroker->borders + side, &ctrl, &end );
- if (error) goto Exit;
- }
- }
- arc -= 2;
- if (arc < bez_stack)
- stroker->angle_in = angle_out;
- }
- stroker->center = *to;
- Exit:
- return error;
- }
- FT_EXPORT_DEF( FT_Error )
- FT_Stroker_CubicTo( FT_Stroker stroker,
- FT_Vector* control1,
- FT_Vector* control2,
- FT_Vector* to )
- {
- FT_Error error = 0;
- FT_Vector bez_stack[37];
- FT_Vector* arc;
- FT_Vector* limit = bez_stack + 32;
- FT_Angle start_angle;
- FT_Bool first_arc = 1;
- 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;
- /* remove compiler warnings */
- angle_in = angle_out = angle_mid = 0;
- if ( arc < limit &&
- !ft_cubic_is_small_enough( arc, &angle_in, &angle_mid, &angle_out ) )
- {
- ft_cubic_split( arc );
- arc += 3;
- continue;
- }
- if ( first_arc )
- {
- first_arc = 0;
- /* process corner if necessary */
- start_angle = angle_in;
- if ( stroker->first_point )
- error = ft_stroker_subpath_start( stroker, start_angle );
- else
- {
- stroker->angle_out = start_angle;
- error = ft_stroker_process_corner( stroker );
- }
- 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;
- FT_Fixed length1, length2;
- FT_Int side;
- theta1 = ft_pos_abs( angle_mid - angle_in )/2;
- theta2 = ft_pos_abs( angle_out - angle_mid )/2;
- phi1 = (angle_mid+angle_in)/2;
- phi2 = (angle_mid+angle_out)/2;
- length1 = FT_DivFix( stroker->radius, FT_Cos(theta1) );
- length2 = FT_DivFix( stroker->radius, FT_Cos(theta2) );
- for ( side = 0; side <= 1; side++ )
- {
- 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;
- error = ft_stroke_border_cubicto( stroker->borders + side, &ctrl1, &ctrl2, &end );
- if (error) goto Exit;
- }
- }
- arc -= 3;
- if (arc < bez_stack)
- stroker->angle_in = angle_out;
- }
- stroker->center = *to;
- Exit:
- return error;
- }
- FT_EXPORT_DEF( FT_Error )
- FT_Stroker_BeginSubPath( FT_Stroker stroker,
- FT_Vector* to,
- FT_Bool open )
- {
- /* we cannot process the first point, because there is not enough */
- /* information regarding its corner/cap. The latter will be processed */
- /* in the "end_subpath" routine */
- /* */
- stroker->first_point = 1;
- stroker->center = *to;
- stroker->subpath_open = open;
- /* record the subpath start point index for each border */
- stroker->subpath_start = *to;
- return 0;
- }
- 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 = 0;
- FT_ASSERT( left->start >= 0 );
- new_points = 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 | FT_STROKE_TAG_END);
- else
- {
- /* switch begin/end tags if necessary.. */
- if (dst_tag[0] & (FT_STROKE_TAG_BEGIN | FT_STROKE_TAG_END))
- dst_tag[0] ^= (FT_STROKE_TAG_BEGIN | FT_STROKE_TAG_END);
- }
- src_point--;
- src_tag--;
- dst_point++;
- dst_tag++;
- }
- }
- left->num_points = left->start;
- right->num_points += new_points;
- right->movable = 0;
- left->movable = 0;
- }
- Exit:
- return error;
- }
- /* there's a lot of magic in this function !! */
- FT_EXPORT_DEF( FT_Error )
- FT_Stroker_EndSubPath( FT_Stroker stroker )
- {
- FT_Error error = 0;
- 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, 1 );
- 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 );
- }
- else
- {
- FT_Angle turn;
- FT_Int inside_side;
- /* 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 */
- inside_side = 0;
- /* otherwise, the inside side is 1 */
- if (turn < 0)
- inside_side = 1;
- /* IMPORTANT: WE DO NOT PROCESS THE INSIDE BORDER HERE !! */
- /* process the inside side */
- /* error = ft_stroker_inside( stroker, inside_side );
- if (error) goto Exit; */
- /* process the outside side */
- error = ft_stroker_outside( stroker, 1-inside_side );
- if (error) goto Exit;
- }
- /* we will first end our two subpaths */
- ft_stroke_border_close( stroker->borders + 0 );
- ft_stroke_border_close( stroker->borders + 1 );
- /* now, add the reversed left subpath to "right" */
- error = ft_stroker_add_reverse_left( stroker, 0 );
- if (error) goto Exit;
- }
- Exit:
- return error;
- }
- 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;
- 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;
- stroker->valid = 1;
- Exit:
- *anum_points = num_points;
- *anum_contours = num_contours;
- return error;
- }
- FT_EXPORT_DEF( void )
- FT_Stroker_Export( FT_Stroker stroker,
- FT_Outline* outline )
- {
- if ( stroker->valid )
- {
- ft_stroke_border_export( stroker->borders+0, outline );
- ft_stroke_border_export( stroker->borders+1, outline );
- }
- }
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