Adding upstream version 115.7.0esr.upstream/115.7.0esr

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 507 insertions, 0 deletions

diff --git a/gfx/skia/skia/src/core/SkClipStack.h b/gfx/skia/skia/src/core/SkClipStack.h
new file mode 100644
index 0000000000..64c086b352
--- /dev/null
+++ b/gfx/skia/skia/src/core/SkClipStack.h
@@ -0,0 +1,507 @@
+/*
+ * Copyright 2011 Google Inc.
+ *
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+
+#ifndef SkClipStack_DEFINED
+#define SkClipStack_DEFINED
+
+#include "include/core/SkCanvas.h"
+#include "include/core/SkPath.h"
+#include "include/core/SkRRect.h"
+#include "include/core/SkRect.h"
+#include "include/core/SkRegion.h"
+#include "include/core/SkShader.h"
+#include "include/private/base/SkDeque.h"
+#include "src/base/SkTLazy.h"
+#include "src/core/SkMessageBus.h"
+
+// Because a single save/restore state can have multiple clips, this class
+// stores the stack depth (fSaveCount) and clips (fDeque) separately.
+// Each clip in fDeque stores the stack state to which it belongs
+// (i.e., the fSaveCount in force when it was added). Restores are thus
+// implemented by removing clips from fDeque that have an fSaveCount larger
+// then the freshly decremented count.
+class SkClipStack {
+public:
+    enum BoundsType {
+        // The bounding box contains all the pixels that can be written to
+        kNormal_BoundsType,
+        // The bounding box contains all the pixels that cannot be written to.
+        // The real bound extends out to infinity and all the pixels outside
+        // of the bound can be written to. Note that some of the pixels inside
+        // the bound may also be writeable but all pixels that cannot be
+        // written to are guaranteed to be inside.
+        kInsideOut_BoundsType
+    };
+
+    /**
+     * An element of the clip stack. It represents a shape combined with the prevoius clip using a
+     * set operator. Each element can be antialiased or not.
+     */
+    class Element {
+    public:
+        /** This indicates the shape type of the clip element in device space. */
+        enum class DeviceSpaceType {
+            //!< This element makes the clip empty (regardless of previous elements).
+            kEmpty,
+            //!< This element combines a device space rect with the current clip.
+            kRect,
+            //!< This element combines a device space round-rect with the current clip.
+            kRRect,
+            //!< This element combines a device space path with the current clip.
+            kPath,
+            //!< This element does not have geometry, but applies a shader to the clip
+            kShader,
+
+            kLastType = kShader
+        };
+        static const int kTypeCnt = (int)DeviceSpaceType::kLastType + 1;
+
+        Element() {
+            this->initCommon(0, SkClipOp::kIntersect, false);
+            this->setEmpty();
+        }
+
+        Element(const Element&);
+
+        Element(const SkRect& rect, const SkMatrix& m, SkClipOp op, bool doAA) {
+            this->initRect(0, rect, m, op, doAA);
+        }
+
+        Element(const SkRRect& rrect, const SkMatrix& m, SkClipOp op, bool doAA) {
+            this->initRRect(0, rrect, m, op, doAA);
+        }
+
+        Element(const SkPath& path, const SkMatrix& m, SkClipOp op, bool doAA) {
+            this->initPath(0, path, m, op, doAA);
+        }
+
+        Element(sk_sp<SkShader> shader) {
+            this->initShader(0, std::move(shader));
+        }
+
+        Element(const SkRect& rect, bool doAA) {
+            this->initReplaceRect(0, rect, doAA);
+        }
+
+        ~Element();
+
+        bool operator== (const Element& element) const;
+        bool operator!= (const Element& element) const { return !(*this == element); }
+
+        //!< Call to get the type of the clip element.
+        DeviceSpaceType getDeviceSpaceType() const { return fDeviceSpaceType; }
+
+        //!< Call to get the save count associated with this clip element.
+        int getSaveCount() const { return fSaveCount; }
+
+        //!< Call if getDeviceSpaceType() is kPath to get the path.
+        const SkPath& getDeviceSpacePath() const {
+            SkASSERT(DeviceSpaceType::kPath == fDeviceSpaceType);
+            return *fDeviceSpacePath;
+        }
+
+        //!< Call if getDeviceSpaceType() is kRRect to get the round-rect.
+        const SkRRect& getDeviceSpaceRRect() const {
+            SkASSERT(DeviceSpaceType::kRRect == fDeviceSpaceType);
+            return fDeviceSpaceRRect;
+        }
+
+        //!< Call if getDeviceSpaceType() is kRect to get the rect.
+        const SkRect& getDeviceSpaceRect() const {
+            SkASSERT(DeviceSpaceType::kRect == fDeviceSpaceType &&
+                     (fDeviceSpaceRRect.isRect() || fDeviceSpaceRRect.isEmpty()));
+            return fDeviceSpaceRRect.getBounds();
+        }
+
+        //!<Call if getDeviceSpaceType() is kShader to get a reference to the clip shader.
+        sk_sp<SkShader> refShader() const {
+            return fShader;
+        }
+        const SkShader* getShader() const {
+            return fShader.get();
+        }
+
+        //!< Call if getDeviceSpaceType() is not kEmpty to get the set operation used to combine
+        //!< this element.
+        SkClipOp getOp() const { return fOp; }
+        // Augments getOps()'s behavior by requiring a clip reset before the op is applied.
+        bool isReplaceOp() const { return fIsReplace; }
+
+        //!< Call to get the element as a path, regardless of its type.
+        void asDeviceSpacePath(SkPath* path) const;
+
+        //!< Call if getType() is not kPath to get the element as a round rect.
+        const SkRRect& asDeviceSpaceRRect() const {
+            SkASSERT(DeviceSpaceType::kPath != fDeviceSpaceType);
+            return fDeviceSpaceRRect;
+        }
+
+        /** If getType() is not kEmpty this indicates whether the clip shape should be anti-aliased
+            when it is rasterized. */
+        bool isAA() const { return fDoAA; }
+
+        //!< Inverts the fill of the clip shape. Note that a kEmpty element remains kEmpty.
+        void invertShapeFillType();
+
+        /** The GenID can be used by clip stack clients to cache representations of the clip. The
+            ID corresponds to the set of clip elements up to and including this element within the
+            stack not to the element itself. That is the same clip path in different stacks will
+            have a different ID since the elements produce different clip result in the context of
+            their stacks. */
+        uint32_t getGenID() const { SkASSERT(kInvalidGenID != fGenID); return fGenID; }
+
+        /**
+         * Gets the bounds of the clip element, either the rect or path bounds. (Whether the shape
+         * is inverse filled is not considered.)
+         */
+        const SkRect& getBounds() const;
+
+        /**
+         * Conservatively checks whether the clip shape contains the rect/rrect. (Whether the shape
+         * is inverse filled is not considered.)
+         */
+        bool contains(const SkRect& rect) const;
+        bool contains(const SkRRect& rrect) const;
+
+        /**
+         * Is the clip shape inverse filled.
+         */
+        bool isInverseFilled() const {
+            return DeviceSpaceType::kPath == fDeviceSpaceType &&
+                   fDeviceSpacePath->isInverseFillType();
+        }
+
+#ifdef SK_DEBUG
+        /**
+         * Dumps the element to SkDebugf. This is intended for Skia development debugging
+         * Don't rely on the existence of this function or the formatting of its output.
+         */
+        void dump() const;
+#endif
+
+    private:
+        friend class SkClipStack;
+
+        SkTLazy<SkPath> fDeviceSpacePath;
+        SkRRect fDeviceSpaceRRect;
+        sk_sp<SkShader> fShader;
+        int fSaveCount;  // save count of stack when this element was added.
+        SkClipOp fOp;
+        DeviceSpaceType fDeviceSpaceType;
+        bool fDoAA;
+        bool fIsReplace;
+
+        /* fFiniteBoundType and fFiniteBound are used to incrementally update the clip stack's
+           bound. When fFiniteBoundType is kNormal_BoundsType, fFiniteBound represents the
+           conservative bounding box of the pixels that aren't clipped (i.e., any pixels that can be
+           drawn to are inside the bound). When fFiniteBoundType is kInsideOut_BoundsType (which
+           occurs when a clip is inverse filled), fFiniteBound represents the conservative bounding
+           box of the pixels that _are_ clipped (i.e., any pixels that cannot be drawn to are inside
+           the bound). When fFiniteBoundType is kInsideOut_BoundsType the actual bound is the
+           infinite plane. This behavior of fFiniteBoundType and fFiniteBound is required so that we
+           can capture the cancelling out of the extensions to infinity when two inverse filled
+           clips are Booleaned together. */
+        SkClipStack::BoundsType fFiniteBoundType;
+        SkRect fFiniteBound;
+
+        // When element is applied to the previous elements in the stack is the result known to be
+        // equivalent to a single rect intersection? IIOW, is the clip effectively a rectangle.
+        bool fIsIntersectionOfRects;
+
+        uint32_t fGenID;
+        Element(int saveCount) {
+            this->initCommon(saveCount, SkClipOp::kIntersect, false);
+            this->setEmpty();
+        }
+
+        Element(int saveCount, const SkRRect& rrect, const SkMatrix& m, SkClipOp op, bool doAA) {
+            this->initRRect(saveCount, rrect, m, op, doAA);
+        }
+
+        Element(int saveCount, const SkRect& rect, const SkMatrix& m, SkClipOp op, bool doAA) {
+            this->initRect(saveCount, rect, m, op, doAA);
+        }
+
+        Element(int saveCount, const SkPath& path, const SkMatrix& m, SkClipOp op, bool doAA) {
+            this->initPath(saveCount, path, m, op, doAA);
+        }
+
+        Element(int saveCount, sk_sp<SkShader> shader) {
+            this->initShader(saveCount, std::move(shader));
+        }
+
+        Element(int saveCount, const SkRect& rect, bool doAA) {
+            this->initReplaceRect(saveCount, rect, doAA);
+        }
+
+        void initCommon(int saveCount, SkClipOp op, bool doAA);
+        void initRect(int saveCount, const SkRect&, const SkMatrix&, SkClipOp, bool doAA);
+        void initRRect(int saveCount, const SkRRect&, const SkMatrix&, SkClipOp, bool doAA);
+        void initPath(int saveCount, const SkPath&, const SkMatrix&, SkClipOp, bool doAA);
+        void initAsPath(int saveCount, const SkPath&, const SkMatrix&, SkClipOp, bool doAA);
+        void initShader(int saveCount, sk_sp<SkShader>);
+        void initReplaceRect(int saveCount, const SkRect&, bool doAA);
+
+        void setEmpty();
+
+        // All Element methods below are only used within SkClipStack.cpp
+        inline void checkEmpty() const;
+        inline bool canBeIntersectedInPlace(int saveCount, SkClipOp op) const;
+        /* This method checks to see if two rect clips can be safely merged into one. The issue here
+          is that to be strictly correct all the edges of the resulting rect must have the same
+          anti-aliasing. */
+        bool rectRectIntersectAllowed(const SkRect& newR, bool newAA) const;
+        /** Determines possible finite bounds for the Element given the previous element of the
+            stack */
+        void updateBoundAndGenID(const Element* prior);
+        // The different combination of fill & inverse fill when combining bounding boxes
+        enum FillCombo {
+            kPrev_Cur_FillCombo,
+            kPrev_InvCur_FillCombo,
+            kInvPrev_Cur_FillCombo,
+            kInvPrev_InvCur_FillCombo
+        };
+        // per-set operation functions used by updateBoundAndGenID().
+        inline void combineBoundsDiff(FillCombo combination, const SkRect& prevFinite);
+        inline void combineBoundsIntersection(int combination, const SkRect& prevFinite);
+    };
+
+    SkClipStack();
+    SkClipStack(void* storage, size_t size);
+    SkClipStack(const SkClipStack& b);
+    ~SkClipStack();
+
+    SkClipStack& operator=(const SkClipStack& b);
+    bool operator==(const SkClipStack& b) const;
+    bool operator!=(const SkClipStack& b) const { return !(*this == b); }
+
+    void reset();
+
+    int getSaveCount() const { return fSaveCount; }
+    void save();
+    void restore();
+
+    class AutoRestore {
+    public:
+        AutoRestore(SkClipStack* cs, bool doSave)
+            : fCS(cs), fSaveCount(cs->getSaveCount())
+        {
+            if (doSave) {
+                fCS->save();
+            }
+        }
+        ~AutoRestore() {
+            SkASSERT(fCS->getSaveCount() >= fSaveCount);  // no underflow
+            while (fCS->getSaveCount() > fSaveCount) {
+                fCS->restore();
+            }
+        }
+
+    private:
+        SkClipStack* fCS;
+        const int    fSaveCount;
+    };
+
+    /**
+     * getBounds places the current finite bound in its first parameter. In its
+     * second, it indicates which kind of bound is being returned. If
+     * 'canvFiniteBound' is a normal bounding box then it encloses all writeable
+     * pixels. If 'canvFiniteBound' is an inside out bounding box then it
+     * encloses all the un-writeable pixels and the true/normal bound is the
+     * infinite plane. isIntersectionOfRects is an optional parameter
+     * that is true if 'canvFiniteBound' resulted from an intersection of rects.
+     */
+    void getBounds(SkRect* canvFiniteBound,
+                   BoundsType* boundType,
+                   bool* isIntersectionOfRects = nullptr) const;
+
+    SkRect bounds(const SkIRect& deviceBounds) const;
+    bool isEmpty(const SkIRect& deviceBounds) const;
+
+    /**
+     * Returns true if the input (r)rect in device space is entirely contained
+     * by the clip. A return value of false does not guarantee that the (r)rect
+     * is not contained by the clip.
+     */
+    bool quickContains(const SkRect& devRect) const {
+        return this->isWideOpen() || this->internalQuickContains(devRect);
+    }
+
+    bool quickContains(const SkRRect& devRRect) const {
+        return this->isWideOpen() || this->internalQuickContains(devRRect);
+    }
+
+    void clipDevRect(const SkIRect& ir, SkClipOp op) {
+        SkRect r;
+        r.set(ir);
+        this->clipRect(r, SkMatrix::I(), op, false);
+    }
+    void clipRect(const SkRect&, const SkMatrix& matrix, SkClipOp, bool doAA);
+    void clipRRect(const SkRRect&, const SkMatrix& matrix, SkClipOp, bool doAA);
+    void clipPath(const SkPath&, const SkMatrix& matrix, SkClipOp, bool doAA);
+    void clipShader(sk_sp<SkShader>);
+    // An optimized version of clipDevRect(emptyRect, kIntersect, ...)
+    void clipEmpty();
+
+    void replaceClip(const SkRect& devRect, bool doAA);
+
+    /**
+     * isWideOpen returns true if the clip state corresponds to the infinite
+     * plane (i.e., draws are not limited at all)
+     */
+    bool isWideOpen() const { return this->getTopmostGenID() == kWideOpenGenID; }
+
+    /**
+     * This method quickly and conservatively determines whether the entire stack is equivalent to
+     * intersection with a rrect given a bounds, where the rrect must not contain the entire bounds.
+     *
+     * @param bounds   A bounds on what will be drawn through the clip. The clip only need be
+     *                 equivalent to a intersection with a rrect for draws within the bounds. The
+     *                 returned rrect must intersect the bounds but need not be contained by the
+     *                 bounds.
+     * @param rrect    If return is true rrect will contain the rrect equivalent to the stack.
+     * @param aa       If return is true aa will indicate whether the equivalent rrect clip is
+     *                 antialiased.
+     * @return true if the stack is equivalent to a single rrect intersect clip, false otherwise.
+     */
+    bool isRRect(const SkRect& bounds, SkRRect* rrect, bool* aa) const;
+
+    /**
+     * The generation ID has three reserved values to indicate special
+     * (potentially ignorable) cases
+     */
+    static const uint32_t kInvalidGenID  = 0;    //!< Invalid id that is never returned by
+                                                 //!< SkClipStack. Useful when caching clips
+                                                 //!< based on GenID.
+    static const uint32_t kEmptyGenID    = 1;    // no pixels writeable
+    static const uint32_t kWideOpenGenID = 2;    // all pixels writeable
+
+    uint32_t getTopmostGenID() const;
+
+#ifdef SK_DEBUG
+    /**
+     * Dumps the contents of the clip stack to SkDebugf. This is intended for Skia development
+     * debugging. Don't rely on the existence of this function or the formatting of its output.
+     */
+    void dump() const;
+#endif
+
+public:
+    class Iter {
+    public:
+        enum IterStart {
+            kBottom_IterStart = SkDeque::Iter::kFront_IterStart,
+            kTop_IterStart = SkDeque::Iter::kBack_IterStart
+        };
+
+        /**
+         * Creates an uninitialized iterator. Must be reset()
+         */
+        Iter();
+
+        Iter(const SkClipStack& stack, IterStart startLoc);
+
+        /**
+         *  Return the clip element for this iterator. If next()/prev() returns NULL, then the
+         *  iterator is done.
+         */
+        const Element* next();
+        const Element* prev();
+
+        /**
+         * Moves the iterator to the topmost element with the specified RegionOp and returns that
+         * element. If no clip element with that op is found, the first element is returned.
+         */
+        const Element* skipToTopmost(SkClipOp op);
+
+        /**
+         * Restarts the iterator on a clip stack.
+         */
+        void reset(const SkClipStack& stack, IterStart startLoc);
+
+    private:
+        const SkClipStack* fStack;
+        SkDeque::Iter      fIter;
+    };
+
+    /**
+     * The B2TIter iterates from the bottom of the stack to the top.
+     * It inherits privately from Iter to prevent access to reverse iteration.
+     */
+    class B2TIter : private Iter {
+    public:
+        B2TIter() {}
+
+        /**
+         * Wrap Iter's 2 parameter ctor to force initialization to the
+         * beginning of the deque/bottom of the stack
+         */
+        B2TIter(const SkClipStack& stack)
+        : INHERITED(stack, kBottom_IterStart) {
+        }
+
+        using Iter::next;
+
+        /**
+         * Wrap Iter::reset to force initialization to the
+         * beginning of the deque/bottom of the stack
+         */
+        void reset(const SkClipStack& stack) {
+            this->INHERITED::reset(stack, kBottom_IterStart);
+        }
+
+    private:
+
+        using INHERITED = Iter;
+    };
+
+    /**
+     * GetConservativeBounds returns a conservative bound of the current clip.
+     * Since this could be the infinite plane (if inverse fills were involved) the
+     * maxWidth and maxHeight parameters can be used to limit the returned bound
+     * to the expected drawing area. Similarly, the offsetX and offsetY parameters
+     * allow the caller to offset the returned bound to account for translated
+     * drawing areas (i.e., those resulting from a saveLayer). For finite bounds,
+     * the translation (+offsetX, +offsetY) is applied before the clamp to the
+     * maximum rectangle: [0,maxWidth) x [0,maxHeight).
+     * isIntersectionOfRects is an optional parameter that is true when
+     * 'devBounds' is the result of an intersection of rects. In this case
+     * 'devBounds' is the exact answer/clip.
+     */
+    void getConservativeBounds(int offsetX,
+                               int offsetY,
+                               int maxWidth,
+                               int maxHeight,
+                               SkRect* devBounds,
+                               bool* isIntersectionOfRects = nullptr) const;
+
+private:
+    friend class Iter;
+
+    SkDeque fDeque;
+    int     fSaveCount;
+
+    bool internalQuickContains(const SkRect& devRect) const;
+    bool internalQuickContains(const SkRRect& devRRect) const;
+
+    /**
+     * Helper for clipDevPath, etc.
+     */
+    void pushElement(const Element& element);
+
+    /**
+     * Restore the stack back to the specified save count.
+     */
+    void restoreTo(int saveCount);
+
+    /**
+     * Return the next unique generation ID.
+     */
+    static uint32_t GetNextGenID();
+};
+
+#endif