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/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* vim: set ts=8 sts=2 et sw=2 tw=80: */
/* 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
#ifndef _MOZILLA_GFX_PATTERNHELPERS_H
#define _MOZILLA_GFX_PATTERNHELPERS_H
#include "mozilla/Alignment.h"
#include "mozilla/gfx/2D.h"
namespace mozilla {
namespace gfx {
/**
* This class is used to allow general pattern creation functions to return
* any type of pattern via an out-paramater without allocating a pattern
* instance on the free-store (an instance of this class being created on the
* stack before passing it in to the creation function). Without this class
* writing pattern creation functions would be a pain since Pattern objects are
* not reference counted, making lifetime management of instances created on
* the free-store and returned from a creation function hazardous. Besides
* that, in the case that ColorPattern's are expected to be common, it is
* particularly desirable to avoid the overhead of allocating on the
* free-store.
*/
class GeneralPattern final {
public:
explicit GeneralPattern() = default;
GeneralPattern(const GeneralPattern& aOther) {}
~GeneralPattern() {
if (mPattern) {
mPattern->~Pattern();
}
}
Pattern* Init(const Pattern& aPattern) {
MOZ_ASSERT(!mPattern);
switch (aPattern.GetType()) {
case PatternType::COLOR:
mPattern = new (mColorPattern.addr())
ColorPattern(static_cast<const ColorPattern&>(aPattern));
break;
case PatternType::LINEAR_GRADIENT:
mPattern = new (mLinearGradientPattern.addr()) LinearGradientPattern(
static_cast<const LinearGradientPattern&>(aPattern));
break;
case PatternType::RADIAL_GRADIENT:
mPattern = new (mRadialGradientPattern.addr()) RadialGradientPattern(
static_cast<const RadialGradientPattern&>(aPattern));
break;
case PatternType::CONIC_GRADIENT:
mPattern = new (mConicGradientPattern.addr()) ConicGradientPattern(
static_cast<const ConicGradientPattern&>(aPattern));
break;
case PatternType::SURFACE:
mPattern = new (mSurfacePattern.addr())
SurfacePattern(static_cast<const SurfacePattern&>(aPattern));
break;
default:
MOZ_MAKE_COMPILER_ASSUME_IS_UNREACHABLE("Unknown pattern type");
}
return mPattern;
}
ColorPattern* InitColorPattern(const DeviceColor& aColor) {
MOZ_ASSERT(!mPattern);
mPattern = new (mColorPattern.addr()) ColorPattern(aColor);
return mColorPattern.addr();
}
LinearGradientPattern* InitLinearGradientPattern(
const Point& aBegin, const Point& aEnd,
already_AddRefed<GradientStops> aStops,
const Matrix& aMatrix = Matrix()) {
MOZ_ASSERT(!mPattern);
mPattern = new (mLinearGradientPattern.addr())
LinearGradientPattern(aBegin, aEnd, std::move(aStops), aMatrix);
return mLinearGradientPattern.addr();
}
RadialGradientPattern* InitRadialGradientPattern(
const Point& aCenter1, const Point& aCenter2, Float aRadius1,
Float aRadius2, already_AddRefed<GradientStops> aStops,
const Matrix& aMatrix = Matrix()) {
MOZ_ASSERT(!mPattern);
mPattern = new (mRadialGradientPattern.addr()) RadialGradientPattern(
aCenter1, aCenter2, aRadius1, aRadius2, std::move(aStops), aMatrix);
return mRadialGradientPattern.addr();
}
ConicGradientPattern* InitConicGradientPattern(
const Point& aCenter, Float aAngle, Float aStartOffset, Float aEndOffset,
already_AddRefed<GradientStops> aStops,
const Matrix& aMatrix = Matrix()) {
MOZ_ASSERT(!mPattern);
mPattern = new (mConicGradientPattern.addr()) ConicGradientPattern(
aCenter, aAngle, aStartOffset, aEndOffset, std::move(aStops), aMatrix);
return mConicGradientPattern.addr();
}
SurfacePattern* InitSurfacePattern(
SourceSurface* aSourceSurface, ExtendMode aExtendMode,
const Matrix& aMatrix = Matrix(),
SamplingFilter aSamplingFilter = SamplingFilter::GOOD,
const IntRect& aSamplingRect = IntRect()) {
MOZ_ASSERT(!mPattern);
mPattern = new (mSurfacePattern.addr()) SurfacePattern(
aSourceSurface, aExtendMode, aMatrix, aSamplingFilter, aSamplingRect);
return mSurfacePattern.addr();
}
Pattern* GetPattern() { return mPattern; }
const Pattern* GetPattern() const { return mPattern; }
operator Pattern&() {
if (!mPattern) {
MOZ_CRASH("GFX: GeneralPattern not initialized");
}
return *mPattern;
}
private:
union {
AlignedStorage2<ColorPattern> mColorPattern;
AlignedStorage2<LinearGradientPattern> mLinearGradientPattern;
AlignedStorage2<RadialGradientPattern> mRadialGradientPattern;
AlignedStorage2<ConicGradientPattern> mConicGradientPattern;
AlignedStorage2<SurfacePattern> mSurfacePattern;
};
Pattern* mPattern = nullptr;
};
} // namespace gfx
} // namespace mozilla
#endif // _MOZILLA_GFX_PATTERNHELPERS_H