1 files changed, 85 insertions, 0 deletions
diff --git a/src/object/algorithms/removeoverlap.cpp b/src/object/algorithms/removeoverlap.cpp
new file mode 100644
index 0000000..8b3064b
--- /dev/null
+++ b/src/object/algorithms/removeoverlap.cpp
@@ -0,0 +1,85 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/** \file
+ * Interface between Inkscape code (SPItem) and remove-overlaps function.
+ */
+/*
+ * Authors:
+ *   Tim Dwyer <tgdwyer@gmail.com>
+ *   Abhishek Sharma
+ *
+ * Copyright (C) 2005 Authors
+ *
+ * Released under GNU GPL v2+, read the file 'COPYING' for more information.
+ */
+
+#include <utility>
+
+#include <2geom/transforms.h>
+
+#include "removeoverlap.h"
+
+#include "libvpsc/rectangle.h"
+
+#include "object/sp-item.h"
+#include "object/sp-item-transform.h"
+
+
+using vpsc::Rectangle;
+
+namespace {
+
+struct Record {
+    SPItem * item;
+    Geom::Point midpoint;
+    Rectangle * vspc_rect;
+
+    Record() : item(nullptr), vspc_rect(nullptr) {}
+    Record(SPItem * i, Geom::Point m, Rectangle * r)
+        : item(i), midpoint(m), vspc_rect(r) {}
+};
+
+}
+
+/**
+* Takes a list of inkscape items and moves them as little as possible
+* such that rectangular bounding boxes are separated by at least xGap
+* horizontally and yGap vertically
+*/
+void removeoverlap(std::vector<SPItem*> const & items, double const xGap, double const yGap) {
+    std::vector<SPItem*> selected = items;
+    std::vector<Record> records;
+    std::vector<Rectangle*> rs;
+
+    Geom::Point const gap(xGap, yGap);
+    for (SPItem * item: selected) {
+        using Geom::X; using Geom::Y;
+        Geom::OptRect item_box(item->desktopVisualBounds());
+        if (item_box) {
+            Geom::Point min(item_box->min() - .5 * gap);
+            Geom::Point max(item_box->max() + .5 * gap);
+            // A negative gap is allowed, but will lead to problems when the gap is larger than
+            // the bounding box (in either X or Y direction, or both); min will have become max
+            // now, which cannot be handled by Rectangle() which is called below. And how will
+            // removeRectangleOverlap handle such a case?
+            // That's why we will enforce some boundaries on min and max here:
+            if (max[X] < min[X]) {
+                min[X] = max[X] = (min[X] + max[X]) / 2.;
+            }
+            if (max[Y] < min[Y]) {
+                min[Y] = max[Y] = (min[Y] + max[Y]) / 2.;
+            }
+            Rectangle * vspc_rect = new Rectangle(min[X], max[X], min[Y], max[Y]);
+            records.emplace_back(item, item_box->midpoint(), vspc_rect);
+            rs.push_back(vspc_rect);
+        }
+    }
+    if (!rs.empty()) {
+        removeoverlaps(rs);
+    }
+    for (Record & rec: records) {
+        Geom::Point const curr = rec.midpoint;
+        Geom::Point const dest(rec.vspc_rect->getCentreX(), rec.vspc_rect->getCentreY());
+        rec.item->move_rel(Geom::Translate(dest - curr));
+        delete rec.vspc_rect;
+    }
+}