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Bug 745066 - Add comments documenting the declaration of nsSVGFilterInstance, its methods and its members. r=longsonr.

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This commit is contained in:
Jonathan Watt 2012-04-13 14:22:06 +01:00
parent 3038face63
commit e0223efe12
3 changed files with 242 additions and 49 deletions
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11
layout/svg/base/src/nsSVGFilterFrame.cpp
View File

@ -100,7 +100,7 @@ public:
const nsIntRect *aDirtyOutputRect,
const nsIntRect *aDirtyInputRect,
const nsIntRect *aOverrideSourceBBox);
~nsAutoFilterInstance();
~nsAutoFilterInstance() {}
// If this returns null, then draw nothing. Either the filter draws
// nothing or it is "in error".
@ -108,9 +108,6 @@ public:
private:
nsAutoPtr<nsSVGFilterInstance> mInstance;
// Store mTarget separately even though mInstance has it, because if
// mInstance creation fails we still need to be able to clean up
nsISVGChildFrame* mTarget;
};
nsAutoFilterInstance::nsAutoFilterInstance(nsIFrame *aTarget,
@ -120,8 +117,6 @@ nsAutoFilterInstance::nsAutoFilterInstance(nsIFrame *aTarget,
const nsIntRect *aDirtyInputRect,
const nsIntRect *aOverrideSourceBBox)
{
mTarget = do_QueryFrame(aTarget);
const nsSVGFilterElement *filter = aFilterFrame->GetFilterContent();
PRUint16 filterUnits =
@ -247,10 +242,6 @@ nsAutoFilterInstance::nsAutoFilterInstance(nsIFrame *aTarget,
primitiveUnits);
}
nsAutoFilterInstance::~nsAutoFilterInstance()
{
}
PRUint16
nsSVGFilterFrame::GetEnumValue(PRUint32 aIndex, nsIContent *aDefault)
{

276
layout/svg/base/src/nsSVGFilterInstance.h
View File

@ -62,10 +62,42 @@ class nsSVGFilterPaintCallback;
* 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 returned by GetFilterRect,
* specifically), and with one unit equal in size to one pixel of the offscreen
* surface into which the filter output would/will be painted.
*/
class NS_STACK_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 aFilterRect 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 aDirtyOutputRect [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 aDirtyInputRect [optional] The bounds of the pre-filter area of the
* filtered element that changed, in filter space. Only required if you
* will call ComputeOutputDirtyRect().
* @param aPrimitiveUnits The value from the 'primitiveUnits' attribute.
*/
nsSVGFilterInstance(nsIFrame *aTargetFrame,
nsSVGFilterPaintCallback *aPaintCallback,
const nsSVGFilterElement *aFilterElement,
@ -84,29 +116,75 @@ public:
mFilterSpaceToDeviceSpaceTransform(aFilterSpaceToDeviceSpaceTransform),
mFilterRect(aFilterRect),
mFilterSpaceSize(aFilterSpaceSize),
mSurfaceRect(nsIntPoint(0, 0), aFilterSpaceSize),
mTargetBounds(aTargetBounds),
mDirtyOutputRect(aDirtyOutputRect),
mDirtyInputRect(aDirtyInputRect),
mSurfaceRect(nsIntPoint(0, 0), aFilterSpaceSize),
mPrimitiveUnits(aPrimitiveUnits) {
}
// The area covered by temporary images, in filter space
void SetSurfaceRect(const nsIntRect& aRect) { mSurfaceRect = aRect; }
/**
* 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 GetFilterRect() const { return mFilterRect; }
/**
* 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; }
PRUint32 GetFilterResX() const { return mFilterSpaceSize.width; }
PRUint32 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; }
PRInt32 GetSurfaceWidth() const { return mSurfaceRect.width; }
PRInt32 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 aDirtyOutputRect argument to the
* nsSVGFilterInstance constructor.
*/
nsresult Render(gfxASurface** aOutput);
/**
* Sets the aDirty 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 aDirtyInputRect argument
* to the nsSVGFilterInstance constructor.
*/
nsresult ComputeOutputDirtyRect(nsIntRect* aDirty);
/**
* 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 aDirtyOutputRect
* 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(PRUint8 aCtxType, const nsSVGNumber2 *aNumber) const
@ -118,17 +196,27 @@ public:
{
return GetPrimitiveNumber(aCtxType, aNumberPair->GetAnimValue(aIndex));
}
/**
* Converts a point and a length in filter primitive units into filter space.
* For object-bounding-box units, the object bounding box offset is applied
* to the point.
* 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;
private:
@ -136,19 +224,50 @@ private:
typedef nsSVGFE::ColorModel ColorModel;
struct PrimitiveInfo {
/// Pointer to the filter primitive element.
nsSVGFE* mFE;
// the bounding box of the result image produced by this primitive, in
// filter space
/**
* 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 bounding box of the part of the result image that is actually
// needed by other primitives or by the filter result, in filter space
// (used for Render only)
/**
* 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 bounding box of the part of the result image that could be
// changed by changes to mDirtyInputRect in the source image(s)
// (used for ComputeOutputDirtyRect only)
/**
* 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.
*/
PRInt32 mImageUsers;
// Can't use nsAutoTArray here, because these Info objects
@ -168,27 +287,76 @@ private:
PrimitiveInfo* mInfo;
};
/**
* Initializes the SourceGraphic and SourceAlpha graph nodes (i.e. sets
* .mImage.mFilterPrimitiveSubregion and .mResultBoundingBox on
* mSourceColorAlpha and mSourceAlpha).
*/
nsresult BuildSources();
// Build graph of PrimitiveInfo nodes describing filter primitives
nsresult BuildPrimitives();
// Compute bounding boxes of the filter primitive outputs
void ComputeResultBoundingBoxes();
// Compute bounding boxes of what we actually *need* from the filter
// primitive outputs
void ComputeNeededBoxes();
// Compute bounding boxes of what could have changed given some changes
// to the source images.
void ComputeResultChangeBoxes();
nsIntRect ComputeUnionOfAllNeededBoxes();
/**
* 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();
// Allocates an image surface that covers mSurfaceRect (it uses
// device offsets so that its origin is positioned at mSurfaceRect.TopLeft()
// when using cairo to draw into the surface). The surface is cleared
// to transparent black.
/**
* 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 mDirtyOutputRect.
* 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 mDirtyInputRect.
* 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);
@ -199,26 +367,58 @@ private:
float GetPrimitiveNumber(PRUint8 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);
}
void ClipToGfxRect(nsIntRect* aRect, const gfxRect& aGfx) const;
/**
* The frame for the element that is currently being filtered.
*/
nsIFrame* mTargetFrame;
nsSVGFilterPaintCallback* mPaintCallback;
const nsSVGFilterElement* mFilterElement;
// Bounding box of the target element, in user space
/**
* The SVG bbox of the element that is being filtered, in user space.
*/
gfxRect mTargetBBox;
gfxMatrix mFilterSpaceToDeviceSpaceTransform;
gfxRect mFilterRect;
nsIntSize mFilterSpaceSize;
// Filter-space bounds of the target image (SourceAlpha/SourceGraphic)
nsIntRect mTargetBounds;
nsIntRect mDirtyOutputRect;
nsIntRect mDirtyInputRect;
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 mDirtyOutputRect;
/**
* 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 mDirtyInputRect;
/**
* The 'primitiveUnits' attribute value (objectBoundingBox or userSpaceOnUse).
*/
PRUint16 mPrimitiveUnits;
PrimitiveInfo mSourceColorAlpha;

4
layout/svg/base/src/nsSVGUtils.h
View File

@ -542,7 +542,9 @@ public:
static gfxRect GetBBox(nsIFrame *aFrame, PRUint32 aFlags = eBBoxIncludeFill);
/**
* Compute a rectangle in userSpaceOnUse or objectBoundingBoxUnits.
* Convert a userSpaceOnUse/objectBoundingBoxUnits rectangle that's specified
* using four nsSVGLength2 values into a user unit rectangle in user space.
*
* @param aXYWH pointer to 4 consecutive nsSVGLength2 objects containing
* the x, y, width and height values in that order
* @param aBBox the bounding box of the object the rect is relative to;