1 files changed, 354 insertions, 0 deletions
diff --git a/image/OrientedImage.cpp b/image/OrientedImage.cpp
new file mode 100644
index 0000000000..9489ceafd0
--- /dev/null
+++ b/image/OrientedImage.cpp
@@ -0,0 +1,354 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* 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/. */
+
+#include "OrientedImage.h"
+
+#include <algorithm>
+
+#include "gfx2DGlue.h"
+#include "gfxDrawable.h"
+#include "gfxPlatform.h"
+#include "gfxUtils.h"
+#include "ImageRegion.h"
+#include "SVGImageContext.h"
+
+using std::swap;
+
+namespace mozilla {
+
+using namespace gfx;
+using layers::LayerManager;
+using layers::ImageContainer;
+
+namespace image {
+
+NS_IMPL_ISUPPORTS_INHERITED0(OrientedImage, ImageWrapper)
+
+NS_IMETHODIMP
+OrientedImage::GetWidth(int32_t* aWidth)
+{
+  if (mOrientation.SwapsWidthAndHeight()) {
+    return InnerImage()->GetHeight(aWidth);
+  } else {
+    return InnerImage()->GetWidth(aWidth);
+  }
+}
+
+NS_IMETHODIMP
+OrientedImage::GetHeight(int32_t* aHeight)
+{
+  if (mOrientation.SwapsWidthAndHeight()) {
+    return InnerImage()->GetWidth(aHeight);
+  } else {
+    return InnerImage()->GetHeight(aHeight);
+  }
+}
+
+NS_IMETHODIMP
+OrientedImage::GetIntrinsicSize(nsSize* aSize)
+{
+  nsresult rv = InnerImage()->GetIntrinsicSize(aSize);
+
+  if (mOrientation.SwapsWidthAndHeight()) {
+    swap(aSize->width, aSize->height);
+  }
+
+  return rv;
+}
+
+NS_IMETHODIMP
+OrientedImage::GetIntrinsicRatio(nsSize* aRatio)
+{
+  nsresult rv = InnerImage()->GetIntrinsicRatio(aRatio);
+
+  if (mOrientation.SwapsWidthAndHeight()) {
+    swap(aRatio->width, aRatio->height);
+  }
+
+  return rv;
+}
+
+NS_IMETHODIMP_(already_AddRefed<SourceSurface>)
+OrientedImage::GetFrame(uint32_t aWhichFrame,
+                        uint32_t aFlags)
+{
+  nsresult rv;
+
+  if (mOrientation.IsIdentity()) {
+    return InnerImage()->GetFrame(aWhichFrame, aFlags);
+  }
+
+  // Get the underlying dimensions.
+  IntSize size;
+  rv = InnerImage()->GetWidth(&size.width);
+  NS_ENSURE_SUCCESS(rv, nullptr);
+  rv = InnerImage()->GetHeight(&size.height);
+  NS_ENSURE_SUCCESS(rv, nullptr);
+
+  // Determine an appropriate format for the surface.
+  gfx::SurfaceFormat surfaceFormat;
+  if (InnerImage()->WillDrawOpaqueNow()) {
+    surfaceFormat = gfx::SurfaceFormat::B8G8R8X8;
+  } else {
+    surfaceFormat = gfx::SurfaceFormat::B8G8R8A8;
+  }
+
+  // Create a surface to draw into.
+  RefPtr<DrawTarget> target =
+    gfxPlatform::GetPlatform()->
+      CreateOffscreenContentDrawTarget(size, surfaceFormat);
+  if (!target || !target->IsValid()) {
+    NS_ERROR("Could not create a DrawTarget");
+    return nullptr;
+  }
+
+
+  // Create our drawable.
+  RefPtr<SourceSurface> innerSurface =
+    InnerImage()->GetFrame(aWhichFrame, aFlags);
+  NS_ENSURE_TRUE(innerSurface, nullptr);
+  RefPtr<gfxDrawable> drawable =
+    new gfxSurfaceDrawable(innerSurface, size);
+
+  // Draw.
+  RefPtr<gfxContext> ctx = gfxContext::CreateOrNull(target);
+  MOZ_ASSERT(ctx); // already checked the draw target above
+  ctx->Multiply(OrientationMatrix(size));
+  gfxUtils::DrawPixelSnapped(ctx, drawable, size, ImageRegion::Create(size),
+                             surfaceFormat, SamplingFilter::LINEAR);
+
+  return target->Snapshot();
+}
+
+NS_IMETHODIMP_(already_AddRefed<SourceSurface>)
+OrientedImage::GetFrameAtSize(const IntSize& aSize,
+                              uint32_t aWhichFrame,
+                              uint32_t aFlags)
+{
+  // XXX(seth): It'd be nice to support downscale-during-decode for this case,
+  // but right now we just fall back to the intrinsic size.
+  return GetFrame(aWhichFrame, aFlags);
+}
+
+NS_IMETHODIMP_(bool)
+OrientedImage::IsImageContainerAvailable(LayerManager* aManager, uint32_t aFlags)
+{
+  if (mOrientation.IsIdentity()) {
+    return InnerImage()->IsImageContainerAvailable(aManager, aFlags);
+  }
+  return false;
+}
+
+NS_IMETHODIMP_(already_AddRefed<ImageContainer>)
+OrientedImage::GetImageContainer(LayerManager* aManager, uint32_t aFlags)
+{
+  // XXX(seth): We currently don't have a way of orienting the result of
+  // GetImageContainer. We work around this by always returning null, but if it
+  // ever turns out that OrientedImage is widely used on codepaths that can
+  // actually benefit from GetImageContainer, it would be a good idea to fix
+  // that method for performance reasons.
+
+  if (mOrientation.IsIdentity()) {
+    return InnerImage()->GetImageContainer(aManager, aFlags);
+  }
+
+  return nullptr;
+}
+
+struct MatrixBuilder
+{
+  explicit MatrixBuilder(bool aInvert) : mInvert(aInvert) { }
+
+  gfxMatrix Build() { return mMatrix; }
+
+  void Scale(gfxFloat aX, gfxFloat aY)
+  {
+    if (mInvert) {
+      mMatrix *= gfxMatrix::Scaling(1.0 / aX, 1.0 / aY);
+    } else {
+      mMatrix.Scale(aX, aY);
+    }
+  }
+
+  void Rotate(gfxFloat aPhi)
+  {
+    if (mInvert) {
+      mMatrix *= gfxMatrix::Rotation(-aPhi);
+    } else {
+      mMatrix.Rotate(aPhi);
+    }
+  }
+
+  void Translate(gfxPoint aDelta)
+  {
+    if (mInvert) {
+      mMatrix *= gfxMatrix::Translation(-aDelta);
+    } else {
+      mMatrix.Translate(aDelta);
+    }
+  }
+
+private:
+  gfxMatrix mMatrix;
+  bool      mInvert;
+};
+
+/*
+ * OrientationMatrix() computes a matrix that applies the rotation and
+ * reflection specified by mOrientation, or that matrix's inverse if aInvert is
+ * true.
+ *
+ * @param aSize The scaled size of the inner image. (When outside code specifies
+ *              the scaled size, as with imgIContainer::Draw and its aSize
+ *              parameter, it's necessary to swap the width and height if
+ *              mOrientation.SwapsWidthAndHeight() is true.)
+ * @param aInvert If true, compute the inverse of the orientation matrix. Prefer
+ *                this approach to OrientationMatrix(..).Invert(), because it's
+ *                more numerically accurate.
+ */
+gfxMatrix
+OrientedImage::OrientationMatrix(const nsIntSize& aSize,
+                                 bool aInvert /* = false */)
+{
+  MatrixBuilder builder(aInvert);
+
+  // Apply reflection, if present. (This logically happens second, but we
+  // apply it first because these transformations are all premultiplied.) A
+  // translation is necessary to place the image back in the first quadrant.
+  switch (mOrientation.flip) {
+    case Flip::Unflipped:
+      break;
+    case Flip::Horizontal:
+      if (mOrientation.SwapsWidthAndHeight()) {
+        builder.Translate(gfxPoint(aSize.height, 0));
+      } else {
+        builder.Translate(gfxPoint(aSize.width, 0));
+      }
+      builder.Scale(-1.0, 1.0);
+      break;
+    default:
+      MOZ_ASSERT(false, "Invalid flip value");
+  }
+
+  // Apply rotation, if present. Again, a translation is used to place the
+  // image back in the first quadrant.
+  switch (mOrientation.rotation) {
+    case Angle::D0:
+      break;
+    case Angle::D90:
+      builder.Translate(gfxPoint(aSize.height, 0));
+      builder.Rotate(-1.5 * M_PI);
+      break;
+    case Angle::D180:
+      builder.Translate(gfxPoint(aSize.width, aSize.height));
+      builder.Rotate(-1.0 * M_PI);
+      break;
+    case Angle::D270:
+      builder.Translate(gfxPoint(0, aSize.width));
+      builder.Rotate(-0.5 * M_PI);
+      break;
+    default:
+      MOZ_ASSERT(false, "Invalid rotation value");
+  }
+
+  return builder.Build();
+}
+
+NS_IMETHODIMP_(DrawResult)
+OrientedImage::Draw(gfxContext* aContext,
+                    const nsIntSize& aSize,
+                    const ImageRegion& aRegion,
+                    uint32_t aWhichFrame,
+                    SamplingFilter aSamplingFilter,
+                    const Maybe<SVGImageContext>& aSVGContext,
+                    uint32_t aFlags)
+{
+  if (mOrientation.IsIdentity()) {
+    return InnerImage()->Draw(aContext, aSize, aRegion,
+                              aWhichFrame, aSamplingFilter,
+                              aSVGContext, aFlags);
+  }
+
+  // Update the image size to match the image's coordinate system. (This could
+  // be done using TransformBounds but since it's only a size a swap is enough.)
+  nsIntSize size(aSize);
+  if (mOrientation.SwapsWidthAndHeight()) {
+    swap(size.width, size.height);
+  }
+
+  // Update the matrix so that we transform the image into the orientation
+  // expected by the caller before drawing.
+  gfxMatrix matrix(OrientationMatrix(size));
+  gfxContextMatrixAutoSaveRestore saveMatrix(aContext);
+  aContext->Multiply(matrix);
+
+  // The region is already in the orientation expected by the caller, but we
+  // need it to be in the image's coordinate system, so we transform it using
+  // the inverse of the orientation matrix.
+  gfxMatrix inverseMatrix(OrientationMatrix(size, /* aInvert = */ true));
+  ImageRegion region(aRegion);
+  region.TransformBoundsBy(inverseMatrix);
+
+  auto orientViewport = [&](const SVGImageContext& aOldContext) {
+    CSSIntSize viewportSize(aOldContext.GetViewportSize());
+    if (mOrientation.SwapsWidthAndHeight()) {
+      swap(viewportSize.width, viewportSize.height);
+    }
+    return SVGImageContext(viewportSize,
+                           aOldContext.GetPreserveAspectRatio());
+  };
+
+  return InnerImage()->Draw(aContext, size, region, aWhichFrame, aSamplingFilter,
+                            aSVGContext.map(orientViewport), aFlags);
+}
+
+nsIntSize
+OrientedImage::OptimalImageSizeForDest(const gfxSize& aDest,
+                                       uint32_t aWhichFrame,
+                                       SamplingFilter aSamplingFilter,
+                                       uint32_t aFlags)
+{
+  if (!mOrientation.SwapsWidthAndHeight()) {
+    return InnerImage()->OptimalImageSizeForDest(aDest, aWhichFrame,
+                                                 aSamplingFilter, aFlags);
+  }
+
+  // Swap the size for the calculation, then swap it back for the caller.
+  gfxSize destSize(aDest.height, aDest.width);
+  nsIntSize innerImageSize(InnerImage()->OptimalImageSizeForDest(destSize,
+                                                                 aWhichFrame,
+                                                                 aSamplingFilter,
+                                                                 aFlags));
+  return nsIntSize(innerImageSize.height, innerImageSize.width);
+}
+
+NS_IMETHODIMP_(nsIntRect)
+OrientedImage::GetImageSpaceInvalidationRect(const nsIntRect& aRect)
+{
+  nsIntRect rect(InnerImage()->GetImageSpaceInvalidationRect(aRect));
+
+  if (mOrientation.IsIdentity()) {
+    return rect;
+  }
+
+  nsIntSize innerSize;
+  nsresult rv = InnerImage()->GetWidth(&innerSize.width);
+  rv = NS_FAILED(rv) ? rv : InnerImage()->GetHeight(&innerSize.height);
+  if (NS_FAILED(rv)) {
+    // Fall back to identity if the width and height aren't available.
+    return rect;
+  }
+
+  // Transform the invalidation rect into the correct orientation.
+  gfxMatrix matrix(OrientationMatrix(innerSize));
+  gfxRect invalidRect(matrix.TransformBounds(gfxRect(rect.x, rect.y,
+                                                     rect.width, rect.height)));
+
+  return IntRect::RoundOut(invalidRect.x, invalidRect.y,
+                           invalidRect.width, invalidRect.height);
+}
+
+} // namespace image
+} // namespace mozilla