X-Git-Url: http://git.jankratochvil.net/?p=reactos.git;a=blobdiff_plain;f=lib%2Ffreetype%2Fsrc%2Fbase%2Fftstroker.c;fp=lib%2Ffreetype%2Fsrc%2Fbase%2Fftstroker.c;h=712020e78f28d1c7ac5b2dc087dc8ada29bca97b;hp=0000000000000000000000000000000000000000;hb=7c0db166f81fbe8c8b913d7f26048e337d383605;hpb=e3ed2d773259cc445c7ff8181ebd934931365328 diff --git a/lib/freetype/src/base/ftstroker.c b/lib/freetype/src/base/ftstroker.c new file mode 100644 index 0000000..712020e --- /dev/null +++ b/lib/freetype/src/base/ftstroker.c @@ -0,0 +1,1577 @@ +#include +#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; + }