--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/src/algorithms/geometry.cpp Sat Mar 24 11:57:24 2018 +0200
@@ -0,0 +1,119 @@
+#include "geometry.h"
+
+/*
+ * getRadialPoint
+ *
+ * Gets an ordinate of a point in circle.
+ * If func == sin, then this gets the Y co-ordinate, if func == cos, then X co-ordinate.
+ */
+QPointF pointOnCircumference(int segment, int divisions)
+{
+ double angle = (segment * 2 * pi) / divisions;
+ return {cos(angle), sin(angle)};
+}
+
+/*
+ * makeCircle
+ *
+ * Creates a possibly partial circle rim.
+ * Divisions is how many segments the circle makes if up if it's full.
+ * Segments is now many segments are added.
+ * Radius is the radius of the circle.
+ *
+ * If divisions == segments, this yields a full circle rim.
+ * The rendered circle is returned as a vector of lines.
+ */
+QVector<QLineF> makeCircle(int segments, int divisions, double radius)
+{
+ QVector<QLineF> lines;
+
+ for (int i = 0; i < segments; i += 1)
+ {
+ QPointF p0 = radius * ::pointOnCircumference(i, divisions);
+ QPointF p1 = radius * ::pointOnCircumference(i + 1, divisions);
+ lines.append({p0, p1});
+ }
+
+ return lines;
+}
+
+/*
+ * Computes the shortest distance from a point to a rectangle.
+ *
+ * The code originates from the Unity3D wiki, and was translated from C# to Qt by me (Teemu Piippo):
+ *
+ * Original code:
+ * http://wiki.unity3d.com/index.php/Distance_from_a_point_to_a_rectangle
+ *
+ * Copyright 2013 Philip Peterson.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to
+ * deal in the Software without restriction, including without limitation the
+ * rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
+ * sell copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+ * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
+ * IN THE SOFTWARE.
+ */
+qreal distanceFromPointToRectangle(const QPointF& point, const QRectF& rectangle)
+{
+ // Calculate a distance between a point and a rectangle.
+ // The area around/in the rectangle is defined in terms of
+ // several regions:
+ //
+ // O--x
+ // |
+ // y
+ //
+ //
+ // I | II | III
+ // ======+==========+====== --yMin
+ // VIII | IX (in) | IV
+ // ======+==========+====== --yMax
+ // VII | VI | V
+ //
+ //
+ // Note that the +y direction is down because of Unity's GUI coordinates.
+ // - I don't care which way is +y in this function because I want a distance --TP
+
+ if (point.x() < rectangle.left())
+ {
+ // Region I, VIII, or VII
+ if (point.y() < rectangle.top()) // I
+ return QLineF {point, rectangle.topLeft()}.length();
+ else if (point.y() > rectangle.bottom()) // VII
+ return QLineF {point, rectangle.bottomLeft()}.length();
+ else // VIII
+ return rectangle.left() - point.x();
+ }
+ else if (point.x() > rectangle.right())
+ {
+ // Region III, IV, or V
+ if (point.y() < rectangle.top()) // III
+ return QLineF {point, rectangle.topRight()}.length();
+ else if (point.y() > rectangle.bottom()) // V
+ return QLineF {point, rectangle.bottomRight()}.length();
+ else // IV
+ return point.x() - rectangle.right();
+ }
+ else
+ {
+ // Region II, IX, or VI
+ if (point.y() < rectangle.top()) // II
+ return rectangle.top() - point.y();
+ else if (point.y() > rectangle.bottom()) // VI
+ return point.y() - rectangle.bottom();
+ else // IX
+ return 0;
+ }
+}