image/OrientedImage.h

   1 /* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
   2 /* This Source Code Form is subject to the terms of the Mozilla Public
   3  * License, v. 2.0. If a copy of the MPL was not distributed with this
   4  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
   5
   6 #ifndef mozilla_image_OrientedImage_h
   7 #define mozilla_image_OrientedImage_h
   8
   9 #include "ImageWrapper.h"
  10 #include "mozilla/gfx/2D.h"
  11 #include "mozilla/RefPtr.h"
  12 #include "Orientation.h"
  13
  14 namespace mozilla {
  15 namespace image {
  16
  17 /**
  18  * An Image wrapper that rotates and/or flips an image according to a specified
  19  * Orientation.
  20  *
  21  * XXX(seth): There a known (performance, not correctness) issue with
  22  * GetImageContainer. See the comments for that method for more information.
  23  */
  24 class OrientedImage : public ImageWrapper {
  25   typedef gfx::SourceSurface SourceSurface;
  26
  27  public:
  28   NS_INLINE_DECL_REFCOUNTING_INHERITED(OrientedImage, ImageWrapper)
  29
  30   NS_IMETHOD GetWidth(int32_t* aWidth) override;
  31   NS_IMETHOD GetHeight(int32_t* aHeight) override;
  32   nsresult GetNativeSizes(nsTArray<gfx::IntSize>& aNativeSizes) const override;
  33   NS_IMETHOD GetIntrinsicSize(nsSize* aSize) override;
  34   Maybe<AspectRatio> GetIntrinsicRatio() override;
  35   NS_IMETHOD_(already_AddRefed<SourceSurface>)
  36   GetFrame(uint32_t aWhichFrame, uint32_t aFlags) override;
  37   NS_IMETHOD_(already_AddRefed<SourceSurface>)
  38   GetFrameAtSize(const gfx::IntSize& aSize, uint32_t aWhichFrame,
  39                  uint32_t aFlags) override;
  40   NS_IMETHOD_(bool)
  41   IsImageContainerAvailable(layers::LayerManager* aManager,
  42                             uint32_t aFlags) override;
  43   NS_IMETHOD_(already_AddRefed<layers::ImageContainer>)
  44   GetImageContainer(layers::LayerManager* aManager, uint32_t aFlags) override;
  45   NS_IMETHOD_(bool)
  46   IsImageContainerAvailableAtSize(layers::LayerManager* aManager,
  47                                   const gfx::IntSize& aSize,
  48                                   uint32_t aFlags) override;
  49   NS_IMETHOD_(ImgDrawResult)
  50   GetImageContainerAtSize(layers::LayerManager* aManager,
  51                           const gfx::IntSize& aSize,
  52                           const Maybe<SVGImageContext>& aSVGContext,
  53                           uint32_t aFlags,
  54                           layers::ImageContainer** aOutContainer) override;
  55   NS_IMETHOD_(ImgDrawResult)
  56   Draw(gfxContext* aContext, const nsIntSize& aSize, const ImageRegion& aRegion,
  57        uint32_t aWhichFrame, gfx::SamplingFilter aSamplingFilter,
  58        const Maybe<SVGImageContext>& aSVGContext, uint32_t aFlags,
  59        float aOpacity) override;
  60   NS_IMETHOD_(nsIntRect)
  61   GetImageSpaceInvalidationRect(const nsIntRect& aRect) override;
  62   nsIntSize OptimalImageSizeForDest(const gfxSize& aDest, uint32_t aWhichFrame,
  63                                     gfx::SamplingFilter aSamplingFilter,
  64                                     uint32_t aFlags) override;
  65
  66   /**
  67    * Computes a matrix that applies the rotation and reflection specified by
  68    * aOrientation, or that matrix's inverse if aInvert is true.
  69    *
  70    * @param aSize The scaled size of the inner image. (When outside code
  71    * specifies the scaled size, as with imgIContainer::Draw and its aSize
  72    * parameter, it's necessary to swap the width and height if
  73    * mOrientation.SwapsWidthAndHeight() is true.)
  74    *
  75    * @param aInvert If true, compute the inverse of the orientation matrix.
  76    * Prefer this approach to OrientationMatrix(..).Invert(), because it's more
  77    * numerically accurate.
  78    */
  79   static gfxMatrix OrientationMatrix(Orientation aOrientation,
  80                                      const nsIntSize& aSize,
  81                                      bool aInvert = false);
  82
  83   /**
  84    * Returns a SourceSurface that is the result of rotating and flipping
  85    * aSurface according to aOrientation.
  86    */
  87   static already_AddRefed<SourceSurface> OrientSurface(Orientation aOrientation,
  88                                                        SourceSurface* aSurface);
  89
  90  protected:
  91   OrientedImage(Image* aImage, Orientation aOrientation)
  92       : ImageWrapper(aImage), mOrientation(aOrientation) {}
  93
  94   virtual ~OrientedImage() {}
  95
  96   gfxMatrix OrientationMatrix(const nsIntSize& aSize, bool aInvert = false) {
  97     return OrientationMatrix(mOrientation, aSize, aInvert);
  98   }
  99
 100  private:
 101   Orientation mOrientation;
 102
 103   friend class ImageOps;
 104 };
 105
 106 }  // namespace image
 107 }  // namespace mozilla
 108
 109 #endif  // mozilla_image_OrientedImage_h