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/* -*- 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
#ifndef LAYOUT_SVG_SVGFILTERINSTANCE_H_
#define LAYOUT_SVG_SVGFILTERINSTANCE_H_
#include "gfxMatrix.h"
#include "gfxRect.h"
#include "SVGAnimatedNumber.h"
#include "SVGAnimatedNumberPair.h"
#include "SVGFilters.h"
#include "mozilla/ServoStyleConsts.h"
namespace mozilla {
class SVGFilterFrame;
namespace dom {
class SVGFilterElement;
} // namespace dom
/**
* This class helps FilterInstance build its filter graph by processing a
* single SVG reference filter.
*
* In BuildPrimitives, this class iterates through the referenced <filter>
* element's primitive elements, creating a FilterPrimitiveDescription for
* each one.
*
* This class uses several different coordinate spaces, defined as follows:
*
* "user space"
* The filtered SVG element's user space or the filtered HTML element's
* CSS pixel space. The origin for an HTML element is the top left corner of
* its border box.
*
* "filter space"
* User space scaled to device pixels. Shares the same origin as user space.
* This space is the same across chained SVG and CSS filters. To compute the
* overall filter space for a chain, we first need to build each filter's
* FilterPrimitiveDescriptions in some common space. That space is
* filter space.
*
* To understand the spaces better, let's take an example filter:
* <filter id="f">...</filter>
*
* And apply the filter to a div element:
* <div style="filter: url(#f); ...">...</div>
*
* And let's say there are 2 device pixels for every 1 CSS pixel.
*
* Finally, let's define an arbitrary point in user space:
* "user space point" = (10, 10)
*
* The point will be inset 10 CSS pixels from both the top and left edges of the
* div element's border box.
*
* Now, let's transform the point from user space to filter space:
* "filter space point" = "user space point" * "device pixels per CSS pixel"
* "filter space point" = (10, 10) * 2
* "filter space point" = (20, 20)
*/
class SVGFilterInstance {
using Point3D = gfx::Point3D;
using IntRect = gfx::IntRect;
using SourceSurface = gfx::SourceSurface;
using FilterPrimitiveDescription = gfx::FilterPrimitiveDescription;
using SVGFilterPrimitiveElement = dom::SVGFilterPrimitiveElement;
using UserSpaceMetrics = dom::UserSpaceMetrics;
public:
/**
* @param aFilter The SVG filter reference from the style system. This class
* stores aFilter by reference, so callers should avoid modifying or
* deleting aFilter during the lifetime of SVGFilterInstance.
* @param aTargetContent The filtered element.
* @param aTargetBBox The SVG bbox to use for the target frame, computed by
* the caller. The caller may decide to override the actual SVG bbox.
*/
SVGFilterInstance(
const StyleFilter& aFilter, SVGFilterFrame* aFilterFrame,
nsIContent* aTargetContent, const UserSpaceMetrics& aMetrics,
const gfxRect& aTargetBBox,
const gfx::MatrixScalesDouble& aUserSpaceToFilterSpaceScale);
/**
* Returns true if the filter instance was created successfully.
*/
bool IsInitialized() const { return mInitialized; }
/**
* Iterates through the <filter> element's primitive elements, creating a
* FilterPrimitiveDescription for each one. Appends the new
* FilterPrimitiveDescription(s) to the aPrimitiveDescrs list. Also, appends
* new images from feImage filter primitive elements to the aInputImages list.
* aInputIsTainted describes whether the input to this filter is tainted, i.e.
* whether it contains security-sensitive content. This is needed to propagate
* taintedness to the FilterPrimitive that take tainted inputs. Something
* being tainted means that it contains security sensitive content. The input
* to this filter is the previous filter's output, i.e. the last element in
* aPrimitiveDescrs, or the SourceGraphic input if this is the first filter in
* the filter chain.
*/
nsresult BuildPrimitives(
nsTArray<FilterPrimitiveDescription>& aPrimitiveDescrs,
nsTArray<RefPtr<SourceSurface>>& aInputImages, bool aInputIsTainted);
float GetPrimitiveNumber(uint8_t aCtxType,
const SVGAnimatedNumber* aNumber) const {
return GetPrimitiveNumber(aCtxType, aNumber->GetAnimValue());
}
float GetPrimitiveNumber(uint8_t aCtxType,
const SVGAnimatedNumberPair* aNumberPair,
SVGAnimatedNumberPair::PairIndex aIndex) const {
return GetPrimitiveNumber(aCtxType, aNumberPair->GetAnimValue(aIndex));
}
/**
* Converts a userSpaceOnUse/objectBoundingBoxUnits unitless point
* into filter space, depending on the value of mPrimitiveUnits. (For
* objectBoundingBoxUnits, the bounding box offset is applied to the point.)
*/
Point3D ConvertLocation(const Point3D& aPoint) const;
/**
* Transform a rect between user space and filter space.
*/
gfxRect UserSpaceToFilterSpace(const gfxRect& aUserSpaceRect) const;
private:
/**
* Computes the filter primitive subregion for the given primitive.
*/
IntRect ComputeFilterPrimitiveSubregion(
SVGFilterPrimitiveElement* aFilterElement,
const nsTArray<FilterPrimitiveDescription>& aPrimitiveDescrs,
const nsTArray<int32_t>& aInputIndices);
/**
* Takes the input indices of a filter primitive and returns for each input
* whether the input's output is tainted.
*/
void GetInputsAreTainted(
const nsTArray<FilterPrimitiveDescription>& aPrimitiveDescrs,
const nsTArray<int32_t>& aInputIndices, bool aFilterInputIsTainted,
nsTArray<bool>& aOutInputsAreTainted);
/**
* Scales a numeric filter primitive length in the X, Y or "XY" directions
* into a length in filter space (no offset is applied).
*/
float GetPrimitiveNumber(uint8_t aCtxType, float aValue) const;
/**
* Returns the transform from frame space to the coordinate space that
* GetCanvasTM transforms to. "Frame space" is the origin of a frame, aka the
* top-left corner of its border box, aka the top left corner of its mRect.
*/
gfxMatrix GetUserSpaceToFrameSpaceInCSSPxTransform() const;
/**
* Appends a new FilterPrimitiveDescription to aPrimitiveDescrs that
* converts the FilterPrimitiveDescription at mSourceGraphicIndex into
* a SourceAlpha input for the next FilterPrimitiveDescription.
*
* The new FilterPrimitiveDescription zeros out the SourceGraphic's RGB
* channels and keeps the alpha channel intact.
*/
int32_t GetOrCreateSourceAlphaIndex(
nsTArray<FilterPrimitiveDescription>& aPrimitiveDescrs);
/**
* Finds the index in aPrimitiveDescrs of each input to aPrimitiveElement.
* For example, if aPrimitiveElement is:
* <feGaussianBlur in="another-primitive" .../>
* Then, the resulting aSourceIndices will contain the index of the
* FilterPrimitiveDescription representing "another-primitive".
*/
nsresult GetSourceIndices(
SVGFilterPrimitiveElement* aPrimitiveElement,
nsTArray<FilterPrimitiveDescription>& aPrimitiveDescrs,
const nsTHashMap<nsStringHashKey, int32_t>& aImageTable,
nsTArray<int32_t>& aSourceIndices);
/**
* Compute the filter region in user space, filter space, and filter
* space.
*/
bool ComputeBounds();
/**
* The SVG reference filter originally from the style system.
*/
const StyleFilter& mFilter;
/**
* The filtered element.
*/
nsIContent* mTargetContent;
/**
* The SVG user space metrics that SVG lengths are resolved against.
*/
const UserSpaceMetrics& mMetrics;
/**
* The filter element referenced by mTargetFrame's element.
*/
const dom::SVGFilterElement* mFilterElement;
/**
* The frame for the SVG filter element.
*/
SVGFilterFrame* mFilterFrame;
/**
* The SVG bbox of the element that is being filtered, in user space.
*/
gfxRect mTargetBBox;
/**
* The "filter region" in various spaces.
*/
nsIntRect mFilterSpaceBounds;
/**
* The scale factors between user space and filter space.
*/
gfx::MatrixScalesDouble mUserSpaceToFilterSpaceScale;
/**
* The 'primitiveUnits' attribute value (objectBoundingBox or userSpaceOnUse).
*/
uint16_t mPrimitiveUnits;
/**
* The index of the FilterPrimitiveDescription that this SVG filter should use
* as its SourceGraphic, or the SourceGraphic keyword index if this is the
* first filter in a chain. Initialized in BuildPrimitives
*/
MOZ_INIT_OUTSIDE_CTOR int32_t mSourceGraphicIndex;
/**
* The index of the FilterPrimitiveDescription that this SVG filter should use
* as its SourceAlpha, or the SourceAlpha keyword index if this is the first
* filter in a chain. Initialized in BuildPrimitives
*/
MOZ_INIT_OUTSIDE_CTOR int32_t mSourceAlphaIndex;
/**
* SourceAlpha is available if GetOrCreateSourceAlphaIndex has been called.
*/
int32_t mSourceAlphaAvailable;
bool mInitialized;
};
} // namespace mozilla
#endif // LAYOUT_SVG_SVGFILTERINSTANCE_H_