From cca66b9ec4e494c1d919bff0f71a820d8afab1fa Mon Sep 17 00:00:00 2001 From: Daniel Baumann Date: Sun, 7 Apr 2024 20:24:48 +0200 Subject: Adding upstream version 1.2.2. Signed-off-by: Daniel Baumann --- src/object/algorithms/unclump.cpp | 397 ++++++++++++++++++++++++++++++++++++++ 1 file changed, 397 insertions(+) create mode 100644 src/object/algorithms/unclump.cpp (limited to 'src/object/algorithms/unclump.cpp') diff --git a/src/object/algorithms/unclump.cpp b/src/object/algorithms/unclump.cpp new file mode 100644 index 0000000..df59f88 --- /dev/null +++ b/src/object/algorithms/unclump.cpp @@ -0,0 +1,397 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/** + * @file + * Unclumping objects. + */ +/* Authors: + * bulia byak + * Jon A. Cruz + * Abhishek Sharma + * + * Copyright (C) 2005 Authors + * Released under GNU GPL v2+, read the file 'COPYING' for more information. + */ + +#include "unclump.h" + +#include <2geom/transforms.h> +#include +#include + +#include "object/sp-item.h" + +class Unclump +{ +public: + double dist(SPItem *item1, SPItem *item2); + double average(SPItem *item, std::list &others); + SPItem *closest(SPItem *item, std::list &others); + SPItem *farthest(SPItem *item, std::list &others); + std::vector unclump_remove_behind(SPItem *item, SPItem *closest, std::list &rest); + void push(SPItem *from, SPItem *what, double dist); + void pull(SPItem *to, SPItem *what, double dist); + +private: + Geom::Point unclump_center(SPItem *item); + Geom::Point unclump_wh(SPItem *item); + + // Taking bbox of an item is an expensive operation, and we need to do it many times, so here we + // cache the centers, widths, and heights of items + + std::map c_cache; + std::map wh_cache; +}; + +/** +Center of bbox of item +*/ +Geom::Point Unclump::unclump_center(SPItem *item) +{ + std::map::iterator i = c_cache.find(item->getId()); + if (i != c_cache.end()) { + return i->second; + } + + Geom::OptRect r = item->desktopVisualBounds(); + if (r) { + Geom::Point const c = r->midpoint(); + c_cache[item->getId()] = c; + return c; + } else { + // FIXME + return Geom::Point(0, 0); + } +} + +Geom::Point Unclump::unclump_wh(SPItem *item) +{ + Geom::Point wh; + std::map::iterator i = wh_cache.find(item->getId()); + if (i != wh_cache.end()) { + wh = i->second; + } else { + Geom::OptRect r = item->desktopVisualBounds(); + if (r) { + wh = r->dimensions(); + wh_cache[item->getId()] = wh; + } else { + wh = Geom::Point(0, 0); + } + } + + return wh; +} + +/** +Distance between "edges" of item1 and item2. An item is considered to be an ellipse inscribed into its w/h, +so its radius (distance from center to edge) depends on the w/h and the angle towards the other item. +May be negative if the edge of item1 is between the center and the edge of item2. +*/ +double Unclump::dist(SPItem *item1, SPItem *item2) +{ + Geom::Point c1 = unclump_center(item1); + Geom::Point c2 = unclump_center(item2); + + Geom::Point wh1 = unclump_wh(item1); + Geom::Point wh2 = unclump_wh(item2); + + // angle from each item's center to the other's, unsqueezed by its w/h, normalized to 0..pi/2 + double a1 = atan2((c2 - c1)[Geom::Y], (c2 - c1)[Geom::X] * wh1[Geom::Y] / wh1[Geom::X]); + a1 = fabs(a1); + if (a1 > M_PI / 2) + a1 = M_PI - a1; + + double a2 = atan2((c1 - c2)[Geom::Y], (c1 - c2)[Geom::X] * wh2[Geom::Y] / wh2[Geom::X]); + a2 = fabs(a2); + if (a2 > M_PI / 2) + a2 = M_PI - a2; + + // get the radius of each item for the given angle + double r1 = 0.5 * (wh1[Geom::X] + (wh1[Geom::Y] - wh1[Geom::X]) * (a1 / (M_PI / 2))); + double r2 = 0.5 * (wh2[Geom::X] + (wh2[Geom::Y] - wh2[Geom::X]) * (a2 / (M_PI / 2))); + + // dist between centers minus angle-adjusted radii + double dist_r = (Geom::L2(c2 - c1) - r1 - r2); + + double stretch1 = wh1[Geom::Y] / wh1[Geom::X]; + double stretch2 = wh2[Geom::Y] / wh2[Geom::X]; + + if ((stretch1 > 1.5 || stretch1 < 0.66) && (stretch2 > 1.5 || stretch2 < 0.66)) { + std::vector dists; + dists.push_back(dist_r); + + // If both objects are not circle-like, find dists between four corners + std::vector c1_points(2); + { + double y_closest; + if (c2[Geom::Y] > c1[Geom::Y] + wh1[Geom::Y] / 2) { + y_closest = c1[Geom::Y] + wh1[Geom::Y] / 2; + } else if (c2[Geom::Y] < c1[Geom::Y] - wh1[Geom::Y] / 2) { + y_closest = c1[Geom::Y] - wh1[Geom::Y] / 2; + } else { + y_closest = c2[Geom::Y]; + } + c1_points[0] = Geom::Point(c1[Geom::X], y_closest); + double x_closest; + if (c2[Geom::X] > c1[Geom::X] + wh1[Geom::X] / 2) { + x_closest = c1[Geom::X] + wh1[Geom::X] / 2; + } else if (c2[Geom::X] < c1[Geom::X] - wh1[Geom::X] / 2) { + x_closest = c1[Geom::X] - wh1[Geom::X] / 2; + } else { + x_closest = c2[Geom::X]; + } + c1_points[1] = Geom::Point(x_closest, c1[Geom::Y]); + } + + std::vector c2_points(2); + { + double y_closest; + if (c1[Geom::Y] > c2[Geom::Y] + wh2[Geom::Y] / 2) { + y_closest = c2[Geom::Y] + wh2[Geom::Y] / 2; + } else if (c1[Geom::Y] < c2[Geom::Y] - wh2[Geom::Y] / 2) { + y_closest = c2[Geom::Y] - wh2[Geom::Y] / 2; + } else { + y_closest = c1[Geom::Y]; + } + c2_points[0] = Geom::Point(c2[Geom::X], y_closest); + double x_closest; + if (c1[Geom::X] > c2[Geom::X] + wh2[Geom::X] / 2) { + x_closest = c2[Geom::X] + wh2[Geom::X] / 2; + } else if (c1[Geom::X] < c2[Geom::X] - wh2[Geom::X] / 2) { + x_closest = c2[Geom::X] - wh2[Geom::X] / 2; + } else { + x_closest = c1[Geom::X]; + } + c2_points[1] = Geom::Point(x_closest, c2[Geom::Y]); + } + + for (int i = 0; i < 2; i++) { + for (int j = 0; j < 2; j++) { + dists.push_back(Geom::L2(c1_points[i] - c2_points[j])); + } + } + + // return the minimum of all dists + return *std::min_element(dists.begin(), dists.end()); + } else { + return dist_r; + } +} + +/** +Average dist from item to others +*/ +double Unclump::average(SPItem *item, std::list &others) +{ + int n = 0; + double sum = 0; + for (SPItem *other : others) { + if (other == item) + continue; + + n++; + sum += dist(item, other); + } + + if (n != 0) + return sum / n; + else + return 0; +} + +/** +Closest to item among others + */ +SPItem *Unclump::closest(SPItem *item, std::list &others) +{ + double min = HUGE_VAL; + SPItem *closest = nullptr; + + for (SPItem *other : others) { + if (other == item) + continue; + + double dist = this->dist(item, other); + if (dist < min && fabs(dist) < 1e6) { + min = dist; + closest = other; + } + } + + return closest; +} + +/** +Most distant from item among others + */ +SPItem *Unclump::farthest(SPItem *item, std::list &others) +{ + double max = -HUGE_VAL; + SPItem *farthest = nullptr; + + for (SPItem *other : others) { + if (other == item) + continue; + + double dist = this->dist(item, other); + if (dist > max && fabs(dist) < 1e6) { + max = dist; + farthest = other; + } + } + + return farthest; +} + +/** +Removes from the \a rest list those items that are "behind" \a closest as seen from \a item, +i.e. those on the other side of the line through \a closest perpendicular to the direction from \a +item to \a closest. Returns a newly created list which must be freed. + */ +std::vector Unclump::unclump_remove_behind(SPItem *item, SPItem *closest, std::list &rest) +{ + Geom::Point it = unclump_center(item); + Geom::Point p1 = unclump_center(closest); + + // perpendicular through closest to the direction to item: + Geom::Point perp = Geom::rot90(it - p1); + Geom::Point p2 = p1 + perp; + + // get the standard Ax + By + C = 0 form for p1-p2: + double A = p1[Geom::Y] - p2[Geom::Y]; + double B = p2[Geom::X] - p1[Geom::X]; + double C = p2[Geom::Y] * p1[Geom::X] - p1[Geom::Y] * p2[Geom::X]; + + // substitute the item into it: + double val_item = A * it[Geom::X] + B * it[Geom::Y] + C; + + std::vector out; + for (SPItem *other : rest) { + if (other == item) + continue; + + Geom::Point o = unclump_center(other); + double val_other = A * o[Geom::X] + B * o[Geom::Y] + C; + + if (val_item * val_other <= 1e-6) { + // different signs, which means item and other are on the different sides of p1-p2 line; skip + } else { + out.push_back(other); + } + } + + return out; +} + +/** +Moves \a what away from \a from by \a dist + */ +void Unclump::push(SPItem *from, SPItem *what, double dist) +{ + Geom::Point it = unclump_center(what); + Geom::Point p = unclump_center(from); + Geom::Point by = dist * Geom::unit_vector(-(p - it)); + + Geom::Affine move = Geom::Translate(by); + + std::map::iterator i = c_cache.find(what->getId()); + if (i != c_cache.end()) { + i->second *= move; + } + + // g_print ("push %s at %g,%g from %g,%g by %g,%g, dist %g\n", what->getId(), it[Geom::X],it[Geom::Y], + // p[Geom::X],p[Geom::Y], by[Geom::X],by[Geom::Y], dist); + + what->set_i2d_affine(what->i2dt_affine() * move); + what->doWriteTransform(what->transform); +} + +/** +Moves \a what towards \a to by \a dist + */ +void Unclump::pull(SPItem *to, SPItem *what, double dist) +{ + Geom::Point it = unclump_center(what); + Geom::Point p = unclump_center(to); + Geom::Point by = dist * Geom::unit_vector(p - it); + + Geom::Affine move = Geom::Translate(by); + + std::map::iterator i = c_cache.find(what->getId()); + if (i != c_cache.end()) { + i->second *= move; + } + + // g_print ("pull %s at %g,%g to %g,%g by %g,%g, dist %g\n", what->getId(), it[Geom::X],it[Geom::Y], + // p[Geom::X],p[Geom::Y], by[Geom::X],by[Geom::Y], dist); + + what->set_i2d_affine(what->i2dt_affine() * move); + what->doWriteTransform(what->transform); +} + +/** +Unclumps the items in \a items, reducing local unevenness in their distribution. Produces an effect +similar to "engraver dots". The only distribution which is unchanged by unclumping is a hexagonal +grid. May be called repeatedly for stronger effect. + */ +void unclump(std::vector &items) +{ + Unclump unclump; + + for (SPItem *item : items) { // for each original/clone x: + std::list nei; + + std::list rest; + for (size_t i = 0; i < items.size(); i++) { + rest.push_front(items[items.size() - i - 1]); + } + rest.remove(item); + + while (!rest.empty()) { + SPItem *closest = unclump.closest(item, rest); + if (closest) { + nei.push_front(closest); + rest.remove(closest); + std::vector new_rest = unclump.unclump_remove_behind(item, closest, rest); + rest.clear(); + for (size_t i = 0; i < new_rest.size(); i++) { + rest.push_front(new_rest[new_rest.size() - i - 1]); + } + } else { + break; + } + } + + if ((nei.size()) >= 2) { + double ave = unclump.average(item, nei); + + SPItem *closest = unclump.closest(item, nei); + SPItem *farthest = unclump.farthest(item, nei); + + double dist_closest = unclump.dist(closest, item); + double dist_farthest = unclump.dist(farthest, item); + + // g_print ("NEI %d for item %s closest %s at %g farthest %s at %g ave %g\n", g_slist_length(nei), + // item->getId(), closest->getId(), dist_closest, farthest->getId(), dist_farthest, ave); + + if (fabs(ave) < 1e6 && fabs(dist_closest) < 1e6 && fabs(dist_farthest) < 1e6) { // otherwise the items are + // bogus + // increase these coefficients to make unclumping more aggressive and less stable + // the pull coefficient is a bit bigger to counteract the long-term expansion trend + unclump.push(closest, item, 0.3 * (ave - dist_closest)); + unclump.pull(farthest, item, 0.35 * (dist_farthest - ave)); + } + } + } +} + +/* + 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=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4:fileencoding=utf-8:textwidth=99 : -- cgit v1.2.3