1 /* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */ 2 /* vim: set ts=8 sts=2 et sw=2 tw=80: */ 3 /* This Source Code Form is subject to the terms of the Mozilla Public 4 * License, v. 2.0. If a copy of the MPL was not distributed with this 5 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */ 6 7 #ifndef _MOZILLA_GFX_PATTERNHELPERS_H 8 #define _MOZILLA_GFX_PATTERNHELPERS_H 9 10 #include "mozilla/Alignment.h" 11 #include "mozilla/gfx/2D.h" 12 13 namespace mozilla { 14 namespace gfx { 15 16 /** 17 * This class is used to allow general pattern creation functions to return 18 * any type of pattern via an out-paramater without allocating a pattern 19 * instance on the free-store (an instance of this class being created on the 20 * stack before passing it in to the creation function). Without this class 21 * writing pattern creation functions would be a pain since Pattern objects are 22 * not reference counted, making lifetime management of instances created on 23 * the free-store and returned from a creation function hazardous. Besides 24 * that, in the case that ColorPattern's are expected to be common, it is 25 * particularly desirable to avoid the overhead of allocating on the 26 * free-store. 27 */ 28 class GeneralPattern final { 29 public: 30 explicit GeneralPattern() = default; 31 GeneralPattern(const GeneralPattern & aOther)32 GeneralPattern(const GeneralPattern& aOther) {} 33 ~GeneralPattern()34 ~GeneralPattern() { 35 if (mPattern) { 36 mPattern->~Pattern(); 37 } 38 } 39 Init(const Pattern & aPattern)40 Pattern* Init(const Pattern& aPattern) { 41 MOZ_ASSERT(!mPattern); 42 switch (aPattern.GetType()) { 43 case PatternType::COLOR: 44 mPattern = new (mColorPattern.addr()) 45 ColorPattern(static_cast<const ColorPattern&>(aPattern)); 46 break; 47 case PatternType::LINEAR_GRADIENT: 48 mPattern = new (mLinearGradientPattern.addr()) LinearGradientPattern( 49 static_cast<const LinearGradientPattern&>(aPattern)); 50 break; 51 case PatternType::RADIAL_GRADIENT: 52 mPattern = new (mRadialGradientPattern.addr()) RadialGradientPattern( 53 static_cast<const RadialGradientPattern&>(aPattern)); 54 break; 55 case PatternType::CONIC_GRADIENT: 56 mPattern = new (mConicGradientPattern.addr()) ConicGradientPattern( 57 static_cast<const ConicGradientPattern&>(aPattern)); 58 break; 59 case PatternType::SURFACE: 60 mPattern = new (mSurfacePattern.addr()) 61 SurfacePattern(static_cast<const SurfacePattern&>(aPattern)); 62 break; 63 default: 64 MOZ_MAKE_COMPILER_ASSUME_IS_UNREACHABLE("Unknown pattern type"); 65 } 66 return mPattern; 67 } 68 InitColorPattern(const DeviceColor & aColor)69 ColorPattern* InitColorPattern(const DeviceColor& aColor) { 70 MOZ_ASSERT(!mPattern); 71 mPattern = new (mColorPattern.addr()) ColorPattern(aColor); 72 return mColorPattern.addr(); 73 } 74 75 LinearGradientPattern* InitLinearGradientPattern( 76 const Point& aBegin, const Point& aEnd, 77 already_AddRefed<GradientStops> aStops, 78 const Matrix& aMatrix = Matrix()) { 79 MOZ_ASSERT(!mPattern); 80 mPattern = new (mLinearGradientPattern.addr()) 81 LinearGradientPattern(aBegin, aEnd, std::move(aStops), aMatrix); 82 return mLinearGradientPattern.addr(); 83 } 84 85 RadialGradientPattern* InitRadialGradientPattern( 86 const Point& aCenter1, const Point& aCenter2, Float aRadius1, 87 Float aRadius2, already_AddRefed<GradientStops> aStops, 88 const Matrix& aMatrix = Matrix()) { 89 MOZ_ASSERT(!mPattern); 90 mPattern = new (mRadialGradientPattern.addr()) RadialGradientPattern( 91 aCenter1, aCenter2, aRadius1, aRadius2, std::move(aStops), aMatrix); 92 return mRadialGradientPattern.addr(); 93 } 94 95 ConicGradientPattern* InitConicGradientPattern( 96 const Point& aCenter, Float aAngle, Float aStartOffset, Float aEndOffset, 97 already_AddRefed<GradientStops> aStops, 98 const Matrix& aMatrix = Matrix()) { 99 MOZ_ASSERT(!mPattern); 100 mPattern = new (mConicGradientPattern.addr()) ConicGradientPattern( 101 aCenter, aAngle, aStartOffset, aEndOffset, std::move(aStops), aMatrix); 102 return mConicGradientPattern.addr(); 103 } 104 105 SurfacePattern* InitSurfacePattern( 106 SourceSurface* aSourceSurface, ExtendMode aExtendMode, 107 const Matrix& aMatrix = Matrix(), 108 SamplingFilter aSamplingFilter = SamplingFilter::GOOD, 109 const IntRect& aSamplingRect = IntRect()) { 110 MOZ_ASSERT(!mPattern); 111 mPattern = new (mSurfacePattern.addr()) SurfacePattern( 112 aSourceSurface, aExtendMode, aMatrix, aSamplingFilter, aSamplingRect); 113 return mSurfacePattern.addr(); 114 } 115 GetPattern()116 Pattern* GetPattern() { return mPattern; } 117 GetPattern()118 const Pattern* GetPattern() const { return mPattern; } 119 120 operator Pattern&() { 121 if (!mPattern) { 122 MOZ_CRASH("GFX: GeneralPattern not initialized"); 123 } 124 return *mPattern; 125 } 126 127 private: 128 union { 129 AlignedStorage2<ColorPattern> mColorPattern; 130 AlignedStorage2<LinearGradientPattern> mLinearGradientPattern; 131 AlignedStorage2<RadialGradientPattern> mRadialGradientPattern; 132 AlignedStorage2<ConicGradientPattern> mConicGradientPattern; 133 AlignedStorage2<SurfacePattern> mSurfacePattern; 134 }; 135 Pattern* mPattern = nullptr; 136 }; 137 138 } // namespace gfx 139 } // namespace mozilla 140 141 #endif // _MOZILLA_GFX_PATTERNHELPERS_H 142