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| author | Johan B. C. Engelen <jbc.engelen@swissonline.ch> | 2012-04-07 21:06:28 +0000 |
|---|---|---|
| committer | Johan B. C. Engelen <j.b.c.engelen@alumnus.utwente.nl> | 2012-04-07 21:06:28 +0000 |
| commit | 096ec6139f4f6ab8229db1692c496770de551698 (patch) | |
| tree | b5f2076a62b7ff04e21c5003ed9623cbf8a91772 /src | |
| parent | powerstroke: previous and this commit fix extrapolated and miter join behavio... (diff) | |
| download | inkscape-096ec6139f4f6ab8229db1692c496770de551698.tar.gz inkscape-096ec6139f4f6ab8229db1692c496770de551698.zip | |
powerstroke: fix line caps for end/start knots with no handle (1st deriv == 0)
(bzr r11178)
Diffstat (limited to 'src')
| -rw-r--r-- | src/live_effects/lpe-powerstroke.cpp | 11 |
1 files changed, 7 insertions, 4 deletions
diff --git a/src/live_effects/lpe-powerstroke.cpp b/src/live_effects/lpe-powerstroke.cpp index 17baa837f..878811275 100644 --- a/src/live_effects/lpe-powerstroke.cpp +++ b/src/live_effects/lpe-powerstroke.cpp @@ -34,6 +34,9 @@ namespace Geom { // should all be moved to 2geom at some point +/** +* note that -unitTangentAt(reverse(a),0.) == unitTangentAt(a,1.) but the former is more reliable (sometimes the sign is wrong for the latter) +*/ Point unitTangentAt( D2<SBasis> const & a, Coord t, unsigned n = 3) { std::vector<Point> derivs = a.valueAndDerivatives(t, n); for (unsigned deriv_n = 1; deriv_n < derivs.size(); deriv_n++) { @@ -525,7 +528,7 @@ LPEPowerStroke::doEffect_path (std::vector<Geom::Path> const & path_in) break; case LINECAP_PEAK: { - Geom::Point end_deriv = unit_vector(der.lastValue()); + Geom::Point end_deriv = -unitTangentAt( reverse(pwd2_in.segs.back()), 0.); double radius = 0.5 * distance(pwd2_out.lastValue(), mirrorpath.firstValue()); Geom::Point midpoint = 0.5*(pwd2_out.lastValue() + mirrorpath.firstValue()) + radius*end_deriv; fixed_path.appendNew<LineSegment>(midpoint); @@ -534,7 +537,7 @@ LPEPowerStroke::doEffect_path (std::vector<Geom::Path> const & path_in) } case LINECAP_SQUARE: { - Geom::Point end_deriv = unit_vector(der.lastValue()); + Geom::Point end_deriv = -unitTangentAt( reverse(pwd2_in.segs.back()), 0.); double radius = 0.5 * distance(pwd2_out.lastValue(), mirrorpath.firstValue()); fixed_path.appendNew<LineSegment>( pwd2_out.lastValue() + radius*end_deriv ); fixed_path.appendNew<LineSegment>( mirrorpath.firstValue() + radius*end_deriv ); @@ -563,7 +566,7 @@ LPEPowerStroke::doEffect_path (std::vector<Geom::Path> const & path_in) break; case LINECAP_PEAK: { - Geom::Point start_deriv = unit_vector(der.firstValue()); + Geom::Point start_deriv = unitTangentAt( pwd2_in.segs.front(), 0.); double radius = 0.5 * distance(pwd2_out.firstValue(), mirrorpath.lastValue()); Geom::Point midpoint = 0.5*(mirrorpath.lastValue() + pwd2_out.firstValue()) - radius*start_deriv; fixed_path.appendNew<LineSegment>( midpoint ); @@ -572,7 +575,7 @@ LPEPowerStroke::doEffect_path (std::vector<Geom::Path> const & path_in) } case LINECAP_SQUARE: { - Geom::Point start_deriv = unit_vector(der.firstValue()); + Geom::Point start_deriv = unitTangentAt( pwd2_in.segs.front(), 0.); double radius = 0.5 * distance(pwd2_out.firstValue(), mirrorpath.lastValue()); fixed_path.appendNew<LineSegment>( mirrorpath.lastValue() - radius*start_deriv ); fixed_path.appendNew<LineSegment>( pwd2_out.firstValue() - radius*start_deriv ); |