gecko-dev/layout/svg/nsSVGFilterInstance.h

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/* -*- 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_SVGFILTERINSTANCE_H__
#define __NS_SVGFILTERINSTANCE_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"
class gfxASurface;
class gfxImageSurface;
class nsIFrame;
class nsSVGFilterPaintCallback;
namespace mozilla {
namespace dom {
class SVGFilterElement;
}
}
/**
* 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 (as specified by our ctor's
* aFilterRegion, and returned by our GetFilterRegion, specifically), 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 nsSVGFilterInstance
{
public:
/**
* @param aTargetFrame The frame of the filtered element under consideration.
* @param aPaintCallback [optional] The callback that Render() should use to
* paint. Only required if you will call Render().
* @param aFilterElement The filter element referenced by aTargetFrame's
* element.
* @param aTargetBBox The filtered element's bbox, in the filtered element's
* user space.
* @param aFilterRegion The "filter region", in the filtered element's user
* space. The caller must have already expanded the region out so that its
* edges coincide with pixel boundaries in the offscreen surface that
* would/will be created to paint the filter output.
* @param aFilterSpaceSize The size of the user specified "filter region",
* in filter space units.
* @param aFilterSpaceToDeviceSpaceTransform The transform from filter
* space to outer-<svg> device space.
* @param aTargetBounds The pre-filter paint bounds of the filtered element,
* in filter space.
* @param aPostFilterDirtyRect [optional] The bounds of the post-filter area
* that has to be repainted, in filter space. Only required if you will
* call ComputeSourceNeededRect() or Render().
* @param aPreFilterDirtyRect [optional] The bounds of the pre-filter area of
* the filtered element that changed, in filter space. Only required if you
* will call ComputePostFilterDirtyRect().
* @param aPrimitiveUnits The value from the 'primitiveUnits' attribute.
*/
nsSVGFilterInstance(nsIFrame *aTargetFrame,
nsSVGFilterPaintCallback *aPaintCallback,
const mozilla::dom::SVGFilterElement *aFilterElement,
const gfxRect &aTargetBBox,
const gfxRect& aFilterRegion,
const nsIntSize& aFilterSpaceSize,
const gfxMatrix &aFilterSpaceToDeviceSpaceTransform,
const gfxMatrix &aFilterSpaceToFrameSpaceInCSSPxTransform,
const nsIntRect& aTargetBounds,
const nsIntRect& aPostFilterDirtyRect,
const nsIntRect& aPreFilterDirtyRect,
uint16_t aPrimitiveUnits) :
mTargetFrame(aTargetFrame),
mPaintCallback(aPaintCallback),
mFilterElement(aFilterElement),
mTargetBBox(aTargetBBox),
mFilterSpaceToDeviceSpaceTransform(aFilterSpaceToDeviceSpaceTransform),
mFilterSpaceToFrameSpaceInCSSPxTransform(aFilterSpaceToFrameSpaceInCSSPxTransform),
mFilterRegion(aFilterRegion),
mFilterSpaceSize(aFilterSpaceSize),
mSurfaceRect(nsIntPoint(0, 0), aFilterSpaceSize),
mTargetBounds(aTargetBounds),
mPostFilterDirtyRect(aPostFilterDirtyRect),
mPreFilterDirtyRect(aPreFilterDirtyRect),
mPrimitiveUnits(aPrimitiveUnits) {
}
/**
* Returns the user specified "filter region", in the filtered element's user
* space, after it has been adjusted out (if necessary) so that its edges
* coincide with pixel boundaries of the offscreen surface into which the
* filtered output would/will be painted.
*/
gfxRect GetFilterRegion() const { return mFilterRegion; }
/**
* Returns the size of the user specified "filter region", in filter space.
* The size will be {filterRes.x by filterRes.y}, whether the user specified
* the filter's filterRes attribute explicitly, or the implementation chose
* the filterRes values. (The top-left of the filter region is the origin of
* filter space, which is why this method returns an nsIntSize and not an
* nsIntRect.)
*/
const nsIntSize& GetFilterSpaceSize() { return mFilterSpaceSize; }
uint32_t GetFilterResX() const { return mFilterSpaceSize.width; }
uint32_t GetFilterResY() const { return mFilterSpaceSize.height; }
/**
* Returns the dimensions of the offscreen surface that is required for the
* output from the current filter operation, in filter space. This rect is
* clipped to, and therefore guaranteed to be fully contained by, the filter
* region.
*/
const nsIntRect& GetSurfaceRect() const { return mSurfaceRect; }
int32_t GetSurfaceWidth() const { return mSurfaceRect.width; }
int32_t GetSurfaceHeight() const { return mSurfaceRect.height; }
/**
* Allocates a gfxASurface, renders the filtered element into the surface,
* and then returns the surface via the aOutput outparam. The area that
* needs to be painted must have been specified before calling this method
* by passing it as the aPostFilterDirtyRect argument to the
* nsSVGFilterInstance constructor.
*/
nsresult Render(gfxASurface** aOutput);
/**
* Sets the aPostFilterDirtyRect outparam to the post-filter bounds in filter
* space of the area 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
* aPreFilterDirtyRect argument to the nsSVGFilterInstance constructor.
*/
nsresult ComputePostFilterDirtyRect(nsIntRect* aPostFilterDirtyRect);
/**
* Sets the aDirty outparam to the pre-filter bounds in filter 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 aPostFilterDirtyRect
* argument to the nsSVGFilterInstance constructor.
*/
nsresult ComputeSourceNeededRect(nsIntRect* aDirty);
/**
* Sets the aDirty outparam to the post-filter bounds in filter space of the
* area that would be dirtied by mTargetFrame if its entire pre-filter area
* is dirtied.
*/
nsresult ComputeOutputBBox(nsIntRect* aBBox);
float GetPrimitiveNumber(uint8_t aCtxType, const nsSVGNumber2 *aNumber) const
{
return GetPrimitiveNumber(aCtxType, aNumber->GetAnimValue());
}
float GetPrimitiveNumber(uint8_t aCtxType, const nsSVGNumberPair *aNumberPair,
nsSVGNumberPair::PairIndex aIndex) const
{
return GetPrimitiveNumber(aCtxType, aNumberPair->GetAnimValue(aIndex));
}
/**
* Converts a userSpaceOnUse/objectBoundingBoxUnits unitless point and length
* into filter space, depending on the value of mPrimitiveUnits. (For
* objectBoundingBoxUnits, the bounding box offset is applied to the point.)
*/
void ConvertLocation(float aValues[3]) const;
/**
* Returns the transform from the filtered element's user space to filter
* space. This will be a simple translation and/or scale.
*/
gfxMatrix GetUserSpaceToFilterSpaceTransform() const;
/**
* Returns the transform from filter space to outer-<svg> device space.
*/
gfxMatrix GetFilterSpaceToDeviceSpaceTransform() const {
return mFilterSpaceToDeviceSpaceTransform;
}
gfxPoint FilterSpaceToUserSpace(const gfxPoint& aPt) const;
/**
* Returns the transform from filter space to frame space, in CSS px. This
* transform does not transform to frame space in its normal app units, since
* app units are ints, requiring appropriate rounding which can't be done by
* a transform matrix. Callers have to do that themselves as appropriate for
* their needs.
*/
gfxMatrix GetFilterSpaceToFrameSpaceInCSSPxTransform() const {
return mFilterSpaceToFrameSpaceInCSSPxTransform;
}
int32_t AppUnitsPerCSSPixel() const {
return mTargetFrame->PresContext()->AppUnitsPerCSSPixel();
}
private:
typedef nsSVGFE::Image Image;
typedef nsSVGFE::ColorModel ColorModel;
struct PrimitiveInfo {
/// Pointer to the filter primitive element.
nsSVGFE* mFE;
/**
* The filter space bounds of this filter primitive's output, were a full
* repaint of mTargetFrame to occur. Note that a filter primitive's output
* (and hence this rect) is always clipped to both the filter region and
* to the filter primitive subregion.
* XXX maybe rename this to mMaxBounds?
*/
nsIntRect mResultBoundingBox;
/**
* The filter space bounds of this filter primitive's output, were we to
* repaint a given post-filter dirty area, and were we to minimize
* repainting for that dirty area. In other words this is the part of the
* primitive's output that is needed by other primitives or the final
* filtered output in order to repaint that area. This rect is guaranteed
* to be contained within mResultBoundingBox and, if we're only painting
* part of the filtered output, may be smaller. This rect is used when
* calling Render() or ComputeSourceNeededRect().
* XXX maybe rename this to just mNeededBounds?
*/
nsIntRect mResultNeededBox;
/**
* The filter space bounds of this filter primitive's output, were only
* part of mTargetFrame's pre-filter output to be dirtied, and were we to
* minimize repainting for that dirty area. This is used when calculating
* the area that needs to be invalidated when only part of a filtered
* element is dirtied. This rect is guaranteed to be contained within
* mResultBoundingBox.
*/
nsIntRect mResultChangeBox;
Image mImage;
/**
* The number of times that this filter primitive's output is used as an
* input by other filter primitives in the filter graph.
* XXX seems like we could better use this to avoid creating images for
* primitives that are not used, or whose ouput in not used during the
* current operation.
*/
int32_t mImageUsers;
// Can't use nsAutoTArray here, because these Info objects
// live in nsTArrays themselves and nsTArray moves the elements
// around in memory, which breaks nsAutoTArray.
nsTArray<PrimitiveInfo*> mInputs;
PrimitiveInfo() : mFE(nullptr), mImageUsers(0) {}
};
class ImageAnalysisEntry : public nsStringHashKey {
public:
ImageAnalysisEntry(KeyTypePointer aStr) : nsStringHashKey(aStr) { }
ImageAnalysisEntry(const ImageAnalysisEntry& toCopy) : nsStringHashKey(toCopy),
mInfo(toCopy.mInfo) { }
PrimitiveInfo* mInfo;
};
/**
* Initializes the keyword nodes e.g. SourceGraphic (i.e. sets
* .mImage.mFilterPrimitiveSubregion and .mResultBoundingBox on
* mSourceColorAlpha and mSourceAlpha).
*/
nsresult BuildSources();
/**
* Creates a gfxImageSurface for either the FillPaint or StrokePaint graph
* nodes
*/
nsresult BuildSourcePaint(PrimitiveInfo *aPrimitive);
/**
* Creates a gfxImageSurface for either the FillPaint and StrokePaint graph
* nodes, fills its contents and assigns it to mFillPaint.mImage.mImage and
* mStrokePaint.mImage.mImage respectively.
*/
nsresult BuildSourcePaints();
/**
* Creates the gfxImageSurfaces for the SourceGraphic and SourceAlpha graph
* nodes, paints their contents, and assigns them to
* mSourceColorAlpha.mImage.mImage and mSourceAlpha.mImage.mImage
* respectively.
*/
nsresult BuildSourceImages();
/**
* Build the graph of PrimitiveInfo nodes that describes the filter's filter
* primitives and their connections. This populates mPrimitives, and sets
* each PrimitiveInfo's mFE, mInputs, mImageUsers, mFilterPrimitiveSubregion,
* etc.
*/
nsresult BuildPrimitives();
/**
* Compute the filter space bounds of the output from each primitive, were we
* to do a full repaint of mTargetFrame. This sets mResultBoundingBox on the
* items in the filter graph, based on the mResultBoundingBox of each item's
* inputs, and clipped to the filter region and each primitive's filter
* primitive subregion.
*/
void ComputeResultBoundingBoxes();
/**
* Computes the filter space bounds of the areas that we actually *need* from
* each filter primitive's output, based on the value of mPostFilterDirtyRect.
* This sets mResultNeededBox on the items in the filter graph.
*/
void ComputeNeededBoxes();
/**
* Computes the filter space bounds of the area of each filter primitive
* that will change, based on the value of mPreFilterDirtyRect.
* This sets mResultChangeBox on the items in the filter graph.
*/
void ComputeResultChangeBoxes();
/**
* Computes and returns the union of all mResultNeededBox rects in the filter
* graph. This is useful for deciding the size of the offscreen surface that
* needs to be created for the filter operation.
*/
nsIntRect ComputeUnionOfAllNeededBoxes();
/**
* Allocates and returns a surface of mSurfaceRect.Size(), and with a device
* offset of -mSurfaceRect.TopLeft(). The surface is cleared to transparent
* black.
*/
already_AddRefed<gfxImageSurface> CreateImage();
/**
* Computes and sets mFilterPrimitiveSubregion for the given primitive.
*/
void ComputeFilterPrimitiveSubregion(PrimitiveInfo* aInfo);
/**
* If the color model of the pixel data in the aPrimitive's image isn't
* already aColorModel, then this method converts its pixel data to that
* color model.
*/
void EnsureColorModel(PrimitiveInfo* aPrimitive,
ColorModel aColorModel);
/**
* 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;
gfxRect UserSpaceToFilterSpace(const gfxRect& aUserSpace) const;
/**
* Clip the filter space rect aRect to the filter region.
*/
void ClipToFilterSpace(nsIntRect* aRect) const
{
nsIntRect filterSpace(nsIntPoint(0, 0), mFilterSpaceSize);
aRect->IntersectRect(*aRect, filterSpace);
}
/**
* The frame for the element that is currently being filtered.
*/
nsIFrame* mTargetFrame;
nsSVGFilterPaintCallback* mPaintCallback;
const mozilla::dom::SVGFilterElement* mFilterElement;
/**
* The SVG bbox of the element that is being filtered, in user space.
*/
gfxRect mTargetBBox;
gfxMatrix mFilterSpaceToDeviceSpaceTransform;
gfxMatrix mFilterSpaceToFrameSpaceInCSSPxTransform;
gfxRect mFilterRegion;
nsIntSize mFilterSpaceSize;
nsIntRect mSurfaceRect;
/**
* Pre-filter paint bounds of the element that is being filtered, in filter
* space.
*/
nsIntRect mTargetBounds;
/**
* If set, this is the filter space bounds of the outer-<svg> device space
* bounds of the dirty area that needs to be repainted. (As bounds-of-bounds,
* this may be a fair bit bigger than we actually need, unfortunately.)
*/
nsIntRect mPostFilterDirtyRect;
/**
* If set, this is the filter space bounds of the outer-<svg> device bounds
* of the pre-filter area of the filtered element that changed. (As
* bounds-of-bounds, this may be a fair bit bigger than we actually need,
* unfortunately.)
*/
nsIntRect mPreFilterDirtyRect;
/**
* The 'primitiveUnits' attribute value (objectBoundingBox or userSpaceOnUse).
*/
uint16_t mPrimitiveUnits;
PrimitiveInfo mSourceColorAlpha;
PrimitiveInfo mSourceAlpha;
PrimitiveInfo mFillPaint;
PrimitiveInfo mStrokePaint;
nsTArray<PrimitiveInfo> mPrimitives;
};
#endif