gfx/2d/ScaleFactor.h@97036ab72558 (annotated)
gfx/2d/ScaleFactor.h
Tue, 06 Jan 2015 21:39:09 +0100
- author
- Michael Schloh von Bennewitz <michael@schloh.com>
- date
- Tue, 06 Jan 2015 21:39:09 +0100
- branch
- TOR_BUG_9701
- changeset 8
- 97036ab72558
- permissions
- -rw-r--r--
Conditionally force memory storage according to privacy.thirdparty.isolate;
This solves Tor bug #9701, complying with disk avoidance documented in
https://www.torproject.org/projects/torbrowser/design/#disk-avoidance.
| michael@0 | 1 | /* -*- Mode: C++; tab-width: 20; indent-tabs-mode: nil; c-basic-offset: 2 -*- |
| michael@0 | 2 | * This Source Code Form is subject to the terms of the Mozilla Public |
| michael@0 | 3 | * License, v. 2.0. If a copy of the MPL was not distributed with this |
| michael@0 | 4 | * file, You can obtain one at http://mozilla.org/MPL/2.0/. */ |
| michael@0 | 5 | |
| michael@0 | 6 | #ifndef MOZILLA_GFX_SCALEFACTOR_H_ |
| michael@0 | 7 | #define MOZILLA_GFX_SCALEFACTOR_H_ |
| michael@0 | 8 | |
| michael@0 | 9 | #include "mozilla/Attributes.h" |
| michael@0 | 10 | |
| michael@0 | 11 | #include "gfxPoint.h" |
| michael@0 | 12 | |
| michael@0 | 13 | namespace mozilla { |
| michael@0 | 14 | namespace gfx { |
| michael@0 | 15 | |
| michael@0 | 16 | /* |
| michael@0 | 17 | * This class represents a scaling factor between two different pixel unit |
| michael@0 | 18 | * systems. This is effectively a type-safe float, intended to be used in |
| michael@0 | 19 | * combination with the known-type instances of gfx::Point, gfx::Rect, etc. |
| michael@0 | 20 | * |
| michael@0 | 21 | * Note that some parts of the code that pre-date this class used separate |
| michael@0 | 22 | * scaling factors for the x and y axes. However, at runtime these values |
| michael@0 | 23 | * were always expected to be the same, so this class uses only one scale |
| michael@0 | 24 | * factor for both axes. The two constructors that take two-axis scaling |
| michael@0 | 25 | * factors check to ensure that this assertion holds. |
| michael@0 | 26 | */ |
| michael@0 | 27 | template<class src, class dst> |
| michael@0 | 28 | struct ScaleFactor { |
| michael@0 | 29 | float scale; |
| michael@0 | 30 | |
| michael@0 | 31 | MOZ_CONSTEXPR ScaleFactor() : scale(1.0) {} |
| michael@0 | 32 | MOZ_CONSTEXPR ScaleFactor(const ScaleFactor<src, dst>& aCopy) : scale(aCopy.scale) {} |
| michael@0 | 33 | explicit MOZ_CONSTEXPR ScaleFactor(float aScale) : scale(aScale) {} |
| michael@0 | 34 | |
| michael@0 | 35 | explicit ScaleFactor(float aX, float aY) : scale(aX) { |
| michael@0 | 36 | MOZ_ASSERT(fabs(aX - aY) < 1e-6); |
| michael@0 | 37 | } |
| michael@0 | 38 | |
| michael@0 | 39 | ScaleFactor<dst, src> Inverse() { |
| michael@0 | 40 | return ScaleFactor<dst, src>(1 / scale); |
| michael@0 | 41 | } |
| michael@0 | 42 | |
| michael@0 | 43 | bool operator==(const ScaleFactor<src, dst>& aOther) const { |
| michael@0 | 44 | return scale == aOther.scale; |
| michael@0 | 45 | } |
| michael@0 | 46 | |
| michael@0 | 47 | bool operator!=(const ScaleFactor<src, dst>& aOther) const { |
| michael@0 | 48 | return !(*this == aOther); |
| michael@0 | 49 | } |
| michael@0 | 50 | |
| michael@0 | 51 | bool operator<(const ScaleFactor<src, dst>& aOther) const { |
| michael@0 | 52 | return scale < aOther.scale; |
| michael@0 | 53 | } |
| michael@0 | 54 | |
| michael@0 | 55 | bool operator<=(const ScaleFactor<src, dst>& aOther) const { |
| michael@0 | 56 | return scale <= aOther.scale; |
| michael@0 | 57 | } |
| michael@0 | 58 | |
| michael@0 | 59 | bool operator>(const ScaleFactor<src, dst>& aOther) const { |
| michael@0 | 60 | return scale > aOther.scale; |
| michael@0 | 61 | } |
| michael@0 | 62 | |
| michael@0 | 63 | bool operator>=(const ScaleFactor<src, dst>& aOther) const { |
| michael@0 | 64 | return scale >= aOther.scale; |
| michael@0 | 65 | } |
| michael@0 | 66 | |
| michael@0 | 67 | template<class other> |
| michael@0 | 68 | ScaleFactor<other, dst> operator/(const ScaleFactor<src, other>& aOther) const { |
| michael@0 | 69 | return ScaleFactor<other, dst>(scale / aOther.scale); |
| michael@0 | 70 | } |
| michael@0 | 71 | |
| michael@0 | 72 | template<class other> |
| michael@0 | 73 | ScaleFactor<src, other> operator/(const ScaleFactor<other, dst>& aOther) const { |
| michael@0 | 74 | return ScaleFactor<src, other>(scale / aOther.scale); |
| michael@0 | 75 | } |
| michael@0 | 76 | |
| michael@0 | 77 | template<class other> |
| michael@0 | 78 | ScaleFactor<src, other> operator*(const ScaleFactor<dst, other>& aOther) const { |
| michael@0 | 79 | return ScaleFactor<src, other>(scale * aOther.scale); |
| michael@0 | 80 | } |
| michael@0 | 81 | |
| michael@0 | 82 | template<class other> |
| michael@0 | 83 | ScaleFactor<other, dst> operator*(const ScaleFactor<other, src>& aOther) const { |
| michael@0 | 84 | return ScaleFactor<other, dst>(scale * aOther.scale); |
| michael@0 | 85 | } |
| michael@0 | 86 | }; |
| michael@0 | 87 | |
| michael@0 | 88 | } |
| michael@0 | 89 | } |
| michael@0 | 90 | |
| michael@0 | 91 | #endif /* MOZILLA_GFX_SCALEFACTOR_H_ */ |
