| /* |
| * Copyright 2020 Google LLC |
| * |
| * Use of this source code is governed by a BSD-style license that can be |
| * found in the LICENSE file. |
| */ |
| #ifndef GrClipStack_DEFINED |
| |
| #define GrClipStack_DEFINED |
| |
| #include "include/core/SkClipOp.h" |
| #include "include/core/SkMatrix.h" |
| #include "include/core/SkShader.h" |
| #include "include/private/GrResourceKey.h" |
| #include "src/gpu/GrClip.h" |
| #include "src/gpu/GrSurfaceProxyView.h" |
| #include "src/gpu/GrTBlockList.h" |
| #include "src/gpu/geometry/GrShape.h" |
| |
| class GrAppliedClip; |
| class GrProxyProvider; |
| class GrRecordingContext; |
| class GrSurfaceDrawContext; |
| class GrSWMaskHelper; |
| |
| class GrClipStack final : public GrClip { |
| public: |
| enum class ClipState : uint8_t { |
| kEmpty, kWideOpen, kDeviceRect, kDeviceRRect, kComplex |
| }; |
| |
| // All data describing a geometric modification to the clip |
| struct Element { |
| GrShape fShape; |
| SkMatrix fLocalToDevice; |
| SkClipOp fOp; |
| GrAA fAA; |
| }; |
| |
| // The SkMatrixProvider must outlive the GrClipStack. |
| GrClipStack(const SkIRect& deviceBounds, const SkMatrixProvider* matrixProvider, bool forceAA); |
| |
| ~GrClipStack() override; |
| |
| GrClipStack(const GrClipStack&) = delete; |
| GrClipStack& operator=(const GrClipStack&) = delete; |
| |
| ClipState clipState() const { return this->currentSaveRecord().state(); } |
| |
| class ElementIter; |
| // Provides for-range over active, valid clip elements from most recent to oldest. |
| // The iterator provides items as "const Element&". |
| inline ElementIter begin() const; |
| inline ElementIter end() const; |
| |
| // Clip stack manipulation |
| void save(); |
| void restore(); |
| |
| void clipRect(const SkMatrix& ctm, const SkRect& rect, GrAA aa, SkClipOp op) { |
| this->clip({ctm, GrShape(rect), aa, op}); |
| } |
| void clipRRect(const SkMatrix& ctm, const SkRRect& rrect, GrAA aa, SkClipOp op) { |
| this->clip({ctm, GrShape(rrect), aa, op}); |
| } |
| void clipPath(const SkMatrix& ctm, const SkPath& path, GrAA aa, SkClipOp op) { |
| this->clip({ctm, GrShape(path), aa, op}); |
| } |
| void clipShader(sk_sp<SkShader> shader); |
| |
| void replaceClip(const SkIRect& rect); |
| |
| // GrClip implementation |
| GrClip::Effect apply(GrRecordingContext*, GrSurfaceDrawContext*, const GrDrawOp* opBeingClipped, |
| GrAAType aa, GrAppliedClip*, SkRect* bounds) const override; |
| GrClip::PreClipResult preApply(const SkRect& drawBounds, GrAA aa) const override; |
| SkIRect getConservativeBounds() const override; |
| |
| #if GR_TEST_UTILS |
| GrUniqueKey testingOnly_getLastSWMaskKey() const { |
| return fMasks.empty() ? GrUniqueKey() : fMasks.back().key(); |
| } |
| #endif |
| |
| private: |
| class SaveRecord; |
| class Mask; |
| |
| // Internally, a lot of clip reasoning is based on an op, outer bounds, and whether a shape |
| // contains another (possibly just conservatively based on inner/outer device-space bounds). |
| // |
| // Element and SaveRecord store this information directly, but a draw fits the same definition |
| // with an implicit intersect op and empty inner bounds. The OpDraw and RRectDraw types provide |
| // the same interface as Element and SaveRecord for internal clip reasoning templates. |
| class Draw; |
| |
| // Wraps the geometric Element data with logic for containment and bounds testing. |
| class RawElement : private Element { |
| public: |
| using Stack = GrTBlockList<RawElement, 1>; |
| |
| RawElement(const SkMatrix& localToDevice, const GrShape& shape, GrAA aa, SkClipOp op); |
| |
| // Common clip type interface |
| SkClipOp op() const { return fOp; } |
| const SkIRect& outerBounds() const { return fOuterBounds; } |
| bool contains(const SaveRecord& s) const; |
| bool contains(const Draw& d) const; |
| bool contains(const RawElement& e) const; |
| |
| // Additional element-specific data |
| const Element& asElement() const { return *this; } |
| |
| const GrShape& shape() const { return fShape; } |
| const SkMatrix& localToDevice() const { return fLocalToDevice; } |
| const SkIRect& innerBounds() const { return fInnerBounds; } |
| GrAA aa() const { return fAA; } |
| |
| ClipState clipType() const; |
| |
| // As new elements are pushed on to the stack, they may make older elements redundant. |
| // The old elements are marked invalid so they are skipped during clip application, but may |
| // become active again when a save record is restored. |
| bool isInvalid() const { return fInvalidatedByIndex >= 0; } |
| void markInvalid(const SaveRecord& current); |
| void restoreValid(const SaveRecord& current); |
| |
| // 'added' represents a new op added to the element stack. Its combination with this element |
| // can result in a number of possibilities: |
| // 1. The entire clip is empty (signaled by both this and 'added' being invalidated). |
| // 2. The 'added' op supercedes this element (this element is invalidated). |
| // 3. This op supercedes the 'added' element (the added element is marked invalidated). |
| // 4. Their combination can be represented by a single new op (in which case this |
| // element should be invalidated, and the combined shape stored in 'added'). |
| // 5. Or both elements remain needed to describe the clip (both are valid and unchanged). |
| // |
| // The calling element will only modify its invalidation index since it could belong |
| // to part of the inactive stack (that might be restored later). All merged state/geometry |
| // is handled by modifying 'added'. |
| void updateForElement(RawElement* added, const SaveRecord& current); |
| |
| void simplify(const SkIRect& deviceBounds, bool forceAA); |
| |
| private: |
| bool combine(const RawElement& other, const SaveRecord& current); |
| |
| SkMatrix fDeviceToLocal; // cached inverse of fLocalToDevice for contains() optimization |
| |
| // Device space bounds, rounded in or out to pixel boundaries and accounting for any |
| // uncertainty around anti-aliasing and rasterization snapping. |
| SkIRect fInnerBounds; |
| SkIRect fOuterBounds; |
| |
| // Elements are invalidated by SaveRecords as the record is updated with new elements that |
| // override old geometry. An invalidated element stores the index of the first element of |
| // the save record that invalidated it. This makes it easy to undo when the save record is |
| // popped from the stack, and is stable as the current save record is modified. |
| int fInvalidatedByIndex; |
| }; |
| |
| // Represents an alpha mask with the rasterized coverage from elements in a draw query that |
| // could not be converted to analytic coverage FPs. |
| // TODO: This is only required for SW masks. Stencil masks and atlas masks don't have resources |
| // owned by the GrClipStack. Once SW masks are no longer needed, this can go away. |
| class Mask { |
| public: |
| using Stack = GrTBlockList<Mask, 1>; |
| |
| Mask(const SaveRecord& current, const SkIRect& bounds); |
| |
| ~Mask() { |
| // The key should have been released by the clip stack before hand |
| SkASSERT(!fKey.isValid()); |
| } |
| |
| const GrUniqueKey& key() const { return fKey; } |
| const SkIRect& bounds() const { return fBounds; } |
| uint32_t genID() const { return fGenID; } |
| |
| bool appliesToDraw(const SaveRecord& current, const SkIRect& drawBounds) const; |
| void invalidate(GrProxyProvider* proxyProvider); |
| |
| SkDEBUGCODE(const SaveRecord* owner() const { return fOwner; }) |
| private: |
| GrUniqueKey fKey; |
| // The gen ID of the save record and the query bounds uniquely define the set of elements |
| // that would go into a mask. If the save record adds new elements, its gen ID would change. |
| // If the draw had different bounds it would select a different set of masked elements. |
| // Repeatedly querying an unmodified save record with the same bounds is idempotent. |
| SkIRect fBounds; |
| uint32_t fGenID; |
| |
| SkDEBUGCODE(const SaveRecord* fOwner;) |
| }; |
| |
| // Represents a saved point in the clip stack, and manages the life time of elements added to |
| // stack within the record's life time. Also provides the logic for determining active elements |
| // given a draw query. |
| class SaveRecord { |
| public: |
| using Stack = GrTBlockList<SaveRecord, 2>; |
| |
| explicit SaveRecord(const SkIRect& deviceBounds); |
| |
| SaveRecord(const SaveRecord& prior, int startingMaskIndex, int startingElementIndex); |
| |
| // The common clip type interface |
| SkClipOp op() const { return fStackOp; } |
| const SkIRect& outerBounds() const { return fOuterBounds; } |
| bool contains(const Draw& d) const; |
| bool contains(const RawElement& e) const; |
| |
| // Additional save record-specific data/functionality |
| const SkShader* shader() const { return fShader.get(); } |
| const SkIRect& innerBounds() const { return fInnerBounds; } |
| int firstActiveElementIndex() const { return fStartingElementIndex; } |
| int oldestElementIndex() const { return fOldestValidIndex; } |
| bool canBeUpdated() const { return (fDeferredSaveCount == 0); } |
| |
| ClipState state() const; |
| uint32_t genID() const; |
| |
| // Deferred save manipulation |
| void pushSave() { |
| SkASSERT(fDeferredSaveCount >= 0); |
| fDeferredSaveCount++; |
| } |
| // Returns true if the record should stay alive. False means the GrClipStack must delete it |
| bool popSave() { |
| fDeferredSaveCount--; |
| SkASSERT(fDeferredSaveCount >= -1); |
| return fDeferredSaveCount >= 0; |
| } |
| |
| // Return true if the element was added to 'elements', or otherwise affected the save record |
| // (e.g. turned it empty). |
| bool addElement(RawElement&& toAdd, RawElement::Stack* elements); |
| |
| void addShader(sk_sp<SkShader> shader); |
| void reset(const SkIRect& bounds); |
| |
| // Remove the elements owned by this save record, which must happen before the save record |
| // itself is removed from the clip stack. |
| void removeElements(RawElement::Stack* elements); |
| |
| // Restore element validity now that this record is the new top of the stack. |
| void restoreElements(RawElement::Stack* elements); |
| |
| void invalidateMasks(GrProxyProvider* proxyProvider, Mask::Stack* masks); |
| |
| private: |
| // These functions modify 'elements' and element-dependent state of the record |
| // (such as valid index and fState). |
| bool appendElement(RawElement&& toAdd, RawElement::Stack* elements); |
| void replaceWithElement(RawElement&& toAdd, RawElement::Stack* elements); |
| |
| // Inner bounds is always contained in outer bounds, or it is empty. All bounds will be |
| // contained in the device bounds. |
| SkIRect fInnerBounds; // Inside is full coverage (stack op == intersect) or 0 cov (diff) |
| SkIRect fOuterBounds; // Outside is 0 coverage (op == intersect) or full cov (diff) |
| |
| // A save record can have up to one shader, multiple shaders are automatically blended |
| sk_sp<SkShader> fShader; |
| |
| const int fStartingMaskIndex; // First mask owned by this save record |
| const int fStartingElementIndex; // First element owned by this save record |
| int fOldestValidIndex; // Index of oldest element that remains valid for this record |
| |
| int fDeferredSaveCount; // Number of save() calls without modifications (yet) |
| |
| // Will be kIntersect unless every valid element is kDifference, which is significant |
| // because if kDifference then there is an implicit extra outer bounds at the device edges. |
| SkClipOp fStackOp; |
| ClipState fState; |
| uint32_t fGenID; |
| }; |
| |
| // Adds the element to the clip, handling allocating a new save record on the stack if |
| // there is a deferred save. |
| void clip(RawElement&& element); |
| |
| const SaveRecord& currentSaveRecord() const { |
| SkASSERT(!fSaves.empty()); |
| return fSaves.back(); |
| } |
| |
| // Will return the current save record, properly updating deferred saves |
| // and initializing a first record if it were empty. |
| SaveRecord& writableSaveRecord(bool* wasDeferred); |
| |
| // Generate or find a cached SW coverage mask and return an FP that samples it. |
| // 'elements' is an array of pointers to elements in the stack. |
| static GrFPResult GetSWMaskFP(GrRecordingContext* context, Mask::Stack* masks, |
| const SaveRecord& current, const SkIRect& bounds, |
| const Element** elements, int count, |
| std::unique_ptr<GrFragmentProcessor> clipFP); |
| |
| RawElement::Stack fElements; |
| SaveRecord::Stack fSaves; // always has one wide open record at the top |
| |
| // The masks are recorded during apply() calls so we can cache them; they are not modifications |
| // of the actual clip stack. |
| // NOTE: These fields can go away once a context has a dedicated clip atlas |
| mutable Mask::Stack fMasks; |
| mutable GrProxyProvider* fProxyProvider; |
| |
| const SkIRect fDeviceBounds; |
| const SkMatrixProvider* fMatrixProvider; |
| |
| // When there's MSAA, clip elements are applied using the stencil buffer. If a backend cannot |
| // disable MSAA per draw, then all elements are effectively AA'ed. Tracking them as such makes |
| // keeps the entire stack as simple as possible. |
| bool fForceAA; |
| }; |
| |
| // Clip element iteration |
| class GrClipStack::ElementIter { |
| public: |
| bool operator!=(const ElementIter& o) const { |
| return o.fItem != fItem && o.fRemaining != fRemaining; |
| } |
| |
| const Element& operator*() const { return (*fItem).asElement(); } |
| |
| ElementIter& operator++() { |
| // Skip over invalidated elements |
| do { |
| fRemaining--; |
| ++fItem; |
| } while(fRemaining > 0 && (*fItem).isInvalid()); |
| |
| return *this; |
| } |
| |
| ElementIter(RawElement::Stack::CRIter::Item item, int r) : fItem(item), fRemaining(r) {} |
| |
| RawElement::Stack::CRIter::Item fItem; |
| int fRemaining; |
| |
| friend class GrClipStack; |
| }; |
| |
| GrClipStack::ElementIter GrClipStack::begin() const { |
| if (this->currentSaveRecord().state() == ClipState::kEmpty || |
| this->currentSaveRecord().state() == ClipState::kWideOpen) { |
| // No visible clip elements when empty or wide open |
| return this->end(); |
| } |
| int count = fElements.count() - this->currentSaveRecord().oldestElementIndex(); |
| return ElementIter(fElements.ritems().begin(), count); |
| } |
| |
| GrClipStack::ElementIter GrClipStack::end() const { |
| return ElementIter(fElements.ritems().end(), 0); |
| } |
| |
| #endif |