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Diffstat (limited to 'src/2geom/svg-path-parser.rl')
| -rw-r--r-- | src/2geom/svg-path-parser.rl | 487 |
1 files changed, 487 insertions, 0 deletions
diff --git a/src/2geom/svg-path-parser.rl b/src/2geom/svg-path-parser.rl new file mode 100644 index 0000000..7b3eb5a --- /dev/null +++ b/src/2geom/svg-path-parser.rl @@ -0,0 +1,487 @@ +/** + * \file + * \brief parse SVG path specifications + * + * Copyright 2007 MenTaLguY <mental@rydia.net> + * Copyright 2007 Aaron Spike <aaron@ekips.org> + * + * This library is free software; you can redistribute it and/or + * modify it either under the terms of the GNU Lesser General Public + * License version 2.1 as published by the Free Software Foundation + * (the "LGPL") or, at your option, under the terms of the Mozilla + * Public License Version 1.1 (the "MPL"). If you do not alter this + * notice, a recipient may use your version of this file under either + * the MPL or the LGPL. + * + * You should have received a copy of the LGPL along with this library + * in the file COPYING-LGPL-2.1; if not, write to the Free Software + * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA + * You should have received a copy of the MPL along with this library + * in the file COPYING-MPL-1.1 + * + * The contents of this file are subject to the Mozilla Public License + * Version 1.1 (the "License"); you may not use this file except in + * compliance with the License. You may obtain a copy of the License at + * http://www.mozilla.org/MPL/ + * + * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY + * OF ANY KIND, either express or implied. See the LGPL or the MPL for + * the specific language governing rights and limitations. + * + */ + +#include <cstdio> +#include <cmath> +#include <vector> +#include <glib.h> + +#include <2geom/point.h> +#include <2geom/svg-path-parser.h> +#include <2geom/angle.h> + +namespace Geom { + +%%{ + machine svg_path; + write data noerror; +}%% + +SVGPathParser::SVGPathParser(PathSink &sink) + : _absolute(false) + , _sink(sink) + , _z_snap_threshold(0) + , _curve(NULL) +{ + reset(); +} + +SVGPathParser::~SVGPathParser() +{ + delete _curve; +} + +void SVGPathParser::reset() { + _absolute = false; + _current = _initial = Point(0, 0); + _quad_tangent = _cubic_tangent = Point(0, 0); + _params.clear(); + delete _curve; + _curve = NULL; + + %%{ + write init; + }%% +} + +void SVGPathParser::parse(char const *str, int len) +{ + if (len < 0) { + len = std::strlen(str); + } + _parse(str, str + len, true); +} + +void SVGPathParser::parse(std::string const &s) +{ + _parse(s.c_str(), s.c_str() + s.size(), true); +} + +void SVGPathParser::feed(char const *str, int len) +{ + if (len < 0) { + len = std::strlen(str); + } + _parse(str, str + len, false); +} + +void SVGPathParser::feed(std::string const &s) +{ + _parse(s.c_str(), s.c_str() + s.size(), false); +} + +void SVGPathParser::finish() +{ + char const *empty = ""; + _parse(empty, empty, true); +} + +void SVGPathParser::_push(Coord value) +{ + _params.push_back(value); +} + +Coord SVGPathParser::_pop() +{ + Coord value = _params.back(); + _params.pop_back(); + return value; +} + +bool SVGPathParser::_pop_flag() +{ + return _pop() != 0.0; +} + +Coord SVGPathParser::_pop_coord(Dim2 axis) +{ + if (_absolute) { + return _pop(); + } else { + return _pop() + _current[axis]; + } +} + +Point SVGPathParser::_pop_point() +{ + Coord y = _pop_coord(Y); + Coord x = _pop_coord(X); + return Point(x, y); +} + +void SVGPathParser::_moveTo(Point const &p) +{ + _pushCurve(NULL); // flush + _sink.moveTo(p); + _quad_tangent = _cubic_tangent = _current = _initial = p; +} + +void SVGPathParser::_lineTo(Point const &p) +{ + _pushCurve(new LineSegment(_current, p)); + _quad_tangent = _cubic_tangent = _current = p; +} + +void SVGPathParser::_curveTo(Point const &c0, Point const &c1, Point const &p) +{ + _pushCurve(new CubicBezier(_current, c0, c1, p)); + _quad_tangent = _current = p; + _cubic_tangent = p + ( p - c1 ); +} + +void SVGPathParser::_quadTo(Point const &c, Point const &p) +{ + _pushCurve(new QuadraticBezier(_current, c, p)); + _cubic_tangent = _current = p; + _quad_tangent = p + ( p - c ); +} + +void SVGPathParser::_arcTo(Coord rx, Coord ry, Coord angle, + bool large_arc, bool sweep, Point const &p) +{ + if (_current == p) { + return; // ignore invalid (ambiguous) arc segments where start and end point are the same (per SVG spec) + } + + _pushCurve(new EllipticalArc(_current, fabs(rx), fabs(ry), angle, large_arc, sweep, p)); + _quad_tangent = _cubic_tangent = _current = p; +} + +void SVGPathParser::_closePath() +{ + if (_curve && (!_absolute || !_moveto_was_absolute) && + are_near(_initial, _current, _z_snap_threshold)) + { + _curve->setFinal(_initial); + } + + _pushCurve(NULL); // flush + _sink.closePath(); + _quad_tangent = _cubic_tangent = _current = _initial; +} + +void SVGPathParser::_pushCurve(Curve *c) +{ + if (_curve) { + _sink.feed(*_curve, false); + delete _curve; + } + _curve = c; +} + +void SVGPathParser::_parse(char const *str, char const *strend, bool finish) +{ + char const *p = str; + char const *pe = strend; + char const *eof = finish ? pe : NULL; + char const *start = NULL; + + %%{ + action start_number { + start = p; + } + + action push_number { + if (start) { + std::string buf(start, p); + _push(g_ascii_strtod(buf.c_str(), NULL)); + start = NULL; + } else { + std::string buf(str, p); + _push(g_ascii_strtod((_number_part + buf).c_str(), NULL)); + _number_part.clear(); + } + } + + action push_true { + _push(1.0); + } + + action push_false { + _push(0.0); + } + + action mode_abs { + _absolute = true; + } + + action mode_rel { + _absolute = false; + } + + action moveto { + _moveto_was_absolute = _absolute; + _moveTo(_pop_point()); + } + + action lineto { + _lineTo(_pop_point()); + } + + action horizontal_lineto { + _lineTo(Point(_pop_coord(X), _current[Y])); + } + + action vertical_lineto { + _lineTo(Point(_current[X], _pop_coord(Y))); + } + + action curveto { + Point p = _pop_point(); + Point c1 = _pop_point(); + Point c0 = _pop_point(); + _curveTo(c0, c1, p); + } + + action smooth_curveto { + Point p = _pop_point(); + Point c1 = _pop_point(); + _curveTo(_cubic_tangent, c1, p); + } + + action quadratic_bezier_curveto { + Point p = _pop_point(); + Point c = _pop_point(); + _quadTo(c, p); + } + + action smooth_quadratic_bezier_curveto { + Point p = _pop_point(); + _quadTo(_quad_tangent, p); + } + + action elliptical_arc { + Point point = _pop_point(); + bool sweep = _pop_flag(); + bool large_arc = _pop_flag(); + double angle = rad_from_deg(_pop()); + double ry = _pop(); + double rx = _pop(); + + _arcTo(rx, ry, angle, large_arc, sweep, point); + } + + action closepath { + _closePath(); + } + + wsp = (' ' | 9 | 10 | 13); + sign = ('+' | '-'); + digit_sequence = digit+; + exponent = ('e' | 'E') sign? digit_sequence; + fractional_constant = + digit_sequence? '.' digit_sequence + | digit_sequence '.'; + floating_point_constant = + fractional_constant exponent? + | digit_sequence exponent; + integer_constant = digit_sequence; + comma = ','; + comma_wsp = (wsp+ comma? wsp*) | (comma wsp*); + + flag = ('0' %push_false | '1' %push_true); + + number = + ( sign? integer_constant + | sign? floating_point_constant ) + >start_number %push_number; + + nonnegative_number = + ( integer_constant + | floating_point_constant) + >start_number %push_number; + + coordinate = number $(number,1) %(number,0); + coordinate_pair = (coordinate $(coordinate_pair_a,1) %(coordinate_pair_a,0) comma_wsp? coordinate $(coordinate_pair_b,1) %(coordinate_pair_b,0)) $(coordinate_pair,1) %(coordinate_pair,0); + elliptical_arc_argument = + (number $(elliptical_arg_a,1) %(elliptical_arg_a,0) comma_wsp? + number $(elliptical_arg_b,1) %(elliptical_arg_b,0) comma_wsp? + number comma_wsp + flag comma_wsp? flag comma_wsp? + coordinate_pair) + %elliptical_arc; + elliptical_arc_argument_sequence = + elliptical_arc_argument $1 %0 + (comma_wsp? elliptical_arc_argument $1 %0)*; + elliptical_arc = + ('A' %mode_abs| 'a' %mode_rel) wsp* + elliptical_arc_argument_sequence; + + smooth_quadratic_bezier_curveto_argument = + coordinate_pair %smooth_quadratic_bezier_curveto; + smooth_quadratic_bezier_curveto_argument_sequence = + smooth_quadratic_bezier_curveto_argument $1 %0 + (comma_wsp? + smooth_quadratic_bezier_curveto_argument $1 %0)*; + smooth_quadratic_bezier_curveto = + ('T' %mode_abs| 't' %mode_rel) wsp* + smooth_quadratic_bezier_curveto_argument_sequence; + + quadratic_bezier_curveto_argument = + (coordinate_pair $1 %0 comma_wsp? coordinate_pair) + %quadratic_bezier_curveto; + quadratic_bezier_curveto_argument_sequence = + quadratic_bezier_curveto_argument $1 %0 + (comma_wsp? quadratic_bezier_curveto_argument $1 %0)*; + quadratic_bezier_curveto = + ('Q' %mode_abs| 'q' %mode_rel) wsp* + quadratic_bezier_curveto_argument_sequence; + + smooth_curveto_argument = + (coordinate_pair $1 %0 comma_wsp? coordinate_pair) + %smooth_curveto; + smooth_curveto_argument_sequence = + smooth_curveto_argument $1 %0 + (comma_wsp? smooth_curveto_argument $1 %0)*; + smooth_curveto = + ('S' %mode_abs| 's' %mode_rel) + wsp* smooth_curveto_argument_sequence; + + curveto_argument = + (coordinate_pair $1 %0 comma_wsp? + coordinate_pair $1 %0 comma_wsp? + coordinate_pair) + %curveto; + curveto_argument_sequence = + curveto_argument $1 %0 + (comma_wsp? curveto_argument $1 %0)*; + curveto = + ('C' %mode_abs| 'c' %mode_rel) + wsp* curveto_argument_sequence; + + vertical_lineto_argument = coordinate %vertical_lineto; + vertical_lineto_argument_sequence = + vertical_lineto_argument $(vertical_lineto_argument_a,1) %(vertical_lineto_argument_a,0) + (comma_wsp? vertical_lineto_argument $(vertical_lineto_argument_b,1) %(vertical_lineto_argument_b,0))*; + vertical_lineto = + ('V' %mode_abs| 'v' %mode_rel) + wsp* vertical_lineto_argument_sequence; + + horizontal_lineto_argument = coordinate %horizontal_lineto; + horizontal_lineto_argument_sequence = + horizontal_lineto_argument $(horizontal_lineto_argument_a,1) %(horizontal_lineto_argument_a,0) + (comma_wsp? horizontal_lineto_argument $(horizontal_lineto_argument_b,1) %(horizontal_lineto_argument_b,0))*; + horizontal_lineto = + ('H' %mode_abs| 'h' %mode_rel) + wsp* horizontal_lineto_argument_sequence; + + lineto_argument = coordinate_pair %lineto; + lineto_argument_sequence = + lineto_argument $1 %0 + (comma_wsp? lineto_argument $1 %0)*; + lineto = + ('L' %mode_abs| 'l' %mode_rel) wsp* + lineto_argument_sequence; + + closepath = ('Z' | 'z') %closepath; + + moveto_argument = coordinate_pair %moveto; + moveto_argument_sequence = + moveto_argument $1 %0 + (comma_wsp? lineto_argument $1 %0)*; + moveto = + ('M' %mode_abs | 'm' %mode_rel) + wsp* moveto_argument_sequence; + + drawto_command = + closepath | lineto | + horizontal_lineto | vertical_lineto | + curveto | smooth_curveto | + quadratic_bezier_curveto | + smooth_quadratic_bezier_curveto | + elliptical_arc; + + drawto_commands = drawto_command (wsp* drawto_command)*; + moveto_drawto_command_group = moveto wsp* drawto_commands?; + moveto_drawto_command_groups = + moveto_drawto_command_group + (wsp* moveto_drawto_command_group)*; + + svg_path = wsp* moveto_drawto_command_groups? wsp*; + + + main := svg_path; + + write exec; + }%% + + if (finish) { + if (cs < svg_path_first_final) { + throw SVGPathParseError(); + } + } else if (start != NULL) { + _number_part = std::string(start, pe); + } + + if (finish) { + _pushCurve(NULL); + _sink.flush(); + reset(); + } +} + +void parse_svg_path(char const *str, PathSink &sink) +{ + SVGPathParser parser(sink); + parser.parse(str); +} + +void parse_svg_path_file(FILE *fi, PathSink &sink) +{ + static const size_t BUFFER_SIZE = 4096; + char buffer[BUFFER_SIZE]; + size_t bytes_read; + SVGPathParser parser(sink); + + while (true) { + bytes_read = fread(buffer, 1, BUFFER_SIZE, fi); + if (bytes_read < BUFFER_SIZE) { + parser.parse(buffer, bytes_read); + break; + } else { + parser.feed(buffer, bytes_read); + } + } +} + +} // namespace Geom + +/* + Local Variables: + mode:c++ + c-file-style:"stroustrup" + c-file-offsets:((innamespace . 0)(inline-open . 0)(case-label . +)) + indent-tabs-mode:nil + fill-column:99 + End: +*/ +// vim: filetype=ragel:cindent:expandtab:shiftwidth=4:softtabstop=4:fileencoding=utf-8:textwidth=99 : |