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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 18:24:48 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 18:24:48 +0000 |
commit | cca66b9ec4e494c1d919bff0f71a820d8afab1fa (patch) | |
tree | 146f39ded1c938019e1ed42d30923c2ac9e86789 /src/pure-transform.cpp | |
parent | Initial commit. (diff) | |
download | inkscape-cca66b9ec4e494c1d919bff0f71a820d8afab1fa.tar.xz inkscape-cca66b9ec4e494c1d919bff0f71a820d8afab1fa.zip |
Adding upstream version 1.2.2.upstream/1.2.2upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to '')
-rw-r--r-- | src/pure-transform.cpp | 374 |
1 files changed, 374 insertions, 0 deletions
diff --git a/src/pure-transform.cpp b/src/pure-transform.cpp new file mode 100644 index 0000000..847bbdb --- /dev/null +++ b/src/pure-transform.cpp @@ -0,0 +1,374 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * Class for pure transformations, such as translating, scaling, stretching, skewing, and rotating + * + * Authors: + * Diederik van Lierop <mail@diedenrezi.nl> + * + * Copyright (C) 2015 Diederik van Lierop + * + * Released under GNU GPL v2+, read the file 'COPYING' for more information. + */ + +#include "pure-transform.h" +#include "snap.h" + +namespace Inkscape + +{ + +void PureTransform::snap(::SnapManager *sm, std::vector<Inkscape::SnapCandidatePoint> const &points, Geom::Point const &pointer) { + std::vector<Inkscape::SnapCandidatePoint> transformed_points; + Geom::Rect bbox; + + long source_num = 0; + for (std::vector<Inkscape::SnapCandidatePoint>::const_iterator i = points.begin(); i != points.end(); ++i) { + + /* Work out the transformed version of this point */ + Geom::Point transformed = getTransformedPoint(*i); // _transformPoint(*i, transformation_type, transformation, origin, dim, uniform); + + // add the current transformed point to the box hulling all transformed points + if (i == points.begin()) { + bbox = Geom::Rect(transformed, transformed); + } else { + bbox.expandTo(transformed); + } + + transformed_points.emplace_back(transformed, (*i).getSourceType(), source_num, Inkscape::SNAPTARGET_UNDEFINED, Geom::OptRect()); + source_num++; + } + + /* The current best metric for the best transformation; lower is better, whereas Geom::infinity() + ** means that we haven't snapped anything. + */ + Inkscape::SnapCandidatePoint best_original_point; + g_assert(best_snapped_point.getAlwaysSnap() == false); // Check initialization of snapped point + g_assert(best_snapped_point.getAtIntersection() == false); + g_assert(best_snapped_point.getSnapped() == false); // Check initialization to catch any regression + + std::vector<Inkscape::SnapCandidatePoint>::iterator j = transformed_points.begin(); + + // std::cout << std::endl; + bool first_free_snap = true; + + for (std::vector<Inkscape::SnapCandidatePoint>::const_iterator i = points.begin(); i != points.end(); ++i) { + + // If we have a collection of SnapCandidatePoints, with mixed constrained snapping and free snapping + // requirements (this can happen when scaling, see PureScale::snap()), then freeSnap might never see the + // SnapCandidatePoint with source_num == 0. The freeSnap() method in the object snapper depends on this, + // because only for source-num == 0 the target nodes will be collected. Therefore we enforce that the first + // SnapCandidatePoint that is to be freeSnapped always has source_num == 0; + // TODO: This is a bit ugly so fix this; do we need sourcenum for anything else? if we don't then get rid + // of it and explicitly communicate to the object snapper that this is a first point + if (first_free_snap) { + (*j).setSourceNum(0); + first_free_snap = false; + } + + Inkscape::SnappedPoint snapped_point = snap(sm, *j, (*i).getPoint(), bbox); // Calls the snap() method of the derived classes + + snapped_point.setPointerDistance(Geom::L2(pointer - (*i).getPoint())); + + /*Find the transformation that describes where the snapped point has + ** ended up, and also the metric for this transformation. + */ + + bool store_best_snap = false; + if (snapped_point.getSnapped()) { + // We snapped; keep track of the best snap + if (best_snapped_point.isOtherSnapBetter(snapped_point, true)) { + store_best_snap = true; + } + } else { + // So we didn't snap for this point + if (!best_snapped_point.getSnapped()) { + // ... and none of the points before snapped either + // We might still need to apply a constraint though, if we tried a constrained snap. And + // in case of a free snap we might have use for the transformed point, so let's return that + // point, whether it's constrained or not + + if (best_snapped_point.isOtherSnapBetter(snapped_point, true) ) { + // .. so we must keep track of the best non-snapped constrained point.. but what + // is the best? There is no best, or is there? We cannot compare on snapped distance + // because neither has snapped, and both have their snapped distance set to infinity. + // There might be a difference in "constrainedness" though, 1D vs 2D snapping + store_best_snap = true; + } + } + } + + if (store_best_snap || i == points.begin()) { + best_original_point = (*i); + best_snapped_point = snapped_point; // Can be a point that didn't snap, but then at least we + // return something meaningful; we might have use for the transformation. The default + // snapped_point, as initialized before this loop, is not very meaningful at all. + } + + ++j; + } + + /* The current best transformation */ + //Geom::Point best_transformation = getResult(best_original_point, best_snapped_point); + storeTransform(best_original_point, best_snapped_point); + + Geom::Coord best_metric = best_snapped_point.getSnapDistance(); + + // Using " < 1e6" instead of " < Geom::infinity()" for catching some rounding errors + // These rounding errors might be caused by NRRects, see bug #1584301 + best_snapped_point.setSnapDistance(best_metric < 1e6 ? best_metric : Geom::infinity()); +} + + + + + +Geom::Point PureTranslate::getTransformedPoint(SnapCandidatePoint const &p) const { + return p.getPoint() + _vector; +} + +void PureTranslate::storeTransform(SnapCandidatePoint const &original_point, SnappedPoint &snapped_point) { + /* Consider the case in which a box is almost aligned with a grid in both + * horizontal and vertical directions. The distance to the intersection of + * the grid lines will always be larger then the distance to a single grid + * line. If we prefer snapping to an intersection over to a single + * grid line, then we cannot use "metric = Geom::L2(result)". Therefore the + * snapped distance will be used as a metric. Please note that the snapped + * distance to an intersection is defined as the distance to the nearest line + * of the intersection, and not to the intersection itself! + */ + // Only for translations, the relevant metric will be the real snapped distance, + // so we don't have to do anything special here + _vector_snapped = snapped_point.getPoint() - original_point.getPoint(); +} + +SnappedPoint PureTranslate::snap(::SnapManager *sm, SnapCandidatePoint const &p, Geom::Point /*pt_orig*/, Geom::OptRect const &bbox_to_snap) const { + return sm->freeSnap(p, bbox_to_snap); +} + +SnappedPoint PureTranslateConstrained::snap(::SnapManager *sm, SnapCandidatePoint const &p, Geom::Point pt_orig, Geom::OptRect const &bbox_to_snap) const { + // Calculate a constraint dedicated for this specific point + // When doing a constrained translation, all points will move in the same direction, i.e. + // either horizontally or vertically. The lines along which they move are therefore all + // parallel, but might not be co-linear. Therefore we will have to specify the point through + // which the constraint-line runs here, for each point individually. + Snapper::SnapConstraint dedicated_constraint = Snapper::SnapConstraint(pt_orig, _direction); + return sm->constrainedSnap(p, dedicated_constraint, bbox_to_snap); +} + + + + + +Geom::Point PureScale::getTransformedPoint(SnapCandidatePoint const &p) const { + return (p.getPoint() - _origin) * _scale + _origin; +} + +void PureScale::storeTransform(SnapCandidatePoint const &original_point, SnappedPoint &snapped_point) { + _scale_snapped = Geom::Scale(Geom::infinity(), Geom::infinity()); + // If this point *i is horizontally or vertically aligned with + // the origin of the scaling, then it will scale purely in X or Y + // We can therefore only calculate the scaling in this direction + // and the scaling factor for the other direction should remain + // untouched (unless scaling is uniform of course) + Geom::Point const a = snapped_point.getPoint() - _origin; // vector to snapped point + Geom::Point const b = original_point.getPoint() - _origin; // vector to original point (not the transformed point!) + for (int index = 0; index < 2; index++) { + if (fabs(b[index]) > 1e-4) { // if SCALING CAN occur in this direction + if (fabs(fabs(a[index]/b[index]) - fabs(_scale[index])) > 1e-7) { // if SNAPPING DID occur in this direction + _scale_snapped[index] = a[index] / b[index]; // then calculate it! + // _scale_snapped will be (1,1) if we haven't snapped, because the snapped point equals the original point + } + // we might have left result[1-index] = Geom::infinity() if scaling didn't occur in the other direction + } + } + + if (_scale_snapped == Geom::Scale(Geom::infinity(), Geom::infinity())) { + // This point must have been at the origin, so we cannot possibly snap; it won't scale (i.e. won't move while dragging) + snapped_point.setSnapDistance(Geom::infinity()); + snapped_point.setSecondSnapDistance(Geom::infinity()); + return; + } + + if (_uniform) { + // Lock the scaling the be uniform, but keep the sign such that we don't change which quadrant we have dragged into + if (fabs(_scale_snapped[0]) < fabs(_scale_snapped[1])) { + _scale_snapped[1] = fabs(_scale_snapped[0]) * Geom::sgn(_scale[1]); + } else { + _scale_snapped[0] = fabs(_scale_snapped[1]) * Geom::sgn(_scale[0]); + } + } + + // Don't ever exit with one of scaling components uninitialized + for (int index = 0; index < 2; index++) { + if (_scale_snapped[index] == Geom::infinity()) { + _scale_snapped[index] = _scale[index]; + } + } + + // Compare the resulting scaling with the desired scaling + Geom::Point scale_metric = _scale_snapped.vector() - _scale.vector(); + snapped_point.setSnapDistance(Geom::L2(scale_metric)); + snapped_point.setSecondSnapDistance(Geom::infinity()); +} + +// When scaling, a point aligned either horizontally or vertically with the origin can only +// move in that specific direction; therefore it should only snap in that direction, so this +// then becomes a constrained snap; otherwise we can use a free snap; +SnappedPoint PureScale::snap(::SnapManager *sm, SnapCandidatePoint const &p, Geom::Point pt_orig, Geom::OptRect const &bbox_to_snap) const { + Geom::Point const b = (pt_orig - _origin); // vector to original point (not the transformed point!) + bool const c1 = fabs(b[Geom::X]) < 1e-6; + bool const c2 = fabs(b[Geom::Y]) < 1e-6; + if ((c1 || c2) && !(c1 && c2)) { + Geom::Point cvec; cvec[c1] = 1.; + Snapper::SnapConstraint dedicated_constraint = Inkscape::Snapper::SnapConstraint(_origin, cvec); + return sm->constrainedSnap(p, dedicated_constraint, bbox_to_snap); + } else { + return sm->freeSnap(p, bbox_to_snap); + } +} + +SnappedPoint PureScaleConstrained::snap(::SnapManager *sm, SnapCandidatePoint const &p, Geom::Point pt_orig, Geom::OptRect const &bbox_to_snap) const { + // When constrained scaling, only uniform scaling is supported. + // When uniformly scaling, each point will have its own unique constraint line, + // running from the scaling origin to the original untransformed point. We will + // calculate that line here as a dedicated constraint + Geom::Point b = pt_orig - _origin; + Snapper::SnapConstraint dedicated_constraint = Inkscape::Snapper::SnapConstraint(_origin, b); + return sm->constrainedSnap(p, dedicated_constraint, bbox_to_snap); +} + + + + + +Geom::Point PureStretchConstrained::getTransformedPoint(SnapCandidatePoint const &p) const { + Geom::Scale s(1, 1); + if (_uniform) + s[Geom::X] = s[Geom::Y] = _magnitude; + else { + s[_direction] = _magnitude; + s[1 - _direction] = 1; + } + return ((p.getPoint() - _origin) * s) + _origin; +} + +SnappedPoint PureStretchConstrained::snap(::SnapManager *sm, SnapCandidatePoint const &p, Geom::Point pt_orig, Geom::OptRect const &bbox_to_snap) const { + Snapper::SnapConstraint dedicated_constraint; + if (_uniform) { + // When uniformly stretching, each point will have its own unique constraint line, + // running from the scaling origin to the original untransformed point. We will + // calculate that line here + Geom::Point b = pt_orig - _origin; + dedicated_constraint = Inkscape::Snapper::SnapConstraint(_origin, b); // dedicated constraint + } else { + Geom::Point cvec; cvec[_direction] = 1.; + dedicated_constraint = Inkscape::Snapper::SnapConstraint(pt_orig, cvec); + } + + return sm->constrainedSnap(p, dedicated_constraint, bbox_to_snap); +} + +void PureStretchConstrained::storeTransform(SnapCandidatePoint const &original_point, SnappedPoint &snapped_point) { + Geom::Point const a = snapped_point.getPoint() - _origin; // vector to snapped point + Geom::Point const b = original_point.getPoint() - _origin; // vector to original point (not the transformed point!) + + _stretch_snapped = Geom::Scale(Geom::infinity(), Geom::infinity()); + if (fabs(b[_direction]) > 1e-4) { // if STRETCHING will occur for this point + _stretch_snapped[_direction] = a[_direction] / b[_direction]; + _stretch_snapped[1-_direction] = _uniform ? _stretch_snapped[_direction] : 1; + } else { // STRETCHING might occur for this point, but only when the stretching is uniform + if (_uniform && fabs(b[1-_direction]) > 1e-4) { + _stretch_snapped[1-_direction] = a[1-_direction] / b[1-_direction]; + _stretch_snapped[_direction] = _stretch_snapped[1-_direction]; + } + } + + // _stretch_snapped might have one or both components at infinity! + + // Store the metric for this transformation as a virtual distance + snapped_point.setSnapDistance(std::abs(_stretch_snapped[_direction] - _magnitude)); + snapped_point.setSecondSnapDistance(Geom::infinity()); +} + + + + + +Geom::Point PureSkewConstrained::getTransformedPoint(SnapCandidatePoint const &p) const { + Geom::Point transformed; + // Apply the skew factor + transformed[_direction] = (p.getPoint())[_direction] + _skew * ((p.getPoint())[1 - _direction] - _origin[1 - _direction]); + // While skewing, mirroring and scaling (by integer multiples) in the opposite direction is also allowed. + // Apply that scale factor here + transformed[1-_direction] = (p.getPoint() - _origin)[1 - _direction] * _scale + _origin[1 - _direction]; + return transformed; +} + +SnappedPoint PureSkewConstrained::snap(::SnapManager *sm, SnapCandidatePoint const &p, Geom::Point pt_orig, Geom::OptRect const &bbox_to_snap) const { + // Snapping the nodes of the bounding box of a selection that is being transformed, will only work if + // the transformation of the bounding box is equal to the transformation of the individual nodes. This is + // NOT the case for example when rotating or skewing. The bounding box itself cannot possibly rotate or skew, + // so it's corners have a different transformation. The snappers cannot handle this, therefore snapping + // of bounding boxes is not allowed here. + g_assert(!(p.getSourceType() & Inkscape::SNAPSOURCE_BBOX_CATEGORY)); + + Geom::Point constraint_vector; + constraint_vector[1-_direction] = 0.0; + constraint_vector[_direction] = 1.0; + + return sm->constrainedSnap(p, Inkscape::Snapper::SnapConstraint(constraint_vector), bbox_to_snap); +} + +void PureSkewConstrained::storeTransform(SnapCandidatePoint const &original_point, SnappedPoint &snapped_point) { + Geom::Point const b = original_point.getPoint() - _origin; // vector to original point (not the transformed point!) + _skew_snapped = (snapped_point.getPoint()[_direction] - (original_point.getPoint())[_direction]) / b[1 - _direction]; // skew factor + + // Store the metric for this transformation as a virtual distance + snapped_point.setSnapDistance(std::abs(_skew_snapped - _skew)); + snapped_point.setSecondSnapDistance(Geom::infinity()); +} + + + + +Geom::Point PureRotateConstrained::getTransformedPoint(SnapCandidatePoint const &p) const { + return (p.getPoint() - _origin) * Geom::Rotate(_angle) + _origin; +} + +SnappedPoint PureRotateConstrained::snap(::SnapManager *sm, SnapCandidatePoint const &p, Geom::Point pt_orig, Geom::OptRect const &bbox_to_snap) const { + // Snapping the nodes of the bounding box of a selection that is being transformed, will only work if + // the transformation of the bounding box is equal to the transformation of the individual nodes. This is + // NOT the case for example when rotating or skewing. The bounding box itself cannot possibly rotate or skew, + // so it's corners have a different transformation. The snappers cannot handle this, therefore snapping + // of bounding boxes is not allowed here. + g_assert(!(p.getSourceType() & Inkscape::SNAPSOURCE_BBOX_CATEGORY)); + + // Calculate a constraint dedicated for this specific point + Geom::Point b = pt_orig - _origin; + Geom::Coord r = Geom::L2(b); // the radius of the circular constraint + Snapper::SnapConstraint dedicated_constraint = Inkscape::Snapper::SnapConstraint(_origin, b, r); + return sm->constrainedSnap(p, dedicated_constraint, bbox_to_snap); +} + +void PureRotateConstrained::storeTransform(SnapCandidatePoint const &original_point, SnappedPoint &snapped_point) { + Geom::Point const a = snapped_point.getPoint() - _origin; // vector to snapped point + Geom::Point const b = (original_point.getPoint() - _origin); // vector to original point (not the transformed point!) + // a is vector to snapped point; b is vector to original point; now lets calculate angle between a and b + _angle_snapped = atan2(Geom::dot(Geom::rot90(b), a), Geom::dot(b, a)); + if (Geom::L2(b) < 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) + snapped_point.setSnapDistance(Geom::infinity()); + // 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. + } else { + snapped_point.setSnapDistance(fabs(_angle_snapped - _angle)); + } + snapped_point.setSecondSnapDistance(Geom::infinity()); + +} + +} |