gecko-dev/layout/painting/MatrixStack.h
Miko Mynttinen ca9f5b45f8 Bug 1477693 - Part 1: Move TransformClipNode and TransformWithNode functions to TransformClipNode.h r=mattwoodrow
MozReview-Commit-ID: 13uSenWdNXJ

--HG--
extra : rebase_source : cd1c6cb203bba00ece5dcae833c0c38e1f1ef322
2018-07-25 21:58:22 +02:00

73 lines
1.5 KiB
C++

/* -*- 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 "nsTArray.h"
#include "mozilla/gfx/MatrixFwd.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 */