michael@0: /* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
michael@0: /* vim: set ts=8 sts=2 et sw=2 tw=80: */
michael@0: /* This Source Code Form is subject to the terms of the Mozilla Public
michael@0:  * License, v. 2.0. If a copy of the MPL was not distributed with this
michael@0:  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
michael@0: 
michael@0: #ifndef MOZ_UNIT_TRANSFORMS_H_
michael@0: #define MOZ_UNIT_TRANSFORMS_H_
michael@0: 
michael@0: #include "Units.h"
michael@0: 
michael@0: namespace mozilla {
michael@0: 
michael@0: // Convenience functions for converting an entity from one strongly-typed
michael@0: // coordinate system to another without changing the values it stores (this
michael@0: // can be thought of as a cast).
michael@0: // To use these functions, you must provide a justification for each use!
michael@0: // Feel free to add more justifications to PixelCastJustification, along with
michael@0: // a comment that explains under what circumstances it is appropriate to use.
michael@0: 
michael@0: MOZ_BEGIN_ENUM_CLASS(PixelCastJustification, uint8_t)
michael@0:   // For the root layer, Screen Pixel = Parent Layer Pixel.
michael@0:   ScreenToParentLayerForRoot,
michael@0:   // For the root composition size we want to view it as layer pixels in any layer
michael@0:   ParentLayerToLayerForRootComposition
michael@0: MOZ_END_ENUM_CLASS(PixelCastJustification)
michael@0: 
michael@0: template <class TargetUnits, class SourceUnits>
michael@0: gfx::SizeTyped<TargetUnits> ViewAs(const gfx::SizeTyped<SourceUnits>& aSize, PixelCastJustification) {
michael@0:   return gfx::SizeTyped<TargetUnits>(aSize.width, aSize.height);
michael@0: }
michael@0: template <class TargetUnits, class SourceUnits>
michael@0: gfx::IntSizeTyped<TargetUnits> ViewAs(const gfx::IntSizeTyped<SourceUnits>& aSize, PixelCastJustification) {
michael@0:   return gfx::IntSizeTyped<TargetUnits>(aSize.width, aSize.height);
michael@0: }
michael@0: 
michael@0: // Convenience functions for casting untyped entities to typed entities.
michael@0: // Using these functions does not require a justification, but once we convert
michael@0: // all code to use strongly typed units they should not be needed any longer.
michael@0: template <class TargetUnits>
michael@0: gfx::PointTyped<TargetUnits> ViewAs(const gfxPoint& aPoint) {
michael@0:   return gfx::PointTyped<TargetUnits>(aPoint.x, aPoint.y);
michael@0: }
michael@0: template <class TargetUnits>
michael@0: gfx::RectTyped<TargetUnits> ViewAs(const gfxRect& aRect) {
michael@0:   return gfx::RectTyped<TargetUnits>(aRect.x, aRect.y, aRect.width, aRect.height);
michael@0: }
michael@0: template <class TargetUnits>
michael@0: gfx::IntSizeTyped<TargetUnits> ViewAs(const nsIntSize& aSize) {
michael@0:   return gfx::IntSizeTyped<TargetUnits>(aSize.width, aSize.height);
michael@0: }
michael@0: template <class TargetUnits>
michael@0: gfx::IntPointTyped<TargetUnits> ViewAs(const nsIntPoint& aPoint) {
michael@0:   return gfx::IntPointTyped<TargetUnits>(aPoint.x, aPoint.y);
michael@0: }
michael@0: template <class TargetUnits>
michael@0: gfx::IntRectTyped<TargetUnits> ViewAs(const nsIntRect& aRect) {
michael@0:   return gfx::IntRectTyped<TargetUnits>(aRect.x, aRect.y, aRect.width, aRect.height);
michael@0: }
michael@0: 
michael@0: // Convenience functions for casting typed entities to untyped entities.
michael@0: // Using these functions does not require a justification, but once we convert
michael@0: // all code to use strongly typed units they should not be needed any longer.
michael@0: template <class SourceUnits>
michael@0: gfxPoint ViewAsUntyped(const gfx::PointTyped<SourceUnits>& aPoint) {
michael@0:   return gfxPoint(aPoint.x, aPoint.y);
michael@0: }
michael@0: template <class SourceUnits>
michael@0: gfxRect ViewAsUntyped(const gfx::RectTyped<SourceUnits>& aRect) {
michael@0:   return gfxRect(aRect.x, aRect.y, aRect.width, aRect.height);
michael@0: }
michael@0: 
michael@0: // Convenience functions for transforming an entity from one strongly-typed
michael@0: // coordinate system to another using the provided transformation matrix.
michael@0: template <typename TargetUnits, typename SourceUnits>
michael@0: static gfx::PointTyped<TargetUnits> TransformTo(const gfx3DMatrix& aTransform,
michael@0:                                                 const gfx::PointTyped<SourceUnits>& aPoint)
michael@0: {
michael@0:   return ViewAs<TargetUnits>(aTransform.Transform(ViewAsUntyped(aPoint)));
michael@0: }
michael@0: template <typename TargetUnits, typename SourceUnits>
michael@0: static gfx::RectTyped<TargetUnits> TransformTo(const gfx3DMatrix& aTransform,
michael@0:                                                const gfx::RectTyped<SourceUnits>& aRect)
michael@0: {
michael@0:   return ViewAs<TargetUnits>(aTransform.TransformBounds(ViewAsUntyped(aRect)));
michael@0: }
michael@0: 
michael@0: 
michael@0: }
michael@0: 
michael@0: #endif