/* -*- 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 MOZ_UNIT_TRANSFORMS_H_ #define MOZ_UNIT_TRANSFORMS_H_ #include "Units.h" #include "mozilla/gfx/Matrix.h" #include "mozilla/Maybe.h" #include "nsRegion.h" namespace mozilla { // 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. enum class 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, // Similar to LayoutDeviceIsScreenForUntransformedEvent, PBrowser handles // some widget/tab dimension information as the OS does -- in screen units. LayoutDeviceIsScreenForTabDims, // 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 }; 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::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, aMargin.right, aMargin.bottom, aMargin.left); } 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); } // Unlike the other functions in this category, this function takes the // target matrix 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 TargetMatrix::FromUnknownMatrix(aMatrix.ToUnknownMatrix()); } // 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::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, this function takes the // target matrix 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 TypedMatrix> TypedMatrix ViewAs(const gfx::Matrix4x4& aMatrix) { return TypedMatrix::FromUnknownMatrix(aMatrix); } // Convenience functions for transforming an entity from one strongly-typed // coordinate system to another using the provided transformation matrix. template <typename TargetUnits, typename SourceUnits> static gfx::PointTyped<TargetUnits> TransformBy(const gfx::Matrix4x4Typed<SourceUnits, TargetUnits>& aTransform, const gfx::PointTyped<SourceUnits>& aPoint) { return aTransform.TransformPoint(aPoint); } template <typename TargetUnits, typename SourceUnits> static gfx::IntPointTyped<TargetUnits> TransformBy(const gfx::Matrix4x4Typed<SourceUnits, TargetUnits>& aTransform, const gfx::IntPointTyped<SourceUnits>& aPoint) { return RoundedToInt(TransformBy(aTransform, gfx::PointTyped<SourceUnits>(aPoint))); } template <typename TargetUnits, typename SourceUnits> static gfx::RectTyped<TargetUnits> TransformBy(const gfx::Matrix4x4Typed<SourceUnits, TargetUnits>& aTransform, const gfx::RectTyped<SourceUnits>& aRect) { return aTransform.TransformBounds(aRect); } template <typename TargetUnits, typename SourceUnits> static gfx::IntRectTyped<TargetUnits> TransformBy(const gfx::Matrix4x4Typed<SourceUnits, TargetUnits>& aTransform, const gfx::IntRectTyped<SourceUnits>& aRect) { return RoundedToInt(TransformBy(aTransform, gfx::RectTyped<SourceUnits>(aRect))); } template <typename TargetUnits, typename SourceUnits> static gfx::IntRegionTyped<TargetUnits> TransformBy(const gfx::Matrix4x4Typed<SourceUnits, TargetUnits>& aTransform, const gfx::IntRegionTyped<SourceUnits>& aRegion) { return ViewAs<TargetUnits>(aRegion.ToUnknownRegion().Transform( aTransform.ToUnknownMatrix())); } // 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)); } template <typename TargetUnits, typename SourceUnits> static Maybe<gfx::PointTyped<TargetUnits>> UntransformVector(const gfx::Matrix4x4Typed<SourceUnits, TargetUnits>& aTransform, const gfx::PointTyped<SourceUnits>& aVector, const gfx::PointTyped<SourceUnits>& aAnchor) { gfx::Point4DTyped<TargetUnits> projectedAnchor = aTransform.ProjectPoint(aAnchor); gfx::Point4DTyped<TargetUnits> projectedTarget = aTransform.ProjectPoint(aAnchor + aVector); if (!projectedAnchor.HasPositiveWCoord() || !projectedTarget.HasPositiveWCoord()){ return Nothing(); } return Some(projectedTarget.As2DPoint() - projectedAnchor.As2DPoint()); } } // namespace mozilla #endif