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Diffstat (limited to 'layout/svg/nsFilterInstance.h')
| -rw-r--r-- | layout/svg/nsFilterInstance.h | 390 |
1 files changed, 390 insertions, 0 deletions
diff --git a/layout/svg/nsFilterInstance.h b/layout/svg/nsFilterInstance.h new file mode 100644 index 000000000..f4158f1c7 --- /dev/null +++ b/layout/svg/nsFilterInstance.h @@ -0,0 +1,390 @@ +/* -*- 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/. */ + +#ifndef __NS_FILTERINSTANCE_H__ +#define __NS_FILTERINSTANCE_H__ + +#include "gfxMatrix.h" +#include "gfxPoint.h" +#include "gfxRect.h" +#include "nsCOMPtr.h" +#include "nsHashKeys.h" +#include "nsPoint.h" +#include "nsRect.h" +#include "nsSize.h" +#include "nsSVGFilters.h" +#include "nsSVGNumber2.h" +#include "nsSVGNumberPair.h" +#include "nsTArray.h" +#include "nsIFrame.h" +#include "mozilla/gfx/2D.h" + +class gfxContext; +class nsIFrame; +class nsSVGFilterPaintCallback; + +namespace mozilla { +namespace dom { +class UserSpaceMetrics; +} // namespace dom +} // namespace mozilla + +/** + * This class performs all filter processing. + * + * We build a graph of the filter image data flow, essentially + * converting the filter graph to SSA. This lets us easily propagate + * analysis data (such as bounding-boxes) over the filter primitive graph. + * + * Definition of "filter space": filter space is a coordinate system that is + * aligned with the user space of the filtered element, with its origin located + * at the top left of the filter region, and with one unit equal in size to one + * pixel of the offscreen surface into which the filter output would/will be + * painted. + * + * The definition of "filter region" can be found here: + * http://www.w3.org/TR/SVG11/filters.html#FilterEffectsRegion + */ +class nsFilterInstance +{ + typedef mozilla::gfx::IntRect IntRect; + typedef mozilla::gfx::SourceSurface SourceSurface; + typedef mozilla::gfx::DrawTarget DrawTarget; + typedef mozilla::gfx::FilterPrimitiveDescription FilterPrimitiveDescription; + typedef mozilla::gfx::FilterDescription FilterDescription; + typedef mozilla::dom::UserSpaceMetrics UserSpaceMetrics; + +public: + /** + * Create a FilterDescription for the supplied filter. All coordinates in + * the description are in filter space. + * @param aFilterInputIsTainted Describes whether the SourceImage / SourceAlpha + * input is tainted. This affects whether feDisplacementMap will respect + * the filter input as its map input, and it affects the IsTainted() state + * on the filter primitives in the FilterDescription. "Tainted" is a term + * from the filters spec and means security-sensitive content, i.e. pixels + * that JS should not be able to read in any way. + * @param aOutAdditionalImages Will contain additional images needed to + * render the filter (from feImage primitives). + * @return A FilterDescription describing the filter. + */ + static FilterDescription GetFilterDescription(nsIContent* aFilteredElement, + const nsTArray<nsStyleFilter>& aFilterChain, + bool aFilterInputIsTainted, + const UserSpaceMetrics& aMetrics, + const gfxRect& aBBox, + nsTArray<RefPtr<SourceSurface>>& aOutAdditionalImages); + + /** + * Paint the given filtered frame. + * @param aDirtyArea The area than needs to be painted, in aFilteredFrame's + * frame space (i.e. relative to its origin, the top-left corner of its + * border box). + */ + static nsresult PaintFilteredFrame(nsIFrame *aFilteredFrame, + DrawTarget* aDrawTarget, + const gfxMatrix& aTransform, + nsSVGFilterPaintCallback *aPaintCallback, + const nsRegion* aDirtyArea); + + /** + * Returns the post-filter area that could be dirtied when the given + * pre-filter area of aFilteredFrame changes. + * @param aPreFilterDirtyRegion The pre-filter area of aFilteredFrame that has + * changed, relative to aFilteredFrame, in app units. + */ + static nsRegion GetPostFilterDirtyArea(nsIFrame *aFilteredFrame, + const nsRegion& aPreFilterDirtyRegion); + + /** + * Returns the pre-filter area that is needed from aFilteredFrame when the + * given post-filter area needs to be repainted. + * @param aPostFilterDirtyRegion The post-filter area that is dirty, relative + * to aFilteredFrame, in app units. + */ + static nsRegion GetPreFilterNeededArea(nsIFrame *aFilteredFrame, + const nsRegion& aPostFilterDirtyRegion); + + /** + * Returns the post-filter visual overflow rect (paint bounds) of + * aFilteredFrame. + * @param aOverrideBBox A user space rect, in user units, that should be used + * as aFilteredFrame's bbox ('bbox' is a specific SVG term), if non-null. + * @param aPreFilterBounds The pre-filter visual overflow rect of + * aFilteredFrame, if non-null. + */ + static nsRect GetPostFilterBounds(nsIFrame *aFilteredFrame, + const gfxRect *aOverrideBBox = nullptr, + const nsRect *aPreFilterBounds = nullptr); + + /** + * @param aTargetFrame The frame of the filtered element under consideration, + * may be null. + * @param aTargetContent The filtered element itself. + * @param aMetrics The metrics to resolve SVG lengths against. + * @param aFilterChain The list of filters to apply. + * @param aFilterInputIsTainted Describes whether the SourceImage / SourceAlpha + * input is tainted. This affects whether feDisplacementMap will respect + * the filter input as its map input. + * @param aPaintCallback [optional] The callback that Render() should use to + * paint. Only required if you will call Render(). + * @param aPaintTransform The transform to apply to convert to + * aTargetFrame's SVG user space. Only used when painting. + * @param aPostFilterDirtyRegion [optional] The post-filter area + * that has to be repainted, in app units. Only required if you will + * call ComputeSourceNeededRect() or Render(). + * @param aPreFilterDirtyRegion [optional] The pre-filter area of + * the filtered element that changed, in app units. Only required if you + * will call ComputePostFilterDirtyRegion(). + * @param aOverridePreFilterVisualOverflowRect [optional] Use a different + * visual overflow rect for the target element. + * @param aOverrideBBox [optional] Use a different SVG bbox for the target + * element. Must be non-null if aTargetFrame is null. + */ + nsFilterInstance(nsIFrame *aTargetFrame, + nsIContent* aTargetContent, + const UserSpaceMetrics& aMetrics, + const nsTArray<nsStyleFilter>& aFilterChain, + bool aFilterInputIsTainted, + nsSVGFilterPaintCallback *aPaintCallback, + const gfxMatrix& aPaintTransform, + const nsRegion *aPostFilterDirtyRegion = nullptr, + const nsRegion *aPreFilterDirtyRegion = nullptr, + const nsRect *aOverridePreFilterVisualOverflowRect = nullptr, + const gfxRect *aOverrideBBox = nullptr); + + /** + * Returns true if the filter instance was created successfully. + */ + bool IsInitialized() const { return mInitialized; } + + /** + * Draws the filter output into aDrawTarget. The area that + * needs to be painted must have been specified before calling this method + * by passing it as the aPostFilterDirtyRegion argument to the + * nsFilterInstance constructor. + */ + nsresult Render(DrawTarget* aDrawTarget); + + const FilterDescription& ExtractDescriptionAndAdditionalImages(nsTArray<RefPtr<SourceSurface>>& aOutAdditionalImages) + { + mInputImages.SwapElements(aOutAdditionalImages); + return mFilterDescription; + } + + /** + * Sets the aPostFilterDirtyRegion outparam to the post-filter area in frame + * space that would be dirtied by mTargetFrame when a given + * pre-filter area of mTargetFrame is dirtied. The pre-filter area must have + * been specified before calling this method by passing it as the + * aPreFilterDirtyRegion argument to the nsFilterInstance constructor. + */ + nsRegion ComputePostFilterDirtyRegion(); + + /** + * Sets the aPostFilterExtents outparam to the post-filter bounds in frame + * space for the whole filter output. This is not necessarily equivalent to + * the area that would be dirtied in the result when the entire pre-filter + * area is dirtied, because some filter primitives can generate output + * without any input. + */ + nsRect ComputePostFilterExtents(); + + /** + * Sets the aDirty outparam to the pre-filter bounds in frame space of the + * area of mTargetFrame that is needed in order to paint the filtered output + * for a given post-filter dirtied area. The post-filter area must have been + * specified before calling this method by passing it as the aPostFilterDirtyRegion + * argument to the nsFilterInstance constructor. + */ + nsRect ComputeSourceNeededRect(); + + + /** + * Returns the transform from filter space to outer-<svg> device space. + */ + gfxMatrix GetFilterSpaceToDeviceSpaceTransform() const { + return mFilterSpaceToDeviceSpaceTransform; + } + +private: + struct SourceInfo { + // Specifies which parts of the source need to be rendered. + // Set by ComputeNeededBoxes(). + nsIntRect mNeededBounds; + + // The surface that contains the input rendering. + // Set by BuildSourceImage / BuildSourcePaint. + RefPtr<SourceSurface> mSourceSurface; + + // The position and size of mSourceSurface in filter space. + // Set by BuildSourceImage / BuildSourcePaint. + IntRect mSurfaceRect; + }; + + /** + * Creates a SourceSurface for either the FillPaint or StrokePaint graph + * nodes + */ + nsresult BuildSourcePaint(SourceInfo *aPrimitive, + DrawTarget* aTargetDT); + + /** + * Creates a SourceSurface for either the FillPaint and StrokePaint graph + * nodes, fills its contents and assigns it to mFillPaint.mSourceSurface and + * mStrokePaint.mSourceSurface respectively. + */ + nsresult BuildSourcePaints(DrawTarget* aTargetDT); + + /** + * Creates the SourceSurface for the SourceGraphic graph node, paints its + * contents, and assigns it to mSourceGraphic.mSourceSurface. + */ + nsresult BuildSourceImage(DrawTarget* aTargetDT); + + /** + * Build the list of FilterPrimitiveDescriptions that describes the filter's + * filter primitives and their connections. This populates + * mPrimitiveDescriptions and mInputImages. aFilterInputIsTainted describes + * whether the SourceGraphic is tainted. + */ + nsresult BuildPrimitives(const nsTArray<nsStyleFilter>& aFilterChain, + nsIFrame* aTargetFrame, + bool aFilterInputIsTainted); + + /** + * Add to the list of FilterPrimitiveDescriptions for a particular SVG + * reference filter or CSS filter. This populates mPrimitiveDescriptions and + * mInputImages. aInputIsTainted describes whether the input to aFilter is + * tainted. + */ + nsresult BuildPrimitivesForFilter(const nsStyleFilter& aFilter, + nsIFrame* aTargetFrame, + bool aInputIsTainted); + + /** + * Computes the filter space bounds of the areas that we actually *need* from + * the filter sources, based on the value of mPostFilterDirtyRegion. + * This sets mNeededBounds on the corresponding SourceInfo structs. + */ + void ComputeNeededBoxes(); + + /** + * Returns the output bounds of the final FilterPrimitiveDescription. + */ + nsIntRect OutputFilterSpaceBounds() const; + + /** + * Compute the scale factors between user space and filter space. + */ + nsresult ComputeUserSpaceToFilterSpaceScale(); + + /** + * Transform a rect between user space and filter space. + */ + gfxRect UserSpaceToFilterSpace(const gfxRect& aUserSpace) const; + gfxRect FilterSpaceToUserSpace(const gfxRect& aFilterSpaceRect) const; + + /** + * Converts an nsRect or an nsRegion that is relative to a filtered frame's + * origin (i.e. the top-left corner of its border box) into filter space, + * rounding out. + * Returns the entire filter region if aRect / aRegion is null, or if the + * result is too large to be stored in an nsIntRect. + */ + nsIntRect FrameSpaceToFilterSpace(const nsRect* aRect) const; + nsIntRegion FrameSpaceToFilterSpace(const nsRegion* aRegion) const; + + /** + * Converts an nsIntRect or an nsIntRegion from filter space into the space + * that is relative to a filtered frame's origin (i.e. the top-left corner + * of its border box) in app units, rounding out. + */ + nsRect FilterSpaceToFrameSpace(const nsIntRect& aRect) const; + nsRegion FilterSpaceToFrameSpace(const nsIntRegion& aRegion) 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; + + /** + * The frame for the element that is currently being filtered. + */ + nsIFrame* mTargetFrame; + + /** + * The filtered element. + */ + nsIContent* mTargetContent; + + /** + * The user space metrics of the filtered frame. + */ + const UserSpaceMetrics& mMetrics; + + nsSVGFilterPaintCallback* mPaintCallback; + + /** + * The SVG bbox of the element that is being filtered, in user space. + */ + gfxRect mTargetBBox; + + /** + * The SVG bbox of the element that is being filtered, in filter space. + */ + nsIntRect mTargetBBoxInFilterSpace; + + /** + * The transform from filter space to outer-<svg> device space. + */ + gfxMatrix mFilterSpaceToDeviceSpaceTransform; + + /** + * Transform rects between filter space and frame space in CSS pixels. + */ + gfxMatrix mFilterSpaceToFrameSpaceInCSSPxTransform; + gfxMatrix mFrameSpaceInCSSPxToFilterSpaceTransform; + + /** + * The scale factors between user space and filter space. + */ + gfxSize mUserSpaceToFilterSpaceScale; + gfxSize mFilterSpaceToUserSpaceScale; + + /** + * Pre-filter paint bounds of the element that is being filtered, in filter + * space. + */ + nsIntRect mTargetBounds; + + /** + * The dirty area that needs to be repainted, in filter space. + */ + nsIntRegion mPostFilterDirtyRegion; + + /** + * The pre-filter area of the filtered element that changed, in filter space. + */ + nsIntRegion mPreFilterDirtyRegion; + + SourceInfo mSourceGraphic; + SourceInfo mFillPaint; + SourceInfo mStrokePaint; + + /** + * The transform to the SVG user space of mTargetFrame. + */ + gfxMatrix mPaintTransform; + + nsTArray<RefPtr<SourceSurface>> mInputImages; + nsTArray<FilterPrimitiveDescription> mPrimitiveDescriptions; + FilterDescription mFilterDescription; + bool mInitialized; +}; + +#endif |