comparison: src/algorithms/geometry.cpp
src/algorithms/geometry.cpp
- changeset 1319
- 39d7a9642eea
- child 1325
- f9abfc7ba676
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| 1318:568fcfc6da71 | 1319:39d7a9642eea |
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| 1 #include "geometry.h" | |
| 2 | |
| 3 /* | |
| 4 * getRadialPoint | |
| 5 * | |
| 6 * Gets an ordinate of a point in circle. | |
| 7 * If func == sin, then this gets the Y co-ordinate, if func == cos, then X co-ordinate. | |
| 8 */ | |
| 9 QPointF pointOnCircumference(int segment, int divisions) | |
| 10 { | |
| 11 double angle = (segment * 2 * pi) / divisions; | |
| 12 return {cos(angle), sin(angle)}; | |
| 13 } | |
| 14 | |
| 15 /* | |
| 16 * makeCircle | |
| 17 * | |
| 18 * Creates a possibly partial circle rim. | |
| 19 * Divisions is how many segments the circle makes if up if it's full. | |
| 20 * Segments is now many segments are added. | |
| 21 * Radius is the radius of the circle. | |
| 22 * | |
| 23 * If divisions == segments, this yields a full circle rim. | |
| 24 * The rendered circle is returned as a vector of lines. | |
| 25 */ | |
| 26 QVector<QLineF> makeCircle(int segments, int divisions, double radius) | |
| 27 { | |
| 28 QVector<QLineF> lines; | |
| 29 | |
| 30 for (int i = 0; i < segments; i += 1) | |
| 31 { | |
| 32 QPointF p0 = radius * ::pointOnCircumference(i, divisions); | |
| 33 QPointF p1 = radius * ::pointOnCircumference(i + 1, divisions); | |
| 34 lines.append({p0, p1}); | |
| 35 } | |
| 36 | |
| 37 return lines; | |
| 38 } | |
| 39 | |
| 40 /* | |
| 41 * Computes the shortest distance from a point to a rectangle. | |
| 42 * | |
| 43 * The code originates from the Unity3D wiki, and was translated from C# to Qt by me (Teemu Piippo): | |
| 44 * | |
| 45 * Original code: | |
| 46 * http://wiki.unity3d.com/index.php/Distance_from_a_point_to_a_rectangle | |
| 47 * | |
| 48 * Copyright 2013 Philip Peterson. | |
| 49 * | |
| 50 * Permission is hereby granted, free of charge, to any person obtaining a copy | |
| 51 * of this software and associated documentation files (the "Software"), to | |
| 52 * deal in the Software without restriction, including without limitation the | |
| 53 * rights to use, copy, modify, merge, publish, distribute, sublicense, and/or | |
| 54 * sell copies of the Software, and to permit persons to whom the Software is | |
| 55 * furnished to do so, subject to the following conditions: | |
| 56 * | |
| 57 * The above copyright notice and this permission notice shall be included in | |
| 58 * all copies or substantial portions of the Software. | |
| 59 * | |
| 60 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR | |
| 61 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, | |
| 62 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE | |
| 63 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER | |
| 64 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING | |
| 65 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS | |
| 66 * IN THE SOFTWARE. | |
| 67 */ | |
| 68 qreal distanceFromPointToRectangle(const QPointF& point, const QRectF& rectangle) | |
| 69 { | |
| 70 // Calculate a distance between a point and a rectangle. | |
| 71 // The area around/in the rectangle is defined in terms of | |
| 72 // several regions: | |
| 73 // | |
| 74 // O--x | |
| 75 // | | |
| 76 // y | |
| 77 // | |
| 78 // | |
| 79 // I | II | III | |
| 80 // ======+==========+====== --yMin | |
| 81 // VIII | IX (in) | IV | |
| 82 // ======+==========+====== --yMax | |
| 83 // VII | VI | V | |
| 84 // | |
| 85 // | |
| 86 // Note that the +y direction is down because of Unity's GUI coordinates. | |
| 87 // - I don't care which way is +y in this function because I want a distance --TP | |
| 88 | |
| 89 if (point.x() < rectangle.left()) | |
| 90 { | |
| 91 // Region I, VIII, or VII | |
| 92 if (point.y() < rectangle.top()) // I | |
| 93 return QLineF {point, rectangle.topLeft()}.length(); | |
| 94 else if (point.y() > rectangle.bottom()) // VII | |
| 95 return QLineF {point, rectangle.bottomLeft()}.length(); | |
| 96 else // VIII | |
| 97 return rectangle.left() - point.x(); | |
| 98 } | |
| 99 else if (point.x() > rectangle.right()) | |
| 100 { | |
| 101 // Region III, IV, or V | |
| 102 if (point.y() < rectangle.top()) // III | |
| 103 return QLineF {point, rectangle.topRight()}.length(); | |
| 104 else if (point.y() > rectangle.bottom()) // V | |
| 105 return QLineF {point, rectangle.bottomRight()}.length(); | |
| 106 else // IV | |
| 107 return point.x() - rectangle.right(); | |
| 108 } | |
| 109 else | |
| 110 { | |
| 111 // Region II, IX, or VI | |
| 112 if (point.y() < rectangle.top()) // II | |
| 113 return rectangle.top() - point.y(); | |
| 114 else if (point.y() > rectangle.bottom()) // VI | |
| 115 return point.y() - rectangle.bottom(); | |
| 116 else // IX | |
| 117 return 0; | |
| 118 } | |
| 119 } |
