/*
* 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 "GrRenderTargetContext.h"
#include "GrRenderTargetContextPriv.h"
#include "GrDrawingManager.h"
#include "GrFixedClip.h"
#include "GrPathRenderer.h"
#include "GrStencilSettings.h"
#include "GrStyle.h"
#include "GrUserStencilSettings.h"
#include "SkClipOpPriv.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, kReplace_SkClipOp, 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 kDifference_SkClipOp:
// 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 kIntersect_SkClipOp:
// 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 kUnion_SkClipOp:
// 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 kXOR_SkClipOp:
// 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 kReverseDifference_SkClipOp:
// 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 kReplace_SkClipOp:
// 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(kXOR_SkClipOp == element->getOp() ||
kReverseDifference_SkClipOp == element->getOp());
fElements.addToHead(SkRect::Make(fIBounds), kReverseDifference_SkClipOp, 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 = kReplace_SkClipOp == newElement->getOp();
if (newElement->isInverseFilled() &&
(kIntersect_SkClipOp == newElement->getOp() || isReplace)) {
newElement->invertShapeFillType();
newElement->setOp(kDifference_SkClipOp);
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 kDifference_SkClipOp:
// subtracting from the empty set yields the empty set.
skippable = InitialTriState::kAllOut == initialTriState;
break;
case kIntersect_SkClipOp:
// 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(kReplace_SkClipOp);
}
break;
case kUnion_SkClipOp:
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(kReplace_SkClipOp);
}
break;
case kXOR_SkClipOp:
if (InitialTriState::kAllOut == initialTriState) {
// xor could be changed to diff in the kAllIn case, not sure it's a win.
element->setOp(kReplace_SkClipOp);
}
break;
case kReverseDifference_SkClipOp:
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(kReplace_SkClipOp);
}
}
break;
case kReplace_SkClipOp:
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(SkClipOp op) {
SkASSERT(static_cast<int>(op) >= 0);
return static_cast<int>(op) <= static_cast<int>(kIntersect_SkClipOp);
GR_STATIC_ASSERT(0 == static_cast<int>(kDifference_SkClipOp));
GR_STATIC_ASSERT(1 == static_cast<int>(kIntersect_SkClipOp));
}
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 (kDifference_SkClipOp != 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(GrRenderTargetContext* rtc,
const GrFixedClip& clip,
const GrUserStencilSettings* ss,
const SkMatrix& viewMatrix,
const SkClipStack::Element* element) {
GrAA aa = GrBoolToAA(element->isAA());
switch (element->getType()) {
case Element::kEmpty_Type:
SkDEBUGFAIL("Should never get here with an empty element.");
break;
case Element::kRect_Type:
return rtc->priv().drawAndStencilRect(clip, ss,
(SkRegion::Op)element->getOp(),
element->isInverseFilled(), aa, viewMatrix,
element->getRect());
break;
default: {
SkPath path;
element->asPath(&path);
if (path.isInverseFillType()) {
path.toggleInverseFillType();
}
return rtc->priv().drawAndStencilPath(clip, ss, (SkRegion::Op)element->getOp(),
element->isInverseFilled(), aa, viewMatrix, path);
break;
}
}
return false;
}
static void draw_element(GrRenderTargetContext* rtc,
const GrClip& clip, // TODO: can this just always be WideOpen?
GrPaint&& paint,
GrAA aa,
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:
rtc->drawRect(clip, std::move(paint), aa, viewMatrix, element->getRect());
break;
default: {
SkPath path;
element->asPath(&path);
if (path.isInverseFillType()) {
path.toggleInverseFillType();
}
rtc->drawPath(clip, std::move(paint), aa, viewMatrix, path, GrStyle::SimpleFill());
break;
}
}
}
bool GrReducedClip::drawAlphaClipMask(GrRenderTargetContext* rtc) 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.makeOffset(-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;
rtc->priv().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();
GrAA aa = GrBoolToAA(element->isAA());
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(rtc, 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 (!rtc->priv().drawAndStencilRect(clip, &kDrawOutsideElement, op, !invert, GrAA::kNo,
translate, SkRect::Make(fIBounds))) {
return false;
}
} else {
// all the remaining ops can just be directly draw into the accumulation buffer
GrPaint paint;
paint.setCoverageSetOpXPFactory(op, false);
draw_element(rtc, clip, std::move(paint), aa, 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, GrWindowRectsState::Mode mode) {
fFixedClip.setWindowRectangles(windows, 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, GrAA*) const override {
return false;
}
bool apply(GrContext* context, GrRenderTargetContext* renderTargetContext, bool useHWAA,
bool hasUserStencilSettings, GrAppliedClip* out, SkRect* bounds) const override {
if (!fFixedClip.apply(context, renderTargetContext, useHWAA, hasUserStencilSettings, out,
bounds)) {
return false;
}
out->addStencilClip();
return true;
}
GrFixedClip fFixedClip;
typedef GrClip INHERITED;
};
bool GrReducedClip::drawStencilClipMask(GrContext* context,
GrRenderTargetContext* renderTargetContext) const {
// We set the current clip to the bounds so that our recursive draws are scissored to them.
StencilClip stencilClip(fIBounds);
if (!fWindowRects.empty()) {
stencilClip.setWindowRectangles(fWindowRects, GrWindowRectsState::Mode::kExclusive);
}
bool initialState = InitialState::kAllIn == this->initialState();
renderTargetContext->priv().clearStencilClip(stencilClip.fixedClip(), initialState);
// 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();
GrAAType aaType = GrAAType::kNone;
if (element->isAA() && renderTargetContext->isStencilBufferMultisampled()) {
aaType = GrAAType::kMSAA;
}
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 = &SkMatrix::I();
canDrawArgs.fShape = &shape;
canDrawArgs.fAAType = aaType;
canDrawArgs.fHasUserStencilSettings = false;
GrDrawingManager* dm = context->contextPriv().drawingManager();
pr = dm->getPathRenderer(canDrawArgs, false, GrPathRendererChain::DrawType::kStencil,
&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()) {
renderTargetContext->priv().stencilRect(stencilClip.fixedClip(), &kDrawToStencil,
aaType, SkMatrix::I(), element->getRect());
} else {
if (!clipPath.isEmpty()) {
GrShape shape(clipPath, GrStyle::SimpleFill());
if (canRenderDirectToStencil) {
GrPaint paint;
paint.setXPFactory(GrDisableColorXPFactory::Get());
GrPathRenderer::DrawPathArgs args{context,
std::move(paint),
&kDrawToStencil,
renderTargetContext,
&stencilClip.fixedClip(),
&SkMatrix::I(),
&shape,
aaType,
false};
pr->drawPath(args);
} else {
GrPathRenderer::StencilPathArgs args;
args.fContext = context;
args.fRenderTargetContext = renderTargetContext;
args.fClip = &stencilClip.fixedClip();
args.fViewMatrix = &SkMatrix::I();
args.fAAType = aaType;
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()) {
renderTargetContext->priv().stencilRect(stencilClip, *pass, aaType,
SkMatrix::I(), element->getRect());
} else {
GrShape shape(clipPath, GrStyle::SimpleFill());
GrPaint paint;
paint.setXPFactory(GrDisableColorXPFactory::Get());
GrPathRenderer::DrawPathArgs args{context,
std::move(paint),
*pass,
renderTargetContext,
&stencilClip,
&SkMatrix::I(),
&shape,
aaType,
false};
pr->drawPath(args);
}
} else {
// The view matrix is setup to do clip space -> stencil space translation, so
// draw rect in clip space.
renderTargetContext->priv().stencilRect(stencilClip, *pass, aaType, SkMatrix::I(),
SkRect::Make(fIBounds));
}
}
}
return true;
}