gecko/layout/svg/nsFilterInstance.h
2014-04-24 10:25:17 +02:00

323 lines
12 KiB
C++

/* -*- 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 gfxASurface;
class nsIFrame;
class nsSVGFilterPaintCallback;
/**
* 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;
public:
/**
* 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(nsRenderingContext *aContext,
nsIFrame *aFilteredFrame,
nsSVGFilterPaintCallback *aPaintCallback,
const nsRegion* aDirtyArea,
nsIFrame* aTransformRoot = nullptr);
/**
* 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.
* @param aPaintCallback [optional] The callback that Render() should use to
* paint. Only required if you will call Render().
* @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.
* @param aTransformRoot [optional] The transform root frame for painting.
*/
nsFilterInstance(nsIFrame *aTargetFrame,
nsSVGFilterPaintCallback *aPaintCallback,
const nsRegion *aPostFilterDirtyRegion = nullptr,
const nsRegion *aPreFilterDirtyRegion = nullptr,
const nsRect *aOverridePreFilterVisualOverflowRect = nullptr,
const gfxRect *aOverrideBBox = nullptr,
nsIFrame* aTransformRoot = nullptr);
/**
* Returns true if the filter instance was created successfully.
*/
bool IsInitialized() const { return mInitialized; }
/**
* Draws the filter output into aContext. 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(gfxContext* aContext);
/**
* 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.
*/
nsresult ComputePostFilterDirtyRegion(nsRegion* aPostFilterDirtyRegion);
/**
* 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.
*/
nsresult ComputePostFilterExtents(nsRect* aPostFilterExtents);
/**
* 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.
*/
nsresult ComputeSourceNeededRect(nsRect* aDirty);
/**
* 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.
mozilla::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,
gfxASurface* aTargetSurface,
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(gfxASurface* aTargetSurface,
DrawTarget* aTargetDT);
/**
* Creates the SourceSurface for the SourceGraphic graph node, paints its
* contents, and assigns it to mSourceGraphic.mSourceSurface.
*/
nsresult BuildSourceImage(gfxASurface* aTargetSurface,
DrawTarget* aTargetDT);
/**
* Build the list of FilterPrimitiveDescriptions that describes the filter's
* filter primitives and their connections. This populates
* mPrimitiveDescriptions and mInputImages.
*/
nsresult BuildPrimitives();
/**
* Add to the list of FilterPrimitiveDescriptions for a particular SVG
* reference filter or CSS filter. This populates mPrimitiveDescrs and
* mInputImages.
*/
nsresult BuildPrimitivesForFilter(const nsStyleFilter& aFilter);
/**
* 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();
/**
* 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;
nsSVGFilterPaintCallback* mPaintCallback;
/**
* The SVG bbox of the element that is being filtered, in user space.
*/
gfxRect mTargetBBox;
/**
* 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 "filter region", in the filtered element's user space.
*/
gfxRect mUserSpaceBounds;
nsIntRect mFilterSpaceBounds;
/**
* 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;
nsIFrame* mTransformRoot;
nsTArray<mozilla::RefPtr<SourceSurface>> mInputImages;
nsTArray<FilterPrimitiveDescription> mPrimitiveDescriptions;
int32_t mAppUnitsPerCSSPx;
bool mInitialized;
};
#endif