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Diffstat (limited to 'gfx/skia/skia/src/gpu/GrReducedClip.cpp')
| -rw-r--r-- | gfx/skia/skia/src/gpu/GrReducedClip.cpp | 849 |
1 files changed, 849 insertions, 0 deletions
diff --git a/gfx/skia/skia/src/gpu/GrReducedClip.cpp b/gfx/skia/skia/src/gpu/GrReducedClip.cpp new file mode 100644 index 000000000..4a912d3b5 --- /dev/null +++ b/gfx/skia/skia/src/gpu/GrReducedClip.cpp @@ -0,0 +1,849 @@ +/* + * Copyright 2016 Google Inc. + * + * Use of this source code is governed by a BSD-style license that can be + * found in the LICENSE file. + */ + +#include "GrReducedClip.h" + +#include "GrAppliedClip.h" +#include "GrClip.h" +#include "GrColor.h" +#include "GrContextPriv.h" +#include "GrDrawContext.h" +#include "GrDrawContextPriv.h" +#include "GrDrawingManager.h" +#include "GrFixedClip.h" +#include "GrPathRenderer.h" +#include "GrStyle.h" +#include "GrUserStencilSettings.h" + +typedef SkClipStack::Element Element; + +/** + * There are plenty of optimizations that could be added here. Maybe flips could be folded into + * earlier operations. Or would inserting flips and reversing earlier ops ever be a win? Perhaps + * for the case where the bounds are kInsideOut_BoundsType. We could restrict earlier operations + * based on later intersect operations, and perhaps remove intersect-rects. We could optionally + * take a rect in case the caller knows a bound on what is to be drawn through this clip. + */ +GrReducedClip::GrReducedClip(const SkClipStack& stack, const SkRect& queryBounds, + int maxWindowRectangles) { + SkASSERT(!queryBounds.isEmpty()); + fHasIBounds = false; + + if (stack.isWideOpen()) { + fInitialState = InitialState::kAllIn; + return; + } + + SkClipStack::BoundsType stackBoundsType; + SkRect stackBounds; + bool iior; + stack.getBounds(&stackBounds, &stackBoundsType, &iior); + + if (stackBounds.isEmpty() || GrClip::IsOutsideClip(stackBounds, queryBounds)) { + bool insideOut = SkClipStack::kInsideOut_BoundsType == stackBoundsType; + fInitialState = insideOut ? InitialState::kAllIn : InitialState::kAllOut; + return; + } + + if (iior) { + // "Is intersection of rects" means the clip is a single rect indicated by the stack bounds. + // This should only be true if aa/non-aa status matches among all elements. + SkASSERT(SkClipStack::kNormal_BoundsType == stackBoundsType); + SkClipStack::Iter iter(stack, SkClipStack::Iter::kTop_IterStart); + if (!iter.prev()->isAA() || GrClip::IsPixelAligned(stackBounds)) { + // The clip is a non-aa rect. This is the one spot where we can actually implement the + // clip (using fIBounds) rather than just telling the caller what it should be. + stackBounds.round(&fIBounds); + fHasIBounds = true; + fInitialState = fIBounds.isEmpty() ? InitialState::kAllOut : InitialState::kAllIn; + return; + } + if (GrClip::IsInsideClip(stackBounds, queryBounds)) { + fInitialState = InitialState::kAllIn; + return; + } + + SkRect tightBounds; + SkAssertResult(tightBounds.intersect(stackBounds, queryBounds)); + fIBounds = GrClip::GetPixelIBounds(tightBounds); + SkASSERT(!fIBounds.isEmpty()); // Empty should have been blocked by IsOutsideClip above. + fHasIBounds = true; + + // Implement the clip with an AA rect element. + fElements.addToHead(stackBounds, SkCanvas::kReplace_Op, true/*doAA*/); + fElementsGenID = stack.getTopmostGenID(); + fRequiresAA = true; + + fInitialState = InitialState::kAllOut; + return; + } + + SkRect tighterQuery = queryBounds; + if (SkClipStack::kNormal_BoundsType == stackBoundsType) { + // Tighten the query by introducing a new clip at the stack's pixel boundaries. (This new + // clip will be enforced by the scissor through fIBounds.) + SkAssertResult(tighterQuery.intersect(GrClip::GetPixelBounds(stackBounds))); + } + + fIBounds = GrClip::GetPixelIBounds(tighterQuery); + SkASSERT(!fIBounds.isEmpty()); // Empty should have been blocked by IsOutsideClip above. + fHasIBounds = true; + + // Now that we have determined the bounds to use and filtered out the trivial cases, call the + // helper that actually walks the stack. + this->walkStack(stack, tighterQuery, maxWindowRectangles); + + if (fWindowRects.count() < maxWindowRectangles) { + this->addInteriorWindowRectangles(maxWindowRectangles); + } +} + +void GrReducedClip::walkStack(const SkClipStack& stack, const SkRect& queryBounds, + int maxWindowRectangles) { + // walk backwards until we get to: + // a) the beginning + // b) an operation that is known to make the bounds all inside/outside + // c) a replace operation + + enum class InitialTriState { + kUnknown = -1, + kAllIn = (int)GrReducedClip::InitialState::kAllIn, + kAllOut = (int)GrReducedClip::InitialState::kAllOut + } initialTriState = InitialTriState::kUnknown; + + // During our backwards walk, track whether we've seen ops that either grow or shrink the clip. + // TODO: track these per saved clip so that we can consider them on the forward pass. + bool embiggens = false; + bool emsmallens = false; + + // We use a slightly relaxed set of query bounds for element containment tests. This is to + // account for floating point rounding error that may have occurred during coord transforms. + SkRect relaxedQueryBounds = queryBounds.makeInset(GrClip::kBoundsTolerance, + GrClip::kBoundsTolerance); + + SkClipStack::Iter iter(stack, SkClipStack::Iter::kTop_IterStart); + int numAAElements = 0; + while (InitialTriState::kUnknown == initialTriState) { + const Element* element = iter.prev(); + if (nullptr == element) { + initialTriState = InitialTriState::kAllIn; + break; + } + if (SkClipStack::kEmptyGenID == element->getGenID()) { + initialTriState = InitialTriState::kAllOut; + break; + } + if (SkClipStack::kWideOpenGenID == element->getGenID()) { + initialTriState = InitialTriState::kAllIn; + break; + } + + bool skippable = false; + bool isFlip = false; // does this op just flip the in/out state of every point in the bounds + + switch (element->getOp()) { + case SkCanvas::kDifference_Op: + // check if the shape subtracted either contains the entire bounds (and makes + // the clip empty) or is outside the bounds and therefore can be skipped. + if (element->isInverseFilled()) { + if (element->contains(relaxedQueryBounds)) { + skippable = true; + } else if (GrClip::IsOutsideClip(element->getBounds(), queryBounds)) { + initialTriState = InitialTriState::kAllOut; + skippable = true; + } + } else { + if (element->contains(relaxedQueryBounds)) { + initialTriState = InitialTriState::kAllOut; + skippable = true; + } else if (GrClip::IsOutsideClip(element->getBounds(), queryBounds)) { + skippable = true; + } else if (fWindowRects.count() < maxWindowRectangles && !embiggens && + !element->isAA() && Element::kRect_Type == element->getType()) { + this->addWindowRectangle(element->getRect(), false); + skippable = true; + } + } + if (!skippable) { + emsmallens = true; + } + break; + case SkCanvas::kIntersect_Op: + // check if the shape intersected contains the entire bounds and therefore can + // be skipped or it is outside the entire bounds and therefore makes the clip + // empty. + if (element->isInverseFilled()) { + if (element->contains(relaxedQueryBounds)) { + initialTriState = InitialTriState::kAllOut; + skippable = true; + } else if (GrClip::IsOutsideClip(element->getBounds(), queryBounds)) { + skippable = true; + } + } else { + if (element->contains(relaxedQueryBounds)) { + skippable = true; + } else if (GrClip::IsOutsideClip(element->getBounds(), queryBounds)) { + initialTriState = InitialTriState::kAllOut; + skippable = true; + } else if (!embiggens && !element->isAA() && + Element::kRect_Type == element->getType()) { + // fIBounds and queryBounds have already acccounted for this element via + // clip stack bounds; here we just apply the non-aa rounding effect. + SkIRect nonaaRect; + element->getRect().round(&nonaaRect); + if (!this->intersectIBounds(nonaaRect)) { + return; + } + skippable = true; + } + } + if (!skippable) { + emsmallens = true; + } + break; + case SkCanvas::kUnion_Op: + // If the union-ed shape contains the entire bounds then after this element + // the bounds is entirely inside the clip. If the union-ed shape is outside the + // bounds then this op can be skipped. + if (element->isInverseFilled()) { + if (element->contains(relaxedQueryBounds)) { + skippable = true; + } else if (GrClip::IsOutsideClip(element->getBounds(), queryBounds)) { + initialTriState = InitialTriState::kAllIn; + skippable = true; + } + } else { + if (element->contains(relaxedQueryBounds)) { + initialTriState = InitialTriState::kAllIn; + skippable = true; + } else if (GrClip::IsOutsideClip(element->getBounds(), queryBounds)) { + skippable = true; + } + } + if (!skippable) { + embiggens = true; + } + break; + case SkCanvas::kXOR_Op: + // If the bounds is entirely inside the shape being xor-ed then the effect is + // to flip the inside/outside state of every point in the bounds. We may be + // able to take advantage of this in the forward pass. If the xor-ed shape + // doesn't intersect the bounds then it can be skipped. + if (element->isInverseFilled()) { + if (element->contains(relaxedQueryBounds)) { + skippable = true; + } else if (GrClip::IsOutsideClip(element->getBounds(), queryBounds)) { + isFlip = true; + } + } else { + if (element->contains(relaxedQueryBounds)) { + isFlip = true; + } else if (GrClip::IsOutsideClip(element->getBounds(), queryBounds)) { + skippable = true; + } + } + if (!skippable) { + emsmallens = embiggens = true; + } + break; + case SkCanvas::kReverseDifference_Op: + // When the bounds is entirely within the rev-diff shape then this behaves like xor + // and reverses every point inside the bounds. If the shape is completely outside + // the bounds then we know after this element is applied that the bounds will be + // all outside the current clip.B + if (element->isInverseFilled()) { + if (element->contains(relaxedQueryBounds)) { + initialTriState = InitialTriState::kAllOut; + skippable = true; + } else if (GrClip::IsOutsideClip(element->getBounds(), queryBounds)) { + isFlip = true; + } + } else { + if (element->contains(relaxedQueryBounds)) { + isFlip = true; + } else if (GrClip::IsOutsideClip(element->getBounds(), queryBounds)) { + initialTriState = InitialTriState::kAllOut; + skippable = true; + } + } + if (!skippable) { + emsmallens = embiggens = true; + } + break; + + case SkCanvas::kReplace_Op: + // Replace will always terminate our walk. We will either begin the forward walk + // at the replace op or detect here than the shape is either completely inside + // or completely outside the bounds. In this latter case it can be skipped by + // setting the correct value for initialTriState. + if (element->isInverseFilled()) { + if (element->contains(relaxedQueryBounds)) { + initialTriState = InitialTriState::kAllOut; + skippable = true; + } else if (GrClip::IsOutsideClip(element->getBounds(), queryBounds)) { + initialTriState = InitialTriState::kAllIn; + skippable = true; + } + } else { + if (element->contains(relaxedQueryBounds)) { + initialTriState = InitialTriState::kAllIn; + skippable = true; + } else if (GrClip::IsOutsideClip(element->getBounds(), queryBounds)) { + initialTriState = InitialTriState::kAllOut; + skippable = true; + } else if (!embiggens && !element->isAA() && + Element::kRect_Type == element->getType()) { + // fIBounds and queryBounds have already acccounted for this element via + // clip stack bounds; here we just apply the non-aa rounding effect. + SkIRect nonaaRect; + element->getRect().round(&nonaaRect); + if (!this->intersectIBounds(nonaaRect)) { + return; + } + initialTriState = InitialTriState::kAllIn; + skippable = true; + } + } + if (!skippable) { + initialTriState = InitialTriState::kAllOut; + embiggens = emsmallens = true; + } + break; + default: + SkDEBUGFAIL("Unexpected op."); + break; + } + if (!skippable) { + if (0 == fElements.count()) { + // This will be the last element. Record the stricter genID. + fElementsGenID = element->getGenID(); + } + + // if it is a flip, change it to a bounds-filling rect + if (isFlip) { + SkASSERT(SkCanvas::kXOR_Op == element->getOp() || + SkCanvas::kReverseDifference_Op == element->getOp()); + fElements.addToHead(SkRect::Make(fIBounds), SkCanvas::kReverseDifference_Op, false); + } else { + Element* newElement = fElements.addToHead(*element); + if (newElement->isAA()) { + ++numAAElements; + } + // Intersecting an inverse shape is the same as differencing the non-inverse shape. + // Replacing with an inverse shape is the same as setting initialState=kAllIn and + // differencing the non-inverse shape. + bool isReplace = SkCanvas::kReplace_Op == newElement->getOp(); + if (newElement->isInverseFilled() && + (SkCanvas::kIntersect_Op == newElement->getOp() || isReplace)) { + newElement->invertShapeFillType(); + newElement->setOp(SkCanvas::kDifference_Op); + if (isReplace) { + SkASSERT(InitialTriState::kAllOut == initialTriState); + initialTriState = InitialTriState::kAllIn; + } + } + } + } + } + + if ((InitialTriState::kAllOut == initialTriState && !embiggens) || + (InitialTriState::kAllIn == initialTriState && !emsmallens)) { + fElements.reset(); + numAAElements = 0; + } else { + Element* element = fElements.headIter().get(); + while (element) { + bool skippable = false; + switch (element->getOp()) { + case SkCanvas::kDifference_Op: + // subtracting from the empty set yields the empty set. + skippable = InitialTriState::kAllOut == initialTriState; + break; + case SkCanvas::kIntersect_Op: + // intersecting with the empty set yields the empty set + if (InitialTriState::kAllOut == initialTriState) { + skippable = true; + } else { + // We can clear to zero and then simply draw the clip element. + initialTriState = InitialTriState::kAllOut; + element->setOp(SkCanvas::kReplace_Op); + } + break; + case SkCanvas::kUnion_Op: + if (InitialTriState::kAllIn == initialTriState) { + // unioning the infinite plane with anything is a no-op. + skippable = true; + } else { + // unioning the empty set with a shape is the shape. + element->setOp(SkCanvas::kReplace_Op); + } + break; + case SkCanvas::kXOR_Op: + if (InitialTriState::kAllOut == initialTriState) { + // xor could be changed to diff in the kAllIn case, not sure it's a win. + element->setOp(SkCanvas::kReplace_Op); + } + break; + case SkCanvas::kReverseDifference_Op: + if (InitialTriState::kAllIn == initialTriState) { + // subtracting the whole plane will yield the empty set. + skippable = true; + initialTriState = InitialTriState::kAllOut; + } else { + // this picks up flips inserted in the backwards pass. + skippable = element->isInverseFilled() ? + GrClip::IsOutsideClip(element->getBounds(), queryBounds) : + element->contains(relaxedQueryBounds); + if (skippable) { + initialTriState = InitialTriState::kAllIn; + } else { + element->setOp(SkCanvas::kReplace_Op); + } + } + break; + case SkCanvas::kReplace_Op: + skippable = false; // we would have skipped it in the backwards walk if we + // could've. + break; + default: + SkDEBUGFAIL("Unexpected op."); + break; + } + if (!skippable) { + break; + } else { + if (element->isAA()) { + --numAAElements; + } + fElements.popHead(); + element = fElements.headIter().get(); + } + } + } + fRequiresAA = numAAElements > 0; + + SkASSERT(InitialTriState::kUnknown != initialTriState); + fInitialState = static_cast<GrReducedClip::InitialState>(initialTriState); +} + +static bool element_is_pure_subtract(SkCanvas::ClipOp op) { + SkASSERT(op >= 0); + return op <= SkCanvas::kIntersect_Op; + + GR_STATIC_ASSERT(0 == SkCanvas::kDifference_Op); + GR_STATIC_ASSERT(1 == SkCanvas::kIntersect_Op); +} + +void GrReducedClip::addInteriorWindowRectangles(int maxWindowRectangles) { + SkASSERT(fWindowRects.count() < maxWindowRectangles); + // Walk backwards through the element list and add window rectangles to the interiors of + // "difference" elements. Quit if we encounter an element that may grow the clip. + ElementList::Iter iter(fElements, ElementList::Iter::kTail_IterStart); + for (; iter.get() && element_is_pure_subtract(iter.get()->getOp()); iter.prev()) { + const Element* element = iter.get(); + if (SkCanvas::kDifference_Op != element->getOp()) { + continue; + } + + if (Element::kRect_Type == element->getType()) { + SkASSERT(element->isAA()); + this->addWindowRectangle(element->getRect(), true); + if (fWindowRects.count() >= maxWindowRectangles) { + return; + } + continue; + } + + if (Element::kRRect_Type == element->getType()) { + // For round rects we add two overlapping windows in the shape of a plus. + const SkRRect& clipRRect = element->getRRect(); + SkVector insetTL = clipRRect.radii(SkRRect::kUpperLeft_Corner); + SkVector insetBR = clipRRect.radii(SkRRect::kLowerRight_Corner); + if (SkRRect::kComplex_Type == clipRRect.getType()) { + const SkVector& insetTR = clipRRect.radii(SkRRect::kUpperRight_Corner); + const SkVector& insetBL = clipRRect.radii(SkRRect::kLowerLeft_Corner); + insetTL.fX = SkTMax(insetTL.x(), insetBL.x()); + insetTL.fY = SkTMax(insetTL.y(), insetTR.y()); + insetBR.fX = SkTMax(insetBR.x(), insetTR.x()); + insetBR.fY = SkTMax(insetBR.y(), insetBL.y()); + } + const SkRect& bounds = clipRRect.getBounds(); + if (insetTL.x() + insetBR.x() >= bounds.width() || + insetTL.y() + insetBR.y() >= bounds.height()) { + continue; // The interior "plus" is empty. + } + + SkRect horzRect = SkRect::MakeLTRB(bounds.left(), bounds.top() + insetTL.y(), + bounds.right(), bounds.bottom() - insetBR.y()); + this->addWindowRectangle(horzRect, element->isAA()); + if (fWindowRects.count() >= maxWindowRectangles) { + return; + } + + SkRect vertRect = SkRect::MakeLTRB(bounds.left() + insetTL.x(), bounds.top(), + bounds.right() - insetBR.x(), bounds.bottom()); + this->addWindowRectangle(vertRect, element->isAA()); + if (fWindowRects.count() >= maxWindowRectangles) { + return; + } + continue; + } + } +} + +inline void GrReducedClip::addWindowRectangle(const SkRect& elementInteriorRect, bool elementIsAA) { + SkIRect window; + if (!elementIsAA) { + elementInteriorRect.round(&window); + } else { + elementInteriorRect.roundIn(&window); + } + if (!window.isEmpty()) { // Skip very thin windows that round to zero or negative dimensions. + fWindowRects.addWindow(window); + } +} + +inline bool GrReducedClip::intersectIBounds(const SkIRect& irect) { + SkASSERT(fHasIBounds); + if (!fIBounds.intersect(irect)) { + fHasIBounds = false; + fWindowRects.reset(); + fElements.reset(); + fRequiresAA = false; + fInitialState = InitialState::kAllOut; + return false; + } + return true; +} + +//////////////////////////////////////////////////////////////////////////////// +// Create a 8-bit clip mask in alpha + +static bool stencil_element(GrDrawContext* dc, + const GrFixedClip& clip, + const GrUserStencilSettings* ss, + const SkMatrix& viewMatrix, + const SkClipStack::Element* element) { + + // TODO: Draw rrects directly here. + switch (element->getType()) { + case Element::kEmpty_Type: + SkDEBUGFAIL("Should never get here with an empty element."); + break; + case Element::kRect_Type: + return dc->drawContextPriv().drawAndStencilRect(clip, ss, + (SkRegion::Op)element->getOp(), + element->isInverseFilled(), + element->isAA(), + viewMatrix, element->getRect()); + break; + default: { + SkPath path; + element->asPath(&path); + if (path.isInverseFillType()) { + path.toggleInverseFillType(); + } + + return dc->drawContextPriv().drawAndStencilPath(clip, ss, + (SkRegion::Op)element->getOp(), + element->isInverseFilled(), + element->isAA(), viewMatrix, path); + break; + } + } + + return false; +} + +static void draw_element(GrDrawContext* dc, + const GrClip& clip, // TODO: can this just always be WideOpen? + const GrPaint &paint, + const SkMatrix& viewMatrix, + const SkClipStack::Element* element) { + + // TODO: Draw rrects directly here. + switch (element->getType()) { + case Element::kEmpty_Type: + SkDEBUGFAIL("Should never get here with an empty element."); + break; + case Element::kRect_Type: + dc->drawRect(clip, paint, viewMatrix, element->getRect()); + break; + default: { + SkPath path; + element->asPath(&path); + if (path.isInverseFillType()) { + path.toggleInverseFillType(); + } + + dc->drawPath(clip, paint, viewMatrix, path, GrStyle::SimpleFill()); + break; + } + } +} + +bool GrReducedClip::drawAlphaClipMask(GrDrawContext* dc) const { + // The texture may be larger than necessary, this rect represents the part of the texture + // we populate with a rasterization of the clip. + GrFixedClip clip(SkIRect::MakeWH(fIBounds.width(), fIBounds.height())); + + if (!fWindowRects.empty()) { + clip.setWindowRectangles(fWindowRects, {fIBounds.left(), fIBounds.top()}, + GrWindowRectsState::Mode::kExclusive); + } + + // The scratch texture that we are drawing into can be substantially larger than the mask. Only + // clear the part that we care about. + GrColor initialCoverage = InitialState::kAllIn == this->initialState() ? -1 : 0; + dc->drawContextPriv().clear(clip, initialCoverage, true); + + // Set the matrix so that rendered clip elements are transformed to mask space from clip space. + SkMatrix translate; + translate.setTranslate(SkIntToScalar(-fIBounds.left()), SkIntToScalar(-fIBounds.top())); + + // walk through each clip element and perform its set op + for (ElementList::Iter iter(fElements); iter.get(); iter.next()) { + const Element* element = iter.get(); + SkRegion::Op op = (SkRegion::Op)element->getOp(); + bool invert = element->isInverseFilled(); + if (invert || SkRegion::kIntersect_Op == op || SkRegion::kReverseDifference_Op == op) { + // draw directly into the result with the stencil set to make the pixels affected + // by the clip shape be non-zero. + static constexpr GrUserStencilSettings kStencilInElement( + GrUserStencilSettings::StaticInit< + 0xffff, + GrUserStencilTest::kAlways, + 0xffff, + GrUserStencilOp::kReplace, + GrUserStencilOp::kReplace, + 0xffff>() + ); + if (!stencil_element(dc, clip, &kStencilInElement, translate, element)) { + return false; + } + + // Draw to the exterior pixels (those with a zero stencil value). + static constexpr GrUserStencilSettings kDrawOutsideElement( + GrUserStencilSettings::StaticInit< + 0x0000, + GrUserStencilTest::kEqual, + 0xffff, + GrUserStencilOp::kZero, + GrUserStencilOp::kZero, + 0xffff>() + ); + if (!dc->drawContextPriv().drawAndStencilRect(clip, &kDrawOutsideElement, + op, !invert, false, + translate, + SkRect::Make(fIBounds))) { + return false; + } + } else { + // all the remaining ops can just be directly draw into the accumulation buffer + GrPaint paint; + paint.setAntiAlias(element->isAA()); + paint.setCoverageSetOpXPFactory(op, false); + + draw_element(dc, clip, paint, translate, element); + } + } + + return true; +} + +//////////////////////////////////////////////////////////////////////////////// +// Create a 1-bit clip mask in the stencil buffer. + +class StencilClip final : public GrClip { +public: + StencilClip(const SkIRect& scissorRect) : fFixedClip(scissorRect) {} + const GrFixedClip& fixedClip() const { return fFixedClip; } + + void setWindowRectangles(const GrWindowRectangles& windows, const SkIPoint& origin, + GrWindowRectsState::Mode mode) { + fFixedClip.setWindowRectangles(windows, origin, mode); + } + +private: + bool quickContains(const SkRect&) const override { + return false; + } + void getConservativeBounds(int width, int height, SkIRect* bounds, bool* iior) const override { + fFixedClip.getConservativeBounds(width, height, bounds, iior); + } + bool isRRect(const SkRect& rtBounds, SkRRect* rr, bool* aa) const override { + return false; + } + bool apply(GrContext* context, GrDrawContext* drawContext, bool useHWAA, + bool hasUserStencilSettings, GrAppliedClip* out) const override { + if (!fFixedClip.apply(context, drawContext, useHWAA, hasUserStencilSettings, out)) { + return false; + } + out->addStencilClip(); + return true; + } + + GrFixedClip fFixedClip; + + typedef GrClip INHERITED; +}; + +bool GrReducedClip::drawStencilClipMask(GrContext* context, + GrDrawContext* drawContext, + const SkIPoint& clipOrigin) const { + // We set the current clip to the bounds so that our recursive draws are scissored to them. + StencilClip stencilClip(fIBounds.makeOffset(-clipOrigin.x(), -clipOrigin.y())); + + if (!fWindowRects.empty()) { + stencilClip.setWindowRectangles(fWindowRects, clipOrigin, + GrWindowRectsState::Mode::kExclusive); + } + + bool initialState = InitialState::kAllIn == this->initialState(); + drawContext->drawContextPriv().clearStencilClip(stencilClip.fixedClip(), initialState); + + // Set the matrix so that rendered clip elements are transformed from clip to stencil space. + SkMatrix viewMatrix; + viewMatrix.setTranslate(SkIntToScalar(-clipOrigin.x()), SkIntToScalar(-clipOrigin.y())); + + // walk through each clip element and perform its set op + // with the existing clip. + for (ElementList::Iter iter(fElements); iter.get(); iter.next()) { + const Element* element = iter.get(); + bool useHWAA = element->isAA() && drawContext->isStencilBufferMultisampled(); + + bool fillInverted = false; + + // This will be used to determine whether the clip shape can be rendered into the + // stencil with arbitrary stencil settings. + GrPathRenderer::StencilSupport stencilSupport; + + SkRegion::Op op = (SkRegion::Op)element->getOp(); + + GrPathRenderer* pr = nullptr; + SkPath clipPath; + if (Element::kRect_Type == element->getType()) { + stencilSupport = GrPathRenderer::kNoRestriction_StencilSupport; + fillInverted = false; + } else { + element->asPath(&clipPath); + fillInverted = clipPath.isInverseFillType(); + if (fillInverted) { + clipPath.toggleInverseFillType(); + } + + GrShape shape(clipPath, GrStyle::SimpleFill()); + GrPathRenderer::CanDrawPathArgs canDrawArgs; + canDrawArgs.fShaderCaps = context->caps()->shaderCaps(); + canDrawArgs.fViewMatrix = &viewMatrix; + canDrawArgs.fShape = &shape; + canDrawArgs.fAntiAlias = false; + canDrawArgs.fHasUserStencilSettings = false; + canDrawArgs.fIsStencilBufferMSAA = drawContext->isStencilBufferMultisampled(); + + GrDrawingManager* dm = context->contextPriv().drawingManager(); + pr = dm->getPathRenderer(canDrawArgs, false, + GrPathRendererChain::kStencilOnly_DrawType, + &stencilSupport); + if (!pr) { + return false; + } + } + + bool canRenderDirectToStencil = + GrPathRenderer::kNoRestriction_StencilSupport == stencilSupport; + bool drawDirectToClip; // Given the renderer, the element, + // fill rule, and set operation should + // we render the element directly to + // stencil bit used for clipping. + GrUserStencilSettings const* const* stencilPasses = + GrStencilSettings::GetClipPasses(op, canRenderDirectToStencil, fillInverted, + &drawDirectToClip); + + // draw the element to the client stencil bits if necessary + if (!drawDirectToClip) { + static constexpr GrUserStencilSettings kDrawToStencil( + GrUserStencilSettings::StaticInit< + 0x0000, + GrUserStencilTest::kAlways, + 0xffff, + GrUserStencilOp::kIncMaybeClamp, + GrUserStencilOp::kIncMaybeClamp, + 0xffff>() + ); + if (Element::kRect_Type == element->getType()) { + drawContext->drawContextPriv().stencilRect(stencilClip.fixedClip(), + &kDrawToStencil, useHWAA, + viewMatrix, element->getRect()); + } else { + if (!clipPath.isEmpty()) { + GrShape shape(clipPath, GrStyle::SimpleFill()); + if (canRenderDirectToStencil) { + GrPaint paint; + paint.setXPFactory(GrDisableColorXPFactory::Make()); + paint.setAntiAlias(element->isAA()); + + GrPathRenderer::DrawPathArgs args; + args.fResourceProvider = context->resourceProvider(); + args.fPaint = &paint; + args.fUserStencilSettings = &kDrawToStencil; + args.fDrawContext = drawContext; + args.fClip = &stencilClip.fixedClip(); + args.fViewMatrix = &viewMatrix; + args.fShape = &shape; + args.fAntiAlias = false; + args.fGammaCorrect = false; + pr->drawPath(args); + } else { + GrPathRenderer::StencilPathArgs args; + args.fResourceProvider = context->resourceProvider(); + args.fDrawContext = drawContext; + args.fClip = &stencilClip.fixedClip(); + args.fViewMatrix = &viewMatrix; + args.fIsAA = element->isAA(); + args.fShape = &shape; + pr->stencilPath(args); + } + } + } + } + + // now we modify the clip bit by rendering either the clip + // element directly or a bounding rect of the entire clip. + for (GrUserStencilSettings const* const* pass = stencilPasses; *pass; ++pass) { + if (drawDirectToClip) { + if (Element::kRect_Type == element->getType()) { + drawContext->drawContextPriv().stencilRect(stencilClip, *pass, useHWAA, + viewMatrix, element->getRect()); + } else { + GrShape shape(clipPath, GrStyle::SimpleFill()); + GrPaint paint; + paint.setXPFactory(GrDisableColorXPFactory::Make()); + paint.setAntiAlias(element->isAA()); + GrPathRenderer::DrawPathArgs args; + args.fResourceProvider = context->resourceProvider(); + args.fPaint = &paint; + args.fUserStencilSettings = *pass; + args.fDrawContext = drawContext; + args.fClip = &stencilClip; + args.fViewMatrix = &viewMatrix; + args.fShape = &shape; + args.fAntiAlias = false; + args.fGammaCorrect = false; + pr->drawPath(args); + } + } else { + // The view matrix is setup to do clip space -> stencil space translation, so + // draw rect in clip space. + drawContext->drawContextPriv().stencilRect(stencilClip, *pass, + false, viewMatrix, + SkRect::Make(fIBounds)); + } + } + } + return true; +} |