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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
* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
#ifndef MOZILLA_PAINTING_MATRIXSTACK_H
#define MOZILLA_PAINTING_MATRIXSTACK_H
#include "mozilla/gfx/MatrixFwd.h"
#include "nsTArray.h"
namespace mozilla {
/**
* MatrixStack stores a stack of matrices and keeps track of the accumulated
* transform matrix.
*/
template <typename T>
class MatrixStack {
public:
MatrixStack() = default;
~MatrixStack() { MOZ_ASSERT(mMatrices.IsEmpty()); }
/**
* Returns the current accumulated transform matrix.
*/
const T& CurrentMatrix() const { return mCurrentMatrix; }
/**
* Returns true if any matrices are currently pushed to the stack.
*/
bool HasTransform() const { return mMatrices.Length() > 0; }
/**
* Pushes the given |aMatrix| to the stack.
*/
void Push(const T& aMatrix) {
mMatrices.AppendElement(mCurrentMatrix);
mCurrentMatrix = aMatrix * mCurrentMatrix;
}
/**
* Pops the most recently added matrix from the stack.
*/
void Pop() {
MOZ_ASSERT(mMatrices.Length() > 0);
mCurrentMatrix = mMatrices.PopLastElement();
}
private:
T mCurrentMatrix;
AutoTArray<T, 2> mMatrices;
};
typedef MatrixStack<gfx::Matrix4x4Flagged> MatrixStack4x4;
} // namespace mozilla
#endif /* MOZILLA_PAINTING_MATRIXSTACK_H */
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