michael@0: /* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
michael@0: /* This Source Code Form is subject to the terms of the Mozilla Public
michael@0:  * License, v. 2.0. If a copy of the MPL was not distributed with this
michael@0:  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
michael@0: 
michael@0: #ifndef __NS_SVGFILTERINSTANCE_H__
michael@0: #define __NS_SVGFILTERINSTANCE_H__
michael@0: 
michael@0: #include "gfxMatrix.h"
michael@0: #include "gfxRect.h"
michael@0: #include "nsSVGFilters.h"
michael@0: #include "nsSVGNumber2.h"
michael@0: #include "nsSVGNumberPair.h"
michael@0: #include "nsTArray.h"
michael@0: #include "nsIFrame.h"
michael@0: 
michael@0: class nsIFrame;
michael@0: class nsSVGFilterFrame;
michael@0: class nsSVGFilterPaintCallback;
michael@0: 
michael@0: namespace mozilla {
michael@0: namespace dom {
michael@0: class SVGFilterElement;
michael@0: }
michael@0: }
michael@0: 
michael@0: /**
michael@0:  * This class helps nsFilterInstance build its filter graph by processing a
michael@0:  * single SVG reference filter.
michael@0:  *
michael@0:  * In BuildPrimitives, this class iterates through the referenced <filter>
michael@0:  * element's primitive elements, creating a FilterPrimitiveDescription for
michael@0:  * each one.
michael@0:  *
michael@0:  * This class uses several different coordinate spaces, defined as follows:
michael@0:  *
michael@0:  * "user space"
michael@0:  *   The filtered SVG element's user space or the filtered HTML element's
michael@0:  *   CSS pixel space. The origin for an HTML element is the top left corner of
michael@0:  *   its border box.
michael@0:  *
michael@0:  * "filter space"
michael@0:  *   User space scaled to device pixels. Shares the same origin as user space.
michael@0:  *   This space is the same across chained SVG and CSS filters. To compute the
michael@0:  *   overall filter space for a chain, we first need to build each filter's
michael@0:  *   FilterPrimitiveDescriptions in some common space. That space is
michael@0:  *   filter space.
michael@0:  *
michael@0:  * To understand the spaces better, let's take an example filter:
michael@0:  *   <filter id="f">...</filter>
michael@0:  *
michael@0:  * And apply the filter to a div element:
michael@0:  *   <div style="filter: url(#f); ...">...</div>
michael@0:  *
michael@0:  * And let's say there are 2 device pixels for every 1 CSS pixel.
michael@0:  *
michael@0:  * Finally, let's define an arbitrary point in user space:
michael@0:  *   "user space point" = (10, 10)
michael@0:  *
michael@0:  * The point will be inset 10 CSS pixels from both the top and left edges of the
michael@0:  * div element's border box.
michael@0:  *
michael@0:  * Now, let's transform the point from user space to filter space:
michael@0:  *   "filter space point" = "user space point" * "device pixels per CSS pixel"
michael@0:  *   "filter space point" = (10, 10) * 2
michael@0:  *   "filter space point" = (20, 20)
michael@0:  */
michael@0: class nsSVGFilterInstance
michael@0: {
michael@0:   typedef mozilla::gfx::Point3D Point3D;
michael@0:   typedef mozilla::gfx::IntRect IntRect;
michael@0:   typedef mozilla::gfx::SourceSurface SourceSurface;
michael@0:   typedef mozilla::gfx::FilterPrimitiveDescription FilterPrimitiveDescription;
michael@0: 
michael@0: public:
michael@0:   /**
michael@0:    * @param aFilter The SVG reference filter to process.
michael@0:    * @param aTargetFrame The frame of the filtered element under consideration.
michael@0:    * @param aTargetBBox The SVG bbox to use for the target frame, computed by
michael@0:    *   the caller. The caller may decide to override the actual SVG bbox.
michael@0:    */
michael@0:   nsSVGFilterInstance(const nsStyleFilter& aFilter,
michael@0:                       nsIFrame *aTargetFrame,
michael@0:                       const gfxRect& aTargetBBox,
michael@0:                       const gfxSize& aUserSpaceToFilterSpaceScale,
michael@0:                       const gfxSize& aFilterSpaceToUserSpaceScale);
michael@0: 
michael@0:   /**
michael@0:    * Returns true if the filter instance was created successfully.
michael@0:    */
michael@0:   bool IsInitialized() const { return mInitialized; }
michael@0: 
michael@0:   /**
michael@0:    * Iterates through the <filter> element's primitive elements, creating a
michael@0:    * FilterPrimitiveDescription for each one. Appends the new
michael@0:    * FilterPrimitiveDescription(s) to the aPrimitiveDescrs list. Also, appends
michael@0:    * new images from feImage filter primitive elements to the aInputImages list.
michael@0:    */
michael@0:   nsresult BuildPrimitives(nsTArray<FilterPrimitiveDescription>& aPrimitiveDescrs,
michael@0:                            nsTArray<mozilla::RefPtr<SourceSurface>>& aInputImages);
michael@0: 
michael@0:   /**
michael@0:    * Returns the user specified "filter region", in the filtered element's user
michael@0:    * space, after it has been adjusted out (if necessary) so that its edges
michael@0:    * coincide with pixel boundaries of the offscreen surface into which the
michael@0:    * filtered output would/will be painted.
michael@0:    */
michael@0:   gfxRect GetFilterRegion() const { return mUserSpaceBounds; }
michael@0: 
michael@0:   /**
michael@0:    * Returns the size of the user specified "filter region", in filter space.
michael@0:    */
michael@0:   nsIntRect GetFilterSpaceBounds() const { return mFilterSpaceBounds; }
michael@0: 
michael@0:   float GetPrimitiveNumber(uint8_t aCtxType, const nsSVGNumber2 *aNumber) const
michael@0:   {
michael@0:     return GetPrimitiveNumber(aCtxType, aNumber->GetAnimValue());
michael@0:   }
michael@0:   float GetPrimitiveNumber(uint8_t aCtxType, const nsSVGNumberPair *aNumberPair,
michael@0:                            nsSVGNumberPair::PairIndex aIndex) const
michael@0:   {
michael@0:     return GetPrimitiveNumber(aCtxType, aNumberPair->GetAnimValue(aIndex));
michael@0:   }
michael@0: 
michael@0:   /**
michael@0:    * Converts a userSpaceOnUse/objectBoundingBoxUnits unitless point
michael@0:    * into filter space, depending on the value of mPrimitiveUnits. (For
michael@0:    * objectBoundingBoxUnits, the bounding box offset is applied to the point.)
michael@0:    */
michael@0:   Point3D ConvertLocation(const Point3D& aPoint) const;
michael@0: 
michael@0:   /**
michael@0:    * Transform a rect between user space and filter space.
michael@0:    */
michael@0:   gfxRect UserSpaceToFilterSpace(const gfxRect& aUserSpaceRect) const;
michael@0: 
michael@0: private:
michael@0:   /**
michael@0:    * Finds the filter frame associated with this SVG filter.
michael@0:    */
michael@0:   nsSVGFilterFrame* GetFilterFrame();
michael@0: 
michael@0:   /**
michael@0:    * Computes the filter primitive subregion for the given primitive.
michael@0:    */
michael@0:   IntRect ComputeFilterPrimitiveSubregion(nsSVGFE* aFilterElement,
michael@0:                                           const nsTArray<FilterPrimitiveDescription>& aPrimitiveDescrs,
michael@0:                                           const nsTArray<int32_t>& aInputIndices);
michael@0: 
michael@0:   /**
michael@0:    * Takes the input indices of a filter primitive and returns for each input
michael@0:    * whether the input's output is tainted.
michael@0:    */
michael@0:   void GetInputsAreTainted(const nsTArray<FilterPrimitiveDescription>& aPrimitiveDescrs,
michael@0:                            const nsTArray<int32_t>& aInputIndices,
michael@0:                            nsTArray<bool>& aOutInputsAreTainted);
michael@0: 
michael@0:   /**
michael@0:    * Scales a numeric filter primitive length in the X, Y or "XY" directions
michael@0:    * into a length in filter space (no offset is applied).
michael@0:    */
michael@0:   float GetPrimitiveNumber(uint8_t aCtxType, float aValue) const;
michael@0: 
michael@0:   /**
michael@0:    * Transform a rect between user space and filter space.
michael@0:    */
michael@0:   gfxRect FilterSpaceToUserSpace(const gfxRect& aFilterSpaceRect) const;
michael@0: 
michael@0:   /**
michael@0:    * Returns the transform from frame space to the coordinate space that
michael@0:    * GetCanvasTM transforms to. "Frame space" is the origin of a frame, aka the
michael@0:    * top-left corner of its border box, aka the top left corner of its mRect.
michael@0:    */
michael@0:   gfxMatrix GetUserSpaceToFrameSpaceInCSSPxTransform() const;
michael@0: 
michael@0:   /**
michael@0:    * Finds the index in aPrimitiveDescrs of each input to aPrimitiveElement.
michael@0:    * For example, if aPrimitiveElement is:
michael@0:    *   <feGaussianBlur in="another-primitive" .../>
michael@0:    * Then, the resulting aSourceIndices will contain the index of the
michael@0:    * FilterPrimitiveDescription representing "another-primitive".
michael@0:    */
michael@0:   nsresult GetSourceIndices(nsSVGFE* aPrimitiveElement,
michael@0:                             const nsTArray<FilterPrimitiveDescription>& aPrimitiveDescrs,
michael@0:                             const nsDataHashtable<nsStringHashKey, int32_t>& aImageTable,
michael@0:                             nsTArray<int32_t>& aSourceIndices);
michael@0: 
michael@0:   /**
michael@0:    * Compute the filter region in user space, filter space, and filter
michael@0:    * space.
michael@0:    */
michael@0:   nsresult ComputeBounds();
michael@0: 
michael@0:   /**
michael@0:    * The SVG reference filter originally from the style system.
michael@0:    */
michael@0:   const nsStyleFilter mFilter;
michael@0: 
michael@0:   /**
michael@0:    * The frame for the element that is currently being filtered.
michael@0:    */
michael@0:   nsIFrame*               mTargetFrame;
michael@0: 
michael@0:   /**
michael@0:    * The filter element referenced by mTargetFrame's element.
michael@0:    */
michael@0:   const mozilla::dom::SVGFilterElement* mFilterElement;
michael@0: 
michael@0:   /**
michael@0:    * The frame for the SVG filter element.
michael@0:    */
michael@0:   nsSVGFilterFrame* mFilterFrame;
michael@0: 
michael@0:   /**
michael@0:    * The SVG bbox of the element that is being filtered, in user space.
michael@0:    */
michael@0:   gfxRect                 mTargetBBox;
michael@0: 
michael@0:   /**
michael@0:    * The "filter region" in various spaces.
michael@0:    */
michael@0:   gfxRect                 mUserSpaceBounds;
michael@0:   nsIntRect               mFilterSpaceBounds;
michael@0: 
michael@0:   /**
michael@0:    * The scale factors between user space and filter space.
michael@0:    */
michael@0:   gfxSize                 mUserSpaceToFilterSpaceScale;
michael@0:   gfxSize                 mFilterSpaceToUserSpaceScale;
michael@0: 
michael@0:   /**
michael@0:    * The 'primitiveUnits' attribute value (objectBoundingBox or userSpaceOnUse).
michael@0:    */
michael@0:   uint16_t                mPrimitiveUnits;
michael@0: 
michael@0:   /**
michael@0:    * The index of the FilterPrimitiveDescription that this SVG filter should use
michael@0:    * as its SourceGraphic, or the SourceGraphic keyword index if this is the
michael@0:    * first filter in a chain.
michael@0:    */
michael@0:   int32_t mSourceGraphicIndex;
michael@0: 
michael@0:   bool                    mInitialized;
michael@0: };
michael@0: 
michael@0: #endif