From ac88f5a63dee454daa483f63afa3797d49f3d938 Mon Sep 17 00:00:00 2001 From: Diederik van Lierop Date: Mon, 26 Jul 2010 22:45:01 +0200 Subject: [PATCH] While rotating, don't try snapping points coincident with the rotation center --- src/snap.cpp | 20 +++++++++++++++----- 1 file changed, 15 insertions(+), 5 deletions(-) diff --git a/src/snap.cpp b/src/snap.cpp index bac37737f..810e2dd8b 100644 --- a/src/snap.cpp +++ b/src/snap.cpp @@ -585,8 +585,18 @@ Inkscape::SnappedPoint SnapManager::_snapTransformed( // calculate that line here dedicated_constraint = Inkscape::Snapper::SnapConstraint(origin, b); } else if (transformation_type == ROTATE) { - // Geom::L2(b) is the radius of the circular constraint - dedicated_constraint = Inkscape::Snapper::SnapConstraint(origin, b, Geom::L2(b)); + Geom::Coord r = Geom::L2(b); // the radius of the circular constraint + if (r < 1e-9) { // points too close to the rotation center will not move. Don't try to snap these + // as they will always yield a perfect snap result if they're already snapped beforehand (e.g. + // when the transformation center has been snapped to a grid intersection in the selector tool) + continue; // skip this SnapCandidate and continue with the next one + // PS1: Apparently we don't have to do this for skewing, but why? + // PS2: We cannot easily filter these points upstream, e.g. in the grab() method (seltrans.cpp) + // because the rotation center will change when pressing shift, and grab() won't be recalled. + // Filtering could be done in handleRequest() (again in seltrans.cpp), by iterating through + // the snap candidates. But hey, we're iterating here anyway. + } + dedicated_constraint = Inkscape::Snapper::SnapConstraint(origin, b, r); } else if (transformation_type == STRETCH) { // when non-uniform stretching { dedicated_constraint = Inkscape::Snapper::SnapConstraint((*i).getPoint(), component_vectors[dim]); } else if (transformation_type == TRANSLATE) { @@ -702,9 +712,9 @@ Inkscape::SnappedPoint SnapManager::_snapTransformed( snapped_point.setSecondSnapDistance(NR_HUGE); break; case ROTATE: - // a is vector to snapped point; b is vector to original point; now lets calculate angle between a and b - result[0] = atan2(Geom::dot(Geom::rot90(b), a), Geom::dot(b, a)); - result[1] = result[1]; // how else should we store an angle in a point ;-) + // a is vector to snapped point; b is vector to original point; now lets calculate angle between a and b + result[0] = atan2(Geom::dot(Geom::rot90(b), a), Geom::dot(b, a)); + result[1] = result[1]; // how else should we store an angle in a point ;-) // Store the metric for this transformation as a virtual distance (we're storing an angle) snapped_point.setSnapDistance(std::abs(result[0] - transformation[0])); snapped_point.setSecondSnapDistance(NR_HUGE); -- 2.30.2