1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/layout/svg/nsSVGFilterInstance.h Wed Dec 31 06:09:35 2014 +0100
1.3 @@ -0,0 +1,246 @@
1.4 +/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
1.5 +/* This Source Code Form is subject to the terms of the Mozilla Public
1.6 + * License, v. 2.0. If a copy of the MPL was not distributed with this
1.7 + * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
1.8 +
1.9 +#ifndef __NS_SVGFILTERINSTANCE_H__
1.10 +#define __NS_SVGFILTERINSTANCE_H__
1.11 +
1.12 +#include "gfxMatrix.h"
1.13 +#include "gfxRect.h"
1.14 +#include "nsSVGFilters.h"
1.15 +#include "nsSVGNumber2.h"
1.16 +#include "nsSVGNumberPair.h"
1.17 +#include "nsTArray.h"
1.18 +#include "nsIFrame.h"
1.19 +
1.20 +class nsIFrame;
1.21 +class nsSVGFilterFrame;
1.22 +class nsSVGFilterPaintCallback;
1.23 +
1.24 +namespace mozilla {
1.25 +namespace dom {
1.26 +class SVGFilterElement;
1.27 +}
1.28 +}
1.29 +
1.30 +/**
1.31 + * This class helps nsFilterInstance build its filter graph by processing a
1.32 + * single SVG reference filter.
1.33 + *
1.34 + * In BuildPrimitives, this class iterates through the referenced <filter>
1.35 + * element's primitive elements, creating a FilterPrimitiveDescription for
1.36 + * each one.
1.37 + *
1.38 + * This class uses several different coordinate spaces, defined as follows:
1.39 + *
1.40 + * "user space"
1.41 + * The filtered SVG element's user space or the filtered HTML element's
1.42 + * CSS pixel space. The origin for an HTML element is the top left corner of
1.43 + * its border box.
1.44 + *
1.45 + * "filter space"
1.46 + * User space scaled to device pixels. Shares the same origin as user space.
1.47 + * This space is the same across chained SVG and CSS filters. To compute the
1.48 + * overall filter space for a chain, we first need to build each filter's
1.49 + * FilterPrimitiveDescriptions in some common space. That space is
1.50 + * filter space.
1.51 + *
1.52 + * To understand the spaces better, let's take an example filter:
1.53 + * <filter id="f">...</filter>
1.54 + *
1.55 + * And apply the filter to a div element:
1.56 + * <div style="filter: url(#f); ...">...</div>
1.57 + *
1.58 + * And let's say there are 2 device pixels for every 1 CSS pixel.
1.59 + *
1.60 + * Finally, let's define an arbitrary point in user space:
1.61 + * "user space point" = (10, 10)
1.62 + *
1.63 + * The point will be inset 10 CSS pixels from both the top and left edges of the
1.64 + * div element's border box.
1.65 + *
1.66 + * Now, let's transform the point from user space to filter space:
1.67 + * "filter space point" = "user space point" * "device pixels per CSS pixel"
1.68 + * "filter space point" = (10, 10) * 2
1.69 + * "filter space point" = (20, 20)
1.70 + */
1.71 +class nsSVGFilterInstance
1.72 +{
1.73 + typedef mozilla::gfx::Point3D Point3D;
1.74 + typedef mozilla::gfx::IntRect IntRect;
1.75 + typedef mozilla::gfx::SourceSurface SourceSurface;
1.76 + typedef mozilla::gfx::FilterPrimitiveDescription FilterPrimitiveDescription;
1.77 +
1.78 +public:
1.79 + /**
1.80 + * @param aFilter The SVG reference filter to process.
1.81 + * @param aTargetFrame The frame of the filtered element under consideration.
1.82 + * @param aTargetBBox The SVG bbox to use for the target frame, computed by
1.83 + * the caller. The caller may decide to override the actual SVG bbox.
1.84 + */
1.85 + nsSVGFilterInstance(const nsStyleFilter& aFilter,
1.86 + nsIFrame *aTargetFrame,
1.87 + const gfxRect& aTargetBBox,
1.88 + const gfxSize& aUserSpaceToFilterSpaceScale,
1.89 + const gfxSize& aFilterSpaceToUserSpaceScale);
1.90 +
1.91 + /**
1.92 + * Returns true if the filter instance was created successfully.
1.93 + */
1.94 + bool IsInitialized() const { return mInitialized; }
1.95 +
1.96 + /**
1.97 + * Iterates through the <filter> element's primitive elements, creating a
1.98 + * FilterPrimitiveDescription for each one. Appends the new
1.99 + * FilterPrimitiveDescription(s) to the aPrimitiveDescrs list. Also, appends
1.100 + * new images from feImage filter primitive elements to the aInputImages list.
1.101 + */
1.102 + nsresult BuildPrimitives(nsTArray<FilterPrimitiveDescription>& aPrimitiveDescrs,
1.103 + nsTArray<mozilla::RefPtr<SourceSurface>>& aInputImages);
1.104 +
1.105 + /**
1.106 + * Returns the user specified "filter region", in the filtered element's user
1.107 + * space, after it has been adjusted out (if necessary) so that its edges
1.108 + * coincide with pixel boundaries of the offscreen surface into which the
1.109 + * filtered output would/will be painted.
1.110 + */
1.111 + gfxRect GetFilterRegion() const { return mUserSpaceBounds; }
1.112 +
1.113 + /**
1.114 + * Returns the size of the user specified "filter region", in filter space.
1.115 + */
1.116 + nsIntRect GetFilterSpaceBounds() const { return mFilterSpaceBounds; }
1.117 +
1.118 + float GetPrimitiveNumber(uint8_t aCtxType, const nsSVGNumber2 *aNumber) const
1.119 + {
1.120 + return GetPrimitiveNumber(aCtxType, aNumber->GetAnimValue());
1.121 + }
1.122 + float GetPrimitiveNumber(uint8_t aCtxType, const nsSVGNumberPair *aNumberPair,
1.123 + nsSVGNumberPair::PairIndex aIndex) const
1.124 + {
1.125 + return GetPrimitiveNumber(aCtxType, aNumberPair->GetAnimValue(aIndex));
1.126 + }
1.127 +
1.128 + /**
1.129 + * Converts a userSpaceOnUse/objectBoundingBoxUnits unitless point
1.130 + * into filter space, depending on the value of mPrimitiveUnits. (For
1.131 + * objectBoundingBoxUnits, the bounding box offset is applied to the point.)
1.132 + */
1.133 + Point3D ConvertLocation(const Point3D& aPoint) const;
1.134 +
1.135 + /**
1.136 + * Transform a rect between user space and filter space.
1.137 + */
1.138 + gfxRect UserSpaceToFilterSpace(const gfxRect& aUserSpaceRect) const;
1.139 +
1.140 +private:
1.141 + /**
1.142 + * Finds the filter frame associated with this SVG filter.
1.143 + */
1.144 + nsSVGFilterFrame* GetFilterFrame();
1.145 +
1.146 + /**
1.147 + * Computes the filter primitive subregion for the given primitive.
1.148 + */
1.149 + IntRect ComputeFilterPrimitiveSubregion(nsSVGFE* aFilterElement,
1.150 + const nsTArray<FilterPrimitiveDescription>& aPrimitiveDescrs,
1.151 + const nsTArray<int32_t>& aInputIndices);
1.152 +
1.153 + /**
1.154 + * Takes the input indices of a filter primitive and returns for each input
1.155 + * whether the input's output is tainted.
1.156 + */
1.157 + void GetInputsAreTainted(const nsTArray<FilterPrimitiveDescription>& aPrimitiveDescrs,
1.158 + const nsTArray<int32_t>& aInputIndices,
1.159 + nsTArray<bool>& aOutInputsAreTainted);
1.160 +
1.161 + /**
1.162 + * Scales a numeric filter primitive length in the X, Y or "XY" directions
1.163 + * into a length in filter space (no offset is applied).
1.164 + */
1.165 + float GetPrimitiveNumber(uint8_t aCtxType, float aValue) const;
1.166 +
1.167 + /**
1.168 + * Transform a rect between user space and filter space.
1.169 + */
1.170 + gfxRect FilterSpaceToUserSpace(const gfxRect& aFilterSpaceRect) const;
1.171 +
1.172 + /**
1.173 + * Returns the transform from frame space to the coordinate space that
1.174 + * GetCanvasTM transforms to. "Frame space" is the origin of a frame, aka the
1.175 + * top-left corner of its border box, aka the top left corner of its mRect.
1.176 + */
1.177 + gfxMatrix GetUserSpaceToFrameSpaceInCSSPxTransform() const;
1.178 +
1.179 + /**
1.180 + * Finds the index in aPrimitiveDescrs of each input to aPrimitiveElement.
1.181 + * For example, if aPrimitiveElement is:
1.182 + * <feGaussianBlur in="another-primitive" .../>
1.183 + * Then, the resulting aSourceIndices will contain the index of the
1.184 + * FilterPrimitiveDescription representing "another-primitive".
1.185 + */
1.186 + nsresult GetSourceIndices(nsSVGFE* aPrimitiveElement,
1.187 + const nsTArray<FilterPrimitiveDescription>& aPrimitiveDescrs,
1.188 + const nsDataHashtable<nsStringHashKey, int32_t>& aImageTable,
1.189 + nsTArray<int32_t>& aSourceIndices);
1.190 +
1.191 + /**
1.192 + * Compute the filter region in user space, filter space, and filter
1.193 + * space.
1.194 + */
1.195 + nsresult ComputeBounds();
1.196 +
1.197 + /**
1.198 + * The SVG reference filter originally from the style system.
1.199 + */
1.200 + const nsStyleFilter mFilter;
1.201 +
1.202 + /**
1.203 + * The frame for the element that is currently being filtered.
1.204 + */
1.205 + nsIFrame* mTargetFrame;
1.206 +
1.207 + /**
1.208 + * The filter element referenced by mTargetFrame's element.
1.209 + */
1.210 + const mozilla::dom::SVGFilterElement* mFilterElement;
1.211 +
1.212 + /**
1.213 + * The frame for the SVG filter element.
1.214 + */
1.215 + nsSVGFilterFrame* mFilterFrame;
1.216 +
1.217 + /**
1.218 + * The SVG bbox of the element that is being filtered, in user space.
1.219 + */
1.220 + gfxRect mTargetBBox;
1.221 +
1.222 + /**
1.223 + * The "filter region" in various spaces.
1.224 + */
1.225 + gfxRect mUserSpaceBounds;
1.226 + nsIntRect mFilterSpaceBounds;
1.227 +
1.228 + /**
1.229 + * The scale factors between user space and filter space.
1.230 + */
1.231 + gfxSize mUserSpaceToFilterSpaceScale;
1.232 + gfxSize mFilterSpaceToUserSpaceScale;
1.233 +
1.234 + /**
1.235 + * The 'primitiveUnits' attribute value (objectBoundingBox or userSpaceOnUse).
1.236 + */
1.237 + uint16_t mPrimitiveUnits;
1.238 +
1.239 + /**
1.240 + * The index of the FilterPrimitiveDescription that this SVG filter should use
1.241 + * as its SourceGraphic, or the SourceGraphic keyword index if this is the
1.242 + * first filter in a chain.
1.243 + */
1.244 + int32_t mSourceGraphicIndex;
1.245 +
1.246 + bool mInitialized;
1.247 +};
1.248 +
1.249 +#endif
