gecko-dev/gfx/2d/BaseRect.h

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/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*-
2012-05-21 15:12:37 +04:00
* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
#ifndef MOZILLA_GFX_BASERECT_H_
#define MOZILLA_GFX_BASERECT_H_
#include <cmath>
#include <mozilla/Assertions.h>
#include <algorithm>
namespace mozilla {
namespace gfx {
/**
* Rectangles have two interpretations: a set of (zero-size) points,
* and a rectangular area of the plane. Most rectangle operations behave
* the same no matter what interpretation is being used, but some operations
* differ:
* -- Equality tests behave differently. When a rectangle represents an area,
* all zero-width and zero-height rectangles are equal to each other since they
* represent the empty area. But when a rectangle represents a set of
* mathematical points, zero-width and zero-height rectangles can be unequal.
* -- The union operation can behave differently. When rectangles represent
* areas, taking the union of a zero-width or zero-height rectangle with
* another rectangle can just ignore the empty rectangle. But when rectangles
* represent sets of mathematical points, we may need to extend the latter
* rectangle to include the points of a zero-width or zero-height rectangle.
*
* To ensure that these interpretations are explicitly disambiguated, we
* deny access to the == and != operators and require use of IsEqualEdges and
* IsEqualInterior instead. Similarly we provide separate Union and UnionEdges
* methods.
*
* Do not use this class directly. Subclass it, pass that subclass as the
* Sub parameter, and only use that subclass.
*/
template <class T, class Sub, class Point, class SizeT, class Margin>
struct BaseRect {
T x, y, width, height;
// Constructors
BaseRect() : x(0), y(0), width(0), height(0) {}
BaseRect(const Point& aOrigin, const SizeT &aSize) :
x(aOrigin.x), y(aOrigin.y), width(aSize.width), height(aSize.height)
{
}
BaseRect(T aX, T aY, T aWidth, T aHeight) :
x(aX), y(aY), width(aWidth), height(aHeight)
{
}
// Emptiness. An empty rect is one that has no area, i.e. its height or width
// is <= 0
bool IsEmpty() const { return height <= 0 || width <= 0; }
void SetEmpty() { width = height = 0; }
// Returns true if this rectangle contains the interior of aRect. Always
// returns true if aRect is empty, and always returns false is aRect is
// nonempty but this rect is empty.
bool Contains(const Sub& aRect) const
{
return aRect.IsEmpty() ||
(x <= aRect.x && aRect.XMost() <= XMost() &&
y <= aRect.y && aRect.YMost() <= YMost());
}
// Returns true if this rectangle contains the rectangle (aX,aY,1,1).
bool Contains(T aX, T aY) const
{
return x <= aX && aX + 1 <= XMost() &&
y <= aY && aY + 1 <= YMost();
}
// Returns true if this rectangle contains the rectangle (aPoint.x,aPoint.y,1,1).
bool Contains(const Point& aPoint) const { return Contains(aPoint.x, aPoint.y); }
// Intersection. Returns TRUE if the receiver's area has non-empty
// intersection with aRect's area, and FALSE otherwise.
// Always returns false if aRect is empty or 'this' is empty.
bool Intersects(const Sub& aRect) const
{
return x < aRect.XMost() && aRect.x < XMost() &&
y < aRect.YMost() && aRect.y < YMost();
}
// Returns the rectangle containing the intersection of the points
// (including edges) of *this and aRect. If there are no points in that
// intersection, returns an empty rectangle with x/y set to the std::max of the x/y
// of *this and aRect.
Sub Intersect(const Sub& aRect) const
{
Sub result;
result.x = std::max(x, aRect.x);
result.y = std::max(y, aRect.y);
result.width = std::min(XMost(), aRect.XMost()) - result.x;
result.height = std::min(YMost(), aRect.YMost()) - result.y;
if (result.width < 0 || result.height < 0) {
result.SizeTo(0, 0);
}
return result;
}
// Sets *this to be the rectangle containing the intersection of the points
// (including edges) of *this and aRect. If there are no points in that
// intersection, sets *this to be an empty rectangle with x/y set to the std::max
// of the x/y of *this and aRect.
//
// 'this' can be the same object as either aRect1 or aRect2
bool IntersectRect(const Sub& aRect1, const Sub& aRect2)
{
*static_cast<Sub*>(this) = aRect1.Intersect(aRect2);
return !IsEmpty();
}
// Returns the smallest rectangle that contains both the area of both
// this and aRect2.
// Thus, empty input rectangles are ignored.
// If both rectangles are empty, returns this.
Sub Union(const Sub& aRect) const
{
if (IsEmpty()) {
return aRect;
} else if (aRect.IsEmpty()) {
return *static_cast<const Sub*>(this);
} else {
return UnionEdges(aRect);
}
}
// Returns the smallest rectangle that contains both the points (including
// edges) of both aRect1 and aRect2.
// Thus, empty input rectangles are allowed to affect the result.
Sub UnionEdges(const Sub& aRect) const
{
Sub result;
result.x = std::min(x, aRect.x);
result.y = std::min(y, aRect.y);
result.width = std::max(XMost(), aRect.XMost()) - result.x;
result.height = std::max(YMost(), aRect.YMost()) - result.y;
return result;
}
// Computes the smallest rectangle that contains both the area of both
// aRect1 and aRect2, and fills 'this' with the result.
// Thus, empty input rectangles are ignored.
// If both rectangles are empty, sets 'this' to aRect2.
//
// 'this' can be the same object as either aRect1 or aRect2
void UnionRect(const Sub& aRect1, const Sub& aRect2)
{
*static_cast<Sub*>(this) = aRect1.Union(aRect2);
}
// Computes the smallest rectangle that contains both the points (including
// edges) of both aRect1 and aRect2.
// Thus, empty input rectangles are allowed to affect the result.
//
// 'this' can be the same object as either aRect1 or aRect2
void UnionRectEdges(const Sub& aRect1, const Sub& aRect2)
{
*static_cast<Sub*>(this) = aRect1.UnionEdges(aRect2);
}
void SetRect(T aX, T aY, T aWidth, T aHeight)
{
x = aX; y = aY; width = aWidth; height = aHeight;
}
void SetRect(const Point& aPt, const SizeT& aSize)
{
SetRect(aPt.x, aPt.y, aSize.width, aSize.height);
}
void MoveTo(T aX, T aY) { x = aX; y = aY; }
void MoveTo(const Point& aPoint) { x = aPoint.x; y = aPoint.y; }
void MoveBy(T aDx, T aDy) { x += aDx; y += aDy; }
void MoveBy(const Point& aPoint) { x += aPoint.x; y += aPoint.y; }
void SizeTo(T aWidth, T aHeight) { width = aWidth; height = aHeight; }
void SizeTo(const SizeT& aSize) { width = aSize.width; height = aSize.height; }
void Inflate(T aD) { Inflate(aD, aD); }
void Inflate(T aDx, T aDy)
{
x -= aDx;
y -= aDy;
width += 2 * aDx;
height += 2 * aDy;
}
void Inflate(const Margin& aMargin)
{
x -= aMargin.left;
y -= aMargin.top;
width += aMargin.LeftRight();
height += aMargin.TopBottom();
}
void Inflate(const SizeT& aSize) { Inflate(aSize.width, aSize.height); }
void Deflate(T aD) { Deflate(aD, aD); }
void Deflate(T aDx, T aDy)
{
x += aDx;
y += aDy;
width = std::max(T(0), width - 2 * aDx);
height = std::max(T(0), height - 2 * aDy);
}
void Deflate(const Margin& aMargin)
{
x += aMargin.left;
y += aMargin.top;
width = std::max(T(0), width - aMargin.LeftRight());
height = std::max(T(0), height - aMargin.TopBottom());
}
void Deflate(const SizeT& aSize) { Deflate(aSize.width, aSize.height); }
// Return true if the rectangles contain the same set of points, including
// points on the edges.
// Use when we care about the exact x/y/width/height values being
// equal (i.e. we care about differences in empty rectangles).
bool IsEqualEdges(const Sub& aRect) const
{
return x == aRect.x && y == aRect.y &&
width == aRect.width && height == aRect.height;
}
// Return true if the rectangles contain the same area of the plane.
// Use when we do not care about differences in empty rectangles.
bool IsEqualInterior(const Sub& aRect) const
{
return IsEqualEdges(aRect) || (IsEmpty() && aRect.IsEmpty());
}
Sub operator+(const Point& aPoint) const
{
return Sub(x + aPoint.x, y + aPoint.y, width, height);
}
Sub operator-(const Point& aPoint) const
{
return Sub(x - aPoint.x, y - aPoint.y, width, height);
}
Sub& operator+=(const Point& aPoint)
{
MoveBy(aPoint);
return *static_cast<Sub*>(this);
}
Sub& operator-=(const Point& aPoint)
{
MoveBy(-aPoint);
return *static_cast<Sub*>(this);
}
// Find difference as a Margin
Margin operator-(const Sub& aRect) const
{
return Margin(aRect.x - x, aRect.y - y,
XMost() - aRect.XMost(), YMost() - aRect.YMost());
}
// Helpers for accessing the vertices
Point TopLeft() const { return Point(x, y); }
Point TopRight() const { return Point(XMost(), y); }
Point BottomLeft() const { return Point(x, YMost()); }
Point BottomRight() const { return Point(XMost(), YMost()); }
Point Center() const { return Point(x, y) + Point(width, height)/2; }
SizeT Size() const { return SizeT(width, height); }
// Helper methods for computing the extents
T X() const { return x; }
T Y() const { return y; }
T Width() const { return width; }
T Height() const { return height; }
T XMost() const { return x + width; }
T YMost() const { return y + height; }
// Moves one edge of the rect without moving the opposite edge.
void SetLeftEdge(T aX) {
MOZ_ASSERT(aX <= XMost());
width = XMost() - aX;
x = aX;
}
void SetRightEdge(T aXMost) {
MOZ_ASSERT(aXMost >= x);
width = aXMost - x;
}
void SetTopEdge(T aY) {
MOZ_ASSERT(aY <= YMost());
height = YMost() - aY;
y = aY;
}
void SetBottomEdge(T aYMost) {
MOZ_ASSERT(aYMost >= y);
height = aYMost - y;
}
// Round the rectangle edges to integer coordinates, such that the rounded
// rectangle has the same set of pixel centers as the original rectangle.
// Edges at offset 0.5 round up.
// Suitable for most places where integral device coordinates
// are needed, but note that any translation should be applied first to
// avoid pixel rounding errors.
// Note that this is *not* rounding to nearest integer if the values are negative.
// They are always rounding as floor(n + 0.5).
// See https://bugzilla.mozilla.org/show_bug.cgi?id=410748#c14
// If you need similar method which is using NS_round(), you should create
// new |RoundAwayFromZero()| method.
void Round()
{
T x0 = static_cast<T>(floor(T(X()) + 0.5));
T y0 = static_cast<T>(floor(T(Y()) + 0.5));
T x1 = static_cast<T>(floor(T(XMost()) + 0.5));
T y1 = static_cast<T>(floor(T(YMost()) + 0.5));
x = x0;
y = y0;
width = x1 - x0;
height = y1 - y0;
}
// Snap the rectangle edges to integer coordinates, such that the
// original rectangle contains the resulting rectangle.
void RoundIn()
{
T x0 = static_cast<T>(ceil(T(X())));
T y0 = static_cast<T>(ceil(T(Y())));
T x1 = static_cast<T>(floor(T(XMost())));
T y1 = static_cast<T>(floor(T(YMost())));
x = x0;
y = y0;
width = x1 - x0;
height = y1 - y0;
}
// Snap the rectangle edges to integer coordinates, such that the
// resulting rectangle contains the original rectangle.
void RoundOut()
{
T x0 = static_cast<T>(floor(T(X())));
T y0 = static_cast<T>(floor(T(Y())));
T x1 = static_cast<T>(ceil(T(XMost())));
T y1 = static_cast<T>(ceil(T(YMost())));
x = x0;
y = y0;
width = x1 - x0;
height = y1 - y0;
}
// Scale 'this' by aScale, converting coordinates to integers so that the result is
// the smallest integer-coordinate rectangle containing the unrounded result.
// Note: this can turn an empty rectangle into a non-empty rectangle
void ScaleRoundOut(double aScale) { ScaleRoundOut(aScale, aScale); }
// Scale 'this' by aXScale and aYScale, converting coordinates to integers so
// that the result is the smallest integer-coordinate rectangle containing the
// unrounded result.
// Note: this can turn an empty rectangle into a non-empty rectangle
void ScaleRoundOut(double aXScale, double aYScale)
{
T right = static_cast<T>(ceil(double(XMost()) * aXScale));
T bottom = static_cast<T>(ceil(double(YMost()) * aYScale));
x = static_cast<T>(floor(double(x) * aXScale));
y = static_cast<T>(floor(double(y) * aYScale));
width = right - x;
height = bottom - y;
}
// Scale 'this' by aScale, converting coordinates to integers so that the result is
// the largest integer-coordinate rectangle contained by the unrounded result.
Bug 637852. Part 6: Implement resolution scaling in FrameLayerBuilder. r=tnikkel FrameLayerBuilder::BuildContainerLayerFor takes responsibility for resolution scaling. The ContainerParameters passed in are added to any transform requested. Then we extract the scale part of the transform, round the scale up to the nearest power of two if the transform may be actively animated (so we don't have to redraw layer contents constantly), pass that scale down to be applied by each child and set the residual transform on the ContainerLayer. For child layers built via BuildLayer, we just pass the requested scale factor in via the ContainerParameters. If the returned layer is a ContainerLayer then BuildLayer is guaranteed to have already done necessary scaling. If the returned layer is not a ContainerLayer then we apply the scale ourselves by adding the scale to the child layer's transform. For child ThebesLayers containing non-layer display items, we scale the drawing of those display items so that the child ThebesLayers are simply larger or smaller (larger or smaller visible regions). We have to scale all visible rects, clip rects etc that are in the coordinates of ThebesLayers or the parent ContainerLayer. To keep things simple we do this whenever we convert from appunits to integer layer coordinates. When a ThebesLayer's resolution changes we need to rerender the whole thing. nsDisplayList::PaintForFrame needs to respect the presshell's resolution setting. We do that by building a layer tree with a ContainerParameters requesting a scale up by the presshell resolution; once that layer tree is built, we adjust the root layer transform to scale back down by the resolution.
2011-06-22 16:11:27 +04:00
void ScaleRoundIn(double aScale) { ScaleRoundIn(aScale, aScale); }
// Scale 'this' by aXScale and aYScale, converting coordinates to integers so
// that the result is the largest integer-coordinate rectangle contained by the
// unrounded result.
Bug 637852. Part 6: Implement resolution scaling in FrameLayerBuilder. r=tnikkel FrameLayerBuilder::BuildContainerLayerFor takes responsibility for resolution scaling. The ContainerParameters passed in are added to any transform requested. Then we extract the scale part of the transform, round the scale up to the nearest power of two if the transform may be actively animated (so we don't have to redraw layer contents constantly), pass that scale down to be applied by each child and set the residual transform on the ContainerLayer. For child layers built via BuildLayer, we just pass the requested scale factor in via the ContainerParameters. If the returned layer is a ContainerLayer then BuildLayer is guaranteed to have already done necessary scaling. If the returned layer is not a ContainerLayer then we apply the scale ourselves by adding the scale to the child layer's transform. For child ThebesLayers containing non-layer display items, we scale the drawing of those display items so that the child ThebesLayers are simply larger or smaller (larger or smaller visible regions). We have to scale all visible rects, clip rects etc that are in the coordinates of ThebesLayers or the parent ContainerLayer. To keep things simple we do this whenever we convert from appunits to integer layer coordinates. When a ThebesLayer's resolution changes we need to rerender the whole thing. nsDisplayList::PaintForFrame needs to respect the presshell's resolution setting. We do that by building a layer tree with a ContainerParameters requesting a scale up by the presshell resolution; once that layer tree is built, we adjust the root layer transform to scale back down by the resolution.
2011-06-22 16:11:27 +04:00
void ScaleRoundIn(double aXScale, double aYScale)
{
T right = static_cast<T>(floor(double(XMost()) * aXScale));
T bottom = static_cast<T>(floor(double(YMost()) * aYScale));
x = static_cast<T>(ceil(double(x) * aXScale));
y = static_cast<T>(ceil(double(y) * aYScale));
width = std::max<T>(0, right - x);
height = std::max<T>(0, bottom - y);
Bug 637852. Part 6: Implement resolution scaling in FrameLayerBuilder. r=tnikkel FrameLayerBuilder::BuildContainerLayerFor takes responsibility for resolution scaling. The ContainerParameters passed in are added to any transform requested. Then we extract the scale part of the transform, round the scale up to the nearest power of two if the transform may be actively animated (so we don't have to redraw layer contents constantly), pass that scale down to be applied by each child and set the residual transform on the ContainerLayer. For child layers built via BuildLayer, we just pass the requested scale factor in via the ContainerParameters. If the returned layer is a ContainerLayer then BuildLayer is guaranteed to have already done necessary scaling. If the returned layer is not a ContainerLayer then we apply the scale ourselves by adding the scale to the child layer's transform. For child ThebesLayers containing non-layer display items, we scale the drawing of those display items so that the child ThebesLayers are simply larger or smaller (larger or smaller visible regions). We have to scale all visible rects, clip rects etc that are in the coordinates of ThebesLayers or the parent ContainerLayer. To keep things simple we do this whenever we convert from appunits to integer layer coordinates. When a ThebesLayer's resolution changes we need to rerender the whole thing. nsDisplayList::PaintForFrame needs to respect the presshell's resolution setting. We do that by building a layer tree with a ContainerParameters requesting a scale up by the presshell resolution; once that layer tree is built, we adjust the root layer transform to scale back down by the resolution.
2011-06-22 16:11:27 +04:00
}
// Scale 'this' by 1/aScale, converting coordinates to integers so that the result is
// the smallest integer-coordinate rectangle containing the unrounded result.
// Note: this can turn an empty rectangle into a non-empty rectangle
void ScaleInverseRoundOut(double aScale) { ScaleInverseRoundOut(aScale, aScale); }
// Scale 'this' by 1/aXScale and 1/aYScale, converting coordinates to integers so
// that the result is the smallest integer-coordinate rectangle containing the
// unrounded result.
// Note: this can turn an empty rectangle into a non-empty rectangle
void ScaleInverseRoundOut(double aXScale, double aYScale)
{
T right = static_cast<T>(ceil(double(XMost()) / aXScale));
T bottom = static_cast<T>(ceil(double(YMost()) / aYScale));
x = static_cast<T>(floor(double(x) / aXScale));
y = static_cast<T>(floor(double(y) / aYScale));
width = right - x;
height = bottom - y;
}
// Scale 'this' by 1/aScale, converting coordinates to integers so that the result is
// the largest integer-coordinate rectangle contained by the unrounded result.
void ScaleInverseRoundIn(double aScale) { ScaleInverseRoundIn(aScale, aScale); }
// Scale 'this' by 1/aXScale and 1/aYScale, converting coordinates to integers so
// that the result is the largest integer-coordinate rectangle contained by the
// unrounded result.
void ScaleInverseRoundIn(double aXScale, double aYScale)
{
T right = static_cast<T>(floor(double(XMost()) / aXScale));
T bottom = static_cast<T>(floor(double(YMost()) / aYScale));
x = static_cast<T>(ceil(double(x) / aXScale));
y = static_cast<T>(ceil(double(y) / aYScale));
width = std::max<T>(0, right - x);
height = std::max<T>(0, bottom - y);
}
/**
* Clamp aPoint to this rectangle. It is allowed to end up on any
* edge of the rectangle.
*/
Point ClampPoint(const Point& aPoint) const
{
return Point(std::max(x, std::min(XMost(), aPoint.x)),
std::max(y, std::min(YMost(), aPoint.y)));
}
private:
// Do not use the default operator== or operator!= !
// Use IsEqualEdges or IsEqualInterior explicitly.
bool operator==(const Sub& aRect) const { return false; }
bool operator!=(const Sub& aRect) const { return false; }
};
}
}
#endif /* MOZILLA_GFX_BASERECT_H_ */