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583 lines
20 KiB
583 lines
20 KiB
/*
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* Copyright 2012 Google Inc.
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*
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* Use of this source code is governed by a BSD-style license that can be
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* found in the LICENSE file.
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*/
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#ifndef SkPathRef_DEFINED
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#define SkPathRef_DEFINED
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#include "SkMatrix.h"
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#include "SkMutex.h"
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#include "SkPoint.h"
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#include "SkRRect.h"
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#include "SkRect.h"
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#include "SkRefCnt.h"
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#include "SkTDArray.h"
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#include "SkTemplates.h"
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#include "SkTo.h"
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#include <atomic>
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#include <limits>
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class SkRBuffer;
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class SkWBuffer;
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/**
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* Holds the path verbs and points. It is versioned by a generation ID. None of its public methods
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* modify the contents. To modify or append to the verbs/points wrap the SkPathRef in an
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* SkPathRef::Editor object. Installing the editor resets the generation ID. It also performs
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* copy-on-write if the SkPathRef is shared by multiple SkPaths. The caller passes the Editor's
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* constructor a pointer to a sk_sp<SkPathRef>, which may be updated to point to a new SkPathRef
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* after the editor's constructor returns.
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*
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* The points and verbs are stored in a single allocation. The points are at the begining of the
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* allocation while the verbs are stored at end of the allocation, in reverse order. Thus the points
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* and verbs both grow into the middle of the allocation until the meet. To access verb i in the
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* verb array use ref.verbs()[~i] (because verbs() returns a pointer just beyond the first
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* logical verb or the last verb in memory).
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*/
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class SK_API SkPathRef final : public SkNVRefCnt<SkPathRef> {
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public:
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class Editor {
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public:
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Editor(sk_sp<SkPathRef>* pathRef,
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int incReserveVerbs = 0,
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int incReservePoints = 0);
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~Editor() { SkDEBUGCODE(fPathRef->fEditorsAttached--;) }
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/**
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* Returns the array of points.
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*/
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SkPoint* points() { return fPathRef->getPoints(); }
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const SkPoint* points() const { return fPathRef->points(); }
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/**
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* Gets the ith point. Shortcut for this->points() + i
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*/
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SkPoint* atPoint(int i) {
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SkASSERT((unsigned) i < (unsigned) fPathRef->fPointCnt);
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return this->points() + i;
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}
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const SkPoint* atPoint(int i) const {
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SkASSERT((unsigned) i < (unsigned) fPathRef->fPointCnt);
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return this->points() + i;
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}
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/**
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* Adds the verb and allocates space for the number of points indicated by the verb. The
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* return value is a pointer to where the points for the verb should be written.
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* 'weight' is only used if 'verb' is kConic_Verb
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*/
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SkPoint* growForVerb(int /*SkPath::Verb*/ verb, SkScalar weight = 0) {
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SkDEBUGCODE(fPathRef->validate();)
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return fPathRef->growForVerb(verb, weight);
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}
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/**
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* Allocates space for multiple instances of a particular verb and the
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* requisite points & weights.
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* The return pointer points at the first new point (indexed normally [<i>]).
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* If 'verb' is kConic_Verb, 'weights' will return a pointer to the
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* space for the conic weights (indexed normally).
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*/
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SkPoint* growForRepeatedVerb(int /*SkPath::Verb*/ verb,
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int numVbs,
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SkScalar** weights = nullptr) {
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return fPathRef->growForRepeatedVerb(verb, numVbs, weights);
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}
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/**
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* Resets the path ref to a new verb and point count. The new verbs and points are
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* uninitialized.
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*/
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void resetToSize(int newVerbCnt, int newPointCnt, int newConicCount) {
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fPathRef->resetToSize(newVerbCnt, newPointCnt, newConicCount);
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}
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/**
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* Gets the path ref that is wrapped in the Editor.
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*/
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SkPathRef* pathRef() { return fPathRef; }
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void setIsOval(bool isOval, bool isCCW, unsigned start) {
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fPathRef->setIsOval(isOval, isCCW, start);
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}
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void setIsRRect(bool isRRect, bool isCCW, unsigned start) {
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fPathRef->setIsRRect(isRRect, isCCW, start);
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}
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void setBounds(const SkRect& rect) { fPathRef->setBounds(rect); }
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private:
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SkPathRef* fPathRef;
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};
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class SK_API Iter {
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public:
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Iter();
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Iter(const SkPathRef&);
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void setPathRef(const SkPathRef&);
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/** Return the next verb in this iteration of the path. When all
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segments have been visited, return kDone_Verb.
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If any point in the path is non-finite, return kDone_Verb immediately.
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@param pts The points representing the current verb and/or segment
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This must not be NULL.
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@return The verb for the current segment
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*/
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uint8_t next(SkPoint pts[4]);
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uint8_t peek() const;
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SkScalar conicWeight() const { return *fConicWeights; }
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private:
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const SkPoint* fPts;
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const uint8_t* fVerbs;
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const uint8_t* fVerbStop;
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const SkScalar* fConicWeights;
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};
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public:
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/**
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* Gets a path ref with no verbs or points.
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*/
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static SkPathRef* CreateEmpty();
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/**
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* Returns true if all of the points in this path are finite, meaning there
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* are no infinities and no NaNs.
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*/
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bool isFinite() const {
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if (fBoundsIsDirty) {
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this->computeBounds();
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}
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return SkToBool(fIsFinite);
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}
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/**
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* Returns a mask, where each bit corresponding to a SegmentMask is
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* set if the path contains 1 or more segments of that type.
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* Returns 0 for an empty path (no segments).
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*/
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uint32_t getSegmentMasks() const { return fSegmentMask; }
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/** Returns true if the path is an oval.
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*
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* @param rect returns the bounding rect of this oval. It's a circle
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* if the height and width are the same.
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* @param isCCW is the oval CCW (or CW if false).
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* @param start indicates where the contour starts on the oval (see
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* SkPath::addOval for intepretation of the index).
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*
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* @return true if this path is an oval.
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* Tracking whether a path is an oval is considered an
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* optimization for performance and so some paths that are in
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* fact ovals can report false.
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*/
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bool isOval(SkRect* rect, bool* isCCW, unsigned* start) const {
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if (fIsOval) {
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if (rect) {
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*rect = this->getBounds();
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}
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if (isCCW) {
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*isCCW = SkToBool(fRRectOrOvalIsCCW);
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}
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if (start) {
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*start = fRRectOrOvalStartIdx;
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}
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}
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return SkToBool(fIsOval);
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}
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bool isRRect(SkRRect* rrect, bool* isCCW, unsigned* start) const {
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if (fIsRRect) {
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if (rrect) {
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*rrect = this->getRRect();
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}
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if (isCCW) {
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*isCCW = SkToBool(fRRectOrOvalIsCCW);
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}
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if (start) {
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*start = fRRectOrOvalStartIdx;
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}
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}
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return SkToBool(fIsRRect);
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}
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bool hasComputedBounds() const {
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return !fBoundsIsDirty;
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}
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/** Returns the bounds of the path's points. If the path contains 0 or 1
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points, the bounds is set to (0,0,0,0), and isEmpty() will return true.
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Note: this bounds may be larger than the actual shape, since curves
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do not extend as far as their control points.
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*/
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const SkRect& getBounds() const {
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if (fBoundsIsDirty) {
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this->computeBounds();
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}
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return fBounds;
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}
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SkRRect getRRect() const;
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/**
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* Transforms a path ref by a matrix, allocating a new one only if necessary.
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*/
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static void CreateTransformedCopy(sk_sp<SkPathRef>* dst,
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const SkPathRef& src,
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const SkMatrix& matrix);
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static SkPathRef* CreateFromBuffer(SkRBuffer* buffer);
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/**
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* Rollsback a path ref to zero verbs and points with the assumption that the path ref will be
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* repopulated with approximately the same number of verbs and points. A new path ref is created
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* only if necessary.
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*/
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static void Rewind(sk_sp<SkPathRef>* pathRef);
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~SkPathRef();
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int countPoints() const { return fPointCnt; }
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int countVerbs() const { return fVerbCnt; }
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int countWeights() const { return fConicWeights.count(); }
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/**
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* Returns a pointer one beyond the first logical verb (last verb in memory order).
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*/
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const uint8_t* verbs() const { return fVerbs; }
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/**
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* Returns a const pointer to the first verb in memory (which is the last logical verb).
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*/
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const uint8_t* verbsMemBegin() const { return this->verbs() - fVerbCnt; }
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/**
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* Returns a const pointer to the first point.
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*/
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const SkPoint* points() const { return fPoints; }
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/**
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* Shortcut for this->points() + this->countPoints()
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*/
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const SkPoint* pointsEnd() const { return this->points() + this->countPoints(); }
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const SkScalar* conicWeights() const { return fConicWeights.begin(); }
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const SkScalar* conicWeightsEnd() const { return fConicWeights.end(); }
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/**
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* Convenience methods for getting to a verb or point by index.
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*/
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uint8_t atVerb(int index) const {
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SkASSERT((unsigned) index < (unsigned) fVerbCnt);
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return this->verbs()[~index];
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}
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const SkPoint& atPoint(int index) const {
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SkASSERT((unsigned) index < (unsigned) fPointCnt);
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return this->points()[index];
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}
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bool operator== (const SkPathRef& ref) const;
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/**
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* Writes the path points and verbs to a buffer.
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*/
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void writeToBuffer(SkWBuffer* buffer) const;
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/**
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* Gets the number of bytes that would be written in writeBuffer()
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*/
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uint32_t writeSize() const;
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void interpolate(const SkPathRef& ending, SkScalar weight, SkPathRef* out) const;
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/**
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* Gets an ID that uniquely identifies the contents of the path ref. If two path refs have the
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* same ID then they have the same verbs and points. However, two path refs may have the same
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* contents but different genIDs.
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*/
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uint32_t genID() const;
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class GenIDChangeListener : public SkRefCnt {
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public:
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GenIDChangeListener() : fShouldUnregisterFromPath(false) {}
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virtual ~GenIDChangeListener() {}
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virtual void onChange() = 0;
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// The caller can use this method to notify the path that it no longer needs to listen. Once
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// called, the path will remove this listener from the list at some future point.
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void markShouldUnregisterFromPath() {
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fShouldUnregisterFromPath.store(true, std::memory_order_relaxed);
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}
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bool shouldUnregisterFromPath() {
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return fShouldUnregisterFromPath.load(std::memory_order_acquire);
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}
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private:
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std::atomic<bool> fShouldUnregisterFromPath;
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};
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void addGenIDChangeListener(sk_sp<GenIDChangeListener>); // Threadsafe.
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bool isValid() const;
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SkDEBUGCODE(void validate() const { SkASSERT(this->isValid()); } )
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private:
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enum SerializationOffsets {
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kLegacyRRectOrOvalStartIdx_SerializationShift = 28, // requires 3 bits, ignored.
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kLegacyRRectOrOvalIsCCW_SerializationShift = 27, // requires 1 bit, ignored.
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kLegacyIsRRect_SerializationShift = 26, // requires 1 bit, ignored.
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kIsFinite_SerializationShift = 25, // requires 1 bit
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kLegacyIsOval_SerializationShift = 24, // requires 1 bit, ignored.
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kSegmentMask_SerializationShift = 0 // requires 4 bits (deprecated)
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};
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SkPathRef() {
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fBoundsIsDirty = true; // this also invalidates fIsFinite
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fPointCnt = 0;
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fVerbCnt = 0;
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fVerbs = nullptr;
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fPoints = nullptr;
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fFreeSpace = 0;
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fGenerationID = kEmptyGenID;
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fSegmentMask = 0;
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fIsOval = false;
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fIsRRect = false;
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// The next two values don't matter unless fIsOval or fIsRRect are true.
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fRRectOrOvalIsCCW = false;
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fRRectOrOvalStartIdx = 0xAC;
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SkDEBUGCODE(fEditorsAttached.store(0);)
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SkDEBUGCODE(this->validate();)
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}
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void copy(const SkPathRef& ref, int additionalReserveVerbs, int additionalReservePoints);
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// Doesn't read fSegmentMask, but (re)computes it from the verbs array
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unsigned computeSegmentMask() const;
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// Return true if the computed bounds are finite.
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static bool ComputePtBounds(SkRect* bounds, const SkPathRef& ref) {
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return bounds->setBoundsCheck(ref.points(), ref.countPoints());
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}
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// called, if dirty, by getBounds()
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void computeBounds() const {
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SkDEBUGCODE(this->validate();)
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// TODO(mtklein): remove fBoundsIsDirty and fIsFinite,
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// using an inverted rect instead of fBoundsIsDirty and always recalculating fIsFinite.
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SkASSERT(fBoundsIsDirty);
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fIsFinite = ComputePtBounds(&fBounds, *this);
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fBoundsIsDirty = false;
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}
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void setBounds(const SkRect& rect) {
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SkASSERT(rect.fLeft <= rect.fRight && rect.fTop <= rect.fBottom);
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fBounds = rect;
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fBoundsIsDirty = false;
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fIsFinite = fBounds.isFinite();
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}
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/** Makes additional room but does not change the counts or change the genID */
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void incReserve(int additionalVerbs, int additionalPoints) {
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SkDEBUGCODE(this->validate();)
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size_t space = additionalVerbs * sizeof(uint8_t) + additionalPoints * sizeof (SkPoint);
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this->makeSpace(space);
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SkDEBUGCODE(this->validate();)
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}
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/** Resets the path ref with verbCount verbs and pointCount points, all uninitialized. Also
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* allocates space for reserveVerb additional verbs and reservePoints additional points.*/
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void resetToSize(int verbCount, int pointCount, int conicCount,
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int reserveVerbs = 0, int reservePoints = 0) {
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SkDEBUGCODE(this->validate();)
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fBoundsIsDirty = true; // this also invalidates fIsFinite
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fGenerationID = 0;
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fSegmentMask = 0;
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fIsOval = false;
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fIsRRect = false;
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size_t newSize = sizeof(uint8_t) * verbCount + sizeof(SkPoint) * pointCount;
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size_t newReserve = sizeof(uint8_t) * reserveVerbs + sizeof(SkPoint) * reservePoints;
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size_t minSize = newSize + newReserve;
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ptrdiff_t sizeDelta = this->currSize() - minSize;
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if (sizeDelta < 0 || static_cast<size_t>(sizeDelta) >= 3 * minSize) {
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sk_free(fPoints);
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fPoints = nullptr;
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fVerbs = nullptr;
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fFreeSpace = 0;
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fVerbCnt = 0;
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fPointCnt = 0;
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this->makeSpace(minSize, true);
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fVerbCnt = verbCount;
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fPointCnt = pointCount;
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fFreeSpace -= newSize;
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} else {
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fPointCnt = pointCount;
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fVerbCnt = verbCount;
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fFreeSpace = this->currSize() - minSize;
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}
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fConicWeights.setCount(conicCount);
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SkDEBUGCODE(this->validate();)
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}
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/**
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* Increases the verb count by numVbs and point count by the required amount.
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* The new points are uninitialized. All the new verbs are set to the specified
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* verb. If 'verb' is kConic_Verb, 'weights' will return a pointer to the
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* uninitialized conic weights.
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*/
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SkPoint* growForRepeatedVerb(int /*SkPath::Verb*/ verb, int numVbs, SkScalar** weights);
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/**
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* Increases the verb count 1, records the new verb, and creates room for the requisite number
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* of additional points. A pointer to the first point is returned. Any new points are
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* uninitialized.
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*/
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SkPoint* growForVerb(int /*SkPath::Verb*/ verb, SkScalar weight);
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/**
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* Ensures that the free space available in the path ref is >= size. The verb and point counts
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* are not changed. May allocate extra capacity, unless |exact| is true.
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*/
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void makeSpace(size_t size, bool exact = false) {
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SkDEBUGCODE(this->validate();)
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if (size <= fFreeSpace) {
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return;
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}
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size_t growSize = size - fFreeSpace;
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size_t oldSize = this->currSize();
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if (!exact) {
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// round to next multiple of 8 bytes
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growSize = (growSize + 7) & ~static_cast<size_t>(7);
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// we always at least double the allocation
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if (growSize < oldSize) {
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growSize = oldSize;
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}
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if (growSize < kMinSize) {
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growSize = kMinSize;
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}
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}
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constexpr size_t maxSize = std::numeric_limits<size_t>::max();
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size_t newSize;
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if (growSize <= maxSize - oldSize) {
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newSize = oldSize + growSize;
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} else {
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SK_ABORT("Path too big.");
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}
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// Note that realloc could memcpy more than we need. It seems to be a win anyway. TODO:
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// encapsulate this.
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fPoints = reinterpret_cast<SkPoint*>(sk_realloc_throw(fPoints, newSize));
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size_t oldVerbSize = fVerbCnt * sizeof(uint8_t);
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void* newVerbsDst = SkTAddOffset<void>(fPoints, newSize - oldVerbSize);
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void* oldVerbsSrc = SkTAddOffset<void>(fPoints, oldSize - oldVerbSize);
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memmove(newVerbsDst, oldVerbsSrc, oldVerbSize);
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fVerbs = SkTAddOffset<uint8_t>(fPoints, newSize);
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fFreeSpace += growSize;
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SkDEBUGCODE(this->validate();)
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}
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/**
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* Private, non-const-ptr version of the public function verbsMemBegin().
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*/
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uint8_t* verbsMemWritable() {
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SkDEBUGCODE(this->validate();)
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return fVerbs - fVerbCnt;
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}
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/**
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* Gets the total amount of space allocated for verbs, points, and reserve.
|
|
*/
|
|
size_t currSize() const {
|
|
return reinterpret_cast<intptr_t>(fVerbs) - reinterpret_cast<intptr_t>(fPoints);
|
|
}
|
|
|
|
/**
|
|
* Called the first time someone calls CreateEmpty to actually create the singleton.
|
|
*/
|
|
friend SkPathRef* sk_create_empty_pathref();
|
|
|
|
void setIsOval(bool isOval, bool isCCW, unsigned start) {
|
|
fIsOval = isOval;
|
|
fRRectOrOvalIsCCW = isCCW;
|
|
fRRectOrOvalStartIdx = SkToU8(start);
|
|
}
|
|
|
|
void setIsRRect(bool isRRect, bool isCCW, unsigned start) {
|
|
fIsRRect = isRRect;
|
|
fRRectOrOvalIsCCW = isCCW;
|
|
fRRectOrOvalStartIdx = SkToU8(start);
|
|
}
|
|
|
|
// called only by the editor. Note that this is not a const function.
|
|
SkPoint* getPoints() {
|
|
SkDEBUGCODE(this->validate();)
|
|
fIsOval = false;
|
|
fIsRRect = false;
|
|
return fPoints;
|
|
}
|
|
|
|
const SkPoint* getPoints() const {
|
|
SkDEBUGCODE(this->validate();)
|
|
return fPoints;
|
|
}
|
|
|
|
void callGenIDChangeListeners();
|
|
|
|
enum {
|
|
kMinSize = 256,
|
|
};
|
|
|
|
mutable SkRect fBounds;
|
|
|
|
SkPoint* fPoints; // points to begining of the allocation
|
|
uint8_t* fVerbs; // points just past the end of the allocation (verbs grow backwards)
|
|
int fVerbCnt;
|
|
int fPointCnt;
|
|
size_t fFreeSpace; // redundant but saves computation
|
|
SkTDArray<SkScalar> fConicWeights;
|
|
|
|
enum {
|
|
kEmptyGenID = 1, // GenID reserved for path ref with zero points and zero verbs.
|
|
};
|
|
mutable uint32_t fGenerationID;
|
|
SkDEBUGCODE(std::atomic<int> fEditorsAttached;) // assert only one editor in use at any time.
|
|
|
|
SkMutex fGenIDChangeListenersMutex;
|
|
SkTDArray<GenIDChangeListener*> fGenIDChangeListeners; // pointers are reffed
|
|
|
|
mutable uint8_t fBoundsIsDirty;
|
|
mutable bool fIsFinite; // only meaningful if bounds are valid
|
|
|
|
bool fIsOval;
|
|
bool fIsRRect;
|
|
// Both the circle and rrect special cases have a notion of direction and starting point
|
|
// The next two variables store that information for either.
|
|
bool fRRectOrOvalIsCCW;
|
|
uint8_t fRRectOrOvalStartIdx;
|
|
uint8_t fSegmentMask;
|
|
|
|
friend class PathRefTest_Private;
|
|
friend class ForceIsRRect_Private; // unit test isRRect
|
|
friend class SkPath;
|
|
friend class SkPathPriv;
|
|
};
|
|
|
|
#endif
|