| #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 ); |
| } |
| } |
