1 /*
2  * Copyright 2016 Google Inc.
3  *
4  * Use of this source code is governed by a BSD-style license that can be
5  * found in the LICENSE file.
6  */
7 
8 #include "GrReducedClip.h"
9 #include "GrAppliedClip.h"
10 #include "GrClip.h"
11 #include "GrColor.h"
12 #include "GrContextPriv.h"
13 #include "GrDrawingManager.h"
14 #include "GrFixedClip.h"
15 #include "GrPathRenderer.h"
16 #include "GrRenderTargetContext.h"
17 #include "GrRenderTargetContextPriv.h"
18 #include "GrShape.h"
19 #include "GrStencilClip.h"
20 #include "GrStencilSettings.h"
21 #include "GrStyle.h"
22 #include "GrUserStencilSettings.h"
23 #include "SkClipOpPriv.h"
24 #include "ccpr/GrCoverageCountingPathRenderer.h"
25 #include "effects/GrAARectEffect.h"
26 #include "effects/GrConvexPolyEffect.h"
27 #include "effects/GrRRectEffect.h"
28 
29 /**
30  * There are plenty of optimizations that could be added here. Maybe flips could be folded into
31  * earlier operations. Or would inserting flips and reversing earlier ops ever be a win? Perhaps
32  * for the case where the bounds are kInsideOut_BoundsType. We could restrict earlier operations
33  * based on later intersect operations, and perhaps remove intersect-rects. We could optionally
34  * take a rect in case the caller knows a bound on what is to be drawn through this clip.
35  */
36 GrReducedClip::GrReducedClip(const SkClipStack& stack, const SkRect& queryBounds,
37                              const GrCaps* caps, int maxWindowRectangles, int maxAnalyticFPs,
38                              int maxCCPRClipPaths)
39         : fCaps(caps)
40         , fMaxWindowRectangles(maxWindowRectangles)
41         , fMaxAnalyticFPs(maxAnalyticFPs)
42         , fMaxCCPRClipPaths(maxCCPRClipPaths) {
43     SkASSERT(!queryBounds.isEmpty());
44     SkASSERT(fMaxWindowRectangles <= GrWindowRectangles::kMaxWindows);
45     SkASSERT(fMaxCCPRClipPaths <= fMaxAnalyticFPs);
46     fHasScissor = false;
47     fAAClipRectGenID = SK_InvalidGenID;
48 
49     if (stack.isWideOpen()) {
50         fInitialState = InitialState::kAllIn;
51         return;
52     }
53 
54     SkClipStack::BoundsType stackBoundsType;
55     SkRect stackBounds;
56     bool iior;
57     stack.getBounds(&stackBounds, &stackBoundsType, &iior);
58 
59     if (GrClip::IsOutsideClip(stackBounds, queryBounds)) {
60         bool insideOut = SkClipStack::kInsideOut_BoundsType == stackBoundsType;
61         fInitialState = insideOut ? InitialState::kAllIn : InitialState::kAllOut;
62         return;
63     }
64 
65     if (iior) {
66         // "Is intersection of rects" means the clip is a single rect indicated by the stack bounds.
67         // This should only be true if aa/non-aa status matches among all elements.
68         SkASSERT(SkClipStack::kNormal_BoundsType == stackBoundsType);
69 
70         if (GrClip::IsInsideClip(stackBounds, queryBounds)) {
71             fInitialState = InitialState::kAllIn;
72             return;
73         }
74 
75         SkClipStack::Iter iter(stack, SkClipStack::Iter::kTop_IterStart);
76 
77         if (!iter.prev()->isAA() || GrClip::IsPixelAligned(stackBounds)) {
78             // The clip is a non-aa rect. Here we just implement the entire thing using fScissor.
79             stackBounds.round(&fScissor);
80             fHasScissor = true;
81             fInitialState = fScissor.isEmpty() ? InitialState::kAllOut : InitialState::kAllIn;
82             return;
83         }
84 
85         SkRect tightBounds;
86         SkAssertResult(tightBounds.intersect(stackBounds, queryBounds));
87         fScissor = GrClip::GetPixelIBounds(tightBounds);
88         if (fScissor.isEmpty()) {
89             fInitialState = InitialState::kAllOut;
90             return;
91         }
92         fHasScissor = true;
93 
94         fAAClipRect = stackBounds;
95         fAAClipRectGenID = stack.getTopmostGenID();
96         SkASSERT(SK_InvalidGenID != fAAClipRectGenID);
97 
98         fInitialState = InitialState::kAllIn;
99     } else {
100         SkRect tighterQuery = queryBounds;
101         if (SkClipStack::kNormal_BoundsType == stackBoundsType) {
102             // Tighten the query by introducing a new clip at the stack's pixel boundaries. (This
103             // new clip will be enforced by the scissor.)
104             SkAssertResult(tighterQuery.intersect(GrClip::GetPixelBounds(stackBounds)));
105         }
106 
107         fScissor = GrClip::GetPixelIBounds(tighterQuery);
108         if (fScissor.isEmpty()) {
109             fInitialState = InitialState::kAllOut;
110             return;
111         }
112         fHasScissor = true;
113 
114         // Now that we have determined the bounds to use and filtered out the trivial cases, call
115         // the helper that actually walks the stack.
116         this->walkStack(stack, tighterQuery);
117     }
118 
119     if (SK_InvalidGenID != fAAClipRectGenID && // Is there an AA clip rect?
120         ClipResult::kNotClipped == this->addAnalyticFP(fAAClipRect, Invert::kNo, GrAA::kYes)) {
121         if (fMaskElements.isEmpty()) {
122             // Use a replace since it is faster than intersect.
123             fMaskElements.addToHead(fAAClipRect, SkMatrix::I(), kReplace_SkClipOp, true /*doAA*/);
124             fInitialState = InitialState::kAllOut;
125         } else {
126             fMaskElements.addToTail(fAAClipRect, SkMatrix::I(), kIntersect_SkClipOp, true /*doAA*/);
127         }
128         fMaskRequiresAA = true;
129         fMaskGenID = fAAClipRectGenID;
130     }
131 }
132 
133 void GrReducedClip::walkStack(const SkClipStack& stack, const SkRect& queryBounds) {
134     // walk backwards until we get to:
135     //  a) the beginning
136     //  b) an operation that is known to make the bounds all inside/outside
137     //  c) a replace operation
138 
139     enum class InitialTriState {
140         kUnknown = -1,
141         kAllIn = (int)GrReducedClip::InitialState::kAllIn,
142         kAllOut = (int)GrReducedClip::InitialState::kAllOut
143     } initialTriState = InitialTriState::kUnknown;
144 
145     // During our backwards walk, track whether we've seen ops that either grow or shrink the clip.
146     // TODO: track these per saved clip so that we can consider them on the forward pass.
147     bool embiggens = false;
148     bool emsmallens = false;
149 
150     // We use a slightly relaxed set of query bounds for element containment tests. This is to
151     // account for floating point rounding error that may have occurred during coord transforms.
152     SkRect relaxedQueryBounds = queryBounds.makeInset(GrClip::kBoundsTolerance,
153                                                       GrClip::kBoundsTolerance);
154     if (relaxedQueryBounds.isEmpty()) {
155         relaxedQueryBounds = queryBounds;
156     }
157 
158     SkClipStack::Iter iter(stack, SkClipStack::Iter::kTop_IterStart);
159     int numAAElements = 0;
160     while (InitialTriState::kUnknown == initialTriState) {
161         const Element* element = iter.prev();
162         if (nullptr == element) {
163             initialTriState = InitialTriState::kAllIn;
164             break;
165         }
166         if (SkClipStack::kEmptyGenID == element->getGenID()) {
167             initialTriState = InitialTriState::kAllOut;
168             break;
169         }
170         if (SkClipStack::kWideOpenGenID == element->getGenID()) {
171             initialTriState = InitialTriState::kAllIn;
172             break;
173         }
174 
175         bool skippable = false;
176         bool isFlip = false; // does this op just flip the in/out state of every point in the bounds
177 
178         switch (element->getOp()) {
179             case kDifference_SkClipOp:
180                 // check if the shape subtracted either contains the entire bounds (and makes
181                 // the clip empty) or is outside the bounds and therefore can be skipped.
182                 if (element->isInverseFilled()) {
183                     if (element->contains(relaxedQueryBounds)) {
184                         skippable = true;
185                     } else if (GrClip::IsOutsideClip(element->getBounds(), queryBounds)) {
186                         initialTriState = InitialTriState::kAllOut;
187                         skippable = true;
188                     } else if (!embiggens) {
189                         ClipResult result = this->clipInsideElement(element);
190                         if (ClipResult::kMadeEmpty == result) {
191                             return;
192                         }
193                         skippable = (ClipResult::kClipped == result);
194                     }
195                 } else {
196                     if (element->contains(relaxedQueryBounds)) {
197                         initialTriState = InitialTriState::kAllOut;
198                         skippable = true;
199                     } else if (GrClip::IsOutsideClip(element->getBounds(), queryBounds)) {
200                         skippable = true;
201                     } else if (!embiggens) {
202                         ClipResult result = this->clipOutsideElement(element);
203                         if (ClipResult::kMadeEmpty == result) {
204                             return;
205                         }
206                         skippable = (ClipResult::kClipped == result);
207                     }
208                 }
209                 if (!skippable) {
210                     emsmallens = true;
211                 }
212                 break;
213             case kIntersect_SkClipOp:
214                 // check if the shape intersected contains the entire bounds and therefore can
215                 // be skipped or it is outside the entire bounds and therefore makes the clip
216                 // empty.
217                 if (element->isInverseFilled()) {
218                     if (element->contains(relaxedQueryBounds)) {
219                         initialTriState = InitialTriState::kAllOut;
220                         skippable = true;
221                     } else if (GrClip::IsOutsideClip(element->getBounds(), queryBounds)) {
222                         skippable = true;
223                     } else if (!embiggens) {
224                         ClipResult result = this->clipOutsideElement(element);
225                         if (ClipResult::kMadeEmpty == result) {
226                             return;
227                         }
228                         skippable = (ClipResult::kClipped == result);
229                     }
230                 } else {
231                     if (element->contains(relaxedQueryBounds)) {
232                         skippable = true;
233                     } else if (GrClip::IsOutsideClip(element->getBounds(), queryBounds)) {
234                         initialTriState = InitialTriState::kAllOut;
235                         skippable = true;
236                     } else if (!embiggens) {
237                         ClipResult result = this->clipInsideElement(element);
238                         if (ClipResult::kMadeEmpty == result) {
239                             return;
240                         }
241                         skippable = (ClipResult::kClipped == result);
242                     }
243                 }
244                 if (!skippable) {
245                     emsmallens = true;
246                 }
247                 break;
248             case kUnion_SkClipOp:
249                 // If the union-ed shape contains the entire bounds then after this element
250                 // the bounds is entirely inside the clip. If the union-ed shape is outside the
251                 // bounds then this op can be skipped.
252                 if (element->isInverseFilled()) {
253                     if (element->contains(relaxedQueryBounds)) {
254                         skippable = true;
255                     } else if (GrClip::IsOutsideClip(element->getBounds(), queryBounds)) {
256                         initialTriState = InitialTriState::kAllIn;
257                         skippable = true;
258                     }
259                 } else {
260                     if (element->contains(relaxedQueryBounds)) {
261                         initialTriState = InitialTriState::kAllIn;
262                         skippable = true;
263                     } else if (GrClip::IsOutsideClip(element->getBounds(), queryBounds)) {
264                         skippable = true;
265                     }
266                 }
267                 if (!skippable) {
268                     embiggens = true;
269                 }
270                 break;
271             case kXOR_SkClipOp:
272                 // If the bounds is entirely inside the shape being xor-ed then the effect is
273                 // to flip the inside/outside state of every point in the bounds. We may be
274                 // able to take advantage of this in the forward pass. If the xor-ed shape
275                 // doesn't intersect the bounds then it can be skipped.
276                 if (element->isInverseFilled()) {
277                     if (element->contains(relaxedQueryBounds)) {
278                         skippable = true;
279                     } else if (GrClip::IsOutsideClip(element->getBounds(), queryBounds)) {
280                         isFlip = true;
281                     }
282                 } else {
283                     if (element->contains(relaxedQueryBounds)) {
284                         isFlip = true;
285                     } else if (GrClip::IsOutsideClip(element->getBounds(), queryBounds)) {
286                         skippable = true;
287                     }
288                 }
289                 if (!skippable) {
290                     emsmallens = embiggens = true;
291                 }
292                 break;
293             case kReverseDifference_SkClipOp:
294                 // When the bounds is entirely within the rev-diff shape then this behaves like xor
295                 // and reverses every point inside the bounds. If the shape is completely outside
296                 // the bounds then we know after this element is applied that the bounds will be
297                 // all outside the current clip.B
298                 if (element->isInverseFilled()) {
299                     if (element->contains(relaxedQueryBounds)) {
300                         initialTriState = InitialTriState::kAllOut;
301                         skippable = true;
302                     } else if (GrClip::IsOutsideClip(element->getBounds(), queryBounds)) {
303                         isFlip = true;
304                     }
305                 } else {
306                     if (element->contains(relaxedQueryBounds)) {
307                         isFlip = true;
308                     } else if (GrClip::IsOutsideClip(element->getBounds(), queryBounds)) {
309                         initialTriState = InitialTriState::kAllOut;
310                         skippable = true;
311                     }
312                 }
313                 if (!skippable) {
314                     emsmallens = embiggens = true;
315                 }
316                 break;
317 
318             case kReplace_SkClipOp:
319                 // Replace will always terminate our walk. We will either begin the forward walk
320                 // at the replace op or detect here than the shape is either completely inside
321                 // or completely outside the bounds. In this latter case it can be skipped by
322                 // setting the correct value for initialTriState.
323                 if (element->isInverseFilled()) {
324                     if (element->contains(relaxedQueryBounds)) {
325                         initialTriState = InitialTriState::kAllOut;
326                         skippable = true;
327                     } else if (GrClip::IsOutsideClip(element->getBounds(), queryBounds)) {
328                         initialTriState = InitialTriState::kAllIn;
329                         skippable = true;
330                     } else if (!embiggens) {
331                         ClipResult result = this->clipOutsideElement(element);
332                         if (ClipResult::kMadeEmpty == result) {
333                             return;
334                         }
335                         if (ClipResult::kClipped == result) {
336                             initialTriState = InitialTriState::kAllIn;
337                             skippable = true;
338                         }
339                     }
340                 } else {
341                     if (element->contains(relaxedQueryBounds)) {
342                         initialTriState = InitialTriState::kAllIn;
343                         skippable = true;
344                     } else if (GrClip::IsOutsideClip(element->getBounds(), queryBounds)) {
345                         initialTriState = InitialTriState::kAllOut;
346                         skippable = true;
347                     } else if (!embiggens) {
348                         ClipResult result = this->clipInsideElement(element);
349                         if (ClipResult::kMadeEmpty == result) {
350                             return;
351                         }
352                         if (ClipResult::kClipped == result) {
353                             initialTriState = InitialTriState::kAllIn;
354                             skippable = true;
355                         }
356                     }
357                 }
358                 if (!skippable) {
359                     initialTriState = InitialTriState::kAllOut;
360                     embiggens = emsmallens = true;
361                 }
362                 break;
363             default:
364                 SkDEBUGFAIL("Unexpected op.");
365                 break;
366         }
367         if (!skippable) {
368             if (fMaskElements.isEmpty()) {
369                 // This will be the last element. Record the stricter genID.
370                 fMaskGenID = element->getGenID();
371             }
372 
373             // if it is a flip, change it to a bounds-filling rect
374             if (isFlip) {
375                 SkASSERT(kXOR_SkClipOp == element->getOp() ||
376                          kReverseDifference_SkClipOp == element->getOp());
377                 fMaskElements.addToHead(SkRect::Make(fScissor), SkMatrix::I(),
378                                         kReverseDifference_SkClipOp, false);
379             } else {
380                 Element* newElement = fMaskElements.addToHead(*element);
381                 if (newElement->isAA()) {
382                     ++numAAElements;
383                 }
384                 // Intersecting an inverse shape is the same as differencing the non-inverse shape.
385                 // Replacing with an inverse shape is the same as setting initialState=kAllIn and
386                 // differencing the non-inverse shape.
387                 bool isReplace = kReplace_SkClipOp == newElement->getOp();
388                 if (newElement->isInverseFilled() &&
389                     (kIntersect_SkClipOp == newElement->getOp() || isReplace)) {
390                     newElement->invertShapeFillType();
391                     newElement->setOp(kDifference_SkClipOp);
392                     if (isReplace) {
393                         SkASSERT(InitialTriState::kAllOut == initialTriState);
394                         initialTriState = InitialTriState::kAllIn;
395                     }
396                 }
397             }
398         }
399     }
400 
401     if ((InitialTriState::kAllOut == initialTriState && !embiggens) ||
402         (InitialTriState::kAllIn == initialTriState && !emsmallens)) {
403         fMaskElements.reset();
404         numAAElements = 0;
405     } else {
406         Element* element = fMaskElements.headIter().get();
407         while (element) {
408             bool skippable = false;
409             switch (element->getOp()) {
410                 case kDifference_SkClipOp:
411                     // subtracting from the empty set yields the empty set.
412                     skippable = InitialTriState::kAllOut == initialTriState;
413                     break;
414                 case kIntersect_SkClipOp:
415                     // intersecting with the empty set yields the empty set
416                     if (InitialTriState::kAllOut == initialTriState) {
417                         skippable = true;
418                     } else {
419                         // We can clear to zero and then simply draw the clip element.
420                         initialTriState = InitialTriState::kAllOut;
421                         element->setOp(kReplace_SkClipOp);
422                     }
423                     break;
424                 case kUnion_SkClipOp:
425                     if (InitialTriState::kAllIn == initialTriState) {
426                         // unioning the infinite plane with anything is a no-op.
427                         skippable = true;
428                     } else {
429                         // unioning the empty set with a shape is the shape.
430                         element->setOp(kReplace_SkClipOp);
431                     }
432                     break;
433                 case kXOR_SkClipOp:
434                     if (InitialTriState::kAllOut == initialTriState) {
435                         // xor could be changed to diff in the kAllIn case, not sure it's a win.
436                         element->setOp(kReplace_SkClipOp);
437                     }
438                     break;
439                 case kReverseDifference_SkClipOp:
440                     if (InitialTriState::kAllIn == initialTriState) {
441                         // subtracting the whole plane will yield the empty set.
442                         skippable = true;
443                         initialTriState = InitialTriState::kAllOut;
444                     } else {
445                         // this picks up flips inserted in the backwards pass.
446                         skippable = element->isInverseFilled() ?
447                             GrClip::IsOutsideClip(element->getBounds(), queryBounds) :
448                             element->contains(relaxedQueryBounds);
449                         if (skippable) {
450                             initialTriState = InitialTriState::kAllIn;
451                         } else {
452                             element->setOp(kReplace_SkClipOp);
453                         }
454                     }
455                     break;
456                 case kReplace_SkClipOp:
457                     skippable = false; // we would have skipped it in the backwards walk if we
458                                        // could've.
459                     break;
460                 default:
461                     SkDEBUGFAIL("Unexpected op.");
462                     break;
463             }
464             if (!skippable) {
465                 break;
466             } else {
467                 if (element->isAA()) {
468                     --numAAElements;
469                 }
470                 fMaskElements.popHead();
471                 element = fMaskElements.headIter().get();
472             }
473         }
474     }
475     fMaskRequiresAA = numAAElements > 0;
476 
477     SkASSERT(InitialTriState::kUnknown != initialTriState);
478     fInitialState = static_cast<GrReducedClip::InitialState>(initialTriState);
479 }
480 
481 GrReducedClip::ClipResult GrReducedClip::clipInsideElement(const Element* element) {
482     SkIRect elementIBounds;
483     if (!element->isAA()) {
484         element->getBounds().round(&elementIBounds);
485     } else {
486         elementIBounds = GrClip::GetPixelIBounds(element->getBounds());
487     }
488     SkASSERT(fHasScissor);
489     if (!fScissor.intersect(elementIBounds)) {
490         this->makeEmpty();
491         return ClipResult::kMadeEmpty;
492     }
493 
494     switch (element->getDeviceSpaceType()) {
495         case Element::DeviceSpaceType::kEmpty:
496             return ClipResult::kMadeEmpty;
497 
498         case Element::DeviceSpaceType::kRect:
499             SkASSERT(element->getBounds() == element->getDeviceSpaceRect());
500             SkASSERT(!element->isInverseFilled());
501             if (element->isAA()) {
502                 if (SK_InvalidGenID == fAAClipRectGenID) { // No AA clip rect yet?
503                     fAAClipRect = element->getDeviceSpaceRect();
504                     // fAAClipRectGenID is the value we should use for fMaskGenID if we end up
505                     // moving the AA clip rect into the mask. The mask GenID is simply the topmost
506                     // element's GenID. And since we walk the stack backwards, this means it's just
507                     // the first element we don't skip during our walk.
508                     fAAClipRectGenID = fMaskElements.isEmpty() ? element->getGenID() : fMaskGenID;
509                     SkASSERT(SK_InvalidGenID != fAAClipRectGenID);
510                 } else if (!fAAClipRect.intersect(element->getDeviceSpaceRect())) {
511                     this->makeEmpty();
512                     return ClipResult::kMadeEmpty;
513                 }
514             }
515             return ClipResult::kClipped;
516 
517         case Element::DeviceSpaceType::kRRect:
518             SkASSERT(!element->isInverseFilled());
519             return this->addAnalyticFP(element->getDeviceSpaceRRect(), Invert::kNo,
520                                        GrAA(element->isAA()));
521 
522         case Element::DeviceSpaceType::kPath:
523             return this->addAnalyticFP(element->getDeviceSpacePath(),
524                                        Invert(element->isInverseFilled()), GrAA(element->isAA()));
525     }
526 
527     SK_ABORT("Unexpected DeviceSpaceType");
528     return ClipResult::kNotClipped;
529 }
530 
531 GrReducedClip::ClipResult GrReducedClip::clipOutsideElement(const Element* element) {
532     switch (element->getDeviceSpaceType()) {
533         case Element::DeviceSpaceType::kEmpty:
534             return ClipResult::kMadeEmpty;
535 
536         case Element::DeviceSpaceType::kRect:
537             SkASSERT(!element->isInverseFilled());
538             if (fWindowRects.count() < fMaxWindowRectangles) {
539                 // Clip out the inside of every rect. We won't be able to entirely skip the AA ones,
540                 // but it saves processing time.
541                 this->addWindowRectangle(element->getDeviceSpaceRect(), element->isAA());
542                 if (!element->isAA()) {
543                     return ClipResult::kClipped;
544                 }
545             }
546             return this->addAnalyticFP(element->getDeviceSpaceRect(), Invert::kYes,
547                                        GrAA(element->isAA()));
548 
549         case Element::DeviceSpaceType::kRRect: {
550             SkASSERT(!element->isInverseFilled());
551             const SkRRect& clipRRect = element->getDeviceSpaceRRect();
552             ClipResult clipResult = this->addAnalyticFP(clipRRect, Invert::kYes,
553                                                         GrAA(element->isAA()));
554             if (fWindowRects.count() >= fMaxWindowRectangles) {
555                 return clipResult;
556             }
557 
558             // Clip out the interiors of round rects with two window rectangles in the shape of a
559             // "plus". This doesn't let us skip the clip element, but still saves processing time.
560             SkVector insetTL = clipRRect.radii(SkRRect::kUpperLeft_Corner);
561             SkVector insetBR = clipRRect.radii(SkRRect::kLowerRight_Corner);
562             if (SkRRect::kComplex_Type == clipRRect.getType()) {
563                 const SkVector& insetTR = clipRRect.radii(SkRRect::kUpperRight_Corner);
564                 const SkVector& insetBL = clipRRect.radii(SkRRect::kLowerLeft_Corner);
565                 insetTL.fX = SkTMax(insetTL.x(), insetBL.x());
566                 insetTL.fY = SkTMax(insetTL.y(), insetTR.y());
567                 insetBR.fX = SkTMax(insetBR.x(), insetTR.x());
568                 insetBR.fY = SkTMax(insetBR.y(), insetBL.y());
569             }
570             const SkRect& bounds = clipRRect.getBounds();
571             if (insetTL.x() + insetBR.x() >= bounds.width() ||
572                 insetTL.y() + insetBR.y() >= bounds.height()) {
573                 return clipResult; // The interior "plus" is empty.
574             }
575 
576             SkRect horzRect = SkRect::MakeLTRB(bounds.left(), bounds.top() + insetTL.y(),
577                                                bounds.right(), bounds.bottom() - insetBR.y());
578             this->addWindowRectangle(horzRect, element->isAA());
579 
580             if (fWindowRects.count() < fMaxWindowRectangles) {
581                 SkRect vertRect = SkRect::MakeLTRB(bounds.left() + insetTL.x(), bounds.top(),
582                                                    bounds.right() - insetBR.x(), bounds.bottom());
583                 this->addWindowRectangle(vertRect, element->isAA());
584             }
585 
586             return clipResult;
587         }
588 
589         case Element::DeviceSpaceType::kPath:
590             return this->addAnalyticFP(element->getDeviceSpacePath(),
591                                        Invert(!element->isInverseFilled()), GrAA(element->isAA()));
592     }
593 
594     SK_ABORT("Unexpected DeviceSpaceType");
595     return ClipResult::kNotClipped;
596 }
597 
598 inline void GrReducedClip::addWindowRectangle(const SkRect& elementInteriorRect, bool elementIsAA) {
599     SkIRect window;
600     if (!elementIsAA) {
601         elementInteriorRect.round(&window);
602     } else {
603         elementInteriorRect.roundIn(&window);
604     }
605     if (!window.isEmpty()) { // Skip very thin windows that round to zero or negative dimensions.
606         fWindowRects.addWindow(window);
607     }
608 }
609 
610 GrClipEdgeType GrReducedClip::GetClipEdgeType(Invert invert, GrAA aa) {
611     if (Invert::kNo == invert) {
612         return (GrAA::kYes == aa) ? GrClipEdgeType::kFillAA : GrClipEdgeType::kFillBW;
613     } else {
614         return (GrAA::kYes == aa) ? GrClipEdgeType::kInverseFillAA : GrClipEdgeType::kInverseFillBW;
615     }
616 }
617 
618 GrReducedClip::ClipResult GrReducedClip::addAnalyticFP(const SkRect& deviceSpaceRect,
619                                                        Invert invert, GrAA aa) {
620     if (this->numAnalyticFPs() >= fMaxAnalyticFPs) {
621         return ClipResult::kNotClipped;
622     }
623 
624     fAnalyticFPs.push_back(GrAARectEffect::Make(GetClipEdgeType(invert, aa), deviceSpaceRect));
625     SkASSERT(fAnalyticFPs.back());
626 
627     return ClipResult::kClipped;
628 }
629 
630 GrReducedClip::ClipResult GrReducedClip::addAnalyticFP(const SkRRect& deviceSpaceRRect,
631                                                        Invert invert, GrAA aa) {
632     if (this->numAnalyticFPs() >= fMaxAnalyticFPs) {
633         return ClipResult::kNotClipped;
634     }
635 
636     if (auto fp = GrRRectEffect::Make(GetClipEdgeType(invert, aa), deviceSpaceRRect,
637                                       *fCaps->shaderCaps())) {
638         fAnalyticFPs.push_back(std::move(fp));
639         return ClipResult::kClipped;
640     }
641 
642     SkPath deviceSpacePath;
643     deviceSpacePath.setIsVolatile(true);
644     deviceSpacePath.addRRect(deviceSpaceRRect);
645     return this->addAnalyticFP(deviceSpacePath, invert, aa);
646 }
647 
648 GrReducedClip::ClipResult GrReducedClip::addAnalyticFP(const SkPath& deviceSpacePath,
649                                                        Invert invert, GrAA aa) {
650     if (this->numAnalyticFPs() >= fMaxAnalyticFPs) {
651         return ClipResult::kNotClipped;
652     }
653 
654     if (auto fp = GrConvexPolyEffect::Make(GetClipEdgeType(invert, aa), deviceSpacePath)) {
655         fAnalyticFPs.push_back(std::move(fp));
656         return ClipResult::kClipped;
657     }
658 
659     if (fCCPRClipPaths.count() < fMaxCCPRClipPaths && GrAA::kYes == aa) {
660         // Set aside CCPR paths for later. We will create their clip FPs once we know the ID of the
661         // opList they will operate in.
662         SkPath& ccprClipPath = fCCPRClipPaths.push_back(deviceSpacePath);
663         if (Invert::kYes == invert) {
664             ccprClipPath.toggleInverseFillType();
665         }
666         return ClipResult::kClipped;
667     }
668 
669     return ClipResult::kNotClipped;
670 }
671 
672 void GrReducedClip::makeEmpty() {
673     fHasScissor = false;
674     fAAClipRectGenID = SK_InvalidGenID;
675     fWindowRects.reset();
676     fMaskElements.reset();
677     fInitialState = InitialState::kAllOut;
678 }
679 
680 ////////////////////////////////////////////////////////////////////////////////
681 // Create a 8-bit clip mask in alpha
682 
683 static bool stencil_element(GrRenderTargetContext* rtc,
684                             const GrFixedClip& clip,
685                             const GrUserStencilSettings* ss,
686                             const SkMatrix& viewMatrix,
687                             const SkClipStack::Element* element) {
688     GrAA aa = GrAA(element->isAA());
689     switch (element->getDeviceSpaceType()) {
690         case SkClipStack::Element::DeviceSpaceType::kEmpty:
691             SkDEBUGFAIL("Should never get here with an empty element.");
692             break;
693         case SkClipStack::Element::DeviceSpaceType::kRect:
694             return rtc->priv().drawAndStencilRect(clip, ss, (SkRegion::Op)element->getOp(),
695                                                   element->isInverseFilled(), aa, viewMatrix,
696                                                   element->getDeviceSpaceRect());
697             break;
698         default: {
699             SkPath path;
700             element->asDeviceSpacePath(&path);
701             if (path.isInverseFillType()) {
702                 path.toggleInverseFillType();
703             }
704 
705             return rtc->priv().drawAndStencilPath(clip, ss, (SkRegion::Op)element->getOp(),
706                                                   element->isInverseFilled(), aa, viewMatrix, path);
707             break;
708         }
709     }
710 
711     return false;
712 }
713 
714 static void draw_element(GrRenderTargetContext* rtc,
715                          const GrClip& clip,  // TODO: can this just always be WideOpen?
716                          GrPaint&& paint,
717                          GrAA aa,
718                          const SkMatrix& viewMatrix,
719                          const SkClipStack::Element* element) {
720     // TODO: Draw rrects directly here.
721     switch (element->getDeviceSpaceType()) {
722         case SkClipStack::Element::DeviceSpaceType::kEmpty:
723             SkDEBUGFAIL("Should never get here with an empty element.");
724             break;
725         case SkClipStack::Element::DeviceSpaceType::kRect:
726             rtc->drawRect(clip, std::move(paint), aa, viewMatrix, element->getDeviceSpaceRect());
727             break;
728         default: {
729             SkPath path;
730             element->asDeviceSpacePath(&path);
731             if (path.isInverseFillType()) {
732                 path.toggleInverseFillType();
733             }
734 
735             rtc->drawPath(clip, std::move(paint), aa, viewMatrix, path, GrStyle::SimpleFill());
736             break;
737         }
738     }
739 }
740 
741 bool GrReducedClip::drawAlphaClipMask(GrRenderTargetContext* rtc) const {
742     // The texture may be larger than necessary, this rect represents the part of the texture
743     // we populate with a rasterization of the clip.
744     GrFixedClip clip(SkIRect::MakeWH(fScissor.width(), fScissor.height()));
745 
746     if (!fWindowRects.empty()) {
747         clip.setWindowRectangles(fWindowRects.makeOffset(-fScissor.left(), -fScissor.top()),
748                                  GrWindowRectsState::Mode::kExclusive);
749     }
750 
751     // The scratch texture that we are drawing into can be substantially larger than the mask. Only
752     // clear the part that we care about.
753     SkPMColor4f initialCoverage =
754         InitialState::kAllIn == this->initialState() ? SK_PMColor4fWHITE : SK_PMColor4fTRANSPARENT;
755     rtc->priv().clear(clip, initialCoverage, GrRenderTargetContext::CanClearFullscreen::kYes);
756 
757     // Set the matrix so that rendered clip elements are transformed to mask space from clip space.
758     SkMatrix translate;
759     translate.setTranslate(SkIntToScalar(-fScissor.left()), SkIntToScalar(-fScissor.top()));
760 
761     // walk through each clip element and perform its set op
762     for (ElementList::Iter iter(fMaskElements); iter.get(); iter.next()) {
763         const Element* element = iter.get();
764         SkRegion::Op op = (SkRegion::Op)element->getOp();
765         GrAA aa = GrAA(element->isAA());
766         bool invert = element->isInverseFilled();
767         if (invert || SkRegion::kIntersect_Op == op || SkRegion::kReverseDifference_Op == op) {
768             // draw directly into the result with the stencil set to make the pixels affected
769             // by the clip shape be non-zero.
770             static constexpr GrUserStencilSettings kStencilInElement(
771                  GrUserStencilSettings::StaticInit<
772                      0xffff,
773                      GrUserStencilTest::kAlways,
774                      0xffff,
775                      GrUserStencilOp::kReplace,
776                      GrUserStencilOp::kReplace,
777                      0xffff>()
778             );
779             if (!stencil_element(rtc, clip, &kStencilInElement, translate, element)) {
780                 return false;
781             }
782 
783             // Draw to the exterior pixels (those with a zero stencil value).
784             static constexpr GrUserStencilSettings kDrawOutsideElement(
785                  GrUserStencilSettings::StaticInit<
786                      0x0000,
787                      GrUserStencilTest::kEqual,
788                      0xffff,
789                      GrUserStencilOp::kZero,
790                      GrUserStencilOp::kZero,
791                      0xffff>()
792             );
793             if (!rtc->priv().drawAndStencilRect(clip, &kDrawOutsideElement, op, !invert, GrAA::kNo,
794                                                 translate, SkRect::Make(fScissor))) {
795                 return false;
796             }
797         } else {
798             // all the remaining ops can just be directly draw into the accumulation buffer
799             GrPaint paint;
800             paint.setCoverageSetOpXPFactory(op, false);
801 
802             draw_element(rtc, clip, std::move(paint), aa, translate, element);
803         }
804     }
805 
806     return true;
807 }
808 
809 ////////////////////////////////////////////////////////////////////////////////
810 // Create a 1-bit clip mask in the stencil buffer.
811 
812 bool GrReducedClip::drawStencilClipMask(GrContext* context,
813                                         GrRenderTargetContext* renderTargetContext) const {
814     // We set the current clip to the bounds so that our recursive draws are scissored to them.
815     GrStencilClip stencilClip(fScissor, this->maskGenID());
816 
817     if (!fWindowRects.empty()) {
818         stencilClip.fixedClip().setWindowRectangles(fWindowRects,
819                                                     GrWindowRectsState::Mode::kExclusive);
820     }
821 
822     bool initialState = InitialState::kAllIn == this->initialState();
823     renderTargetContext->priv().clearStencilClip(stencilClip.fixedClip(), initialState);
824 
825     // walk through each clip element and perform its set op with the existing clip.
826     for (ElementList::Iter iter(fMaskElements); iter.get(); iter.next()) {
827         const Element* element = iter.get();
828         GrAAType aaType = GrAAType::kNone;
829         if (element->isAA() && GrFSAAType::kNone != renderTargetContext->fsaaType()) {
830             aaType = GrAAType::kMSAA;
831         }
832 
833         bool fillInverted = false;
834 
835         // This will be used to determine whether the clip shape can be rendered into the
836         // stencil with arbitrary stencil settings.
837         GrPathRenderer::StencilSupport stencilSupport;
838 
839         SkRegion::Op op = (SkRegion::Op)element->getOp();
840 
841         GrPathRenderer* pr = nullptr;
842         SkPath clipPath;
843         if (Element::DeviceSpaceType::kRect == element->getDeviceSpaceType()) {
844             stencilSupport = GrPathRenderer::kNoRestriction_StencilSupport;
845             fillInverted = false;
846         } else {
847             element->asDeviceSpacePath(&clipPath);
848             fillInverted = clipPath.isInverseFillType();
849             if (fillInverted) {
850                 clipPath.toggleInverseFillType();
851             }
852 
853             GrShape shape(clipPath, GrStyle::SimpleFill());
854             GrPathRenderer::CanDrawPathArgs canDrawArgs;
855             canDrawArgs.fCaps = context->contextPriv().caps();
856             canDrawArgs.fClipConservativeBounds = &stencilClip.fixedClip().scissorRect();
857             canDrawArgs.fViewMatrix = &SkMatrix::I();
858             canDrawArgs.fShape = &shape;
859             canDrawArgs.fAAType = aaType;
860             canDrawArgs.fHasUserStencilSettings = false;
861             canDrawArgs.fTargetIsWrappedVkSecondaryCB = renderTargetContext->wrapsVkSecondaryCB();
862 
863             GrDrawingManager* dm = context->contextPriv().drawingManager();
864             pr = dm->getPathRenderer(canDrawArgs, false, GrPathRendererChain::DrawType::kStencil,
865                                      &stencilSupport);
866             if (!pr) {
867                 return false;
868             }
869         }
870 
871         bool canRenderDirectToStencil =
872             GrPathRenderer::kNoRestriction_StencilSupport == stencilSupport;
873         bool drawDirectToClip; // Given the renderer, the element,
874                                // fill rule, and set operation should
875                                // we render the element directly to
876                                // stencil bit used for clipping.
877         GrUserStencilSettings const* const* stencilPasses =
878             GrStencilSettings::GetClipPasses(op, canRenderDirectToStencil, fillInverted,
879                                              &drawDirectToClip);
880 
881         // draw the element to the client stencil bits if necessary
882         if (!drawDirectToClip) {
883             static constexpr GrUserStencilSettings kDrawToStencil(
884                  GrUserStencilSettings::StaticInit<
885                      0x0000,
886                      GrUserStencilTest::kAlways,
887                      0xffff,
888                      GrUserStencilOp::kIncMaybeClamp,
889                      GrUserStencilOp::kIncMaybeClamp,
890                      0xffff>()
891             );
892             if (Element::DeviceSpaceType::kRect == element->getDeviceSpaceType()) {
893                 renderTargetContext->priv().stencilRect(stencilClip.fixedClip(), &kDrawToStencil,
894                                                         aaType, SkMatrix::I(),
895                                                         element->getDeviceSpaceRect());
896             } else {
897                 if (!clipPath.isEmpty()) {
898                     GrShape shape(clipPath, GrStyle::SimpleFill());
899                     if (canRenderDirectToStencil) {
900                         GrPaint paint;
901                         paint.setXPFactory(GrDisableColorXPFactory::Get());
902 
903                         GrPathRenderer::DrawPathArgs args{context,
904                                                           std::move(paint),
905                                                           &kDrawToStencil,
906                                                           renderTargetContext,
907                                                           &stencilClip.fixedClip(),
908                                                           &stencilClip.fixedClip().scissorRect(),
909                                                           &SkMatrix::I(),
910                                                           &shape,
911                                                           aaType,
912                                                           false};
913                         pr->drawPath(args);
914                     } else {
915                         GrPathRenderer::StencilPathArgs args;
916                         args.fContext = context;
917                         args.fRenderTargetContext = renderTargetContext;
918                         args.fClip = &stencilClip.fixedClip();
919                         args.fClipConservativeBounds = &stencilClip.fixedClip().scissorRect();
920                         args.fViewMatrix = &SkMatrix::I();
921                         args.fAAType = aaType;
922                         args.fShape = &shape;
923                         pr->stencilPath(args);
924                     }
925                 }
926             }
927         }
928 
929         // now we modify the clip bit by rendering either the clip
930         // element directly or a bounding rect of the entire clip.
931         for (GrUserStencilSettings const* const* pass = stencilPasses; *pass; ++pass) {
932             if (drawDirectToClip) {
933                 if (Element::DeviceSpaceType::kRect == element->getDeviceSpaceType()) {
934                     renderTargetContext->priv().stencilRect(stencilClip, *pass, aaType,
935                                                             SkMatrix::I(),
936                                                             element->getDeviceSpaceRect());
937                 } else {
938                     GrShape shape(clipPath, GrStyle::SimpleFill());
939                     GrPaint paint;
940                     paint.setXPFactory(GrDisableColorXPFactory::Get());
941                     GrPathRenderer::DrawPathArgs args{context,
942                                                       std::move(paint),
943                                                       *pass,
944                                                       renderTargetContext,
945                                                       &stencilClip,
946                                                       &stencilClip.fixedClip().scissorRect(),
947                                                       &SkMatrix::I(),
948                                                       &shape,
949                                                       aaType,
950                                                       false};
951                     pr->drawPath(args);
952                 }
953             } else {
954                 // The view matrix is setup to do clip space -> stencil space translation, so
955                 // draw rect in clip space.
956                 renderTargetContext->priv().stencilRect(stencilClip, *pass, aaType, SkMatrix::I(),
957                                                         SkRect::Make(fScissor));
958             }
959         }
960     }
961     return true;
962 }
963 
964 std::unique_ptr<GrFragmentProcessor> GrReducedClip::finishAndDetachAnalyticFPs(
965         GrCoverageCountingPathRenderer* ccpr, uint32_t opListID, int rtWidth, int rtHeight) {
966     // Make sure finishAndDetachAnalyticFPs hasn't been called already.
967     SkDEBUGCODE(for (const auto& fp : fAnalyticFPs) { SkASSERT(fp); })
968 
969     if (!fCCPRClipPaths.empty()) {
970         fAnalyticFPs.reserve(fAnalyticFPs.count() + fCCPRClipPaths.count());
971         for (const SkPath& ccprClipPath : fCCPRClipPaths) {
972             SkASSERT(ccpr);
973             SkASSERT(fHasScissor);
974             auto fp = ccpr->makeClipProcessor(opListID, ccprClipPath, fScissor, rtWidth, rtHeight,
975                                               *fCaps);
976             fAnalyticFPs.push_back(std::move(fp));
977         }
978         fCCPRClipPaths.reset();
979     }
980 
981     return GrFragmentProcessor::RunInSeries(fAnalyticFPs.begin(), fAnalyticFPs.count());
982 }
983