layout/svg/SVGIntegrationUtils.cpp

   1 /* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
   2 /* vim: set ts=8 sts=2 et sw=2 tw=80: */
   3 /* This Source Code Form is subject to the terms of the Mozilla Public
   4  * License, v. 2.0. If a copy of the MPL was not distributed with this
   5  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
   6
   7 // Main header first:
   8 #include "SVGIntegrationUtils.h"
   9
  10 // Keep others in (case-insensitive) order:
  11 #include "gfxDrawable.h"
  12
  13 #include "nsCSSAnonBoxes.h"
  14 #include "nsCSSRendering.h"
  15 #include "nsDisplayList.h"
  16 #include "nsLayoutUtils.h"
  17 #include "gfxContext.h"
  18 #include "SVGPaintServerFrame.h"
  19 #include "mozilla/gfx/Point.h"
  20 #include "mozilla/CSSClipPathInstance.h"
  21 #include "mozilla/FilterInstance.h"
  22 #include "mozilla/StaticPrefs_layers.h"
  23 #include "mozilla/SVGClipPathFrame.h"
  24 #include "mozilla/SVGObserverUtils.h"
  25 #include "mozilla/SVGMaskFrame.h"
  26 #include "mozilla/SVGUtils.h"
  27 #include "mozilla/Unused.h"
  28 #include "mozilla/dom/SVGElement.h"
  29
  30 using namespace mozilla::dom;
  31 using namespace mozilla::layers;
  32 using namespace mozilla::gfx;
  33 using namespace mozilla::image;
  34
  35 namespace mozilla {
  36
  37 /**
  38  * This class is used to get the pre-effects ink overflow rect of a frame,
  39  * or, in the case of a frame with continuations, to collect the union of the
  40  * pre-effects ink overflow rects of all the continuations. The result is
  41  * relative to the origin (top left corner of the border box) of the frame, or,
  42  * if the frame has continuations, the origin of the  _first_ continuation.
  43  */
  44 class PreEffectsInkOverflowCollector : public nsLayoutUtils::BoxCallback {
  45  public:
  46   /**
  47    * If the pre-effects ink overflow rect of the frame being examined
  48    * happens to be known, it can be passed in as aCurrentFrame and its
  49    * pre-effects ink overflow rect can be passed in as
  50    * aCurrentFrameOverflowArea. This is just an optimization to save a
  51    * frame property lookup - these arguments are optional.
  52    */
  53   PreEffectsInkOverflowCollector(nsIFrame* aFirstContinuation,
  54                                  nsIFrame* aCurrentFrame,
  55                                  const nsRect& aCurrentFrameOverflowArea,
  56                                  bool aInReflow)
  57       : mFirstContinuation(aFirstContinuation),
  58         mCurrentFrame(aCurrentFrame),
  59         mCurrentFrameOverflowArea(aCurrentFrameOverflowArea),
  60         mInReflow(aInReflow) {
  61     NS_ASSERTION(!mFirstContinuation->GetPrevContinuation(),
  62                  "We want the first continuation here");
  63   }
  64
  65   void AddBox(nsIFrame* aFrame) override {
  66     nsRect overflow = (aFrame == mCurrentFrame)
  67                           ? mCurrentFrameOverflowArea
  68                           : PreEffectsInkOverflowRect(aFrame, mInReflow);
  69     mResult.UnionRect(mResult,
  70                       overflow + aFrame->GetOffsetTo(mFirstContinuation));
  71   }
  72
  73   nsRect GetResult() const { return mResult; }
  74
  75  private:
  76   static nsRect PreEffectsInkOverflowRect(nsIFrame* aFrame, bool aInReflow) {
  77     nsRect* r = aFrame->GetProperty(nsIFrame::PreEffectsBBoxProperty());
  78     if (r) {
  79       return *r;
  80     }
  81
  82 #ifdef DEBUG
  83     // Having PreTransformOverflowAreasProperty cached means
  84     // InkOverflowRect() will return post-effect rect, which is not what
  85     // we want. This function intentional reports pre-effect rect. But it does
  86     // not matter if there is no SVG effect on this frame, since no effect
  87     // means post-effect rect matches pre-effect rect.
  88     //
  89     // This function may be called during reflow or painting. We should only
  90     // do this check in painting process since the PreEffectsBBoxProperty of
  91     // continuations are not set correctly while reflowing.
  92     if (SVGIntegrationUtils::UsingOverflowAffectingEffects(aFrame) &&
  93         !aInReflow) {
  94       OverflowAreas* preTransformOverflows =
  95           aFrame->GetProperty(nsIFrame::PreTransformOverflowAreasProperty());
  96
  97       MOZ_ASSERT(!preTransformOverflows,
  98                  "InkOverflowRect() won't return the pre-effects rect!");
  99     }
 100 #endif
 101     return aFrame->InkOverflowRectRelativeToSelf();
 102   }
 103
 104   nsIFrame* mFirstContinuation;
 105   nsIFrame* mCurrentFrame;
 106   const nsRect& mCurrentFrameOverflowArea;
 107   nsRect mResult;
 108   bool mInReflow;
 109 };
 110
 111 /**
 112  * Gets the union of the pre-effects ink overflow rects of all of a frame's
 113  * continuations, in "user space".
 114  */
 115 static nsRect GetPreEffectsInkOverflowUnion(
 116     nsIFrame* aFirstContinuation, nsIFrame* aCurrentFrame,
 117     const nsRect& aCurrentFramePreEffectsOverflow,
 118     const nsPoint& aFirstContinuationToUserSpace, bool aInReflow) {
 119   NS_ASSERTION(!aFirstContinuation->GetPrevContinuation(),
 120                "Need first continuation here");
 121   PreEffectsInkOverflowCollector collector(aFirstContinuation, aCurrentFrame,
 122                                            aCurrentFramePreEffectsOverflow,
 123                                            aInReflow);
 124   // Compute union of all overflow areas relative to aFirstContinuation:
 125   nsLayoutUtils::GetAllInFlowBoxes(aFirstContinuation, &collector);
 126   // Return the result in user space:
 127   return collector.GetResult() + aFirstContinuationToUserSpace;
 128 }
 129
 130 /**
 131  * Gets the pre-effects ink overflow rect of aCurrentFrame in "user space".
 132  */
 133 static nsRect GetPreEffectsInkOverflow(
 134     nsIFrame* aFirstContinuation, nsIFrame* aCurrentFrame,
 135     const nsPoint& aFirstContinuationToUserSpace) {
 136   NS_ASSERTION(!aFirstContinuation->GetPrevContinuation(),
 137                "Need first continuation here");
 138   PreEffectsInkOverflowCollector collector(aFirstContinuation, nullptr,
 139                                            nsRect(), false);
 140   // Compute overflow areas of current frame relative to aFirstContinuation:
 141   nsLayoutUtils::AddBoxesForFrame(aCurrentFrame, &collector);
 142   // Return the result in user space:
 143   return collector.GetResult() + aFirstContinuationToUserSpace;
 144 }
 145
 146 bool SVGIntegrationUtils::UsingOverflowAffectingEffects(
 147     const nsIFrame* aFrame) {
 148   // Currently overflow don't take account of SVG or other non-absolute
 149   // positioned clipping, or masking.
 150   return aFrame->StyleEffects()->HasFilters();
 151 }
 152
 153 bool SVGIntegrationUtils::UsingEffectsForFrame(const nsIFrame* aFrame) {
 154   // Even when SVG display lists are disabled, returning true for SVG frames
 155   // does not adversely affect any of our callers. Therefore we don't bother
 156   // checking the SDL prefs here, since we don't know if we're being called for
 157   // painting or hit-testing anyway.
 158   const nsStyleSVGReset* style = aFrame->StyleSVGReset();
 159   const nsStyleEffects* effects = aFrame->StyleEffects();
 160   // TODO(cbrewster): remove backdrop-filter from this list once it is supported
 161   // in preserve-3d cases.
 162   return effects->HasFilters() || effects->HasBackdropFilters() ||
 163          style->HasClipPath() || style->HasMask();
 164 }
 165
 166 nsPoint SVGIntegrationUtils::GetOffsetToBoundingBox(nsIFrame* aFrame) {
 167   if (aFrame->HasAnyStateBits(NS_FRAME_SVG_LAYOUT)) {
 168     // Do NOT call GetAllInFlowRectsUnion for SVG - it will get the
 169     // covered region relative to the SVGOuterSVGFrame, which is absolutely
 170     // not what we want. SVG frames are always in user space, so they have
 171     // no offset adjustment to make.
 172     return nsPoint();
 173   }
 174
 175   // The GetAllInFlowRectsUnion() call gets the union of the frame border-box
 176   // rects over all continuations, relative to the origin (top-left of the
 177   // border box) of its second argument (here, aFrame, the first continuation).
 178   return -nsLayoutUtils::GetAllInFlowRectsUnion(aFrame, aFrame).TopLeft();
 179 }
 180
 181 struct EffectOffsets {
 182   // The offset between the reference frame and the bounding box of the
 183   // target frame in app unit.
 184   nsPoint offsetToBoundingBox;
 185   // The offset between the reference frame and the bounding box of the
 186   // target frame in app unit.
 187   nsPoint offsetToUserSpace;
 188   // The offset between the reference frame and the bounding box of the
 189   // target frame in device unit.
 190   gfxPoint offsetToUserSpaceInDevPx;
 191 };
 192
 193 static EffectOffsets ComputeEffectOffset(
 194     nsIFrame* aFrame, const SVGIntegrationUtils::PaintFramesParams& aParams) {
 195   EffectOffsets result;
 196
 197   result.offsetToBoundingBox =
 198       aParams.builder->ToReferenceFrame(aFrame) -
 199       SVGIntegrationUtils::GetOffsetToBoundingBox(aFrame);
 200   if (!aFrame->IsSVGFrame()) {
 201     /* Snap the offset if the reference frame is not a SVG frame,
 202      * since other frames will be snapped to pixel when rendering. */
 203     result.offsetToBoundingBox =
 204         nsPoint(aFrame->PresContext()->RoundAppUnitsToNearestDevPixels(
 205                     result.offsetToBoundingBox.x),
 206                 aFrame->PresContext()->RoundAppUnitsToNearestDevPixels(
 207                     result.offsetToBoundingBox.y));
 208   }
 209
 210   // After applying only "aOffsetToBoundingBox", aParams.ctx would have its
 211   // origin at the top left corner of frame's bounding box (over all
 212   // continuations).
 213   // However, SVG painting needs the origin to be located at the origin of the
 214   // SVG frame's "user space", i.e. the space in which, for example, the
 215   // frame's BBox lives.
 216   // SVG geometry frames and foreignObject frames apply their own offsets, so
 217   // their position is relative to their user space. So for these frame types,
 218   // if we want aParams.ctx to be in user space, we first need to subtract the
 219   // frame's position so that SVG painting can later add it again and the
 220   // frame is painted in the right place.
 221   gfxPoint toUserSpaceGfx =
 222       SVGUtils::FrameSpaceInCSSPxToUserSpaceOffset(aFrame);
 223   nsPoint toUserSpace =
 224       nsPoint(nsPresContext::CSSPixelsToAppUnits(float(toUserSpaceGfx.x)),
 225               nsPresContext::CSSPixelsToAppUnits(float(toUserSpaceGfx.y)));
 226
 227   result.offsetToUserSpace = result.offsetToBoundingBox - toUserSpace;
 228
 229 #ifdef DEBUG
 230   bool hasSVGLayout = aFrame->HasAnyStateBits(NS_FRAME_SVG_LAYOUT);
 231   NS_ASSERTION(
 232       hasSVGLayout || result.offsetToBoundingBox == result.offsetToUserSpace,
 233       "For non-SVG frames there shouldn't be any additional offset");
 234 #endif
 235
 236   result.offsetToUserSpaceInDevPx = nsLayoutUtils::PointToGfxPoint(
 237       result.offsetToUserSpace, aFrame->PresContext()->AppUnitsPerDevPixel());
 238
 239   return result;
 240 }
 241
 242 /**
 243  * Setup transform matrix of a gfx context by a specific frame. Move the
 244  * origin of aParams.ctx to the user space of aFrame.
 245  */
 246 static EffectOffsets MoveContextOriginToUserSpace(
 247     nsIFrame* aFrame, const SVGIntegrationUtils::PaintFramesParams& aParams) {
 248   EffectOffsets offset = ComputeEffectOffset(aFrame, aParams);
 249
 250   aParams.ctx.SetMatrixDouble(aParams.ctx.CurrentMatrixDouble().PreTranslate(
 251       offset.offsetToUserSpaceInDevPx));
 252
 253   return offset;
 254 }
 255
 256 gfxPoint SVGIntegrationUtils::GetOffsetToUserSpaceInDevPx(
 257     nsIFrame* aFrame, const PaintFramesParams& aParams) {
 258   nsIFrame* firstFrame =
 259       nsLayoutUtils::FirstContinuationOrIBSplitSibling(aFrame);
 260   EffectOffsets offset = ComputeEffectOffset(firstFrame, aParams);
 261   return offset.offsetToUserSpaceInDevPx;
 262 }
 263
 264 /* static */
 265 nsSize SVGIntegrationUtils::GetContinuationUnionSize(nsIFrame* aNonSVGFrame) {
 266   NS_ASSERTION(!aNonSVGFrame->IsSVGFrame(), "SVG frames should not get here");
 267   nsIFrame* firstFrame =
 268       nsLayoutUtils::FirstContinuationOrIBSplitSibling(aNonSVGFrame);
 269   return nsLayoutUtils::GetAllInFlowRectsUnion(firstFrame, firstFrame).Size();
 270 }
 271
 272 /* static */ gfx::Size SVGIntegrationUtils::GetSVGCoordContextForNonSVGFrame(
 273     nsIFrame* aNonSVGFrame) {
 274   NS_ASSERTION(!aNonSVGFrame->IsSVGFrame(), "SVG frames should not get here");
 275   nsIFrame* firstFrame =
 276       nsLayoutUtils::FirstContinuationOrIBSplitSibling(aNonSVGFrame);
 277   nsRect r = nsLayoutUtils::GetAllInFlowRectsUnion(firstFrame, firstFrame);
 278   return gfx::Size(nsPresContext::AppUnitsToFloatCSSPixels(r.width),
 279                    nsPresContext::AppUnitsToFloatCSSPixels(r.height));
 280 }
 281
 282 gfxRect SVGIntegrationUtils::GetSVGBBoxForNonSVGFrame(
 283     nsIFrame* aNonSVGFrame, bool aUnionContinuations) {
 284   // Except for SVGOuterSVGFrame, we shouldn't be getting here with SVG
 285   // frames at all. This function is for elements that are laid out using the
 286   // CSS box model rules.
 287   NS_ASSERTION(!aNonSVGFrame->HasAnyStateBits(NS_FRAME_SVG_LAYOUT),
 288                "Frames with SVG layout should not get here");
 289
 290   nsIFrame* firstFrame =
 291       nsLayoutUtils::FirstContinuationOrIBSplitSibling(aNonSVGFrame);
 292   // 'r' is in "user space":
 293   nsRect r = (aUnionContinuations)
 294                  ? GetPreEffectsInkOverflowUnion(
 295                        firstFrame, nullptr, nsRect(),
 296                        GetOffsetToBoundingBox(firstFrame), false)
 297                  : GetPreEffectsInkOverflow(firstFrame, aNonSVGFrame,
 298                                             GetOffsetToBoundingBox(firstFrame));
 299
 300   return nsLayoutUtils::RectToGfxRect(r, AppUnitsPerCSSPixel());
 301 }
 302
 303 // XXX Since we're called during reflow, this method is broken for frames with
 304 // continuations. When we're called for a frame with continuations, we're
 305 // called for each continuation in turn as it's reflowed. However, it isn't
 306 // until the last continuation is reflowed that this method's
 307 // GetOffsetToBoundingBox() and GetPreEffectsInkOverflowUnion() calls will
 308 // obtain valid border boxes for all the continuations. As a result, we'll
 309 // end up returning bogus post-filter ink overflow rects for all the prior
 310 // continuations. Unfortunately, by the time the last continuation is
 311 // reflowed, it's too late to go back and set and propagate the overflow
 312 // rects on the previous continuations.
 313 //
 314 // The reason that we need to pass an override bbox to
 315 // GetPreEffectsInkOverflowUnion rather than just letting it call into our
 316 // GetSVGBBoxForNonSVGFrame method is because we get called by
 317 // ComputeEffectsRect when it has been called with
 318 // aStoreRectProperties set to false. In this case the pre-effects visual
 319 // overflow rect that it has been passed may be different to that stored on
 320 // aFrame, resulting in a different bbox.
 321 //
 322 // XXXjwatt The pre-effects ink overflow rect passed to
 323 // ComputeEffectsRect won't include continuation overflows, so
 324 // for frames with continuation the following filter analysis will likely end
 325 // up being carried out with a bbox created as if the frame didn't have
 326 // continuations.
 327 //
 328 // XXXjwatt Using aPreEffectsOverflowRect to create the bbox isn't really right
 329 // for SVG frames, since for SVG frames the SVG spec defines the bbox to be
 330 // something quite different to the pre-effects ink overflow rect. However,
 331 // we're essentially calculating an invalidation area here, and using the
 332 // pre-effects overflow rect will actually overestimate that area which, while
 333 // being a bit wasteful, isn't otherwise a problem.
 334 //
 335 nsRect SVGIntegrationUtils::ComputePostEffectsInkOverflowRect(
 336     nsIFrame* aFrame, const nsRect& aPreEffectsOverflowRect) {
 337   MOZ_ASSERT(!aFrame->HasAnyStateBits(NS_FRAME_SVG_LAYOUT),
 338              "Don't call this on SVG child frames");
 339
 340   MOZ_ASSERT(aFrame->StyleEffects()->HasFilters(),
 341              "We should only be called if the frame is filtered, since filters "
 342              "are the only effect that affects overflow.");
 343
 344   nsIFrame* firstFrame =
 345       nsLayoutUtils::FirstContinuationOrIBSplitSibling(aFrame);
 346   // Note: we do not return here for eHasNoRefs since we must still handle any
 347   // CSS filter functions.
 348   // TODO: we should really return an empty rect for eHasRefsSomeInvalid since
 349   // in that case we disable painting of the element.
 350   nsTArray<SVGFilterFrame*> filterFrames;
 351   if (SVGObserverUtils::GetAndObserveFilters(firstFrame, &filterFrames) ==
 352       SVGObserverUtils::eHasRefsSomeInvalid) {
 353     return aPreEffectsOverflowRect;
 354   }
 355
 356   // Create an override bbox - see comment above:
 357   nsPoint firstFrameToBoundingBox = GetOffsetToBoundingBox(firstFrame);
 358   // overrideBBox is in "user space", in _CSS_ pixels:
 359   // XXX Why are we rounding out to pixel boundaries? We don't do that in
 360   // GetSVGBBoxForNonSVGFrame, and it doesn't appear to be necessary.
 361   gfxRect overrideBBox = nsLayoutUtils::RectToGfxRect(
 362       GetPreEffectsInkOverflowUnion(firstFrame, aFrame, aPreEffectsOverflowRect,
 363                                     firstFrameToBoundingBox, true),
 364       AppUnitsPerCSSPixel());
 365   overrideBBox.RoundOut();
 366
 367   Maybe<nsRect> overflowRect = FilterInstance::GetPostFilterBounds(
 368       firstFrame, filterFrames, &overrideBBox);
 369   if (!overflowRect) {
 370     return aPreEffectsOverflowRect;
 371   }
 372
 373   // Return overflowRect relative to aFrame, rather than "user space":
 374   return overflowRect.value() -
 375          (aFrame->GetOffsetTo(firstFrame) + firstFrameToBoundingBox);
 376 }
 377
 378 nsRect SVGIntegrationUtils::GetRequiredSourceForInvalidArea(
 379     nsIFrame* aFrame, const nsRect& aDirtyRect) {
 380   nsIFrame* firstFrame =
 381       nsLayoutUtils::FirstContinuationOrIBSplitSibling(aFrame);
 382
 383   // If we have any filters to observe then we should have started doing that
 384   // during reflow/ComputeFrameEffectsRect, so we use GetFiltersIfObserving
 385   // here to avoid needless work (or masking bugs by setting up observers at
 386   // the wrong time).
 387   nsTArray<SVGFilterFrame*> filterFrames;
 388   if (!aFrame->StyleEffects()->HasFilters() ||
 389       SVGObserverUtils::GetFiltersIfObserving(firstFrame, &filterFrames) ==
 390           SVGObserverUtils::eHasRefsSomeInvalid) {
 391     return aDirtyRect;
 392   }
 393
 394   // Convert aDirtyRect into "user space" in app units:
 395   nsPoint toUserSpace =
 396       aFrame->GetOffsetTo(firstFrame) + GetOffsetToBoundingBox(firstFrame);
 397   nsRect postEffectsRect = aDirtyRect + toUserSpace;
 398
 399   // Return ther result, relative to aFrame, not in user space:
 400   return FilterInstance::GetPreFilterNeededArea(firstFrame, filterFrames,
 401                                                 postEffectsRect)
 402              .GetBounds() -
 403          toUserSpace;
 404 }
 405
 406 bool SVGIntegrationUtils::HitTestFrameForEffects(nsIFrame* aFrame,
 407                                                  const nsPoint& aPt) {
 408   nsIFrame* firstFrame =
 409       nsLayoutUtils::FirstContinuationOrIBSplitSibling(aFrame);
 410   // Convert aPt to user space:
 411   nsPoint toUserSpace;
 412   if (aFrame->HasAnyStateBits(NS_FRAME_SVG_LAYOUT)) {
 413     // XXXmstange Isn't this wrong for svg:use and innerSVG frames?
 414     toUserSpace = aFrame->GetPosition();
 415   } else {
 416     toUserSpace =
 417         aFrame->GetOffsetTo(firstFrame) + GetOffsetToBoundingBox(firstFrame);
 418   }
 419   nsPoint pt = aPt + toUserSpace;
 420   gfxPoint userSpacePt = gfxPoint(pt.x, pt.y) / AppUnitsPerCSSPixel();
 421   return SVGUtils::HitTestClip(firstFrame, userSpacePt);
 422 }
 423
 424 using PaintFramesParams = SVGIntegrationUtils::PaintFramesParams;
 425
 426 /**
 427  * Paint css-positioned-mask onto a given target(aMaskDT).
 428  * Return value indicates if mask is complete.
 429  */
 430 static bool PaintMaskSurface(const PaintFramesParams& aParams,
 431                              DrawTarget* aMaskDT, float aOpacity,
 432                              const ComputedStyle* aSC,
 433                              const nsTArray<SVGMaskFrame*>& aMaskFrames,
 434                              const nsPoint& aOffsetToUserSpace) {
 435   MOZ_ASSERT(aMaskFrames.Length() > 0);
 436   MOZ_ASSERT(aMaskDT->GetFormat() == SurfaceFormat::A8);
 437   MOZ_ASSERT(aOpacity == 1.0 || aMaskFrames.Length() == 1);
 438
 439   const nsStyleSVGReset* svgReset = aSC->StyleSVGReset();
 440   gfxMatrix cssPxToDevPxMatrix = SVGUtils::GetCSSPxToDevPxMatrix(aParams.frame);
 441
 442   nsPresContext* presContext = aParams.frame->PresContext();
 443   gfxPoint devPixelOffsetToUserSpace = nsLayoutUtils::PointToGfxPoint(
 444       aOffsetToUserSpace, presContext->AppUnitsPerDevPixel());
 445
 446   gfxContext maskContext(aMaskDT, /* aPreserveTransform */ true);
 447
 448   bool isMaskComplete = true;
 449
 450   // Multiple SVG masks interleave with image mask. Paint each layer onto
 451   // aMaskDT one at a time.
 452   for (int i = aMaskFrames.Length() - 1; i >= 0; i--) {
 453     SVGMaskFrame* maskFrame = aMaskFrames[i];
 454     CompositionOp compositionOp =
 455         (i == int(aMaskFrames.Length() - 1))
 456             ? CompositionOp::OP_OVER
 457             : nsCSSRendering::GetGFXCompositeMode(
 458                   svgReset->mMask.mLayers[i].mComposite);
 459
 460     // maskFrame != nullptr means we get a SVG mask.
 461     // maskFrame == nullptr means we get an image mask.
 462     if (maskFrame) {
 463       SVGMaskFrame::MaskParams params(
 464           maskContext.GetDrawTarget(), aParams.frame, cssPxToDevPxMatrix,
 465           aOpacity, svgReset->mMask.mLayers[i].mMaskMode, aParams.imgParams);
 466       RefPtr<SourceSurface> svgMask = maskFrame->GetMaskForMaskedFrame(params);
 467       if (svgMask) {
 468         Matrix tmp = aMaskDT->GetTransform();
 469         aMaskDT->SetTransform(Matrix());
 470         aMaskDT->MaskSurface(ColorPattern(DeviceColor(0.0, 0.0, 0.0, 1.0)),
 471                              svgMask, Point(0, 0),
 472                              DrawOptions(1.0, compositionOp));
 473         aMaskDT->SetTransform(tmp);
 474       }
 475     } else if (svgReset->mMask.mLayers[i].mImage.IsResolved()) {
 476       gfxContextMatrixAutoSaveRestore matRestore(&maskContext);
 477
 478       maskContext.Multiply(gfxMatrix::Translation(-devPixelOffsetToUserSpace));
 479       nsCSSRendering::PaintBGParams params =
 480           nsCSSRendering::PaintBGParams::ForSingleLayer(
 481               *presContext, aParams.dirtyRect, aParams.borderArea,
 482               aParams.frame,
 483               aParams.builder->GetBackgroundPaintFlags() |
 484                   nsCSSRendering::PAINTBG_MASK_IMAGE,
 485               i, compositionOp, aOpacity);
 486
 487       aParams.imgParams.result &= nsCSSRendering::PaintStyleImageLayerWithSC(
 488           params, maskContext, aSC, *aParams.frame->StyleBorder());
 489     } else {
 490       isMaskComplete = false;
 491     }
 492   }
 493
 494   return isMaskComplete;
 495 }
 496
 497 struct MaskPaintResult {
 498   RefPtr<SourceSurface> maskSurface;
 499   Matrix maskTransform;
 500   bool transparentBlackMask;
 501   bool opacityApplied;
 502
 503   MaskPaintResult() : transparentBlackMask(false), opacityApplied(false) {}
 504 };
 505
 506 static MaskPaintResult CreateAndPaintMaskSurface(
 507     const PaintFramesParams& aParams, float aOpacity, const ComputedStyle* aSC,
 508     const nsTArray<SVGMaskFrame*>& aMaskFrames,
 509     const nsPoint& aOffsetToUserSpace) {
 510   const nsStyleSVGReset* svgReset = aSC->StyleSVGReset();
 511   MOZ_ASSERT(aMaskFrames.Length() > 0);
 512   MaskPaintResult paintResult;
 513
 514   gfxContext& ctx = aParams.ctx;
 515
 516   // Optimization for single SVG mask.
 517   if (((aMaskFrames.Length() == 1) && aMaskFrames[0])) {
 518     gfxMatrix cssPxToDevPxMatrix =
 519         SVGUtils::GetCSSPxToDevPxMatrix(aParams.frame);
 520     paintResult.opacityApplied = true;
 521     SVGMaskFrame::MaskParams params(
 522         ctx.GetDrawTarget(), aParams.frame, cssPxToDevPxMatrix, aOpacity,
 523         svgReset->mMask.mLayers[0].mMaskMode, aParams.imgParams);
 524     paintResult.maskSurface = aMaskFrames[0]->GetMaskForMaskedFrame(params);
 525     paintResult.maskTransform = ctx.CurrentMatrix();
 526     paintResult.maskTransform.Invert();
 527     if (!paintResult.maskSurface) {
 528       paintResult.transparentBlackMask = true;
 529     }
 530
 531     return paintResult;
 532   }
 533
 534   const LayoutDeviceRect& maskSurfaceRect =
 535       aParams.maskRect.valueOr(LayoutDeviceRect());
 536   if (aParams.maskRect.isSome() && maskSurfaceRect.IsEmpty()) {
 537     // XXX: Is this ever true?
 538     paintResult.transparentBlackMask = true;
 539     return paintResult;
 540   }
 541
 542   RefPtr<DrawTarget> maskDT = ctx.GetDrawTarget()->CreateClippedDrawTarget(
 543       maskSurfaceRect.ToUnknownRect(), SurfaceFormat::A8);
 544   if (!maskDT || !maskDT->IsValid()) {
 545     return paintResult;
 546   }
 547
 548   // We can paint mask along with opacity only if
 549   // 1. There is only one mask, or
 550   // 2. No overlap among masks.
 551   // Collision detect in #2 is not that trivial, we only accept #1 here.
 552   paintResult.opacityApplied = (aMaskFrames.Length() == 1);
 553
 554   // Set context's matrix on maskContext, offset by the maskSurfaceRect's
 555   // position. This makes sure that we combine the masks in device space.
 556   Matrix maskSurfaceMatrix = ctx.CurrentMatrix();
 557
 558   bool isMaskComplete = PaintMaskSurface(
 559       aParams, maskDT, paintResult.opacityApplied ? aOpacity : 1.0, aSC,
 560       aMaskFrames, aOffsetToUserSpace);
 561
 562   if (!isMaskComplete ||
 563       (aParams.imgParams.result != ImgDrawResult::SUCCESS &&
 564        aParams.imgParams.result != ImgDrawResult::SUCCESS_NOT_COMPLETE &&
 565        aParams.imgParams.result != ImgDrawResult::WRONG_SIZE)) {
 566     // Now we know the status of mask resource since we used it while painting.
 567     // According to the return value of PaintMaskSurface, we know whether mask
 568     // resource is resolvable or not.
 569     //
 570     // For a HTML doc:
 571     //   According to css-masking spec, always create a mask surface when
 572     //   we have any item in maskFrame even if all of those items are
 573     //   non-resolvable <mask-sources> or <images>.
 574     //   Set paintResult.transparentBlackMask as true,  the caller should stop
 575     //   painting masked content as if this mask is a transparent black one.
 576     // For a SVG doc:
 577     //   SVG 1.1 say that if we fail to resolve a mask, we should draw the
 578     //   object unmasked.
 579     //   Left paintResult.maskSurface empty, the caller should paint all
 580     //   masked content as if this mask is an opaque white one(no mask).
 581     paintResult.transparentBlackMask =
 582         !aParams.frame->HasAnyStateBits(NS_FRAME_SVG_LAYOUT);
 583
 584     MOZ_ASSERT(!paintResult.maskSurface);
 585     return paintResult;
 586   }
 587
 588   paintResult.maskTransform = maskSurfaceMatrix;
 589   if (!paintResult.maskTransform.Invert()) {
 590     return paintResult;
 591   }
 592
 593   paintResult.maskSurface = maskDT->Snapshot();
 594   return paintResult;
 595 }
 596
 597 static bool ValidateSVGFrame(nsIFrame* aFrame) {
 598   NS_ASSERTION(
 599       !aFrame->HasAllStateBits(NS_FRAME_SVG_LAYOUT | NS_FRAME_IS_NONDISPLAY),
 600       "Should not use SVGIntegrationUtils on this SVG frame");
 601
 602   if (aFrame->HasAnyStateBits(NS_FRAME_SVG_LAYOUT)) {
 603 #ifdef DEBUG
 604     ISVGDisplayableFrame* svgFrame = do_QueryFrame(aFrame);
 605     MOZ_ASSERT(svgFrame && aFrame->GetContent()->IsSVGElement(),
 606                "A non-SVG frame carries NS_FRAME_SVG_LAYOUT flag?");
 607 #endif
 608
 609     const nsIContent* content = aFrame->GetContent();
 610     if (!static_cast<const SVGElement*>(content)->HasValidDimensions()) {
 611       // The SVG spec says not to draw _anything_
 612       return false;
 613     }
 614   }
 615
 616   return true;
 617 }
 618
 619 bool SVGIntegrationUtils::PaintMask(const PaintFramesParams& aParams,
 620                                     bool& aOutIsMaskComplete) {
 621   aOutIsMaskComplete = true;
 622
 623   SVGUtils::MaskUsage maskUsage =
 624       SVGUtils::DetermineMaskUsage(aParams.frame, aParams.handleOpacity);
 625   if (!maskUsage.ShouldDoSomething()) {
 626     return false;
 627   }
 628
 629   nsIFrame* frame = aParams.frame;
 630   if (!ValidateSVGFrame(frame)) {
 631     return false;
 632   }
 633
 634   gfxContext& ctx = aParams.ctx;
 635   RefPtr<DrawTarget> maskTarget = ctx.GetDrawTarget();
 636
 637   if (maskUsage.ShouldGenerateMaskLayer() && maskUsage.HasSVGClip()) {
 638     // We will paint both mask of positioned mask and clip-path into
 639     // maskTarget.
 640     //
 641     // Create one extra draw target for drawing positioned mask, so that we do
 642     // not have to copy the content of maskTarget before painting
 643     // clip-path into it.
 644     maskTarget = maskTarget->CreateClippedDrawTarget(Rect(), SurfaceFormat::A8);
 645   }
 646
 647   nsIFrame* firstFrame =
 648       nsLayoutUtils::FirstContinuationOrIBSplitSibling(frame);
 649   nsTArray<SVGMaskFrame*> maskFrames;
 650   // XXX check return value?
 651   SVGObserverUtils::GetAndObserveMasks(firstFrame, &maskFrames);
 652
 653   gfxGroupForBlendAutoSaveRestore autoPop(&ctx);
 654   bool shouldPushOpacity = !maskUsage.IsOpaque() && maskFrames.Length() != 1;
 655   if (shouldPushOpacity) {
 656     autoPop.PushGroupForBlendBack(gfxContentType::COLOR_ALPHA,
 657                                   maskUsage.Opacity());
 658   }
 659
 660   gfxContextMatrixAutoSaveRestore matSR;
 661
 662   // Paint clip-path-basic-shape onto ctx
 663   gfxContextAutoSaveRestore basicShapeSR;
 664   if (maskUsage.ShouldApplyBasicShapeOrPath()) {
 665     matSR.SetContext(&ctx);
 666
 667     MoveContextOriginToUserSpace(firstFrame, aParams);
 668
 669     basicShapeSR.SetContext(&ctx);
 670     gfxMatrix mat = SVGUtils::GetCSSPxToDevPxMatrix(frame);
 671     if (!maskUsage.ShouldGenerateMaskLayer()) {
 672       // Only have basic-shape clip-path effect. Fill clipped region by
 673       // opaque white.
 674       ctx.SetDeviceColor(DeviceColor::MaskOpaqueWhite());
 675       RefPtr<Path> path = CSSClipPathInstance::CreateClipPathForFrame(
 676           ctx.GetDrawTarget(), frame, mat);
 677       if (path) {
 678         ctx.SetPath(path);
 679         ctx.Fill();
 680       }
 681
 682       return true;
 683     }
 684     CSSClipPathInstance::ApplyBasicShapeOrPathClip(ctx, frame, mat);
 685   }
 686
 687   // Paint mask into maskTarget.
 688   if (maskUsage.ShouldGenerateMaskLayer()) {
 689     matSR.Restore();
 690     matSR.SetContext(&ctx);
 691
 692     EffectOffsets offsets = ComputeEffectOffset(frame, aParams);
 693     maskTarget->SetTransform(maskTarget->GetTransform().PreTranslate(
 694         ToPoint(offsets.offsetToUserSpaceInDevPx)));
 695     aOutIsMaskComplete = PaintMaskSurface(
 696         aParams, maskTarget, shouldPushOpacity ? 1.0f : maskUsage.Opacity(),
 697         firstFrame->Style(), maskFrames, offsets.offsetToUserSpace);
 698   }
 699
 700   // Paint clip-path onto ctx.
 701   if (maskUsage.HasSVGClip()) {
 702     matSR.Restore();
 703     matSR.SetContext(&ctx);
 704
 705     MoveContextOriginToUserSpace(firstFrame, aParams);
 706     Matrix clipMaskTransform;
 707     gfxMatrix cssPxToDevPxMatrix = SVGUtils::GetCSSPxToDevPxMatrix(frame);
 708
 709     SVGClipPathFrame* clipPathFrame;
 710     // XXX check return value?
 711     SVGObserverUtils::GetAndObserveClipPath(firstFrame, &clipPathFrame);
 712     RefPtr<SourceSurface> maskSurface =
 713         maskUsage.ShouldGenerateMaskLayer() ? maskTarget->Snapshot() : nullptr;
 714     clipPathFrame->PaintClipMask(ctx, frame, cssPxToDevPxMatrix, maskSurface);
 715   }
 716
 717   return true;
 718 }
 719
 720 template <class T>
 721 void PaintMaskAndClipPathInternal(const PaintFramesParams& aParams,
 722                                   const T& aPaintChild) {
 723 #ifdef DEBUG
 724   const nsStyleSVGReset* style = aParams.frame->StyleSVGReset();
 725   MOZ_ASSERT(style->HasClipPath() || style->HasMask(),
 726              "Should not use this method when no mask or clipPath effect"
 727              "on this frame");
 728 #endif
 729
 730   /* SVG defines the following rendering model:
 731    *
 732    *  1. Render geometry
 733    *  2. Apply filter
 734    *  3. Apply clipping, masking, group opacity
 735    *
 736    * We handle #3 here and perform a couple of optimizations:
 737    *
 738    * + Use cairo's clipPath when representable natively (single object
 739    *   clip region).
 740    *
 741    * + Merge opacity and masking if both used together.
 742    */
 743   nsIFrame* frame = aParams.frame;
 744   if (!ValidateSVGFrame(frame)) {
 745     return;
 746   }
 747
 748   SVGUtils::MaskUsage maskUsage =
 749       SVGUtils::DetermineMaskUsage(aParams.frame, aParams.handleOpacity);
 750
 751   if (maskUsage.IsTransparent()) {
 752     return;
 753   }
 754
 755   gfxContext& context = aParams.ctx;
 756   gfxContextMatrixAutoSaveRestore matrixAutoSaveRestore(&context);
 757
 758   nsIFrame* firstFrame =
 759       nsLayoutUtils::FirstContinuationOrIBSplitSibling(frame);
 760
 761   SVGClipPathFrame* clipPathFrame;
 762   // XXX check return value?
 763   SVGObserverUtils::GetAndObserveClipPath(firstFrame, &clipPathFrame);
 764
 765   nsTArray<SVGMaskFrame*> maskFrames;
 766   // XXX check return value?
 767   SVGObserverUtils::GetAndObserveMasks(firstFrame, &maskFrames);
 768
 769   gfxMatrix cssPxToDevPxMatrix = SVGUtils::GetCSSPxToDevPxMatrix(frame);
 770
 771   bool shouldPushMask = false;
 772
 773   gfxGroupForBlendAutoSaveRestore autoGroupForBlend(&context);
 774
 775   /* Check if we need to do additional operations on this child's
 776    * rendering, which necessitates rendering into another surface. */
 777   if (maskUsage.ShouldGenerateMask()) {
 778     gfxContextMatrixAutoSaveRestore matSR;
 779
 780     RefPtr<SourceSurface> maskSurface;
 781     bool opacityApplied = false;
 782
 783     if (maskUsage.ShouldGenerateMaskLayer()) {
 784       matSR.SetContext(&context);
 785
 786       // For css-mask, we want to generate a mask for each continuation frame,
 787       // so we setup context matrix by the position of the current frame,
 788       // instead of the first continuation frame.
 789       EffectOffsets offsets = MoveContextOriginToUserSpace(frame, aParams);
 790       MaskPaintResult paintResult = CreateAndPaintMaskSurface(
 791           aParams, maskUsage.Opacity(), firstFrame->Style(), maskFrames,
 792           offsets.offsetToUserSpace);
 793
 794       if (paintResult.transparentBlackMask) {
 795         return;
 796       }
 797
 798       maskSurface = paintResult.maskSurface;
 799       if (maskSurface) {
 800         shouldPushMask = true;
 801
 802         opacityApplied = paintResult.opacityApplied;
 803       }
 804     }
 805
 806     if (maskUsage.ShouldGenerateClipMaskLayer()) {
 807       matSR.Restore();
 808       matSR.SetContext(&context);
 809
 810       MoveContextOriginToUserSpace(firstFrame, aParams);
 811       RefPtr<SourceSurface> clipMaskSurface = clipPathFrame->GetClipMask(
 812           context, frame, cssPxToDevPxMatrix, maskSurface);
 813
 814       if (clipMaskSurface) {
 815         maskSurface = clipMaskSurface;
 816       } else {
 817         // Either entire surface is clipped out, or gfx buffer allocation
 818         // failure in SVGClipPathFrame::GetClipMask.
 819         return;
 820       }
 821
 822       shouldPushMask = true;
 823     }
 824
 825     // opacity != 1.0f.
 826     if (!maskUsage.ShouldGenerateLayer()) {
 827       MOZ_ASSERT(!maskUsage.IsOpaque());
 828
 829       matSR.SetContext(&context);
 830       MoveContextOriginToUserSpace(firstFrame, aParams);
 831       shouldPushMask = true;
 832     }
 833
 834     if (shouldPushMask) {
 835       // We want the mask to be untransformed so use the inverse of the
 836       // current transform as the maskTransform to compensate.
 837       Matrix maskTransform = context.CurrentMatrix();
 838       maskTransform.Invert();
 839
 840       autoGroupForBlend.PushGroupForBlendBack(
 841           gfxContentType::COLOR_ALPHA,
 842           opacityApplied ? 1.0f : maskUsage.Opacity(), maskSurface,
 843           maskTransform);
 844     }
 845   }
 846
 847   /* If this frame has only a trivial clipPath, set up cairo's clipping now so
 848    * we can just do normal painting and get it clipped appropriately.
 849    */
 850   if (maskUsage.ShouldApplyClipPath() ||
 851       maskUsage.ShouldApplyBasicShapeOrPath()) {
 852     gfxContextMatrixAutoSaveRestore matSR(&context);
 853
 854     MoveContextOriginToUserSpace(firstFrame, aParams);
 855
 856     MOZ_ASSERT(!maskUsage.ShouldApplyClipPath() ||
 857                !maskUsage.ShouldApplyBasicShapeOrPath());
 858     if (maskUsage.ShouldApplyClipPath()) {
 859       clipPathFrame->ApplyClipPath(context, frame, cssPxToDevPxMatrix);
 860     } else {
 861       CSSClipPathInstance::ApplyBasicShapeOrPathClip(context, frame,
 862                                                      cssPxToDevPxMatrix);
 863     }
 864   }
 865
 866   /* Paint the child */
 867   context.SetMatrix(matrixAutoSaveRestore.Matrix());
 868   aPaintChild();
 869
 870   if (StaticPrefs::layers_draw_mask_debug()) {
 871     gfxContextAutoSaveRestore saver(&context);
 872
 873     context.NewPath();
 874     gfxRect drawingRect = nsLayoutUtils::RectToGfxRect(
 875         aParams.borderArea, frame->PresContext()->AppUnitsPerDevPixel());
 876     context.SnappedRectangle(drawingRect);
 877     sRGBColor overlayColor(0.0f, 0.0f, 0.0f, 0.8f);
 878     if (maskUsage.ShouldGenerateMaskLayer()) {
 879       overlayColor.r = 1.0f;  // red represents css positioned mask.
 880     }
 881     if (maskUsage.HasSVGClip()) {
 882       overlayColor.g = 1.0f;  // green represents clip-path:<clip-source>.
 883     }
 884     if (maskUsage.ShouldApplyBasicShapeOrPath()) {
 885       overlayColor.b = 1.0f;  // blue represents
 886                               // clip-path:<basic-shape>||<geometry-box>.
 887     }
 888
 889     context.SetColor(overlayColor);
 890     context.Fill();
 891   }
 892
 893   if (maskUsage.ShouldApplyClipPath() ||
 894       maskUsage.ShouldApplyBasicShapeOrPath()) {
 895     context.PopClip();
 896   }
 897 }
 898
 899 void SVGIntegrationUtils::PaintMaskAndClipPath(
 900     const PaintFramesParams& aParams,
 901     const std::function<void()>& aPaintChild) {
 902   PaintMaskAndClipPathInternal(aParams, aPaintChild);
 903 }
 904
 905 void SVGIntegrationUtils::PaintFilter(const PaintFramesParams& aParams,
 906                                       Span<const StyleFilter> aFilters,
 907                                       const SVGFilterPaintCallback& aCallback) {
 908   MOZ_ASSERT(!aParams.builder->IsForGenerateGlyphMask(),
 909              "Filter effect is discarded while generating glyph mask.");
 910   MOZ_ASSERT(!aFilters.IsEmpty(),
 911              "Should not use this method when no filter effect on this frame");
 912
 913   nsIFrame* frame = aParams.frame;
 914   if (!ValidateSVGFrame(frame)) {
 915     return;
 916   }
 917
 918   float opacity = SVGUtils::ComputeOpacity(frame, aParams.handleOpacity);
 919   if (opacity == 0.0f) {
 920     return;
 921   }
 922
 923   // Properties are added lazily and may have been removed by a restyle, so make
 924   // sure all applicable ones are set again.
 925   nsIFrame* firstFrame =
 926       nsLayoutUtils::FirstContinuationOrIBSplitSibling(frame);
 927   // Note: we do not return here for eHasNoRefs since we must still handle any
 928   // CSS filter functions.
 929   // XXX: Do we need to check for eHasRefsSomeInvalid here given that
 930   // nsDisplayFilter::BuildLayer returns nullptr for eHasRefsSomeInvalid?
 931   // Or can we just assert !eHasRefsSomeInvalid?
 932   nsTArray<SVGFilterFrame*> filterFrames;
 933   if (SVGObserverUtils::GetAndObserveFilters(firstFrame, &filterFrames) ==
 934       SVGObserverUtils::eHasRefsSomeInvalid) {
 935     aCallback(aParams.ctx, aParams.imgParams, nullptr, nullptr);
 936     return;
 937   }
 938
 939   gfxContext& context = aParams.ctx;
 940
 941   gfxContextAutoSaveRestore autoSR(&context);
 942   EffectOffsets offsets = MoveContextOriginToUserSpace(firstFrame, aParams);
 943
 944   /* Paint the child and apply filters */
 945   nsRegion dirtyRegion = aParams.dirtyRect - offsets.offsetToBoundingBox;
 946
 947   FilterInstance::PaintFilteredFrame(frame, aFilters, filterFrames, &context,
 948                                      aCallback, &dirtyRegion, aParams.imgParams,
 949                                      opacity);
 950 }
 951
 952 bool SVGIntegrationUtils::CreateWebRenderCSSFilters(
 953     Span<const StyleFilter> aFilters, nsIFrame* aFrame,
 954     WrFiltersHolder& aWrFilters) {
 955   // All CSS filters are supported by WebRender. SVG filters are not fully
 956   // supported, those use NS_STYLE_FILTER_URL and are handled separately.
 957
 958   // If there are too many filters to render, then just pretend that we
 959   // succeeded, and don't render any of them.
 960   if (aFilters.Length() >
 961       StaticPrefs::gfx_webrender_max_filter_ops_per_chain()) {
 962     return true;
 963   }
 964   aWrFilters.filters.SetCapacity(aFilters.Length());
 965   auto& wrFilters = aWrFilters.filters;
 966   for (const StyleFilter& filter : aFilters) {
 967     switch (filter.tag) {
 968       case StyleFilter::Tag::Brightness:
 969         wrFilters.AppendElement(
 970             wr::FilterOp::Brightness(filter.AsBrightness()));
 971         break;
 972       case StyleFilter::Tag::Contrast:
 973         wrFilters.AppendElement(wr::FilterOp::Contrast(filter.AsContrast()));
 974         break;
 975       case StyleFilter::Tag::Grayscale:
 976         wrFilters.AppendElement(wr::FilterOp::Grayscale(filter.AsGrayscale()));
 977         break;
 978       case StyleFilter::Tag::Invert:
 979         wrFilters.AppendElement(wr::FilterOp::Invert(filter.AsInvert()));
 980         break;
 981       case StyleFilter::Tag::Opacity: {
 982         float opacity = filter.AsOpacity();
 983         wrFilters.AppendElement(wr::FilterOp::Opacity(
 984             wr::PropertyBinding<float>::Value(opacity), opacity));
 985         break;
 986       }
 987       case StyleFilter::Tag::Saturate:
 988         wrFilters.AppendElement(wr::FilterOp::Saturate(filter.AsSaturate()));
 989         break;
 990       case StyleFilter::Tag::Sepia:
 991         wrFilters.AppendElement(wr::FilterOp::Sepia(filter.AsSepia()));
 992         break;
 993       case StyleFilter::Tag::HueRotate: {
 994         wrFilters.AppendElement(
 995             wr::FilterOp::HueRotate(filter.AsHueRotate().ToDegrees()));
 996         break;
 997       }
 998       case StyleFilter::Tag::Blur: {
 999         // TODO(emilio): we should go directly from css pixels -> device pixels.
1000         float appUnitsPerDevPixel =
1001             aFrame->PresContext()->AppUnitsPerDevPixel();
1002         float radius = NSAppUnitsToFloatPixels(filter.AsBlur().ToAppUnits(),
1003                                                appUnitsPerDevPixel);
1004         wrFilters.AppendElement(wr::FilterOp::Blur(radius, radius));
1005         break;
1006       }
1007       case StyleFilter::Tag::DropShadow: {
1008         float appUnitsPerDevPixel =
1009             aFrame->PresContext()->AppUnitsPerDevPixel();
1010         const StyleSimpleShadow& shadow = filter.AsDropShadow();
1011         nscolor color = shadow.color.CalcColor(aFrame);
1012
1013         wr::Shadow wrShadow;
1014         wrShadow.offset = {
1015             NSAppUnitsToFloatPixels(shadow.horizontal.ToAppUnits(),
1016                                     appUnitsPerDevPixel),
1017             NSAppUnitsToFloatPixels(shadow.vertical.ToAppUnits(),
1018                                     appUnitsPerDevPixel)};
1019         wrShadow.blur_radius = NSAppUnitsToFloatPixels(shadow.blur.ToAppUnits(),
1020                                                        appUnitsPerDevPixel);
1021         wrShadow.color = {NS_GET_R(color) / 255.0f, NS_GET_G(color) / 255.0f,
1022                           NS_GET_B(color) / 255.0f, NS_GET_A(color) / 255.0f};
1023         wrFilters.AppendElement(wr::FilterOp::DropShadow(wrShadow));
1024         break;
1025       }
1026       default:
1027         return false;
1028     }
1029   }
1030
1031   return true;
1032 }
1033
1034 bool SVGIntegrationUtils::BuildWebRenderFilters(
1035     nsIFrame* aFilteredFrame, Span<const StyleFilter> aFilters,
1036     StyleFilterType aStyleFilterType, WrFiltersHolder& aWrFilters,
1037     bool& aInitialized) {
1038   return FilterInstance::BuildWebRenderFilters(
1039       aFilteredFrame, aFilters, aStyleFilterType, aWrFilters, aInitialized);
1040 }
1041
1042 bool SVGIntegrationUtils::CanCreateWebRenderFiltersForFrame(nsIFrame* aFrame) {
1043   WrFiltersHolder wrFilters;
1044   auto filterChain = aFrame->StyleEffects()->mFilters.AsSpan();
1045   bool initialized = true;
1046   return CreateWebRenderCSSFilters(filterChain, aFrame, wrFilters) ||
1047          BuildWebRenderFilters(aFrame, filterChain, StyleFilterType::Filter,
1048                                wrFilters, initialized);
1049 }
1050
1051 bool SVGIntegrationUtils::UsesSVGEffectsNotSupportedInCompositor(
1052     nsIFrame* aFrame) {
1053   // WebRender supports masks / clip-paths and some filters in the compositor.
1054   if (aFrame->StyleEffects()->HasFilters()) {
1055     return !SVGIntegrationUtils::CanCreateWebRenderFiltersForFrame(aFrame);
1056   }
1057   return false;
1058 }
1059
1060 class PaintFrameCallback : public gfxDrawingCallback {
1061  public:
1062   PaintFrameCallback(nsIFrame* aFrame, const nsSize aPaintServerSize,
1063                      const IntSize aRenderSize, uint32_t aFlags)
1064       : mFrame(aFrame),
1065         mPaintServerSize(aPaintServerSize),
1066         mRenderSize(aRenderSize),
1067         mFlags(aFlags) {}
1068   virtual bool operator()(gfxContext* aContext, const gfxRect& aFillRect,
1069                           const SamplingFilter aSamplingFilter,
1070                           const gfxMatrix& aTransform) override;
1071
1072  private:
1073   nsIFrame* mFrame;
1074   nsSize mPaintServerSize;
1075   IntSize mRenderSize;
1076   uint32_t mFlags;
1077 };
1078
1079 bool PaintFrameCallback::operator()(gfxContext* aContext,
1080                                     const gfxRect& aFillRect,
1081                                     const SamplingFilter aSamplingFilter,
1082                                     const gfxMatrix& aTransform) {
1083   if (mFrame->HasAnyStateBits(NS_FRAME_DRAWING_AS_PAINTSERVER)) {
1084     return false;
1085   }
1086
1087   AutoSetRestorePaintServerState paintServer(mFrame);
1088
1089   aContext->Save();
1090
1091   // Clip to aFillRect so that we don't paint outside.
1092   aContext->Clip(aFillRect);
1093
1094   gfxMatrix invmatrix = aTransform;
1095   if (!invmatrix.Invert()) {
1096     return false;
1097   }
1098   aContext->Multiply(invmatrix);
1099
1100   // nsLayoutUtils::PaintFrame will anchor its painting at mFrame. But we want
1101   // to have it anchored at the top left corner of the bounding box of all of
1102   // mFrame's continuations. So we add a translation transform.
1103   int32_t appUnitsPerDevPixel = mFrame->PresContext()->AppUnitsPerDevPixel();
1104   nsPoint offset = SVGIntegrationUtils::GetOffsetToBoundingBox(mFrame);
1105   gfxPoint devPxOffset = gfxPoint(offset.x, offset.y) / appUnitsPerDevPixel;
1106   aContext->Multiply(gfxMatrix::Translation(devPxOffset));
1107
1108   gfxSize paintServerSize =
1109       gfxSize(mPaintServerSize.width, mPaintServerSize.height) /
1110       mFrame->PresContext()->AppUnitsPerDevPixel();
1111
1112   // nsLayoutUtils::PaintFrame wants to render with paintServerSize, but we
1113   // want it to render with mRenderSize, so we need to set up a scale transform.
1114   gfxFloat scaleX = mRenderSize.width / paintServerSize.width;
1115   gfxFloat scaleY = mRenderSize.height / paintServerSize.height;
1116   aContext->Multiply(gfxMatrix::Scaling(scaleX, scaleY));
1117
1118   // Draw.
1119   nsRect dirty(-offset.x, -offset.y, mPaintServerSize.width,
1120                mPaintServerSize.height);
1121
1122   using PaintFrameFlags = nsLayoutUtils::PaintFrameFlags;
1123   PaintFrameFlags flags = PaintFrameFlags::InTransform;
1124   if (mFlags & SVGIntegrationUtils::FLAG_SYNC_DECODE_IMAGES) {
1125     flags |= PaintFrameFlags::SyncDecodeImages;
1126   }
1127   nsLayoutUtils::PaintFrame(aContext, mFrame, dirty, NS_RGBA(0, 0, 0, 0),
1128                             nsDisplayListBuilderMode::Painting, flags);
1129
1130   nsIFrame* currentFrame = mFrame;
1131   while ((currentFrame = currentFrame->GetNextContinuation()) != nullptr) {
1132     offset = currentFrame->GetOffsetToCrossDoc(mFrame);
1133     devPxOffset = gfxPoint(offset.x, offset.y) / appUnitsPerDevPixel;
1134
1135     aContext->Save();
1136     aContext->Multiply(gfxMatrix::Scaling(1 / scaleX, 1 / scaleY));
1137     aContext->Multiply(gfxMatrix::Translation(devPxOffset));
1138     aContext->Multiply(gfxMatrix::Scaling(scaleX, scaleY));
1139
1140     nsLayoutUtils::PaintFrame(aContext, currentFrame, dirty - offset,
1141                               NS_RGBA(0, 0, 0, 0),
1142                               nsDisplayListBuilderMode::Painting, flags);
1143
1144     aContext->Restore();
1145   }
1146
1147   aContext->Restore();
1148
1149   return true;
1150 }
1151
1152 /* static */
1153 already_AddRefed<gfxDrawable> SVGIntegrationUtils::DrawableFromPaintServer(
1154     nsIFrame* aFrame, nsIFrame* aTarget, const nsSize& aPaintServerSize,
1155     const IntSize& aRenderSize, const DrawTarget* aDrawTarget,
1156     const gfxMatrix& aContextMatrix, uint32_t aFlags) {
1157   // aPaintServerSize is the size that would be filled when using
1158   // background-repeat:no-repeat and background-size:auto. For normal background
1159   // images, this would be the intrinsic size of the image; for gradients and
1160   // patterns this would be the whole target frame fill area.
1161   // aRenderSize is what we will be actually filling after accounting for
1162   // background-size.
1163   if (SVGPaintServerFrame* server = do_QueryFrame(aFrame)) {
1164     // aFrame is either a pattern or a gradient. These fill the whole target
1165     // frame by default, so aPaintServerSize is the whole target background fill
1166     // area.
1167     gfxRect overrideBounds(0, 0, aPaintServerSize.width,
1168                            aPaintServerSize.height);
1169     overrideBounds.Scale(1.0 / aFrame->PresContext()->AppUnitsPerDevPixel());
1170     uint32_t imgFlags = imgIContainer::FLAG_ASYNC_NOTIFY;
1171     if (aFlags & SVGIntegrationUtils::FLAG_SYNC_DECODE_IMAGES) {
1172       imgFlags |= imgIContainer::FLAG_SYNC_DECODE;
1173     }
1174     imgDrawingParams imgParams(imgFlags);
1175     RefPtr<gfxPattern> pattern = server->GetPaintServerPattern(
1176         aTarget, aDrawTarget, aContextMatrix, &nsStyleSVG::mFill, 1.0,
1177         imgParams, &overrideBounds);
1178
1179     if (!pattern) {
1180       return nullptr;
1181     }
1182
1183     // pattern is now set up to fill aPaintServerSize. But we want it to
1184     // fill aRenderSize, so we need to add a scaling transform.
1185     // We couldn't just have set overrideBounds to aRenderSize - it would have
1186     // worked for gradients, but for patterns it would result in a different
1187     // pattern size.
1188     gfxFloat scaleX = overrideBounds.Width() / aRenderSize.width;
1189     gfxFloat scaleY = overrideBounds.Height() / aRenderSize.height;
1190     gfxMatrix scaleMatrix = gfxMatrix::Scaling(scaleX, scaleY);
1191     pattern->SetMatrix(scaleMatrix * pattern->GetMatrix());
1192     return do_AddRef(new gfxPatternDrawable(pattern, aRenderSize));
1193   }
1194
1195   if (aFrame->IsSVGFrame() &&
1196       !static_cast<ISVGDisplayableFrame*>(do_QueryFrame(aFrame))) {
1197     MOZ_ASSERT_UNREACHABLE(
1198         "We should prevent painting of unpaintable SVG "
1199         "before we get here");
1200     return nullptr;
1201   }
1202
1203   // We don't want to paint into a surface as long as we don't need to, so we
1204   // set up a drawing callback.
1205   RefPtr<gfxDrawingCallback> cb =
1206       new PaintFrameCallback(aFrame, aPaintServerSize, aRenderSize, aFlags);
1207   return do_AddRef(new gfxCallbackDrawable(cb, aRenderSize));
1208 }
1209
1210 }  // namespace mozilla