impeller::TRect< T > Struct Template Reference

#include <rect.h>

Public Member Functions
constexpr	TRect ()
constexpr bool	operator== (const TRect &r) const
constexpr bool	operator!= (const TRect &r) const
constexpr TRect	Scale (Type scale) const
constexpr TRect	Scale (Type scale_x, Type scale_y) const
constexpr TRect	Scale (TPoint< T > scale) const
constexpr TRect	Scale (TSize< T > scale) const
constexpr bool	Contains (const TPoint< Type > &p) const
	Returns true iff the provided point |p| is inside the half-open interior of this rectangle. More...
constexpr bool	ContainsInclusive (const TPoint< Type > &p) const
	Returns true iff the provided point |p| is inside the closed-range interior of this rectangle. More...
constexpr bool	Contains (const TRect &o) const
	Returns true iff this rectangle is not empty and it also contains every point considered inside the provided rectangle |o| (as determined by |Contains(TPoint)|). More...
	IsFinite () const
	Returns true if all of the fields of this floating point rectangle are finite. More...
constexpr bool	IsEmpty () const
	Returns true if either of the width or height are 0, negative, or NaN. More...
constexpr bool	IsSquare () const
	Returns true if width and height are equal and neither is NaN. More...
constexpr bool	IsMaximum () const
constexpr TPoint< Type >	GetOrigin () const
	Returns the upper left corner of the rectangle as specified by the left/top or x/y values when it was constructed. More...
constexpr TSize< Type >	GetSize () const
	Returns the size of the rectangle which may be negative in either width or height and may have been clipped to the maximum integer values for integer rects whose size overflows. More...
constexpr Type	GetX () const
	Returns the X coordinate of the upper left corner, equivalent to |GetOrigin().x|. More...
constexpr Type	GetY () const
	Returns the Y coordinate of the upper left corner, equivalent to |GetOrigin().y|. More...
constexpr Type	GetWidth () const
	Returns the width of the rectangle, equivalent to |GetSize().width|. More...
constexpr Type	GetHeight () const
	Returns the height of the rectangle, equivalent to |GetSize().height|. More...
constexpr auto	GetLeft () const
constexpr auto	GetTop () const
constexpr auto	GetRight () const
constexpr auto	GetBottom () const
constexpr TPoint< T >	GetLeftTop () const
constexpr TPoint< T >	GetRightTop () const
constexpr TPoint< T >	GetLeftBottom () const
constexpr TPoint< T >	GetRightBottom () const
constexpr T	Area () const
	Get the area of the rectangle, equivalent to |GetSize().Area()|. More...
constexpr Point	GetCenter () const
	Get the center point as a |Point|. More...
constexpr std::array< T, 4 >	GetLTRB () const
constexpr std::array< T, 4 >	GetXYWH () const
	Get the x, y coordinates of the origin and the width and height of the rectangle in an array. More...
constexpr TRect	GetPositive () const
	Get a version of this rectangle that has a non-negative size. More...
constexpr std::array< TPoint< T >, 4 >	GetPoints () const
	Get the points that represent the 4 corners of this rectangle in a Z order that is compatible with triangle strips or a set of all zero points if the rectangle is empty. The order is: Top left, top right, bottom left, bottom right. More...
constexpr std::array< TPoint< T >, 4 >	GetTransformedPoints (const Matrix &transform) const
constexpr TRect	TransformAndClipBounds (const Matrix &transform) const
	Creates a new bounding box that contains this transformed rectangle, clipped against the near clipping plane if necessary. More...
constexpr TRect	TransformBounds (const Matrix &transform) const
	Creates a new bounding box that contains this transformed rectangle. More...
constexpr Matrix	GetNormalizingTransform () const
	Constructs a Matrix that will map all points in the coordinate space of the rectangle into a new normalized coordinate space where the upper left corner of the rectangle maps to (0, 0) and the lower right corner of the rectangle maps to (1, 1). More...
constexpr TRect	Union (const TRect &o) const
constexpr std::optional< TRect >	Intersection (const TRect &o) const
constexpr bool	IntersectsWithRect (const TRect &o) const
constexpr std::optional< TRect< T > >	Cutout (const TRect &o) const
	Returns the new boundary rectangle that would result from this rectangle being cut out by the specified rectangle. More...
constexpr TRect	CutoutOrEmpty (const TRect &o) const
constexpr TRect< T >	Shift (T dx, T dy) const
	Returns a new rectangle translated by the given offset. More...
constexpr TRect< T >	Shift (TPoint< T > offset) const
	Returns a new rectangle translated by the given offset. More...
constexpr TRect< T >	Expand (T left, T top, T right, T bottom) const
	Returns a rectangle with expanded edges. Negative expansion results in shrinking. More...
constexpr TRect< T >	Expand (T amount) const
	Returns a rectangle with expanded edges in all directions. Negative expansion results in shrinking. More...
constexpr TRect< T >	Expand (T horizontal_amount, T vertical_amount) const
	Returns a rectangle with expanded edges in all directions. Negative expansion results in shrinking. More...
constexpr TRect< T >	Expand (TPoint< T > amount) const
	Returns a rectangle with expanded edges in all directions. Negative expansion results in shrinking. More...
constexpr TRect< T >	Expand (TSize< T > amount) const
	Returns a rectangle with expanded edges in all directions. Negative expansion results in shrinking. More...
constexpr TRect< T >	Project (TRect< T > source) const
	Returns a new rectangle that represents the projection of the source rectangle onto this rectangle. In other words, the source rectangle is redefined in terms of the coordinate space of this rectangle. More...
	RoundOut (const TRect< U > &r)
	Round (const TRect< U > &r)

Static Public Member Functions
static constexpr TRect	MakeLTRB (Type left, Type top, Type right, Type bottom)
static constexpr TRect	MakeXYWH (Type x, Type y, Type width, Type height)
static constexpr TRect	MakeOriginSize (const TPoint< Type > &origin, const TSize< Type > &size)
template<class U >
static constexpr TRect	MakeSize (const TSize< U > &size)
template<typename U >
static constexpr std::optional< TRect >	MakePointBounds (const U &value)
template<typename PointIter >
static constexpr std::optional< TRect >	MakePointBounds (const PointIter first, const PointIter last)
static constexpr TRect	MakeMaximum ()
static constexpr std::optional< TRect >	Union (const TRect &a, const std::optional< TRect > b)
static constexpr std::optional< TRect >	Union (const std::optional< TRect > a, const TRect &b)
static constexpr std::optional< TRect >	Union (const std::optional< TRect > a, const std::optional< TRect > b)
static constexpr std::optional< TRect >	Intersection (const TRect &a, const std::optional< TRect > b)
static constexpr std::optional< TRect >	Intersection (const std::optional< TRect > a, const TRect &b)
static constexpr std::optional< TRect >	Intersection (const std::optional< TRect > a, const std::optional< TRect > b)

Detailed Description

template<class T>
struct impeller::TRect< T >

Templated struct for holding an axis-aligned rectangle.

Rectangles are defined as 4 axis-aligned edges that might contain space. They can be viewed as 2 X coordinates that define the left and right edges and 2 Y coordinates that define the top and bottom edges; or they can be viewed as an origin and horizontal and vertical dimensions (width and height).

When the left and right edges are equal or reversed (right <= left) or the top and bottom edges are equal or reversed (bottom <= top), the rectangle is considered empty. Considering the rectangle in XYWH form, the width and/or the height would be negative or zero. Such reversed/empty rectangles contain no space and act as such in the methods that operate on them (Intersection, Union, IntersectsWithRect, Contains, Cutout, etc.)

Rectangles cannot be modified by any method and a new value can only be stored into an existing rect using assignment. This keeps the API clean compared to implementations that might have similar methods that produce the answer in place, or construct a new object with the answer, or place the result in an indicated result object.

Methods that might fail to produce an answer will use |std::optional| to indicate that success or failure (see |Intersection| and |CutOut|). For convenience, |Intersection| and |Union| both have overloaded variants that take |std::optional| arguments and treat them as if the argument was an empty rect to allow chaining multiple such methods and only needing to check the optional condition of the final result. The primary methods also provide |...OrEmpty| overloaded variants that translate an empty optional answer into a simple empty rectangle of the same type.

Rounding instance methods are not provided as the return value might be wanted as another floating point rectangle or sometimes as an integer rectangle. Instead a |RoundOut| factory, defined only for floating point input rectangles, is provided to provide control over the result type.

NaN and Infinity values

Constructing an LTRB rectangle using Infinity values should work as expected with either 0 or +Infinity returned as dimensions depending on which side the Infinity values are on and the sign.

Constructing an XYWH rectangle using Infinity values will usually not work if the math requires the object to compute a right or bottom edge from ([xy] -Infinity + [wh] +Infinity). Other combinations might work.

The special factory |MakeMaximum| is provided to construct a rectangle of the indicated coordinate type that covers all finite coordinates. It does not use infinity values, but rather the largest finite values to avoid math that might produce a NaN value from various getters.

Any rectangle that is constructed with, or computed to have a NaN value will be considered the same as any empty rectangle.

Empty Rectangle canonical results summary:

Union will ignore any empty rects and return the other rect Intersection will return nullopt if either rect is empty IntersectsWithRect will return false if either rect is empty Cutout will return the source rect if the argument is empty Cutout will return nullopt if the source rectangle is empty Contains(Point) will return false if the source rectangle is empty Contains(Rect) will return false if the source rectangle is empty Contains(Rect) will otherwise return true if the argument is empty Specifically, EmptyRect.Contains(EmptyRect) returns false

---

Special notes on problems using the XYWH form of specifying rectangles:

It is possible to have integer rectangles whose dimensions exceed the maximum number that their coordinates can represent since (MAX_INT - MIN_INT) overflows the representable positive numbers. Floating point rectangles technically have a similar issue in that overflow can occur, but it will be automatically converted into either an infinity, or a finite-overflow value and still be representable, just with little to no precision.

Secondly, specifying a rectangle using XYWH leads to cases where the math for (x+w) and/or (y+h) are also beyond the maximum representable coordinates. For N-bit integer rectangles declared as XYWH, the maximum right coordinate will require N+1 signed bits which cannot be stored in storage that uses N-bit integers.

Saturated math is used when constructing a rectangle from XYWH values and when returning the dimensions of the rectangle. Constructing an integer rectangle from values such that xy + wh is beyond the range of the integer type will place the right or bottom edges at the maximum value for the integer type. Similarly, constructing an integer rectangle such that the distance from the left to the right (or top to bottom) is greater than the range of the integer type will simply return the maximum integer value as the dimension. Floating point rectangles are naturally saturated by the rules of IEEE arithmetic.

Definition at line 122 of file rect.h.

Constructor & Destructor Documentation

TRect()

template<class T >

constexpr impeller::TRect< T >::TRect ( )

inlineconstexpr

Definition at line 127 of file rect.h.

: left_(0), top_(0), right_(0), bottom_(0) {}

Member Function Documentation

Area()

template<class T >

constexpr T impeller::TRect< T >::Area ( ) const

inlineconstexpr

Get the area of the rectangle, equivalent to |GetSize().Area()|.

Definition at line 366 of file rect.h.

                                         {
    // TODO(flutter/flutter#141710) - Use saturated math to avoid overflow
    // https://github.com/flutter/flutter/issues/141710
    return IsEmpty() ? 0 : (right_ - left_) * (bottom_ - top_);
  }

Contains() [1/2]

template<class T >

constexpr bool impeller::TRect< T >::Contains ( const TPoint< Type > &  p ) const

inlineconstexpr

Returns true iff the provided point |p| is inside the half-open interior of this rectangle.

For purposes of containment, a rectangle contains points along the top and left edges but not points along the right and bottom edges so that a point is only ever considered inside one of two abutting rectangles.

Definition at line 221 of file rect.h.

                                                                     {
    return !this->IsEmpty() &&  //
           p.x >= left_ &&      //
           p.y >= top_ &&       //
           p.x < right_ &&      //
           p.y < bottom_;
  }

Contains() [2/2]

template<class T >

constexpr bool impeller::TRect< T >::Contains ( const TRect< T > &  o ) const

inlineconstexpr

Returns true iff this rectangle is not empty and it also contains every point considered inside the provided rectangle |o| (as determined by |Contains(TPoint)|).

This is similar to a definition where the result is true iff the union of the two rectangles is equal to this rectangle, ignoring precision issues with performing those operations and assuming that empty rectangles are never equal.

An empty rectangle can contain no other rectangle.

An empty rectangle is, however, contained within any other non-empy rectangle as the set of points it contains is an empty set and so there are no points to fail the containment criteria.

Definition at line 263 of file rect.h.

                                                              {
    return !this->IsEmpty() &&                     //
           (o.IsEmpty() || (o.left_ >= left_ &&    //
                            o.top_ >= top_ &&      //
                            o.right_ <= right_ &&  //
                            o.bottom_ <= bottom_));
  }

ContainsInclusive()

template<class T >

constexpr bool impeller::TRect< T >::ContainsInclusive ( const TPoint< Type > &  p ) const

inlineconstexpr

Returns true iff the provided point |p| is inside the closed-range interior of this rectangle.

Unlike the regular |Contains(TPoint)| method, this method considers all points along the boundary of the rectangle to be contained within the rectangle - useful for testing if vertices that define a filled shape would carry the interior of that shape outside the bounds of the rectangle. Since both geometries are defining half-open spaces, their defining geometry needs to consider their boundaries to be equivalent with respect to interior and exterior.

Definition at line 240 of file rect.h.

                                                                              {
    return !this->IsEmpty() &&  //
           p.x >= left_ &&      //
           p.y >= top_ &&       //
           p.x <= right_ &&     //
           p.y <= bottom_;
  }

Cutout()

template<class T >

constexpr std::optional< TRect< T > > impeller::TRect< T >::Cutout ( const TRect< T > &  o ) const

inlineconstexpr

Returns the new boundary rectangle that would result from this rectangle being cut out by the specified rectangle.

Definition at line 544 of file rect.h.

                                                                             {
    if (IsEmpty()) {
      // This test isn't just a short-circuit, it also prevents the concise
      // math below from returning the wrong answer on empty rects.
      // Once we know that this rectangle is not empty, the math below can
      // only succeed in computing a value if o is also non-empty and non-nan.
      // Otherwise, the method returns *this by default.
      return std::nullopt;
    }
 
    const auto& [a_left, a_top, a_right, a_bottom] = GetLTRB();  // Source rect.
    const auto& [b_left, b_top, b_right, b_bottom] = o.GetLTRB();  // Cutout.
    if (b_left <= a_left && b_right >= a_right) {
      if (b_top <= a_top && b_bottom >= a_bottom) {
        // Full cutout.
        return std::nullopt;
      }
      if (b_top <= a_top && b_bottom > a_top) {
        // Cuts off the top.
        return TRect::MakeLTRB(a_left, b_bottom, a_right, a_bottom);
      }
      if (b_bottom >= a_bottom && b_top < a_bottom) {
        // Cuts off the bottom.
        return TRect::MakeLTRB(a_left, a_top, a_right, b_top);
      }
    }
    if (b_top <= a_top && b_bottom >= a_bottom) {
      if (b_left <= a_left && b_right > a_left) {
        // Cuts off the left.
        return TRect::MakeLTRB(b_right, a_top, a_right, a_bottom);
      }
      if (b_right >= a_right && b_left < a_right) {
        // Cuts off the right.
        return TRect::MakeLTRB(a_left, a_top, b_left, a_bottom);
      }
    }
 
    return *this;
  }

CutoutOrEmpty()

template<class T >

constexpr TRect impeller::TRect< T >::CutoutOrEmpty ( const TRect< T > &  o ) const

inlineconstexpr

Definition at line 584 of file rect.h.

                                                                    {
    return Cutout(o).value_or(TRect());
  }

Expand() [1/5]

template<class T >

constexpr TRect< T > impeller::TRect< T >::Expand ( T  amount ) const

inlineconstexpr

Returns a rectangle with expanded edges in all directions. Negative expansion results in shrinking.

Definition at line 619 of file rect.h.

                                                          {
    return {
        saturated::Sub(left_, amount),    //
        saturated::Sub(top_, amount),     //
        saturated::Add(right_, amount),   //
        saturated::Add(bottom_, amount),  //
    };
  }

Expand() [2/5]

template<class T >

constexpr TRect< T > impeller::TRect< T >::Expand ( T  horizontal_amount, T  vertical_amount  ) const

inlineconstexpr

Returns a rectangle with expanded edges in all directions. Negative expansion results in shrinking.

Definition at line 630 of file rect.h.

                                                                   {
    return {
        saturated::Sub(left_, horizontal_amount),   //
        saturated::Sub(top_, vertical_amount),      //
        saturated::Add(right_, horizontal_amount),  //
        saturated::Add(bottom_, vertical_amount),   //
    };
  }

Expand() [3/5]

template<class T >

constexpr TRect< T > impeller::TRect< T >::Expand ( T  left, T  top, T  right, T  bottom  ) const

inlineconstexpr

Returns a rectangle with expanded edges. Negative expansion results in shrinking.

Definition at line 605 of file rect.h.

                                                          {
    return {
        saturated::Sub(left_, left),      //
        saturated::Sub(top_, top),        //
        saturated::Add(right_, right),    //
        saturated::Add(bottom_, bottom),  //
    };
  }

Expand() [4/5]

template<class T >

constexpr TRect< T > impeller::TRect< T >::Expand ( TPoint< T >  amount ) const

inlineconstexpr

Returns a rectangle with expanded edges in all directions. Negative expansion results in shrinking.

Definition at line 642 of file rect.h.

                                                                  {
    return Expand(amount.x, amount.y);
  }

Expand() [5/5]

template<class T >

constexpr TRect< T > impeller::TRect< T >::Expand ( TSize< T >  amount ) const

inlineconstexpr

Returns a rectangle with expanded edges in all directions. Negative expansion results in shrinking.

Definition at line 648 of file rect.h.

                                                                 {
    return Expand(amount.width, amount.height);
  }

GetBottom()

template<class T >

constexpr auto impeller::TRect< T >::GetBottom ( ) const

inlineconstexpr

Definition at line 347 of file rect.h.

{ return bottom_; }

GetCenter()

template<class T >

constexpr Point impeller::TRect< T >::GetCenter ( ) const

inlineconstexpr

Get the center point as a |Point|.

Definition at line 373 of file rect.h.

                                                  {
    return {saturated::AverageScalar(left_, right_),
            saturated::AverageScalar(top_, bottom_)};
  }

GetHeight()

template<class T >

constexpr Type impeller::TRect< T >::GetHeight ( ) const

inlineconstexpr

Returns the height of the rectangle, equivalent to |GetSize().height|.

Definition at line 337 of file rect.h.

                                                 {
    return saturated::Sub(bottom_, top_);
  }

GetLeft()

template<class T >

constexpr auto impeller::TRect< T >::GetLeft ( ) const

inlineconstexpr

Definition at line 341 of file rect.h.

{ return left_; }

GetLeftBottom()

template<class T >

constexpr TPoint< T > impeller::TRect< T >::GetLeftBottom ( ) const

inlineconstexpr

Definition at line 357 of file rect.h.

                                                          {
    return {left_, bottom_};
  }

GetLeftTop()

template<class T >

constexpr TPoint< T > impeller::TRect< T >::GetLeftTop ( ) const

inlineconstexpr

Definition at line 349 of file rect.h.

                                                       {  //
    return {left_, top_};
  }

GetLTRB()

template<class T >

constexpr std::array< T, 4 > impeller::TRect< T >::GetLTRB ( ) const

inlineconstexpr

Definition at line 378 of file rect.h.

                                                         {
    return {left_, top_, right_, bottom_};
  }

GetNormalizingTransform()

template<class T >

constexpr Matrix impeller::TRect< T >::GetNormalizingTransform ( ) const

inlineconstexpr

Constructs a Matrix that will map all points in the coordinate space of the rectangle into a new normalized coordinate space where the upper left corner of the rectangle maps to (0, 0) and the lower right corner of the rectangle maps to (1, 1).

Empty and non-finite rectangles will return a zero-scaling transform that maps all points to (0, 0).

Definition at line 482 of file rect.h.

                                                                 {
    if (!IsEmpty()) {
      Scalar sx = 1.0 / GetWidth();
      Scalar sy = 1.0 / GetHeight();
      Scalar tx = left_ * -sx;
      Scalar ty = top_ * -sy;
 
      // Exclude NaN and infinities and either scale underflowing to zero
      if (sx != 0.0 && sy != 0.0 && 0.0 * sx * sy * tx * ty == 0.0) {
        // clang-format off
        return Matrix(  sx, 0.0f, 0.0f, 0.0f,
                      0.0f,   sy, 0.0f, 0.0f,
                      0.0f, 0.0f, 1.0f, 0.0f,
                        tx,   ty, 0.0f, 1.0f);
        // clang-format on
      }
    }
 
    // Map all coordinates to the origin.
    return Matrix::MakeScale({0.0f, 0.0f, 1.0f});
  }

GetOrigin()

template<class T >

constexpr TPoint< Type > impeller::TRect< T >::GetOrigin ( ) const

inlineconstexpr

Returns the upper left corner of the rectangle as specified by the left/top or x/y values when it was constructed.

Definition at line 310 of file rect.h.

                                                         {
    return {left_, top_};
  }

GetPoints()

template<class T >

constexpr std::array< TPoint< T >, 4 > impeller::TRect< T >::GetPoints ( ) const

inlineconstexpr

Get the points that represent the 4 corners of this rectangle in a Z order that is compatible with triangle strips or a set of all zero points if the rectangle is empty. The order is: Top left, top right, bottom left, bottom right.

Definition at line 405 of file rect.h.

                                                                   {
    if (IsEmpty()) {
      return {};
    }
    return {
        TPoint{left_, top_},
        TPoint{right_, top_},
        TPoint{left_, bottom_},
        TPoint{right_, bottom_},
    };
  }

GetPositive()

template<class T >

constexpr TRect impeller::TRect< T >::GetPositive ( ) const

inlineconstexpr

Get a version of this rectangle that has a non-negative size.

Definition at line 389 of file rect.h.

                                                    {
    if (!IsEmpty()) {
      return *this;
    }
    return {
        std::min(left_, right_),
        std::min(top_, bottom_),
        std::max(left_, right_),
        std::max(top_, bottom_),
    };
  }

GetRight()

template<class T >

constexpr auto impeller::TRect< T >::GetRight ( ) const

inlineconstexpr

Definition at line 345 of file rect.h.

{ return right_; }

GetRightBottom()

template<class T >

constexpr TPoint< T > impeller::TRect< T >::GetRightBottom ( ) const

inlineconstexpr

Definition at line 361 of file rect.h.

                                                           {
    return {right_, bottom_};
  }

GetRightTop()

template<class T >

constexpr TPoint< T > impeller::TRect< T >::GetRightTop ( ) const

inlineconstexpr

Definition at line 353 of file rect.h.

                                                        {
    return {right_, top_};
  }

GetSize()

template<class T >

constexpr TSize< Type > impeller::TRect< T >::GetSize ( ) const

inlineconstexpr

Returns the size of the rectangle which may be negative in either width or height and may have been clipped to the maximum integer values for integer rects whose size overflows.

Definition at line 317 of file rect.h.

                                                      {
    return {GetWidth(), GetHeight()};
  }

GetTop()

template<class T >

constexpr auto impeller::TRect< T >::GetTop ( ) const

inlineconstexpr

Definition at line 343 of file rect.h.

{ return top_; }

GetTransformedPoints()

template<class T >

constexpr std::array< TPoint< T >, 4 > impeller::TRect< T >::GetTransformedPoints ( const Matrix &  transform ) const

inlineconstexpr

Definition at line 417 of file rect.h.

                                     {
    auto points = GetPoints();
    for (size_t i = 0; i < points.size(); i++) {
      points[i] = transform * points[i];
    }
    return points;
  }

GetWidth()

template<class T >

constexpr Type impeller::TRect< T >::GetWidth ( ) const

inlineconstexpr

Returns the width of the rectangle, equivalent to |GetSize().width|.

Definition at line 331 of file rect.h.

                                                {
    return saturated::Sub(right_, left_);
  }

GetX()

template<class T >

constexpr Type impeller::TRect< T >::GetX ( ) const

inlineconstexpr

Returns the X coordinate of the upper left corner, equivalent to |GetOrigin().x|.

Definition at line 323 of file rect.h.

{ return left_; }

GetXYWH()

template<class T >

constexpr std::array< T, 4 > impeller::TRect< T >::GetXYWH ( ) const

inlineconstexpr

Get the x, y coordinates of the origin and the width and height of the rectangle in an array.

Definition at line 384 of file rect.h.

                                                         {
    return {left_, top_, GetWidth(), GetHeight()};
  }

GetY()

template<class T >

constexpr Type impeller::TRect< T >::GetY ( ) const

inlineconstexpr

Returns the Y coordinate of the upper left corner, equivalent to |GetOrigin().y|.

Definition at line 327 of file rect.h.

{ return top_; }

Intersection() [1/4]

template<class T >

static constexpr std::optional< TRect > impeller::TRect< T >::Intersection ( const std::optional< TRect< T > >  a, const std::optional< TRect< T > >  b  )

inlinestaticconstexpr

Definition at line 711 of file rect.h.

                                  {
    return a.has_value() ? Intersection(a.value(), b) : b;
  }

Intersection() [2/4]

template<class T >

static constexpr std::optional< TRect > impeller::TRect< T >::Intersection ( const std::optional< TRect< T > >  a, const TRect< T > &  b  )

inlinestaticconstexpr

Definition at line 705 of file rect.h.

                      {
    return a.has_value() ? a->Intersection(b) : b;
  }

Intersection() [3/4]

template<class T >

static constexpr std::optional< TRect > impeller::TRect< T >::Intersection ( const TRect< T > &  a, const std::optional< TRect< T > >  b  )

inlinestaticconstexpr

Definition at line 699 of file rect.h.

                                  {
    return b.has_value() ? a.Intersection(b.value()) : a;
  }

Intersection() [4/4]

template<class T >

constexpr std::optional< TRect > impeller::TRect< T >::Intersection ( const TRect< T > &  o ) const

inlineconstexpr

Definition at line 519 of file rect.h.

                            {
    if (IntersectsWithRect(o)) {
      return TRect{
          std::max(left_, o.left_),
          std::max(top_, o.top_),
          std::min(right_, o.right_),
          std::min(bottom_, o.bottom_),
      };
    } else {
      return std::nullopt;
    }
  }

IntersectsWithRect()

template<class T >

constexpr bool impeller::TRect< T >::IntersectsWithRect ( const TRect< T > &  o ) const

inlineconstexpr

Definition at line 533 of file rect.h.

                                                                        {
    return !IsEmpty() &&        //
           !o.IsEmpty() &&      //
           left_ < o.right_ &&  //
           top_ < o.bottom_ &&  //
           right_ > o.left_ &&  //
           bottom_ > o.top_;
  }

IsEmpty()

template<class T >

constexpr bool impeller::TRect< T >::IsEmpty ( ) const

inlineconstexpr

Returns true if either of the width or height are 0, negative, or NaN.

Definition at line 287 of file rect.h.

                                               {
    // Computing the non-empty condition and negating the result causes any
    // NaN value to return true - i.e. is considered empty.
    return !(left_ < right_ && top_ < bottom_);
  }

IsFinite()

template<class T >

impeller::TRect< T >::IsFinite ( ) const

inline

Returns true if all of the fields of this floating point rectangle are finite.

Note that the results of |GetWidth()| and |GetHeight()| may still be infinite due to overflow even if the fields themselves are finite.

Definition at line 278 of file rect.h.

                   {
    return std::isfinite(left_) &&   //
           std::isfinite(top_) &&    //
           std::isfinite(right_) &&  //
           std::isfinite(bottom_);
  }

IsMaximum()

template<class T >

constexpr bool impeller::TRect< T >::IsMaximum ( ) const

inlineconstexpr

Definition at line 304 of file rect.h.

                                                 {
    return *this == MakeMaximum();
  }

IsSquare()

template<class T >

constexpr bool impeller::TRect< T >::IsSquare ( ) const

inlineconstexpr

Returns true if width and height are equal and neither is NaN.

Definition at line 294 of file rect.h.

                                                {
    // empty rectangles can technically be "square", but would be
    // misleading to most callers. Using |IsEmpty| also prevents
    // "non-empty and non-overflowing" computations from happening
    // to be equal to "empty and overflowing" results.
    // (Consider LTRB(10, 15, MAX-2, MIN+2) which is empty, but both
    //  w/h subtractions equal "5").
    return !IsEmpty() && (right_ - left_) == (bottom_ - top_);
  }

MakeLTRB()

template<class T >

static constexpr TRect impeller::TRect< T >::MakeLTRB ( Type  left, Type  top, Type  right, Type  bottom  )

inlinestaticconstexpr

Definition at line 129 of file rect.h.

                                               {
    return TRect(left, top, right, bottom);
  }

MakeMaximum()

template<class T >

static constexpr TRect impeller::TRect< T >::MakeMaximum ( )

inlinestaticconstexpr

Definition at line 174 of file rect.h.

                                                     {
    return TRect::MakeLTRB(std::numeric_limits<Type>::lowest(),
                           std::numeric_limits<Type>::lowest(),
                           std::numeric_limits<Type>::max(),
                           std::numeric_limits<Type>::max());
  }

MakeOriginSize()

template<class T >

static constexpr TRect impeller::TRect< T >::MakeOriginSize ( const TPoint< Type > &  origin, const TSize< Type > &  size  )

inlinestaticconstexpr

Definition at line 140 of file rect.h.

                                                                 {
    return MakeXYWH(origin.x, origin.y, size.width, size.height);
  }

MakePointBounds() [1/2]

template<class T >

template<typename PointIter >

static constexpr std::optional< TRect > impeller::TRect< T >::MakePointBounds ( const PointIter  first, const PointIter  last  )

inlinestaticconstexpr

Definition at line 156 of file rect.h.

                                                                              {
    if (first == last) {
      return std::nullopt;
    }
    auto left = first->x;
    auto top = first->y;
    auto right = first->x;
    auto bottom = first->y;
    for (auto it = first + 1; it < last; ++it) {
      left = std::min(left, it->x);
      top = std::min(top, it->y);
      right = std::max(right, it->x);
      bottom = std::max(bottom, it->y);
    }
    return TRect::MakeLTRB(left, top, right, bottom);
  }

MakePointBounds() [2/2]

template<class T >

template<typename U >

static constexpr std::optional< TRect > impeller::TRect< T >::MakePointBounds ( const U &  value )

inlinestaticconstexpr

Definition at line 151 of file rect.h.

                                                                      {
    return MakePointBounds(value.begin(), value.end());
  }

MakeSize()

template<class T >

template<class U >

static constexpr TRect impeller::TRect< T >::MakeSize ( const TSize< U > &  size )

inlinestaticconstexpr

Definition at line 146 of file rect.h.

                                                        {
    return TRect(0.0, 0.0, size.width, size.height);
  }

MakeXYWH()

template<class T >

static constexpr TRect impeller::TRect< T >::MakeXYWH ( Type  x, Type  y, Type  width, Type  height  )

inlinestaticconstexpr

Definition at line 136 of file rect.h.

                                                                           {
    return TRect(x, y, saturated::Add(x, width), saturated::Add(y, height));
  }

operator!=()

template<class T >

constexpr bool impeller::TRect< T >::operator!= ( const TRect< T > &  r ) const

inlineconstexpr

Definition at line 188 of file rect.h.

                                                                {
    return !(*this == r);
  }

operator==()

template<class T >

constexpr bool impeller::TRect< T >::operator== ( const TRect< T > &  r ) const

inlineconstexpr

Definition at line 181 of file rect.h.

                                                                {
    return left_ == r.left_ &&    //
           top_ == r.top_ &&      //
           right_ == r.right_ &&  //
           bottom_ == r.bottom_;
  }

Project()

template<class T >

constexpr TRect< T > impeller::TRect< T >::Project ( TRect< T >  source ) const

inlineconstexpr

Returns a new rectangle that represents the projection of the source rectangle onto this rectangle. In other words, the source rectangle is redefined in terms of the coordinate space of this rectangle.

Definition at line 656 of file rect.h.

                                                                  {
    if (IsEmpty()) {
      return {};
    }
    return source.Shift(-left_, -top_)
        .Scale(1.0 / static_cast<Scalar>(GetWidth()),
               1.0 / static_cast<Scalar>(GetHeight()));
  }

Round()

template<class T >

impeller::TRect< T >::Round ( const TRect< U > &  r )

inline

Definition at line 674 of file rect.h.

                           {
    return TRect::MakeLTRB(saturated::Cast<U, Type>(round(r.GetLeft())),
                           saturated::Cast<U, Type>(round(r.GetTop())),
                           saturated::Cast<U, Type>(round(r.GetRight())),
                           saturated::Cast<U, Type>(round(r.GetBottom())));
  }

RoundOut()

template<class T >

impeller::TRect< T >::RoundOut ( const TRect< U > &  r )

inline

Definition at line 666 of file rect.h.

                              {
    return TRect::MakeLTRB(saturated::Cast<U, Type>(floor(r.GetLeft())),
                           saturated::Cast<U, Type>(floor(r.GetTop())),
                           saturated::Cast<U, Type>(ceil(r.GetRight())),
                           saturated::Cast<U, Type>(ceil(r.GetBottom())));
  }

Scale() [1/4]

template<class T >

constexpr TRect impeller::TRect< T >::Scale ( TPoint< T >  scale ) const

inlineconstexpr

Definition at line 206 of file rect.h.

                                                             {
    return Scale(scale.x, scale.y);
  }

Scale() [2/4]

template<class T >

constexpr TRect impeller::TRect< T >::Scale ( TSize< T >  scale ) const

inlineconstexpr

Definition at line 210 of file rect.h.

                                                            {
    return Scale(scale.width, scale.height);
  }

Scale() [3/4]

template<class T >

constexpr TRect impeller::TRect< T >::Scale ( Type  scale ) const

inlineconstexpr

Definition at line 192 of file rect.h.

                                                        {
    return TRect(left_ * scale,   //
                 top_ * scale,    //
                 right_ * scale,  //
                 bottom_ * scale);
  }

Scale() [4/4]

template<class T >

constexpr TRect impeller::TRect< T >::Scale ( Type  scale_x, Type  scale_y  ) const

inlineconstexpr

Definition at line 199 of file rect.h.

                                                                        {
    return TRect(left_ * scale_x,   //
                 top_ * scale_y,    //
                 right_ * scale_x,  //
                 bottom_ * scale_y);
  }

Shift() [1/2]

template<class T >

constexpr TRect< T > impeller::TRect< T >::Shift ( T  dx, T  dy  ) const

inlineconstexpr

Returns a new rectangle translated by the given offset.

Definition at line 589 of file rect.h.

                                                           {
    return {
        saturated::Add(left_, dx),    //
        saturated::Add(top_, dy),     //
        saturated::Add(right_, dx),   //
        saturated::Add(bottom_, dy),  //
    };
  }

Shift() [2/2]

template<class T >

constexpr TRect< T > impeller::TRect< T >::Shift ( TPoint< T >  offset ) const

inlineconstexpr

Returns a new rectangle translated by the given offset.

Definition at line 599 of file rect.h.

                                                                 {
    return Shift(offset.x, offset.y);
  }

TransformAndClipBounds()

template<class T >

constexpr TRect impeller::TRect< T >::TransformAndClipBounds ( const Matrix &  transform ) const

inlineconstexpr

Creates a new bounding box that contains this transformed rectangle, clipped against the near clipping plane if necessary.

Definition at line 429 of file rect.h.

                                     {
    if (!transform.HasPerspective2D()) {
      return TransformBounds(transform);
    }
 
    if (IsEmpty()) {
      return {};
    }
 
    auto ul = transform.TransformHomogenous({left_, top_});
    auto ur = transform.TransformHomogenous({right_, top_});
    auto ll = transform.TransformHomogenous({left_, bottom_});
    auto lr = transform.TransformHomogenous({right_, bottom_});
 
    // It can probably be proven that we only ever have 5 points at most
    // which happens when only 1 corner is clipped and we get 2 points
    // in return for it as we interpolate against its neighbors.
    Point points[8];
    int index = 0;
 
    // Process (clip and interpolate) each point against its 2 neighbors:
    //                                 left, pt, right
    index = ClipAndInsert(points, index, ll, ul, ur);
    index = ClipAndInsert(points, index, ul, ur, lr);
    index = ClipAndInsert(points, index, ur, lr, ll);
    index = ClipAndInsert(points, index, lr, ll, ul);
 
    auto bounds = TRect::MakePointBounds(points, points + index);
    return bounds.value_or(TRect{});
  }

TransformBounds()

template<class T >

constexpr TRect impeller::TRect< T >::TransformBounds ( const Matrix &  transform ) const

inlineconstexpr

Creates a new bounding box that contains this transformed rectangle.

Definition at line 463 of file rect.h.

                                                                               {
    if (IsEmpty()) {
      return {};
    }
    auto points = GetTransformedPoints(transform);
    auto bounds = TRect::MakePointBounds(points.begin(), points.end());
    if (bounds.has_value()) {
      return bounds.value();
    }
    FML_UNREACHABLE();
  }

Union() [1/4]

template<class T >

static constexpr std::optional< TRect > impeller::TRect< T >::Union ( const std::optional< TRect< T > >  a, const std::optional< TRect< T > >  b  )

inlinestaticconstexpr

Definition at line 693 of file rect.h.

                                  {
    return a.has_value() ? Union(a.value(), b) : b;
  }

Union() [2/4]

template<class T >

static constexpr std::optional< TRect > impeller::TRect< T >::Union ( const std::optional< TRect< T > >  a, const TRect< T > &  b  )

inlinestaticconstexpr

Definition at line 687 of file rect.h.

                      {
    return a.has_value() ? a->Union(b) : b;
  }

Union() [3/4]

template<class T >

static constexpr std::optional< TRect > impeller::TRect< T >::Union ( const TRect< T > &  a, const std::optional< TRect< T > >  b  )

inlinestaticconstexpr

Definition at line 681 of file rect.h.

                                  {
    return b.has_value() ? a.Union(b.value()) : a;
  }

Union() [4/4]

template<class T >

constexpr TRect impeller::TRect< T >::Union ( const TRect< T > &  o ) const

inlineconstexpr

Definition at line 504 of file rect.h.

                                                            {
    if (IsEmpty()) {
      return o;
    }
    if (o.IsEmpty()) {
      return *this;
    }
    return {
        std::min(left_, o.left_),
        std::min(top_, o.top_),
        std::max(right_, o.right_),
        std::max(bottom_, o.bottom_),
    };
  }

---

The documentation for this struct was generated from the following file:

• impeller/geometry/rect.h