source/modules/juce_graphics/geometry/juce_Parallelogram.h

   1 /*
   2   ==============================================================================
   3
   4    This file is part of the JUCE library.
   5    Copyright (c) 2022 - Raw Material Software Limited
   6
   7    JUCE is an open source library subject to commercial or open-source
   8    licensing.
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  10    By using JUCE, you agree to the terms of both the JUCE 7 End-User License
  11    Agreement and JUCE Privacy Policy.
  12
  13    End User License Agreement: www.juce.com/juce-7-licence
  14    Privacy Policy: www.juce.com/juce-privacy-policy
  15
  16    Or: You may also use this code under the terms of the GPL v3 (see
  17    www.gnu.org/licenses).
  18
  19    JUCE IS PROVIDED "AS IS" WITHOUT ANY WARRANTY, AND ALL WARRANTIES, WHETHER
  20    EXPRESSED OR IMPLIED, INCLUDING MERCHANTABILITY AND FITNESS FOR PURPOSE, ARE
  21    DISCLAIMED.
  22
  23   ==============================================================================
  24 */
  25
  26 namespace juce
  27 {
  28
  29 //==============================================================================
  30 /**
  31     Represents a parallelogram that is defined by 3 points.
  32     @see Rectangle, Point, Line
  33
  34     @tags{Graphics}
  35 */
  36 template <typename ValueType>
  37 class Parallelogram
  38 {
  39 public:
  40     //==============================================================================
  41     /** Creates a parallelogram with zero size at the origin.
  42     */
  43     Parallelogram() = default;
  44
  45     /** Creates a copy of another parallelogram. */
  46     Parallelogram (const Parallelogram&) = default;
  47
  48     /** Creates a parallelogram based on 3 points. */
  49     Parallelogram (Point<ValueType> topLeftPosition,
  50                    Point<ValueType> topRightPosition,
  51                    Point<ValueType> bottomLeftPosition) noexcept
  52        : topLeft (topLeftPosition), topRight (topRightPosition), bottomLeft (bottomLeftPosition)
  53     {
  54     }
  55
  56     /** Creates a parallelogram from a rectangle. */
  57     Parallelogram (Rectangle<ValueType> rectangle) noexcept
  58        : topLeft (rectangle.getTopLeft()),
  59          topRight (rectangle.getTopRight()),
  60          bottomLeft (rectangle.getBottomLeft())
  61     {
  62     }
  63
  64     Parallelogram& operator= (const Parallelogram&) = default;
  65
  66     /** Destructor. */
  67     ~Parallelogram() = default;
  68
  69     //==============================================================================
  70     /** Returns true if the parallelogram has a width or height of more than zero. */
  71     bool isEmpty() const noexcept                                   { return topLeft != topRight || topLeft != bottomLeft; }
  72
  73     /** Returns true if the parallelogram's coordinates are all finite numbers, i.e. not NaN or infinity. */
  74     inline bool isFinite() const noexcept                           { return topLeft.isFinite() && topRight.isFinite() && bottomLeft.isFinite(); }
  75
  76     /** Returns the width of the parallelogram (i.e. the straight-line distance between the top-left and top-right. */
  77     inline ValueType getWidth() const noexcept                      { return Line<ValueType> (topLeft, topRight).getLength(); }
  78
  79     /** Returns the height of the parallelogram (i.e. the straight-line distance between the top-left and bottom-left. */
  80     inline ValueType getHeight() const noexcept                     { return Line<ValueType> (topLeft, bottomLeft).getLength(); }
  81
  82     //==============================================================================
  83     /** Returns the parallelogram's top-left position as a Point. */
  84     Point<ValueType> getTopLeft() const noexcept                    { return topLeft; }
  85
  86     /** Returns the parallelogram's top-right position as a Point. */
  87     Point<ValueType> getTopRight() const noexcept                   { return topRight; }
  88
  89     /** Returns the parallelogram's bottom-left position as a Point. */
  90     Point<ValueType> getBottomLeft() const noexcept                 { return bottomLeft; }
  91
  92     /** Returns the parallelogram's bottom-right position as a Point. */
  93     Point<ValueType> getBottomRight() const noexcept                { return topRight + (bottomLeft - topLeft); }
  94
  95     //==============================================================================
  96     /** Returns true if the two parallelograms are identical. */
  97     bool operator== (const Parallelogram& other) const noexcept     { return topLeft == other.topLeft && topRight == other.topRight && bottomLeft == other.bottomLeft; }
  98
  99     /** Returns true if the two parallelograms are not identical. */
 100     bool operator!= (const Parallelogram& other) const noexcept     { return ! operator== (other); }
 101
 102     //==============================================================================
 103     /** Returns a parallelogram which is the same as this one moved by a given amount. */
 104     Parallelogram operator+ (Point<ValueType> deltaPosition) const noexcept
 105     {
 106         auto p = *this;
 107         p += deltaPosition;
 108         return p;
 109     }
 110
 111     /** Moves this parallelogram by a given amount. */
 112     Parallelogram& operator+= (Point<ValueType> deltaPosition) noexcept
 113     {
 114         topLeft += deltaPosition;
 115         topRight += deltaPosition;
 116         bottomLeft += deltaPosition;
 117         return *this;
 118     }
 119
 120     /** Returns a parallelogram which is the same as this one moved by a given amount. */
 121     Parallelogram operator- (Point<ValueType> deltaPosition) const noexcept
 122     {
 123         return operator+ (-deltaPosition);
 124     }
 125
 126     /** Moves this parallelogram by a given amount. */
 127     Parallelogram& operator-= (Point<ValueType> deltaPosition) noexcept
 128     {
 129         return operator-= (-deltaPosition);
 130     }
 131
 132     /** Returns a parallelogram that has been scaled by the given amount, centred around the origin. */
 133     template <typename PointOrScalarType>
 134     Parallelogram operator* (PointOrScalarType scaleFactor) const noexcept
 135     {
 136         auto p = *this;
 137         p *= scaleFactor;
 138         return p;
 139     }
 140
 141     /** Scales this parallelogram by the given amount, centred around the origin. */
 142     template <typename PointOrScalarType>
 143     Parallelogram operator*= (PointOrScalarType scaleFactor) noexcept
 144     {
 145         topLeft *= scaleFactor;
 146         topRight *= scaleFactor;
 147         bottomLeft *= scaleFactor;
 148         return *this;
 149     }
 150
 151     //==============================================================================
 152     /** Returns a point within this parallelogram, specified as proportional coordinates.
 153         The relative X and Y values should be between 0 and 1, where 0 is the left or
 154         top of this parallelogram, and 1 is the right or bottom. (Out-of-bounds values
 155         will return a point outside the parallelogram).
 156     */
 157     Point<ValueType> getRelativePoint (Point<ValueType> relativePosition) const noexcept
 158     {
 159         return topLeft
 160                 + (topRight - topLeft) * relativePosition.x
 161                 + (bottomLeft - topLeft) * relativePosition.y;
 162     }
 163
 164     /** Returns a transformed version of the parallelogram. */
 165     Parallelogram transformedBy (const AffineTransform& transform) const noexcept
 166     {
 167         auto p = *this;
 168         transform.transformPoints (p.topLeft.x, p.topLeft.y,
 169                                    p.topRight.x, p.topRight.y,
 170                                    p.bottomLeft.x, p.bottomLeft.y);
 171
 172         return p;
 173     }
 174
 175     /** Returns the smallest rectangle that encloses this parallelogram. */
 176     Rectangle<ValueType> getBoundingBox() const noexcept
 177     {
 178         const Point<ValueType> points[] = { topLeft, topRight, bottomLeft, getBottomRight() };
 179         return Rectangle<ValueType>::findAreaContainingPoints (points, 4);
 180     }
 181
 182     Point<ValueType> topLeft, topRight, bottomLeft;
 183 };
 184
 185 } // namespace juce