1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/gfx/2d/Tools.h Wed Dec 31 06:09:35 2014 +0100
1.3 @@ -0,0 +1,145 @@
1.4 +/* -*- Mode: C++; tab-width: 20; indent-tabs-mode: nil; c-basic-offset: 2 -*-
1.5 + * This Source Code Form is subject to the terms of the Mozilla Public
1.6 + * License, v. 2.0. If a copy of the MPL was not distributed with this
1.7 + * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
1.8 +
1.9 +#ifndef MOZILLA_GFX_TOOLS_H_
1.10 +#define MOZILLA_GFX_TOOLS_H_
1.11 +
1.12 +#include "Types.h"
1.13 +#include "Point.h"
1.14 +#include <math.h>
1.15 +#if defined(_MSC_VER) && (_MSC_VER < 1600)
1.16 +#define hypotf _hypotf
1.17 +#endif
1.18 +
1.19 +namespace mozilla {
1.20 +namespace gfx {
1.21 +
1.22 +static inline bool
1.23 +IsOperatorBoundByMask(CompositionOp aOp) {
1.24 + switch (aOp) {
1.25 + case CompositionOp::OP_IN:
1.26 + case CompositionOp::OP_OUT:
1.27 + case CompositionOp::OP_DEST_IN:
1.28 + case CompositionOp::OP_DEST_ATOP:
1.29 + case CompositionOp::OP_SOURCE:
1.30 + return false;
1.31 + default:
1.32 + return true;
1.33 + }
1.34 +}
1.35 +
1.36 +template <class T>
1.37 +struct ClassStorage
1.38 +{
1.39 + char bytes[sizeof(T)];
1.40 +
1.41 + const T *addr() const { return (const T *)bytes; }
1.42 + T *addr() { return (T *)(void *)bytes; }
1.43 +};
1.44 +
1.45 +static inline bool
1.46 +FuzzyEqual(Float aA, Float aB, Float aErr)
1.47 +{
1.48 + if ((aA + aErr >= aB) && (aA - aErr <= aB)) {
1.49 + return true;
1.50 + }
1.51 + return false;
1.52 +}
1.53 +
1.54 +static inline void
1.55 +NudgeToInteger(float *aVal)
1.56 +{
1.57 + float r = floorf(*aVal + 0.5f);
1.58 + // The error threshold should be proportional to the rounded value. This
1.59 + // bounds the relative error introduced by the nudge operation. However,
1.60 + // when the rounded value is 0, the error threshold can't be proportional
1.61 + // to the rounded value (we'd never round), so we just choose the same
1.62 + // threshold as for a rounded value of 1.
1.63 + if (FuzzyEqual(r, *aVal, r == 0.0f ? 1e-6f : fabs(r*1e-6f))) {
1.64 + *aVal = r;
1.65 + }
1.66 +}
1.67 +
1.68 +static inline Float
1.69 +Distance(Point aA, Point aB)
1.70 +{
1.71 + return hypotf(aB.x - aA.x, aB.y - aA.y);
1.72 +}
1.73 +
1.74 +static inline int
1.75 +BytesPerPixel(SurfaceFormat aFormat)
1.76 +{
1.77 + switch (aFormat) {
1.78 + case SurfaceFormat::A8:
1.79 + return 1;
1.80 + case SurfaceFormat::R5G6B5:
1.81 + return 2;
1.82 + default:
1.83 + return 4;
1.84 + }
1.85 +}
1.86 +
1.87 +template<typename T, int alignment = 16>
1.88 +struct AlignedArray
1.89 +{
1.90 + AlignedArray()
1.91 + : mStorage(nullptr)
1.92 + , mPtr(nullptr)
1.93 + {
1.94 + }
1.95 +
1.96 + MOZ_ALWAYS_INLINE AlignedArray(size_t aSize)
1.97 + : mStorage(nullptr)
1.98 + {
1.99 + Realloc(aSize);
1.100 + }
1.101 +
1.102 + MOZ_ALWAYS_INLINE ~AlignedArray()
1.103 + {
1.104 + delete [] mStorage;
1.105 + }
1.106 +
1.107 + void Dealloc()
1.108 + {
1.109 + delete [] mStorage;
1.110 + mStorage = mPtr = nullptr;
1.111 + }
1.112 +
1.113 + MOZ_ALWAYS_INLINE void Realloc(size_t aSize)
1.114 + {
1.115 + delete [] mStorage;
1.116 + mStorage = new (std::nothrow) T[aSize + (alignment - 1)];
1.117 + if (uintptr_t(mStorage) % alignment) {
1.118 + // Our storage does not start at a <alignment>-byte boundary. Make sure mData does!
1.119 + mPtr = (T*)(uintptr_t(mStorage) +
1.120 + (alignment - (uintptr_t(mStorage) % alignment)));
1.121 + } else {
1.122 + mPtr = mStorage;
1.123 + }
1.124 + }
1.125 +
1.126 + MOZ_ALWAYS_INLINE operator T*()
1.127 + {
1.128 + return mPtr;
1.129 + }
1.130 +
1.131 + T *mStorage;
1.132 + T *mPtr;
1.133 +};
1.134 +
1.135 +template<int alignment>
1.136 +int32_t GetAlignedStride(int32_t aStride)
1.137 +{
1.138 + if (aStride % alignment) {
1.139 + return aStride + (alignment - (aStride % alignment));
1.140 + }
1.141 +
1.142 + return aStride;
1.143 +}
1.144 +
1.145 +}
1.146 +}
1.147 +
1.148 +#endif /* MOZILLA_GFX_TOOLS_H_ */
