1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/layout/base/UnitTransforms.h Wed Dec 31 06:09:35 2014 +0100
1.3 @@ -0,0 +1,91 @@
1.4 +/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
1.5 +/* vim: set ts=8 sts=2 et sw=2 tw=80: */
1.6 +/* This Source Code Form is subject to the terms of the Mozilla Public
1.7 + * License, v. 2.0. If a copy of the MPL was not distributed with this
1.8 + * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
1.9 +
1.10 +#ifndef MOZ_UNIT_TRANSFORMS_H_
1.11 +#define MOZ_UNIT_TRANSFORMS_H_
1.12 +
1.13 +#include "Units.h"
1.14 +
1.15 +namespace mozilla {
1.16 +
1.17 +// Convenience functions for converting an entity from one strongly-typed
1.18 +// coordinate system to another without changing the values it stores (this
1.19 +// can be thought of as a cast).
1.20 +// To use these functions, you must provide a justification for each use!
1.21 +// Feel free to add more justifications to PixelCastJustification, along with
1.22 +// a comment that explains under what circumstances it is appropriate to use.
1.23 +
1.24 +MOZ_BEGIN_ENUM_CLASS(PixelCastJustification, uint8_t)
1.25 + // For the root layer, Screen Pixel = Parent Layer Pixel.
1.26 + ScreenToParentLayerForRoot,
1.27 + // For the root composition size we want to view it as layer pixels in any layer
1.28 + ParentLayerToLayerForRootComposition
1.29 +MOZ_END_ENUM_CLASS(PixelCastJustification)
1.30 +
1.31 +template <class TargetUnits, class SourceUnits>
1.32 +gfx::SizeTyped<TargetUnits> ViewAs(const gfx::SizeTyped<SourceUnits>& aSize, PixelCastJustification) {
1.33 + return gfx::SizeTyped<TargetUnits>(aSize.width, aSize.height);
1.34 +}
1.35 +template <class TargetUnits, class SourceUnits>
1.36 +gfx::IntSizeTyped<TargetUnits> ViewAs(const gfx::IntSizeTyped<SourceUnits>& aSize, PixelCastJustification) {
1.37 + return gfx::IntSizeTyped<TargetUnits>(aSize.width, aSize.height);
1.38 +}
1.39 +
1.40 +// Convenience functions for casting untyped entities to typed entities.
1.41 +// Using these functions does not require a justification, but once we convert
1.42 +// all code to use strongly typed units they should not be needed any longer.
1.43 +template <class TargetUnits>
1.44 +gfx::PointTyped<TargetUnits> ViewAs(const gfxPoint& aPoint) {
1.45 + return gfx::PointTyped<TargetUnits>(aPoint.x, aPoint.y);
1.46 +}
1.47 +template <class TargetUnits>
1.48 +gfx::RectTyped<TargetUnits> ViewAs(const gfxRect& aRect) {
1.49 + return gfx::RectTyped<TargetUnits>(aRect.x, aRect.y, aRect.width, aRect.height);
1.50 +}
1.51 +template <class TargetUnits>
1.52 +gfx::IntSizeTyped<TargetUnits> ViewAs(const nsIntSize& aSize) {
1.53 + return gfx::IntSizeTyped<TargetUnits>(aSize.width, aSize.height);
1.54 +}
1.55 +template <class TargetUnits>
1.56 +gfx::IntPointTyped<TargetUnits> ViewAs(const nsIntPoint& aPoint) {
1.57 + return gfx::IntPointTyped<TargetUnits>(aPoint.x, aPoint.y);
1.58 +}
1.59 +template <class TargetUnits>
1.60 +gfx::IntRectTyped<TargetUnits> ViewAs(const nsIntRect& aRect) {
1.61 + return gfx::IntRectTyped<TargetUnits>(aRect.x, aRect.y, aRect.width, aRect.height);
1.62 +}
1.63 +
1.64 +// Convenience functions for casting typed entities to untyped entities.
1.65 +// Using these functions does not require a justification, but once we convert
1.66 +// all code to use strongly typed units they should not be needed any longer.
1.67 +template <class SourceUnits>
1.68 +gfxPoint ViewAsUntyped(const gfx::PointTyped<SourceUnits>& aPoint) {
1.69 + return gfxPoint(aPoint.x, aPoint.y);
1.70 +}
1.71 +template <class SourceUnits>
1.72 +gfxRect ViewAsUntyped(const gfx::RectTyped<SourceUnits>& aRect) {
1.73 + return gfxRect(aRect.x, aRect.y, aRect.width, aRect.height);
1.74 +}
1.75 +
1.76 +// Convenience functions for transforming an entity from one strongly-typed
1.77 +// coordinate system to another using the provided transformation matrix.
1.78 +template <typename TargetUnits, typename SourceUnits>
1.79 +static gfx::PointTyped<TargetUnits> TransformTo(const gfx3DMatrix& aTransform,
1.80 + const gfx::PointTyped<SourceUnits>& aPoint)
1.81 +{
1.82 + return ViewAs<TargetUnits>(aTransform.Transform(ViewAsUntyped(aPoint)));
1.83 +}
1.84 +template <typename TargetUnits, typename SourceUnits>
1.85 +static gfx::RectTyped<TargetUnits> TransformTo(const gfx3DMatrix& aTransform,
1.86 + const gfx::RectTyped<SourceUnits>& aRect)
1.87 +{
1.88 + return ViewAs<TargetUnits>(aTransform.TransformBounds(ViewAsUntyped(aRect)));
1.89 +}
1.90 +
1.91 +
1.92 +}
1.93 +
1.94 +#endif
