LCOV - code coverage report
Current view: directory - objdir/dist/include/mozilla/gfx - BaseRect.h (source / functions) Found Hit Coverage
Test: app.info Lines: 169 47 27.8 %
Date: 2012-06-02 Functions: 173 27 15.6 %

       1                 : /* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*-
       2                 :  * ***** BEGIN LICENSE BLOCK *****
       3                 :  * Version: MPL 1.1/GPL 2.0/LGPL 2.1
       4                 :  *
       5                 :  * The contents of this file are subject to the Mozilla Public License Version
       6                 :  * 1.1 (the "License"); you may not use this file except in compliance with
       7                 :  * the License. You may obtain a copy of the License at
       8                 :  * http://www.mozilla.org/MPL/
       9                 :  *
      10                 :  * Software distributed under the License is distributed on an "AS IS" basis,
      11                 :  * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
      12                 :  * for the specific language governing rights and limitations under the
      13                 :  * License.
      14                 :  *
      15                 :  * The Original Code is Mozilla Corporation code.
      16                 :  *
      17                 :  * The Initial Developer of the Original Code is Mozilla Foundation.
      18                 :  * Portions created by the Initial Developer are Copyright (C) 2011
      19                 :  * the Initial Developer. All Rights Reserved.
      20                 :  *
      21                 :  * Contributor(s):
      22                 :  *   Robert O'Callahan <robert@ocallahan.org>
      23                 :  *
      24                 :  * Alternatively, the contents of this file may be used under the terms of
      25                 :  * either the GNU General Public License Version 2 or later (the "GPL"), or
      26                 :  * the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
      27                 :  * in which case the provisions of the GPL or the LGPL are applicable instead
      28                 :  * of those above. If you wish to allow use of your version of this file only
      29                 :  * under the terms of either the GPL or the LGPL, and not to allow others to
      30                 :  * use your version of this file under the terms of the MPL, indicate your
      31                 :  * decision by deleting the provisions above and replace them with the notice
      32                 :  * and other provisions required by the GPL or the LGPL. If you do not delete
      33                 :  * the provisions above, a recipient may use your version of this file under
      34                 :  * the terms of any one of the MPL, the GPL or the LGPL.
      35                 :  *
      36                 :  * ***** END LICENSE BLOCK ***** */
      37                 : 
      38                 : #ifndef MOZILLA_GFX_BASERECT_H_
      39                 : #define MOZILLA_GFX_BASERECT_H_
      40                 : 
      41                 : #include <cmath>
      42                 : 
      43                 : namespace mozilla {
      44                 : namespace gfx {
      45                 : 
      46                 : // XXX - <algorithm> conflicts with exceptions on 10.6. Define our own gfx_min/gfx_max
      47                 : // functions here. Avoid min/max to avoid conflicts with existing #defines on windows.
      48                 : template<typename T>
      49             468 : T gfx_min(T aVal1, T aVal2)
      50                 : {
      51             468 :   return (aVal1 < aVal2) ? aVal1 : aVal2;
      52                 : }
      53                 : 
      54                 : template<typename T>
      55             468 : T gfx_max(T aVal1, T aVal2)
      56                 : {
      57             468 :   return (aVal1 > aVal2) ? aVal1 : aVal2;
      58                 : }
      59                 : 
      60                 : /**
      61                 :  * Rectangles have two interpretations: a set of (zero-size) points,
      62                 :  * and a rectangular area of the plane. Most rectangle operations behave
      63                 :  * the same no matter what interpretation is being used, but some operations
      64                 :  * differ:
      65                 :  * -- Equality tests behave differently. When a rectangle represents an area,
      66                 :  * all zero-width and zero-height rectangles are equal to each other since they
      67                 :  * represent the empty area. But when a rectangle represents a set of
      68                 :  * mathematical points, zero-width and zero-height rectangles can be unequal.
      69                 :  * -- The union operation can behave differently. When rectangles represent
      70                 :  * areas, taking the union of a zero-width or zero-height rectangle with
      71                 :  * another rectangle can just ignore the empty rectangle. But when rectangles
      72                 :  * represent sets of mathematical points, we may need to extend the latter
      73                 :  * rectangle to include the points of a zero-width or zero-height rectangle.
      74                 :  *
      75                 :  * To ensure that these interpretations are explicitly disambiguated, we
      76                 :  * deny access to the == and != operators and require use of IsEqualEdges and
      77                 :  * IsEqualInterior instead. Similarly we provide separate Union and UnionEdges
      78                 :  * methods.
      79                 :  *
      80                 :  * Do not use this class directly. Subclass it, pass that subclass as the
      81                 :  * Sub parameter, and only use that subclass.
      82                 :  */
      83                 : template <class T, class Sub, class Point, class SizeT, class Margin>
      84                 : struct BaseRect {
      85                 :   T x, y, width, height;
      86                 : 
      87                 :   // Constructors
      88            1740 :   BaseRect() : x(0), y(0), width(0), height(0) {}
      89              60 :   BaseRect(const Point& aOrigin, const SizeT &aSize) :
      90              60 :       x(aOrigin.x), y(aOrigin.y), width(aSize.width), height(aSize.height)
      91                 :   {
      92              60 :   }
      93            1727 :   BaseRect(T aX, T aY, T aWidth, T aHeight) :
      94            1727 :       x(aX), y(aY), width(aWidth), height(aHeight)
      95                 :   {
      96            1727 :   }
      97                 : 
      98                 :   // Emptiness. An empty rect is one that has no area, i.e. its height or width
      99                 :   // is <= 0
     100             574 :   bool IsEmpty() const { return height <= 0 || width <= 0; }
     101              32 :   void SetEmpty() { width = height = 0; }
     102                 : 
     103                 :   // Returns true if this rectangle contains the interior of aRect. Always
     104                 :   // returns true if aRect is empty, and always returns false is aRect is
     105                 :   // nonempty but this rect is empty.
     106               0 :   bool Contains(const Sub& aRect) const
     107                 :   {
     108                 :     return aRect.IsEmpty() ||
     109                 :            (x <= aRect.x && aRect.XMost() <= XMost() &&
     110               0 :             y <= aRect.y && aRect.YMost() <= YMost());
     111                 :   }
     112                 :   // Returns true if this rectangle contains the rectangle (aX,aY,1,1).
     113               0 :   bool Contains(T aX, T aY) const
     114                 :   {
     115                 :     return x <= aX && aX + 1 <= XMost() &&
     116               0 :            y <= aY && aY + 1 <= YMost();
     117                 :   }
     118                 :   // Returns true if this rectangle contains the rectangle (aPoint.x,aPoint.y,1,1).
     119               0 :   bool Contains(const Point& aPoint) const { return Contains(aPoint.x, aPoint.y); }
     120                 : 
     121                 :   // Intersection. Returns TRUE if the receiver's area has non-empty
     122                 :   // intersection with aRect's area, and FALSE otherwise.
     123                 :   // Always returns false if aRect is empty or 'this' is empty.
     124               0 :   bool Intersects(const Sub& aRect) const
     125                 :   {
     126                 :     return x < aRect.XMost() && aRect.x < XMost() &&
     127               0 :            y < aRect.YMost() && aRect.y < YMost();
     128                 :   }
     129                 :   // Returns the rectangle containing the intersection of the points
     130                 :   // (including edges) of *this and aRect. If there are no points in that
     131                 :   // intersection, returns an empty rectangle with x/y set to the gfx_max of the x/y
     132                 :   // of *this and aRect.
     133              36 :   Sub Intersect(const Sub& aRect) const
     134                 :   {
     135              36 :     Sub result;
     136              36 :     result.x = gfx_max(x, aRect.x);
     137              36 :     result.y = gfx_max(y, aRect.y);
     138              36 :     result.width = gfx_min(XMost(), aRect.XMost()) - result.x;
     139              36 :     result.height = gfx_min(YMost(), aRect.YMost()) - result.y;
     140              36 :     if (result.width < 0 || result.height < 0) {
     141               0 :       result.SizeTo(0, 0);
     142                 :     }
     143                 :     return result;
     144                 :   }
     145                 :   // Sets *this to be the rectangle containing the intersection of the points
     146                 :   // (including edges) of *this and aRect. If there are no points in that
     147                 :   // intersection, sets *this to be an empty rectangle with x/y set to the gfx_max
     148                 :   // of the x/y of *this and aRect.
     149                 :   //
     150                 :   // 'this' can be the same object as either aRect1 or aRect2
     151              36 :   bool IntersectRect(const Sub& aRect1, const Sub& aRect2)
     152                 :   {
     153              36 :     *static_cast<Sub*>(this) = aRect1.Intersect(aRect2);
     154              36 :     return !IsEmpty();
     155                 :   }
     156                 : 
     157                 :   // Returns the smallest rectangle that contains both the area of both
     158                 :   // this and aRect2.
     159                 :   // Thus, empty input rectangles are ignored.
     160                 :   // If both rectangles are empty, returns this.
     161             247 :   Sub Union(const Sub& aRect) const
     162                 :   {
     163             247 :     if (IsEmpty()) {
     164              49 :       return aRect;
     165             198 :     } else if (aRect.IsEmpty()) {
     166               0 :       return *static_cast<const Sub*>(this);
     167                 :     } else {
     168             198 :       return UnionEdges(aRect);
     169                 :     }
     170                 :   }
     171                 :   // Returns the smallest rectangle that contains both the points (including
     172                 :   // edges) of both aRect1 and aRect2.
     173                 :   // Thus, empty input rectangles are allowed to affect the result.
     174             198 :   Sub UnionEdges(const Sub& aRect) const
     175                 :   {
     176             198 :     Sub result;
     177             198 :     result.x = gfx_min(x, aRect.x);
     178             198 :     result.y = gfx_min(y, aRect.y);
     179             198 :     result.width = gfx_max(XMost(), aRect.XMost()) - result.x;
     180             198 :     result.height = gfx_max(YMost(), aRect.YMost()) - result.y;
     181                 :     return result;
     182                 :   }
     183                 :   // Computes the smallest rectangle that contains both the area of both
     184                 :   // aRect1 and aRect2, and fills 'this' with the result.
     185                 :   // Thus, empty input rectangles are ignored.
     186                 :   // If both rectangles are empty, sets 'this' to aRect2.
     187                 :   //
     188                 :   // 'this' can be the same object as either aRect1 or aRect2
     189             247 :   void UnionRect(const Sub& aRect1, const Sub& aRect2)
     190                 :   {
     191             247 :     *static_cast<Sub*>(this) = aRect1.Union(aRect2);
     192             247 :   }
     193                 : 
     194                 :   // Computes the smallest rectangle that contains both the points (including
     195                 :   // edges) of both aRect1 and aRect2.
     196                 :   // Thus, empty input rectangles are allowed to affect the result.
     197                 :   //
     198                 :   // 'this' can be the same object as either aRect1 or aRect2
     199                 :   void UnionRectEdges(const Sub& aRect1, const Sub& aRect2)
     200                 :   {
     201                 :     *static_cast<Sub*>(this) = aRect1.UnionEdges(aRect2);
     202                 :   }
     203                 : 
     204               1 :   void SetRect(T aX, T aY, T aWidth, T aHeight)
     205                 :   {
     206               1 :     x = aX; y = aY; width = aWidth; height = aHeight;
     207               1 :   }
     208               0 :   void SetRect(const Point& aPt, const SizeT& aSize)
     209                 :   {
     210               0 :     SetRect(aPt.x, aPt.y, aSize.width, aSize.height);
     211               0 :   }
     212               0 :   void MoveTo(T aX, T aY) { x = aX; y = aY; }
     213               0 :   void MoveTo(const Point& aPoint) { x = aPoint.x; y = aPoint.y; }
     214               0 :   void MoveBy(T aDx, T aDy) { x += aDx; y += aDy; }
     215               0 :   void MoveBy(const Point& aPoint) { x += aPoint.x; y += aPoint.y; }
     216               0 :   void SizeTo(T aWidth, T aHeight) { width = aWidth; height = aHeight; }
     217               0 :   void SizeTo(const SizeT& aSize) { width = aSize.width; height = aSize.height; }
     218                 : 
     219               0 :   void Inflate(T aD) { Inflate(aD, aD); }
     220               0 :   void Inflate(T aDx, T aDy)
     221                 :   {
     222               0 :     x -= aDx;
     223               0 :     y -= aDy;
     224               0 :     width += 2 * aDx;
     225               0 :     height += 2 * aDy;
     226               0 :   }
     227               0 :   void Inflate(const Margin& aMargin)
     228                 :   {
     229               0 :     x -= aMargin.left;
     230               0 :     y -= aMargin.top;
     231               0 :     width += aMargin.LeftRight();
     232               0 :     height += aMargin.TopBottom();
     233               0 :   }
     234               0 :   void Inflate(const SizeT& aSize) { Inflate(aSize.width, aSize.height); }
     235                 : 
     236               0 :   void Deflate(T aD) { Deflate(aD, aD); }
     237               0 :   void Deflate(T aDx, T aDy)
     238                 :   {
     239               0 :     x += aDx;
     240               0 :     y += aDy;
     241               0 :     width = gfx_max(T(0), width - 2 * aDx);
     242               0 :     height = gfx_max(T(0), height - 2 * aDy);
     243               0 :   }
     244               0 :   void Deflate(const Margin& aMargin)
     245                 :   {
     246               0 :     x += aMargin.left;
     247               0 :     y += aMargin.top;
     248               0 :     width = gfx_max(T(0), width - aMargin.LeftRight());
     249               0 :     height = gfx_max(T(0), height - aMargin.TopBottom());
     250               0 :   }
     251               0 :   void Deflate(const SizeT& aSize) { Deflate(aSize.width, aSize.height); }
     252                 : 
     253                 :   // Return true if the rectangles contain the same set of points, including
     254                 :   // points on the edges.
     255                 :   // Use when we care about the exact x/y/width/height values being
     256                 :   // equal (i.e. we care about differences in empty rectangles).
     257               0 :   bool IsEqualEdges(const Sub& aRect) const
     258                 :   {
     259                 :     return x == aRect.x && y == aRect.y &&
     260               0 :            width == aRect.width && height == aRect.height;
     261                 :   }
     262                 :   // Return true if the rectangles contain the same area of the plane.
     263                 :   // Use when we do not care about differences in empty rectangles.
     264               0 :   bool IsEqualInterior(const Sub& aRect) const
     265                 :   {
     266               0 :     return IsEqualEdges(aRect) || (IsEmpty() && aRect.IsEmpty());
     267                 :   }
     268                 : 
     269               0 :   Sub operator+(const Point& aPoint) const
     270                 :   {
     271               0 :     return Sub(x + aPoint.x, y + aPoint.y, width, height);
     272                 :   }
     273               0 :   Sub operator-(const Point& aPoint) const
     274                 :   {
     275               0 :     return Sub(x - aPoint.x, y - aPoint.y, width, height);
     276                 :   }
     277               0 :   Sub& operator+=(const Point& aPoint)
     278                 :   {
     279               0 :     MoveBy(aPoint);
     280               0 :     return *static_cast<Sub*>(this);
     281                 :   }
     282               0 :   Sub& operator-=(const Point& aPoint)
     283                 :   {
     284               0 :     MoveBy(-aPoint);
     285               0 :     return *static_cast<Sub*>(this);
     286                 :   }
     287                 : 
     288                 :   // Find difference as a Margin
     289               0 :   Margin operator-(const Sub& aRect) const
     290                 :   {
     291                 :     return Margin(aRect.x - x, aRect.y - y,
     292               0 :                   XMost() - aRect.XMost(), YMost() - aRect.YMost());
     293                 :   }
     294                 : 
     295                 :   // Helpers for accessing the vertices
     296              19 :   Point TopLeft() const { return Point(x, y); }
     297               0 :   Point TopRight() const { return Point(XMost(), y); }
     298               0 :   Point BottomLeft() const { return Point(x, YMost()); }
     299               0 :   Point BottomRight() const { return Point(XMost(), YMost()); }
     300               0 :   Point Center() const { return Point(x, y) + Point(width, height)/2; }
     301               0 :   SizeT Size() const { return SizeT(width, height); }
     302                 : 
     303                 :   // Helper methods for computing the extents
     304              21 :   T X() const { return x; }
     305              21 :   T Y() const { return y; }
     306              21 :   T Width() const { return width; }
     307              21 :   T Height() const { return height; }
     308             471 :   T XMost() const { return x + width; }
     309             470 :   T YMost() const { return y + height; }
     310                 : 
     311                 :   // Round the rectangle edges to integer coordinates, such that the rounded
     312                 :   // rectangle has the same set of pixel centers as the original rectangle.
     313                 :   // Edges at offset 0.5 round up.
     314                 :   // Suitable for most places where integral device coordinates
     315                 :   // are needed, but note that any translation should be applied first to
     316                 :   // avoid pixel rounding errors.
     317                 :   // Note that this is *not* rounding to nearest integer if the values are negative.
     318                 :   // They are always rounding as floor(n + 0.5).
     319                 :   // See https://bugzilla.mozilla.org/show_bug.cgi?id=410748#c14
     320                 :   // If you need similar method which is using NS_round(), you should create
     321                 :   // new |RoundAwayFromZero()| method.
     322               0 :   void Round()
     323                 :   {
     324               0 :     T x0 = static_cast<T>(floor(T(X()) + 0.5));
     325               0 :     T y0 = static_cast<T>(floor(T(Y()) + 0.5));
     326               0 :     T x1 = static_cast<T>(floor(T(XMost()) + 0.5));
     327               0 :     T y1 = static_cast<T>(floor(T(YMost()) + 0.5));
     328                 : 
     329               0 :     x = x0;
     330               0 :     y = y0;
     331                 : 
     332               0 :     width = x1 - x0;
     333               0 :     height = y1 - y0;
     334               0 :   }
     335                 : 
     336                 :   // Snap the rectangle edges to integer coordinates, such that the
     337                 :   // original rectangle contains the resulting rectangle.
     338               0 :   void RoundIn()
     339                 :   {
     340               0 :     T x0 = static_cast<T>(ceil(T(X())));
     341               0 :     T y0 = static_cast<T>(ceil(T(Y())));
     342               0 :     T x1 = static_cast<T>(floor(T(XMost())));
     343               0 :     T y1 = static_cast<T>(floor(T(YMost())));
     344                 : 
     345               0 :     x = x0;
     346               0 :     y = y0;
     347                 : 
     348               0 :     width = x1 - x0;
     349               0 :     height = y1 - y0;
     350               0 :   }
     351                 : 
     352                 :   // Snap the rectangle edges to integer coordinates, such that the
     353                 :   // resulting rectangle contains the original rectangle.
     354               0 :   void RoundOut()
     355                 :   {
     356               0 :     T x0 = static_cast<T>(floor(T(X())));
     357               0 :     T y0 = static_cast<T>(floor(T(Y())));
     358               0 :     T x1 = static_cast<T>(ceil(T(XMost())));
     359               0 :     T y1 = static_cast<T>(ceil(T(YMost())));
     360                 : 
     361               0 :     x = x0;
     362               0 :     y = y0;
     363                 : 
     364               0 :     width = x1 - x0;
     365               0 :     height = y1 - y0;
     366               0 :   }
     367                 : 
     368                 :   // Scale 'this' by aScale, converting coordinates to integers so that the result is
     369                 :   // the smallest integer-coordinate rectangle containing the unrounded result.
     370                 :   // Note: this can turn an empty rectangle into a non-empty rectangle
     371               0 :   void ScaleRoundOut(double aScale) { ScaleRoundOut(aScale, aScale); }
     372                 :   // Scale 'this' by aXScale and aYScale, converting coordinates to integers so
     373                 :   // that the result is the smallest integer-coordinate rectangle containing the
     374                 :   // unrounded result.
     375                 :   // Note: this can turn an empty rectangle into a non-empty rectangle
     376               0 :   void ScaleRoundOut(double aXScale, double aYScale)
     377                 :   {
     378               0 :     T right = static_cast<T>(ceil(double(XMost()) * aXScale));
     379               0 :     T bottom = static_cast<T>(ceil(double(YMost()) * aYScale));
     380               0 :     x = static_cast<T>(floor(double(x) * aXScale));
     381               0 :     y = static_cast<T>(floor(double(y) * aYScale));
     382               0 :     width = right - x;
     383               0 :     height = bottom - y;
     384               0 :   }
     385                 :   // Scale 'this' by aScale, converting coordinates to integers so that the result is
     386                 :   // the largest integer-coordinate rectangle contained by the unrounded result.
     387                 :   void ScaleRoundIn(double aScale) { ScaleRoundIn(aScale, aScale); }
     388                 :   // Scale 'this' by aXScale and aYScale, converting coordinates to integers so
     389                 :   // that the result is the largest integer-coordinate rectangle contained by the
     390                 :   // unrounded result.
     391               0 :   void ScaleRoundIn(double aXScale, double aYScale)
     392                 :   {
     393               0 :     T right = static_cast<T>(floor(double(XMost()) * aXScale));
     394               0 :     T bottom = static_cast<T>(floor(double(YMost()) * aYScale));
     395               0 :     x = static_cast<T>(ceil(double(x) * aXScale));
     396               0 :     y = static_cast<T>(ceil(double(y) * aYScale));
     397               0 :     width = gfx_max<T>(0, right - x);
     398               0 :     height = gfx_max<T>(0, bottom - y);
     399               0 :   }
     400                 :   // Scale 'this' by 1/aScale, converting coordinates to integers so that the result is
     401                 :   // the smallest integer-coordinate rectangle containing the unrounded result.
     402                 :   // Note: this can turn an empty rectangle into a non-empty rectangle
     403                 :   void ScaleInverseRoundOut(double aScale) { ScaleInverseRoundOut(aScale, aScale); }
     404                 :   // Scale 'this' by 1/aXScale and 1/aYScale, converting coordinates to integers so
     405                 :   // that the result is the smallest integer-coordinate rectangle containing the
     406                 :   // unrounded result.
     407                 :   // Note: this can turn an empty rectangle into a non-empty rectangle
     408               0 :   void ScaleInverseRoundOut(double aXScale, double aYScale)
     409                 :   {
     410               0 :     T right = static_cast<T>(ceil(double(XMost()) / aXScale));
     411               0 :     T bottom = static_cast<T>(ceil(double(YMost()) / aYScale));
     412               0 :     x = static_cast<T>(floor(double(x) / aXScale));
     413               0 :     y = static_cast<T>(floor(double(y) / aYScale));
     414               0 :     width = right - x;
     415               0 :     height = bottom - y;
     416               0 :   }
     417                 : 
     418                 : private:
     419                 :   // Do not use the default operator== or operator!= !
     420                 :   // Use IsEqualEdges or IsEqualInterior explicitly.
     421                 :   bool operator==(const Sub& aRect) const { return false; }
     422                 :   bool operator!=(const Sub& aRect) const { return false; }
     423                 : };
     424                 : 
     425                 : }
     426                 : }
     427                 : 
     428                 : #endif /* MOZILLA_GFX_BASERECT_H_ */

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