/* -*- 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/. */
// Convenience functions for converting an entity from one strongly-typed // coordinate system to another without changing the values it stores (this // can be thought of as a cast). // To use these functions, you must provide a justification for each use! // Feel free to add more justifications to PixelCastJustification, along with // a comment that explains under what circumstances it is appropriate to use.
enumclass PixelCastJustification : uint8_t { // For the root layer, Screen Pixel = Parent Layer Pixel.
ScreenIsParentLayerForRoot, // On the layout side, Screen Pixel = LayoutDevice at the outer-window level.
LayoutDeviceIsScreenForBounds, // For the root layer, Render Target Pixel = Parent Layer Pixel.
RenderTargetIsParentLayerForRoot, // For the root composition size we want to view it as layer pixels in any // layer
ParentLayerToLayerForRootComposition, // The Layer coordinate space for one layer is the ParentLayer coordinate // space for its children
MovingDownToChildren, // The transform that is usually used to convert between two coordinate // systems is not available (for example, because the object that stores it // is being destroyed), so fall back to the identity.
TransformNotAvailable, // When an OS event is initially constructed, its reference point is // technically in screen pixels, as it has not yet accounted for any // asynchronous transforms. This justification is for viewing the initial // reference point as a screen point. The reverse is useful when synthetically // created WidgetEvents need to be converted back to InputData.
LayoutDeviceIsScreenForUntransformedEvent, // A combination of LayoutDeviceIsScreenForBounds and // ScreenIsParentLayerForRoot, which is how we're using it.
LayoutDeviceIsParentLayerForRCDRSF, // Used to treat the product of AsyncTransformComponentMatrix objects // as an AsyncTransformMatrix. See the definitions of these matrices in // LayersTypes.h for details.
MultipleAsyncTransforms, // We have reason to believe a layer doesn't have a local transform. // Should only be used if we've already checked or asserted this.
NoTransformOnLayer, // LayerPixels are ImagePixels
LayerIsImage, // External pixels are the same scale as screen pixels
ExternalIsScreen, // LayerToScreenMatrix is used as LayoutDeviceToLayoutDevice, because // out-of-process iframes uses LayoutDevicePixels as the type system-visible // type of their top-level event coordinate space even if technically // inaccurate.
ContentProcessIsLayerInUiProcess, // Propagating TransformToAncestorScale to a child process.
PropagatingToChildProcess, // A quantity represents a proportion of a page length, e.g. "0.5 pages". // The proportion does not need to be scaled when converting between // units (the page length that it's mutlipled by will be scaled instead).
DeltaIsPageProportion, // Used to cast between CSS and OuterCSS pixels when moving between code // that deals with content outside a scroll frame generically (which would // use CSS pixels) and code related to the scroll frame in APZ (which wants // such quantities in OuterCSS pixels).
CSSPixelsOfSurroundingContent,
};
template <class TargetUnits, class SourceUnits>
gfx::CoordTyped<TargetUnits> ViewAs(const gfx::CoordTyped<SourceUnits>& aCoord,
PixelCastJustification) { return gfx::CoordTyped<TargetUnits>(aCoord.value);
} template <class TargetUnits, class SourceUnits>
gfx::IntCoordTyped<TargetUnits> ViewAs( const gfx::IntCoordTyped<SourceUnits>& aCoord, PixelCastJustification) { return gfx::IntCoordTyped<TargetUnits>(aCoord.value);
} template <class TargetUnits, class SourceUnits>
gfx::SizeTyped<TargetUnits> ViewAs(const gfx::SizeTyped<SourceUnits>& aSize,
PixelCastJustification) { return gfx::SizeTyped<TargetUnits>(aSize.width, aSize.height);
} template <class TargetUnits, class SourceUnits>
gfx::IntSizeTyped<TargetUnits> ViewAs( const gfx::IntSizeTyped<SourceUnits>& aSize, PixelCastJustification) { return gfx::IntSizeTyped<TargetUnits>(aSize.width, aSize.height);
} template <class TargetUnits, class SourceUnits>
gfx::PointTyped<TargetUnits> ViewAs(const gfx::PointTyped<SourceUnits>& aPoint,
PixelCastJustification) { return gfx::PointTyped<TargetUnits>(aPoint.x, aPoint.y);
} template <class TargetUnits, class SourceUnits>
gfx::IntPointTyped<TargetUnits> ViewAs( const gfx::IntPointTyped<SourceUnits>& aPoint, PixelCastJustification) { return gfx::IntPointTyped<TargetUnits>(aPoint.x, aPoint.y);
} template <class TargetUnits, class SourceUnits>
gfx::RectTyped<TargetUnits> ViewAs(const gfx::RectTyped<SourceUnits>& aRect,
PixelCastJustification) { return gfx::RectTyped<TargetUnits>(aRect.x, aRect.y, aRect.Width(),
aRect.Height());
} template <class TargetUnits, class SourceUnits>
gfx::IntRectTyped<TargetUnits> ViewAs( const gfx::IntRectTyped<SourceUnits>& aRect, PixelCastJustification) { return gfx::IntRectTyped<TargetUnits>(aRect.x, aRect.y, aRect.Width(),
aRect.Height());
} template <class TargetUnits, class SourceUnits>
gfx::MarginTyped<TargetUnits> ViewAs( const gfx::MarginTyped<SourceUnits>& aMargin, PixelCastJustification) { return gfx::MarginTyped<TargetUnits>(aMargin.top.value, aMargin.right.value,
aMargin.bottom.value,
aMargin.left.value);
} template <class TargetUnits, class SourceUnits>
gfx::IntMarginTyped<TargetUnits> ViewAs( const gfx::IntMarginTyped<SourceUnits>& aMargin, PixelCastJustification) { return gfx::IntMarginTyped<TargetUnits>(aMargin.top, aMargin.right,
aMargin.bottom, aMargin.left);
} template <class TargetUnits, class SourceUnits>
gfx::IntRegionTyped<TargetUnits> ViewAs( const gfx::IntRegionTyped<SourceUnits>& aRegion, PixelCastJustification) { return gfx::IntRegionTyped<TargetUnits>::FromUnknownRegion(
aRegion.ToUnknownRegion());
} template <class NewTargetUnits, class OldTargetUnits, class SourceUnits>
gfx::ScaleFactor<SourceUnits, NewTargetUnits> ViewTargetAs( const gfx::ScaleFactor<SourceUnits, OldTargetUnits>& aScaleFactor,
PixelCastJustification) { return gfx::ScaleFactor<SourceUnits, NewTargetUnits>(aScaleFactor.scale);
} template <class NewTargetUnits, class OldTargetUnits, class SourceUnits>
gfx::ScaleFactors2D<SourceUnits, NewTargetUnits> ViewTargetAs( const gfx::ScaleFactors2D<SourceUnits, OldTargetUnits>& aScaleFactors,
PixelCastJustification) { return gfx::ScaleFactors2D<SourceUnits, NewTargetUnits>(aScaleFactors.xScale,
aScaleFactors.yScale);
} template <class TargetUnits, class SourceUnits>
Maybe<gfx::IntRectTyped<TargetUnits>> ViewAs( const Maybe<gfx::IntRectTyped<SourceUnits>>& aRect,
PixelCastJustification aJustification) { if (aRect.isSome()) { return Some(ViewAs<TargetUnits>(aRect.value(), aJustification));
} return Nothing();
} // Unlike the other functions in this category, these functions take the // target matrix or scale type, rather than its source and target unit types, as // the explicit template argument, so an example invocation is: // ViewAs<ScreenToLayerMatrix4x4>(otherTypedMatrix, justification) // The reason is that if it took the source and target unit types as two // template arguments, there may be some confusion as to which is the // source and which is the target. template <class TargetMatrix, class SourceMatrixSourceUnits, class SourceMatrixTargetUnits>
TargetMatrix ViewAs(const gfx::Matrix4x4Typed<SourceMatrixSourceUnits,
SourceMatrixTargetUnits>& aMatrix,
PixelCastJustification) { return aMatrix.template Cast<TargetMatrix>();
} template <class TargetMatrix, class SourceMatrixSourceUnits, class SourceMatrixTargetUnits>
Maybe<TargetMatrix> ViewAs( const Maybe<gfx::Matrix4x4Typed<SourceMatrixSourceUnits,
SourceMatrixTargetUnits>>& aMatrix,
PixelCastJustification) { if (aMatrix.isSome()) { return Some(aMatrix->template Cast<TargetMatrix>());
} return Nothing();
} template <class TargetScale, class SourceScaleSourceUnits, class SourceScaleTargetUnits>
TargetScale ViewAs(const gfx::ScaleFactor<SourceScaleSourceUnits,
SourceScaleTargetUnits>& aScale,
PixelCastJustification) { return TargetScale{aScale.scale};
}
// A non-member overload of ToUnknownMatrix() for use on a Maybe<Matrix>. // We can't make this a member because we can't inject a member into Maybe. template <typename SourceUnits, typename TargetUnits>
Maybe<gfx::Matrix4x4> ToUnknownMatrix( const Maybe<gfx::Matrix4x4Typed<SourceUnits, TargetUnits>>& aMatrix) { if (aMatrix.isSome()) { return Some(aMatrix->ToUnknownMatrix());
} return Nothing();
}
// Convenience functions for casting untyped entities to typed entities. // Using these functions does not require a justification, but once we convert // all code to use strongly typed units they should not be needed any longer. template <class TargetUnits>
gfx::CoordTyped<TargetUnits> ViewAs(const gfx::Coord& aCoord) { return gfx::CoordTyped<TargetUnits>(aCoord.value);
} template <class TargetUnits>
gfx::PointTyped<TargetUnits> ViewAs(const gfxPoint& aPoint) { return gfx::PointTyped<TargetUnits>(aPoint.x, aPoint.y);
} template <class TargetUnits>
gfx::PointTyped<TargetUnits> ViewAs(const gfx::Point& aPoint) { return gfx::PointTyped<TargetUnits>(aPoint.x, aPoint.y);
} template <class TargetUnits>
gfx::RectTyped<TargetUnits> ViewAs(const gfx::Rect& aRect) { return gfx::RectTyped<TargetUnits>(aRect.x, aRect.y, aRect.Width(),
aRect.Height());
} template <class TargetUnits>
gfx::IntSizeTyped<TargetUnits> ViewAs(const nsIntSize& aSize) { return gfx::IntSizeTyped<TargetUnits>(aSize.width, aSize.height);
} template <class TargetUnits>
gfx::IntPointTyped<TargetUnits> ViewAs(const nsIntPoint& aPoint) { return gfx::IntPointTyped<TargetUnits>(aPoint.x, aPoint.y);
} template <class TargetUnits>
gfx::IntRectTyped<TargetUnits> ViewAs(const nsIntRect& aRect) { return gfx::IntRectTyped<TargetUnits>(aRect.x, aRect.y, aRect.Width(),
aRect.Height());
} template <class TargetUnits>
gfx::IntRegionTyped<TargetUnits> ViewAs(const nsIntRegion& aRegion) { return gfx::IntRegionTyped<TargetUnits>::FromUnknownRegion(aRegion);
} // Unlike the other functions in this category, these functions take the // target matrix or scale type, rather than its source and target unit // types, as the template argument, so an example invocation is: // ViewAs<ScreenToLayerMatrix4x4>(untypedMatrix) // The reason is that if it took the source and target unit types as two // template arguments, there may be some confusion as to which is the // source and which is the target. template <class TypedScale>
TypedScale ViewAs(const Scale2D& aScale) { return TypedScale(aScale.xScale, aScale.yScale);
} template <class TypedMatrix>
TypedMatrix ViewAs(const gfx::Matrix4x4& aMatrix) { return TypedMatrix::FromUnknownMatrix(aMatrix);
}
// Transform |aVector|, which is anchored at |aAnchor|, by the given transform // matrix, yielding a point in |TargetUnits|. // The anchor is necessary because with 3D tranforms, the location of the // vector can affect the result of the transform. template <typename TargetUnits, typename SourceUnits> static gfx::PointTyped<TargetUnits> TransformVector( const gfx::Matrix4x4Typed<SourceUnits, TargetUnits>& aTransform, const gfx::PointTyped<SourceUnits>& aVector, const gfx::PointTyped<SourceUnits>& aAnchor) {
gfx::PointTyped<TargetUnits> transformedStart =
TransformBy(aTransform, aAnchor);
gfx::PointTyped<TargetUnits> transformedEnd =
TransformBy(aTransform, aAnchor + aVector); return transformedEnd - transformedStart;
}
// UntransformBy() and UntransformVector() are like TransformBy() and // TransformVector(), respectively, but are intended for cases where // the transformation matrix is the inverse of a 3D projection. When // using such transforms, the resulting Point4D is only meaningful // if it has a positive w-coordinate. To handle this, these functions // return a Maybe object which contains a value if and only if the // result is meaningful template <typename TargetUnits, typename SourceUnits> static Maybe<gfx::PointTyped<TargetUnits>> UntransformBy( const gfx::Matrix4x4Typed<SourceUnits, TargetUnits>& aTransform, const gfx::PointTyped<SourceUnits>& aPoint) {
gfx::Point4DTyped<TargetUnits> point = aTransform.ProjectPoint(aPoint); if (!point.HasPositiveWCoord()) { return Nothing();
} return Some(point.As2DPoint());
} template <typename TargetUnits, typename SourceUnits> static Maybe<gfx::IntPointTyped<TargetUnits>> UntransformBy( const gfx::Matrix4x4Typed<SourceUnits, TargetUnits>& aTransform, const gfx::IntPointTyped<SourceUnits>& aPoint) {
gfx::PointTyped<SourceUnits> p = aPoint;
gfx::Point4DTyped<TargetUnits> point = aTransform.ProjectPoint(p); if (!point.HasPositiveWCoord()) { return Nothing();
} return Some(RoundedToInt(point.As2DPoint()));
}
// The versions of UntransformBy() that take a rectangle also take a clip, // which represents the bounds within which the target must fall. The // result of the transform is intersected with this clip, and is considered // meaningful if the intersection is not empty. template <typename TargetUnits, typename SourceUnits> static Maybe<gfx::RectTyped<TargetUnits>> UntransformBy( const gfx::Matrix4x4Typed<SourceUnits, TargetUnits>& aTransform, const gfx::RectTyped<SourceUnits>& aRect, const gfx::RectTyped<TargetUnits>& aClip) {
gfx::RectTyped<TargetUnits> rect = aTransform.ProjectRectBounds(aRect, aClip); if (rect.IsEmpty()) { return Nothing();
} return Some(rect);
} template <typename TargetUnits, typename SourceUnits> static Maybe<gfx::IntRectTyped<TargetUnits>> UntransformBy( const gfx::Matrix4x4Typed<SourceUnits, TargetUnits>& aTransform, const gfx::IntRectTyped<SourceUnits>& aRect, const gfx::IntRectTyped<TargetUnits>& aClip) {
gfx::RectTyped<TargetUnits> rect = aTransform.ProjectRectBounds(aRect, aClip); if (rect.IsEmpty()) { return Nothing();
} return Some(RoundedToInt(rect));
}
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