gfx/2d/Tools.h@97036ab72558 (annotated)
gfx/2d/Tools.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_TOOLS_H_ |
| michael@0 | 7 | #define MOZILLA_GFX_TOOLS_H_ |
| michael@0 | 8 | |
| michael@0 | 9 | #include "Types.h" |
| michael@0 | 10 | #include "Point.h" |
| michael@0 | 11 | #include <math.h> |
| michael@0 | 12 | #if defined(_MSC_VER) && (_MSC_VER < 1600) |
| michael@0 | 13 | #define hypotf _hypotf |
| michael@0 | 14 | #endif |
| michael@0 | 15 | |
| michael@0 | 16 | namespace mozilla { |
| michael@0 | 17 | namespace gfx { |
| michael@0 | 18 | |
| michael@0 | 19 | static inline bool |
| michael@0 | 20 | IsOperatorBoundByMask(CompositionOp aOp) { |
| michael@0 | 21 | switch (aOp) { |
| michael@0 | 22 | case CompositionOp::OP_IN: |
| michael@0 | 23 | case CompositionOp::OP_OUT: |
| michael@0 | 24 | case CompositionOp::OP_DEST_IN: |
| michael@0 | 25 | case CompositionOp::OP_DEST_ATOP: |
| michael@0 | 26 | case CompositionOp::OP_SOURCE: |
| michael@0 | 27 | return false; |
| michael@0 | 28 | default: |
| michael@0 | 29 | return true; |
| michael@0 | 30 | } |
| michael@0 | 31 | } |
| michael@0 | 32 | |
| michael@0 | 33 | template <class T> |
| michael@0 | 34 | struct ClassStorage |
| michael@0 | 35 | { |
| michael@0 | 36 | char bytes[sizeof(T)]; |
| michael@0 | 37 | |
| michael@0 | 38 | const T *addr() const { return (const T *)bytes; } |
| michael@0 | 39 | T *addr() { return (T *)(void *)bytes; } |
| michael@0 | 40 | }; |
| michael@0 | 41 | |
| michael@0 | 42 | static inline bool |
| michael@0 | 43 | FuzzyEqual(Float aA, Float aB, Float aErr) |
| michael@0 | 44 | { |
| michael@0 | 45 | if ((aA + aErr >= aB) && (aA - aErr <= aB)) { |
| michael@0 | 46 | return true; |
| michael@0 | 47 | } |
| michael@0 | 48 | return false; |
| michael@0 | 49 | } |
| michael@0 | 50 | |
| michael@0 | 51 | static inline void |
| michael@0 | 52 | NudgeToInteger(float *aVal) |
| michael@0 | 53 | { |
| michael@0 | 54 | float r = floorf(*aVal + 0.5f); |
| michael@0 | 55 | // The error threshold should be proportional to the rounded value. This |
| michael@0 | 56 | // bounds the relative error introduced by the nudge operation. However, |
| michael@0 | 57 | // when the rounded value is 0, the error threshold can't be proportional |
| michael@0 | 58 | // to the rounded value (we'd never round), so we just choose the same |
| michael@0 | 59 | // threshold as for a rounded value of 1. |
| michael@0 | 60 | if (FuzzyEqual(r, *aVal, r == 0.0f ? 1e-6f : fabs(r*1e-6f))) { |
| michael@0 | 61 | *aVal = r; |
| michael@0 | 62 | } |
| michael@0 | 63 | } |
| michael@0 | 64 | |
| michael@0 | 65 | static inline Float |
| michael@0 | 66 | Distance(Point aA, Point aB) |
| michael@0 | 67 | { |
| michael@0 | 68 | return hypotf(aB.x - aA.x, aB.y - aA.y); |
| michael@0 | 69 | } |
| michael@0 | 70 | |
| michael@0 | 71 | static inline int |
| michael@0 | 72 | BytesPerPixel(SurfaceFormat aFormat) |
| michael@0 | 73 | { |
| michael@0 | 74 | switch (aFormat) { |
| michael@0 | 75 | case SurfaceFormat::A8: |
| michael@0 | 76 | return 1; |
| michael@0 | 77 | case SurfaceFormat::R5G6B5: |
| michael@0 | 78 | return 2; |
| michael@0 | 79 | default: |
| michael@0 | 80 | return 4; |
| michael@0 | 81 | } |
| michael@0 | 82 | } |
| michael@0 | 83 | |
| michael@0 | 84 | template<typename T, int alignment = 16> |
| michael@0 | 85 | struct AlignedArray |
| michael@0 | 86 | { |
| michael@0 | 87 | AlignedArray() |
| michael@0 | 88 | : mStorage(nullptr) |
| michael@0 | 89 | , mPtr(nullptr) |
| michael@0 | 90 | { |
| michael@0 | 91 | } |
| michael@0 | 92 | |
| michael@0 | 93 | MOZ_ALWAYS_INLINE AlignedArray(size_t aSize) |
| michael@0 | 94 | : mStorage(nullptr) |
| michael@0 | 95 | { |
| michael@0 | 96 | Realloc(aSize); |
| michael@0 | 97 | } |
| michael@0 | 98 | |
| michael@0 | 99 | MOZ_ALWAYS_INLINE ~AlignedArray() |
| michael@0 | 100 | { |
| michael@0 | 101 | delete [] mStorage; |
| michael@0 | 102 | } |
| michael@0 | 103 | |
| michael@0 | 104 | void Dealloc() |
| michael@0 | 105 | { |
| michael@0 | 106 | delete [] mStorage; |
| michael@0 | 107 | mStorage = mPtr = nullptr; |
| michael@0 | 108 | } |
| michael@0 | 109 | |
| michael@0 | 110 | MOZ_ALWAYS_INLINE void Realloc(size_t aSize) |
| michael@0 | 111 | { |
| michael@0 | 112 | delete [] mStorage; |
| michael@0 | 113 | mStorage = new (std::nothrow) T[aSize + (alignment - 1)]; |
| michael@0 | 114 | if (uintptr_t(mStorage) % alignment) { |
| michael@0 | 115 | // Our storage does not start at a <alignment>-byte boundary. Make sure mData does! |
| michael@0 | 116 | mPtr = (T*)(uintptr_t(mStorage) + |
| michael@0 | 117 | (alignment - (uintptr_t(mStorage) % alignment))); |
| michael@0 | 118 | } else { |
| michael@0 | 119 | mPtr = mStorage; |
| michael@0 | 120 | } |
| michael@0 | 121 | } |
| michael@0 | 122 | |
| michael@0 | 123 | MOZ_ALWAYS_INLINE operator T*() |
| michael@0 | 124 | { |
| michael@0 | 125 | return mPtr; |
| michael@0 | 126 | } |
| michael@0 | 127 | |
| michael@0 | 128 | T *mStorage; |
| michael@0 | 129 | T *mPtr; |
| michael@0 | 130 | }; |
| michael@0 | 131 | |
| michael@0 | 132 | template<int alignment> |
| michael@0 | 133 | int32_t GetAlignedStride(int32_t aStride) |
| michael@0 | 134 | { |
| michael@0 | 135 | if (aStride % alignment) { |
| michael@0 | 136 | return aStride + (alignment - (aStride % alignment)); |
| michael@0 | 137 | } |
| michael@0 | 138 | |
| michael@0 | 139 | return aStride; |
| michael@0 | 140 | } |
| michael@0 | 141 | |
| michael@0 | 142 | } |
| michael@0 | 143 | } |
| michael@0 | 144 | |
| michael@0 | 145 | #endif /* MOZILLA_GFX_TOOLS_H_ */ |
