diff options
| -rw-r--r-- | src/helper/geom-pathstroke.cpp | 183 |
1 files changed, 112 insertions, 71 deletions
diff --git a/src/helper/geom-pathstroke.cpp b/src/helper/geom-pathstroke.cpp index 1b8f90104..6fcfb79d5 100644 --- a/src/helper/geom-pathstroke.cpp +++ b/src/helper/geom-pathstroke.cpp @@ -11,6 +11,7 @@ #include <2geom/bezier-curve.h> #include <2geom/svg-elliptical-arc.h> #include <2geom/sbasis-to-bezier.h> // cubicbezierpath_from_sbasis +#include <2geom/path-intersection.h> #include "helper/geom-pathstroke.h" @@ -57,16 +58,28 @@ static Circle touching_circle( D2<SBasis> const &curve, double t, double tol=0.0 namespace { +// Join functions may: +// - inspect any curve of the current path +// - append any type of curve to the current path +// - inspect the outgoing path +// +// Join functions must: +// - append the outgoing curve +// OR +// - end at outgoing.finalPoint + typedef void join_func(Geom::Path& res, Geom::Curve const& outgoing, double miter, double width); void bevel_join(Geom::Path& res, Geom::Curve const& outgoing, double /*miter*/, double /*width*/) { res.appendNew<Geom::LineSegment>(outgoing.initialPoint()); + res.append(outgoing); } void round_join(Geom::Path& res, Geom::Curve const& outgoing, double /*miter*/, double width) { res.appendNew<Geom::SVGEllipticalArc>(width, width, 0, false, width <= 0, outgoing.initialPoint()); + res.append(outgoing); } void miter_join(Geom::Path& res, Geom::Curve const& outgoing, double miter, double width) @@ -81,18 +94,25 @@ void miter_join(Geom::Path& res, Geom::Curve const& outgoing, double miter, doub double len = Geom::distance(p, point_on_path); if (len <= miter) { // miter OK, check to see if we can do a relocation - // TODO FIXME - /*if (auto line = cast(const(LineSegment))res.back_open) { - Curve copy = line.duplicate; - copy.setFinal(p); - res.erase_last(); - res.append(copy); - } else {*/ + bool ls = dynamic_cast<Geom::LineSegment const*>(&res.back_open()); + if (ls) { + res.setFinal(p); + } else { res.appendNew<Geom::LineSegment>(p); - //} + } } } + res.appendNew<Geom::LineSegment>(outgoing.initialPoint()); + + // check if we can do another relocation + + bool ls = dynamic_cast<Geom::LineSegment const*>(&outgoing); + if (ls) { + res.setFinal(outgoing.finalPoint()); + } else { + res.append(outgoing); + } } // might need a little reworking @@ -152,6 +172,7 @@ void extrapolate_join(Geom::Path& path_builder, Geom::Curve const& outgoing, dou printf("WARNING: Error extrapolating line join: %s\n", ex.what()); path_builder.appendNew<Geom::LineSegment>(endPt); } + path_builder.append(outgoing); } else { // 1 or no solutions found, default to miter miter_join(path_builder, outgoing, miter_limit, line_width); @@ -164,11 +185,36 @@ void extrapolate_join(Geom::Path& path_builder, Geom::Curve const& outgoing, dou void join_inside(Geom::Path& res, Geom::Curve const& outgoing) { - res.appendNew<Geom::LineSegment>(outgoing.initialPoint()); + Geom::Curve const& incoming = res.back_open(); + Geom::Crossings cross = Geom::crossings(incoming, outgoing); + + if (!cross.empty()) { + // yeah if we could avoid allocing that'd be great + Geom::Curve *d1 = incoming.portion(0., cross[0].ta); + res.erase_last(); + res.append(*d1); + delete d1; + + Geom::Curve *d2 = outgoing.portion(cross[0].tb, 1.); + res.setFinal(d2->initialPoint()); + res.append(*d2); + delete d2; + } else { + res.appendNew<Geom::LineSegment>(outgoing.initialPoint()); + res.append(outgoing); + } } void outline_helper(Geom::Path& res, Geom::Path const& to_add, double width, double miter, Inkscape::LineJoinType join) { + Geom::Curve const& outgoing = to_add[0]; + if (Geom::are_near(res.finalPoint(), outgoing.initialPoint())) { + // if the points are /that/ close, just ignore this one + res.setFinal(outgoing.initialPoint()); + res.append(outgoing); + return; + } + Geom::Point tang1 = -Geom::unitTangentAt(reverse(res.back().toSBasis()), 0.); //Geom::Point tang2 = to_add[0].unitTangentAt(0); Geom::Point discontinuity_vec = to_add.initialPoint() - res.finalPoint(); @@ -189,12 +235,10 @@ void outline_helper(Geom::Path& res, Geom::Path const& to_add, double width, dou default: jf = &miter_join; } - jf(res, to_add[0], miter, width); + jf(res, outgoing, miter, width); } else { - join_inside(res, to_add[0]); + join_inside(res, outgoing); } - - res.append(to_add); } // Offsetting a line segment is mathematically stable and quick to do @@ -359,8 +403,40 @@ void offset_curve(Geom::Path& res, Geom::Curve const* current, double width) } } +typedef void cap_func(Geom::PathBuilder& res, Geom::Path const& with_dir, Geom::Path const& against_dir, double width); + +void flat_cap(Geom::PathBuilder& res, Geom::Path const&, Geom::Path const& against_dir, double) +{ + res.lineTo(against_dir.initialPoint()); +} + +void round_cap(Geom::PathBuilder& res, Geom::Path const&, Geom::Path const& against_dir, double width) +{ + res.arcTo(width / 2., width / 2., 0., true, false, against_dir.initialPoint()); +} + +void square_cap(Geom::PathBuilder& res, Geom::Path const& with_dir, Geom::Path const& against_dir, double width) +{ + width /= 2.; + Geom::Point normal_1 = -Geom::unitTangentAt(Geom::reverse(with_dir.back().toSBasis()), 0.); + Geom::Point normal_2 = -against_dir[0].unitTangentAt(0.); + res.lineTo(with_dir.finalPoint() + normal_1*width); + res.lineTo(against_dir.initialPoint() + normal_2*width); + res.lineTo(against_dir.initialPoint()); +} + +void peak_cap(Geom::PathBuilder& res, Geom::Path const& with_dir, Geom::Path const& against_dir, double width) +{ + width /= 2.; + Geom::Point normal_1 = -Geom::unitTangentAt(Geom::reverse(with_dir.back().toSBasis()), 0.); + Geom::Point normal_2 = -against_dir[0].unitTangentAt(0.); + Geom::Point midpoint = ((with_dir.finalPoint() + normal_1*width) + (against_dir.initialPoint() + normal_2*width)) * 0.5; + res.lineTo(midpoint); + res.lineTo(against_dir.initialPoint()); } +} // namespace + namespace Inkscape { Geom::PathVector outline(Geom::Path const& input, double width, double miter, LineJoinType join, LineCapType butt) @@ -374,33 +450,24 @@ Geom::PathVector outline(Geom::Path const& input, double width, double miter, Li res.moveTo(with_dir[0].initialPoint()); res.append(with_dir); + cap_func *cf; + switch (butt) { + case BUTT_ROUND: + cf = &round_cap; + break; + case BUTT_SQUARE: + cf = &square_cap; + break; + case BUTT_PEAK: + cf = &peak_cap; + break; + default: + cf = &flat_cap; + } + // glue caps if (!input.closed()) { - switch (butt) { - case BUTT_ROUND: - res.arcTo(width / 2., width / 2., 0., true, false, against_dir.initialPoint()); - break; - case BUTT_SQUARE: { - Geom::Point end_deriv = -Geom::unitTangentAt(Geom::reverse(input[input.size()-1].toSBasis()), 0.); - double radius = 0.5 * Geom::distance(with_dir.finalPoint(), against_dir.initialPoint()); - res.lineTo(with_dir.finalPoint() + end_deriv*radius); - res.lineTo(against_dir.initialPoint() + end_deriv*radius); - res.lineTo(against_dir.initialPoint()); - break; - } - case BUTT_PEAK: { - Geom::Point end_deriv = -Geom::unitTangentAt(Geom::reverse(input[input.size()-1].toSBasis()), 0.); - double radius = 0.5 * Geom::distance(with_dir.finalPoint(), against_dir.initialPoint()); - Geom::Point midpoint = ((with_dir.finalPoint() + against_dir.initialPoint()) * 0.5) + end_deriv*radius; - res.lineTo(midpoint); - res.lineTo(against_dir.initialPoint()); - break; - } - case BUTT_FLAT: - default: - res.lineTo(against_dir.initialPoint()); - break; - } + cf(res, with_dir, against_dir, width); } else { res.moveTo(against_dir.initialPoint()); } @@ -408,30 +475,7 @@ Geom::PathVector outline(Geom::Path const& input, double width, double miter, Li res.append(against_dir); if (!input.closed()) { - switch(butt) { - case BUTT_ROUND: - res.arcTo(width / 2., width / 2., 0., true, false, with_dir.initialPoint()); - break; - case BUTT_SQUARE: { - Geom::Point end_deriv = -input[0].unitTangentAt(0.); - double radius = 0.5 * Geom::distance(against_dir.finalPoint(), with_dir.initialPoint()); - res.lineTo(against_dir.finalPoint() + end_deriv*radius); - res.lineTo(with_dir.initialPoint() + end_deriv*radius); - res.lineTo(with_dir.initialPoint()); - break; - } - case BUTT_PEAK: { - Geom::Point end_deriv = -input[0].unitTangentAt(0.); - double radius = 0.5 * Geom::distance(against_dir.finalPoint(), with_dir.initialPoint()); - Geom::Point midpoint = ((against_dir.finalPoint() + with_dir.initialPoint()) * 0.5) + end_deriv*radius; - res.lineTo(midpoint); - res.lineTo(with_dir.initialPoint()); - break; - } - case BUTT_FLAT: - default: - res.lineTo(with_dir.initialPoint()); - } + cf(res, against_dir, with_dir, width); res.closePath(); } @@ -451,7 +495,8 @@ Geom::Path half_outline(Geom::Path const& input, double width, double miter, Lin res.start(start); // Do two curves at a time for efficiency, since the join function needs to know the outgoing curve as well - const size_t k = input.size_default(); + const size_t k = (input.back_closed().isDegenerate() && input.closed()) + ?input.size_default()-1:input.size_default(); for (size_t u = 0; u < k; u += 2) { temp = Geom::Path(); @@ -462,6 +507,7 @@ Geom::Path half_outline(Geom::Path const& input, double width, double miter, Lin res.append(temp); } else { outline_helper(res, temp, width, miter, join); + res.insert(res.end(), ++temp.begin(), temp.end()); } // odd number of paths @@ -469,15 +515,11 @@ Geom::Path half_outline(Geom::Path const& input, double width, double miter, Lin temp = Geom::Path(); offset_curve(temp, &input[u+1], width); outline_helper(res, temp, width, miter, join); + res.insert(res.end(), ++temp.begin(), temp.end()); } } if (input.closed()) { - if (input.back_closed().isDegenerate()) { - res.erase_last(); - res.erase_last(); // ? - } - Geom::Curve const &c1 = res.back(); Geom::Curve const &c2 = res.front(); temp = Geom::Path(); @@ -485,9 +527,8 @@ Geom::Path half_outline(Geom::Path const& input, double width, double miter, Lin Geom::Path temp2; temp2.append(c2); outline_helper(temp, temp2, width, miter, join); - temp.erase_last(); // we already outlined c2 - temp.erase(temp.begin()); // we already outlined c1 - + res.erase(res.begin()); + res.erase_last(); // res.append(temp); res.close(); |