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      1 // Copyright (c) 2012 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 #include "ppapi/cpp/rect.h"
      6 
      7 #include <algorithm>
      8 
      9 namespace {
     10 
     11 void AdjustAlongAxis(int32_t dst_origin, int32_t dst_size,
     12                      int32_t* origin, int32_t* size) {
     13   if (*origin < dst_origin) {
     14     *origin = dst_origin;
     15     *size = std::min(dst_size, *size);
     16   } else {
     17     *size = std::min(dst_size, *size);
     18     *origin = std::min(dst_origin + dst_size, *origin + *size) - *size;
     19   }
     20 }
     21 
     22 }  // namespace
     23 
     24 namespace pp {
     25 
     26 void Rect::Inset(int32_t left, int32_t top, int32_t right, int32_t bottom) {
     27   Offset(left, top);
     28   set_width(std::max<int32_t>(width() - left - right, 0));
     29   set_height(std::max<int32_t>(height() - top - bottom, 0));
     30 }
     31 
     32 void Rect::Offset(int32_t horizontal, int32_t vertical) {
     33   rect_.point.x += horizontal;
     34   rect_.point.y += vertical;
     35 }
     36 
     37 bool Rect::Contains(int32_t point_x, int32_t point_y) const {
     38   return (point_x >= x()) && (point_x < right()) &&
     39          (point_y >= y()) && (point_y < bottom());
     40 }
     41 
     42 bool Rect::Contains(const Rect& rect) const {
     43   return (rect.x() >= x() && rect.right() <= right() &&
     44           rect.y() >= y() && rect.bottom() <= bottom());
     45 }
     46 
     47 bool Rect::Intersects(const Rect& rect) const {
     48   return !(rect.x() >= right() || rect.right() <= x() ||
     49            rect.y() >= bottom() || rect.bottom() <= y());
     50 }
     51 
     52 Rect Rect::Intersect(const Rect& rect) const {
     53   int32_t rx = std::max(x(), rect.x());
     54   int32_t ry = std::max(y(), rect.y());
     55   int32_t rr = std::min(right(), rect.right());
     56   int32_t rb = std::min(bottom(), rect.bottom());
     57 
     58   if (rx >= rr || ry >= rb)
     59     rx = ry = rr = rb = 0;  // non-intersecting
     60 
     61   return Rect(rx, ry, rr - rx, rb - ry);
     62 }
     63 
     64 Rect Rect::Union(const Rect& rect) const {
     65   // special case empty rects...
     66   if (IsEmpty())
     67     return rect;
     68   if (rect.IsEmpty())
     69     return *this;
     70 
     71   int32_t rx = std::min(x(), rect.x());
     72   int32_t ry = std::min(y(), rect.y());
     73   int32_t rr = std::max(right(), rect.right());
     74   int32_t rb = std::max(bottom(), rect.bottom());
     75 
     76   return Rect(rx, ry, rr - rx, rb - ry);
     77 }
     78 
     79 Rect Rect::Subtract(const Rect& rect) const {
     80   // boundary cases:
     81   if (!Intersects(rect))
     82     return *this;
     83   if (rect.Contains(*this))
     84     return Rect();
     85 
     86   int32_t rx = x();
     87   int32_t ry = y();
     88   int32_t rr = right();
     89   int32_t rb = bottom();
     90 
     91   if (rect.y() <= y() && rect.bottom() >= bottom()) {
     92     // complete intersection in the y-direction
     93     if (rect.x() <= x()) {
     94       rx = rect.right();
     95     } else {
     96       rr = rect.x();
     97     }
     98   } else if (rect.x() <= x() && rect.right() >= right()) {
     99     // complete intersection in the x-direction
    100     if (rect.y() <= y()) {
    101       ry = rect.bottom();
    102     } else {
    103       rb = rect.y();
    104     }
    105   }
    106   return Rect(rx, ry, rr - rx, rb - ry);
    107 }
    108 
    109 Rect Rect::AdjustToFit(const Rect& rect) const {
    110   int32_t new_x = x();
    111   int32_t new_y = y();
    112   int32_t new_width = width();
    113   int32_t new_height = height();
    114   AdjustAlongAxis(rect.x(), rect.width(), &new_x, &new_width);
    115   AdjustAlongAxis(rect.y(), rect.height(), &new_y, &new_height);
    116   return Rect(new_x, new_y, new_width, new_height);
    117 }
    118 
    119 Point Rect::CenterPoint() const {
    120   return Point(x() + (width() + 1) / 2, y() + (height() + 1) / 2);
    121 }
    122 
    123 bool Rect::SharesEdgeWith(const Rect& rect) const {
    124   return (y() == rect.y() && height() == rect.height() &&
    125              (x() == rect.right() || right() == rect.x())) ||
    126          (x() == rect.x() && width() == rect.width() &&
    127              (y() == rect.bottom() || bottom() == rect.y()));
    128 }
    129 
    130 }  // namespace pp
    131