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      1 // Copyright (c) 2011 The Chromium Authors. All rights reserved.
      2 // Use of this source code is governed by a BSD-style license that can be
      3 // found in the LICENSE file.
      4 
      5 #ifndef PPAPI_CPP_RECT_H_
      6 #define PPAPI_CPP_RECT_H_
      7 
      8 #include "ppapi/c/pp_rect.h"
      9 #include "ppapi/cpp/point.h"
     10 #include "ppapi/cpp/size.h"
     11 
     12 /// @file
     13 /// This file defines the APIs for creating a 2 dimensional rectangle.
     14 
     15 namespace pp {
     16 
     17 /// A 2 dimensional rectangle. A rectangle is represented by x and y (which
     18 /// identifies the upper-left corner of the rectangle), width, and height.
     19 class Rect {
     20  public:
     21 
     22   /// The default constructor. Creates a <code>Rect</code> in the upper-left
     23   /// at 0,0 with height and width of 0.
     24   Rect() {
     25     rect_.point.x = 0;
     26     rect_.point.y = 0;
     27     rect_.size.width = 0;
     28     rect_.size.height = 0;
     29   }
     30 
     31   /// A constructor accepting a reference to a <code>PP_Rect and</code>
     32   /// converting the <code>PP_Rect</code> to a <code>Rect</code>. This is an
     33   /// implicit conversion constructor.
     34   ///
     35   /// @param[in] rect A <code>PP_Rect</code>.
     36   Rect(const PP_Rect& rect) {  // Implicit.
     37     set_x(rect.point.x);
     38     set_y(rect.point.y);
     39     set_width(rect.size.width);
     40     set_height(rect.size.height);
     41   }
     42 
     43   /// A constructor accepting two int32_t values for width and height and
     44   /// converting them to a <code>Rect</code> in the upper-left starting
     45   /// coordinate of 0,0.
     46   ///
     47   /// @param[in] w An int32_t value representing a width.
     48   /// @param[in] h An int32_t value representing a height.
     49   Rect(int32_t w, int32_t h) {
     50     set_x(0);
     51     set_y(0);
     52     set_width(w);
     53     set_height(h);
     54   }
     55 
     56   /// A constructor accepting four int32_t values for width, height, x, and y.
     57   ///
     58   /// @param[in] x An int32_t value representing a horizontal coordinate
     59   /// of a point, starting with 0 as the left-most coordinate.
     60   /// @param[in] y An int32_t value representing a vertical coordinate
     61   /// of a point, starting with 0 as the top-most coordinate.
     62   /// @param[in] w An int32_t value representing a width.
     63   /// @param[in] h An int32_t value representing a height.
     64   Rect(int32_t x, int32_t y, int32_t w, int32_t h) {
     65     set_x(x);
     66     set_y(y);
     67     set_width(w);
     68     set_height(h);
     69   }
     70 
     71   /// A constructor accepting a pointer to a Size and converting the
     72   /// <code>Size</code> to a <code>Rect</code> in the upper-left starting
     73   /// coordinate of 0,0.
     74   ///
     75   /// @param[in] s A pointer to a <code>Size</code>.
     76   explicit Rect(const Size& s) {
     77     set_x(0);
     78     set_y(0);
     79     set_size(s);
     80   }
     81 
     82   /// A constructor accepting a pointer to a <code>Point</code> representing
     83   /// the origin of the rectangle and a pointer to a <code>Size</code>
     84   /// representing the height and width.
     85   ///
     86   /// @param[in] origin A pointer to a <code>Point</code> representing the
     87   /// upper-left starting coordinate.
     88   /// @param[in] size A pointer to a <code>Size</code> representing the height
     89   /// and width.
     90   Rect(const Point& origin, const Size& size) {
     91     set_point(origin);
     92     set_size(size);
     93   }
     94 
     95   /// Destructor.
     96   ~Rect() {
     97   }
     98 
     99   /// PP_Rect() allows implicit conversion of a <code>Rect</code> to a
    100   /// <code>PP_Rect</code>.
    101   ///
    102   /// @return A <code>Point</code>.
    103   operator PP_Rect() const {
    104     return rect_;
    105   }
    106 
    107   /// Getter function for returning the internal <code>PP_Rect</code> struct.
    108   ///
    109   /// @return A const reference to the internal <code>PP_Rect</code> struct.
    110   const PP_Rect& pp_rect() const {
    111     return rect_;
    112   }
    113 
    114   /// Getter function for returning the internal <code>PP_Rect</code> struct.
    115   ///
    116   /// @return A mutable reference to the <code>PP_Rect</code> struct.
    117   PP_Rect& pp_rect() {
    118     return rect_;
    119   }
    120 
    121 
    122   /// Getter function for returning the value of x.
    123   ///
    124   /// @return The value of x for this <code>Point</code>.
    125   int32_t x() const {
    126     return rect_.point.x;
    127   }
    128 
    129   /// Setter function for setting the value of x.
    130   ///
    131   /// @param[in] in_x A new x value.
    132   void set_x(int32_t in_x) {
    133     rect_.point.x = in_x;
    134   }
    135 
    136   /// Getter function for returning the value of y.
    137   ///
    138   /// @return The value of y for this <code>Point</code>.
    139   int32_t y() const {
    140     return rect_.point.y;
    141   }
    142 
    143   /// Setter function for setting the value of y.
    144   ///
    145   /// @param[in] in_y A new y value.
    146   void set_y(int32_t in_y) {
    147     rect_.point.y = in_y;
    148   }
    149 
    150   /// Getter function for returning the value of width.
    151   ///
    152   /// @return The value of width for this <code>Rect</code>.
    153   int32_t width() const {
    154     return rect_.size.width;
    155   }
    156 
    157   /// Setter function for setting the value of width.
    158   ///
    159   /// @param[in] w A new width value.
    160   void set_width(int32_t w) {
    161     if (w < 0) {
    162       PP_DCHECK(w >= 0);
    163       w = 0;
    164     }
    165     rect_.size.width = w;
    166   }
    167 
    168   /// Getter function for returning the value of height.
    169   ///
    170   /// @return The value of height for this <code>Rect</code>.
    171   int32_t height() const {
    172     return rect_.size.height;
    173   }
    174 
    175   /// Setter function for setting the value of height.
    176   ///
    177   /// @param[in] h A new width height.
    178   void set_height(int32_t h) {
    179     if (h < 0) {
    180       PP_DCHECK(h >= 0);
    181       h = 0;
    182     }
    183     rect_.size.height = h;
    184   }
    185 
    186   /// Getter function for returning the <code>Point</code>.
    187   ///
    188   /// @return A <code>Point</code>.
    189   Point point() const {
    190     return Point(rect_.point);
    191   }
    192 
    193   /// Setter function for setting the value of the <code>Point</code>.
    194   ///
    195   /// @param[in] origin A <code>Point</code> representing the upper-left
    196   /// starting coordinate.
    197   void set_point(const Point& origin) {
    198     rect_.point = origin;
    199   }
    200 
    201   /// Getter function for returning the <code>Size</code>.
    202   ///
    203   /// @return The size of the rectangle.
    204   Size size() const {
    205     return Size(rect_.size);
    206   }
    207 
    208   /// Setter function for setting the <code>Size</code>.
    209   ///
    210   /// @param[in] s A pointer to a <code>Size</code> representing the height
    211   /// and width.
    212   void set_size(const Size& s) {
    213     rect_.size.width = s.width();
    214     rect_.size.height = s.height();
    215   }
    216 
    217   /// Getter function to get the upper-bound for the x-coordinates of the
    218   /// rectangle.  Note that this coordinate value is one past the highest x
    219   /// value of pixels in the rectangle.  This loop will access all the pixels
    220   /// in a horizontal line in the rectangle:
    221   /// <code>for (int32_t x = rect.x(); x < rect.right(); ++x) {}</code>
    222   ///
    223   /// @return The value of x + width for this point.
    224   int32_t right() const {
    225     return x() + width();
    226   }
    227 
    228   /// Getter function to get the upper-bound for the y-coordinates of the
    229   /// rectangle.  Note that this coordinate value is one past the highest xy
    230   /// value of pixels in the rectangle.  This loop will access all the pixels
    231   /// in a horizontal line in the rectangle:
    232   /// <code>for (int32_t y = rect.y(); y < rect.bottom(); ++y) {}</code>
    233   ///
    234   /// @return The value of y + height for this point.
    235   int32_t bottom() const {
    236     return y() + height();
    237   }
    238 
    239   /// Setter function for setting the value of the <code>Rect</code>.
    240   ///
    241   /// @param[in] x A new x value.
    242   /// @param[in] y A new y value.
    243   /// @param[in] w A new width value.
    244   /// @param[in] h A new height value.
    245   void SetRect(int32_t x, int32_t y, int32_t w, int32_t h) {
    246     set_x(x);
    247     set_y(y);
    248     set_width(w);
    249     set_height(h);
    250   }
    251 
    252   /// Setter function for setting the value of the <code>Rect</code>.
    253   ///
    254   /// @param[in] rect A pointer to a <code>PP_Rect</code>.
    255   void SetRect(const PP_Rect& rect) {
    256     rect_ = rect;
    257   }
    258 
    259   /// Inset() shrinks the rectangle by a horizontal and vertical
    260   /// distance on all sides.
    261   ///
    262   /// @param[in] horizontal An int32_t value representing a horizontal
    263   /// shrinking distance.
    264   /// @param[in] vertical An int32_t value representing a vertical
    265   /// shrinking distance.
    266   void Inset(int32_t horizontal, int32_t vertical) {
    267     Inset(horizontal, vertical, horizontal, vertical);
    268   }
    269 
    270   /// Inset() shrinks the rectangle by the specified amount on each
    271   /// side.
    272   ///
    273   /// @param[in] left An int32_t value representing a left
    274   /// shrinking distance.
    275   /// @param[in] top An int32_t value representing a top
    276   /// shrinking distance.
    277   /// @param[in] right An int32_t value representing a right
    278   /// shrinking distance.
    279   /// @param[in] bottom An int32_t value representing a bottom
    280   /// shrinking distance.
    281   void Inset(int32_t left, int32_t top, int32_t right, int32_t bottom);
    282 
    283   /// Offset() moves the rectangle by a horizontal and vertical distance.
    284   ///
    285   /// @param[in] horizontal An int32_t value representing a horizontal
    286   /// move distance.
    287   /// @param[in] vertical An int32_t value representing a vertical
    288   /// move distance.
    289   void Offset(int32_t horizontal, int32_t vertical);
    290 
    291   /// Offset() moves the rectangle by a horizontal and vertical distance.
    292   ///
    293   /// @param[in] point A pointer to a <code>Point</code> representing the
    294   /// horizontal and vertical move distances.
    295   void Offset(const Point& point) {
    296     Offset(point.x(), point.y());
    297   }
    298 
    299   /// IsEmpty() determines if the area of a rectangle is zero. Returns true if
    300   /// the area of the rectangle is zero.
    301   ///
    302   /// @return true if the area of the rectangle is zero.
    303   bool IsEmpty() const {
    304     return rect_.size.width == 0 && rect_.size.height == 0;
    305   }
    306 
    307   /// Contains() determines if the point identified by point_x and point_y
    308   /// falls inside this rectangle. The point (x, y) is inside the rectangle,
    309   /// but the point (x + width, y + height) is not.
    310   ///
    311   /// @param[in] point_x An int32_t value representing a x value.
    312   /// @param[in] point_y An int32_t value representing a y value.
    313   ///
    314   /// @return true if the point_x and point_y fall inside the rectangle.
    315   bool Contains(int32_t point_x, int32_t point_y) const;
    316 
    317   /// Contains() determines if the specified point is contained by this
    318   /// rectangle.
    319   ///
    320   /// @param[in] point A pointer to a Point representing a 2D coordinate.
    321   ///
    322   /// @return true if the point_x and point_y fall inside the rectangle.
    323   bool Contains(const Point& point) const {
    324     return Contains(point.x(), point.y());
    325   }
    326 
    327   /// Contains() determines if this rectangle contains the specified rectangle.
    328   ///
    329   /// @param[in] rect A pointer to a <code>Rect</code>.
    330   ///
    331   /// @return true if the rectangle fall inside this rectangle.
    332   bool Contains(const Rect& rect) const;
    333 
    334   /// Intersects() determines if this rectangle intersects the specified
    335   /// rectangle.
    336   ///
    337   /// @param[in] rect A pointer to a <code>Rect</code>.
    338   ///
    339   /// @return true if the rectangle intersects  this rectangle.
    340   bool Intersects(const Rect& rect) const;
    341 
    342   /// Intersect() computes the intersection of this rectangle with the given
    343   /// rectangle.
    344   ///
    345   /// @param[in] rect A pointer to a <code>Rect</code>.
    346   ///
    347   /// @return A <code>Rect</code> representing the intersection.
    348   Rect Intersect(const Rect& rect) const;
    349 
    350   /// Union() computes the union of this rectangle with the given rectangle.
    351   /// The union is the smallest rectangle containing both rectangles.
    352   ///
    353   /// @param[in] rect A pointer to a <code>Rect</code>.
    354   ///
    355   /// @return A <code>Rect</code> representing the union.
    356   Rect Union(const Rect& rect) const;
    357 
    358   /// Subtract() computes the rectangle resulting from subtracting
    359   /// <code>rect</code> from this Rect.  If <code>rect</code>does not intersect
    360   /// completely in either the x or y direction, then <code>*this</code> is
    361   /// returned. If <code>rect</code> contains <code>this</code>, then an empty
    362   /// <code>Rect</code> is returned.
    363   ///
    364   /// @param[in] rect A pointer to a <code>Rect</code>.
    365   ///
    366   /// @return A <code>Rect</code> representing the subtraction.
    367   Rect Subtract(const Rect& rect) const;
    368 
    369   /// AdjustToFit() fits as much of the receiving rectangle within
    370   /// the supplied rectangle as possible, returning the result. For example,
    371   /// if the receiver had a x-location of 2 and a width of 4, and the supplied
    372   /// rectangle had an x-location of 0 with a width of 5, the returned
    373   /// rectangle would have an x-location of 1 with a width of 4.
    374   ///
    375   /// @param[in] rect A pointer to a <code>Rect</code>.
    376   ///
    377   /// @return A <code>Rect</code> representing the difference between this
    378   /// rectangle and the receiving rectangle.
    379   Rect AdjustToFit(const Rect& rect) const;
    380 
    381   /// CenterPoint() determines the center of this rectangle.
    382   ///
    383   /// @return A <code>Point</code> representing the center of this rectangle.
    384   Point CenterPoint() const;
    385 
    386   /// SharesEdgeWith() determines if this rectangle shares an entire edge
    387   /// (same width or same height) with the given rectangle, and the
    388   /// rectangles do not overlap.
    389   ///
    390   /// @param[in] rect A pointer to a <code>Rect</code>.
    391   ///
    392   /// @return true if this rectangle and supplied rectangle share an edge.
    393   bool SharesEdgeWith(const Rect& rect) const;
    394 
    395  private:
    396   PP_Rect rect_;
    397 };
    398 
    399 }  // namespace pp
    400 
    401 /// This function determines whether the x, y, width, and height values of two
    402 /// rectangles and are equal.
    403 ///
    404 /// @param[in] lhs The <code>Rect</code> on the left-hand side of the equation.
    405 /// @param[in] rhs The <code>Rect</code> on the right-hand side of the equation.
    406 ///
    407 /// @return true if they are equal, false if unequal.
    408 inline bool operator==(const pp::Rect& lhs, const pp::Rect& rhs) {
    409   return lhs.x() == rhs.x() &&
    410          lhs.y() == rhs.y() &&
    411          lhs.width() == rhs.width() &&
    412          lhs.height() == rhs.height();
    413 }
    414 
    415 /// This function determines whether two Rects are not equal.
    416 ///
    417 /// @param[in] lhs The <code>Rect</code> on the left-hand side of the equation.
    418 /// @param[in] rhs The <code>Rect</code> on the right-hand side of the
    419 /// equation.
    420 ///
    421 /// @return true if the given Rects are equal, otherwise false.
    422 inline bool operator!=(const pp::Rect& lhs, const pp::Rect& rhs) {
    423   return !(lhs == rhs);
    424 }
    425 
    426 #endif
    427 
    428