--- /dev/null
+#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 );
+
+ /* don't record empty paths !! */
+ if ( border->num_points > (FT_UInt)border->start )
+ {
+ 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--, 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 )
+ {
+ 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++, 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;
+ phi = stroker->angle_in;
+ }
+ else
+ {
+ theta = theta/2;
+ phi = stroker->angle_in + theta + rotate;
+ }
+
+ thcos = FT_Cos( theta );
+ sigma = FT_MulFix( stroker->miter_limit, thcos );
+
+ if ( sigma >= 0x10000L )
+ miter = 0;
+
+
+ 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 );
+ }
+ }
+
+
+
+
+
+ /*
+ * 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 */
+ FT_Int in_path;
+
+ if ( !outline || !stroker )
+ return FT_Err_Invalid_Argument;
+
+ first = 0;
+
+ in_path = 0;
+
+ for ( n = 0; n < outline->n_contours; n++ )
+ {
+ FT_Int last; /* index of last point in contour */
+
+
+ last = outline->contours[n];
+ limit = outline->points + last;
+
+ 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 and record its position */
+ /* for closure */
+ v_start.x = ( v_start.x + v_last.x ) / 2;
+ v_start.y = ( v_start.y + v_last.y ) / 2;
+
+ v_last = v_start;
+ }
+ point--;
+ tags--;
+ }
+
+ error = FT_Stroker_BeginSubPath( stroker, &v_start, opened );
+ if ( error )
+ goto Exit;
+
+ in_path = 1;
+
+ 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;
+
+ error = FT_Stroker_EndSubPath( stroker );
+ if ( error )
+ goto Exit;
+
+ first = last + 1;
+ }
+
+ return 0;
+
+ Exit:
+ return error;
+
+ Invalid_Outline:
+ return FT_Err_Invalid_Outline;
+ }