Remove Matrix/Clip State collapse code

src/core/SkMatrixClipStateMgr.h

-/*
- * Copyright 2014 Google Inc.
- *
- * Use of this source code is governed by a BSD-style license that can be
- * found in the LICENSE file.
- */
-#ifndef SkMatrixClipStateMgr_DEFINED
-#define SkMatrixClipStateMgr_DEFINED
-
-#include "SkCanvas.h"
-#include "SkMatrix.h"
-#include "SkRegion.h"
-#include "SkRRect.h"
-#include "SkTypes.h"
-#include "SkTDArray.h"
-
-class SkPictureRecord;
-class SkWriter32;
-
-// The SkMatrixClipStateMgr collapses the matrix/clip state of an SkPicture into
-// a series of save/restore blocks of consistent matrix clip state, e.g.:
-//
-//   save
-//     clip(s)
-//     concat
-//     ... draw ops ...
-//   restore
-//
-// SaveLayers simply add another level, e.g.:
-//
-//   save
-//     clip(s)
-//     concat
-//     ... draw ops ...
-//     saveLayer
-//       save
-//         clip(s)
-//         concat
-//         ... draw ops ...
-//       restore
-//     restore
-//   restore
-//
-// As a side effect of this process all saves and saveLayers will become
-// kMatrixClip_SaveFlag style saves/saveLayers.
-
-// The SkMatrixClipStateMgr works by intercepting all the save*, restore, clip*,
-// and matrix calls sent to SkCanvas in order to track the current matrix/clip
-// state. All the other canvas calls get funnelled into a generic "call" entry
-// point that signals that a state block is required.
-class SkMatrixClipStateMgr {
-public:
-    static const int32_t kIdentityWideOpenStateID = 0;
-    static const int kIdentityMatID = 0;
-
-    class MatrixClipState : SkNoncopyable {
-    public:
-        class MatrixInfo {
-        public:
-            void reset() {
-                fMatrixID = kIdentityMatID;
-                fMatrix.reset();
-            }
-
-            void preTranslate(SkScalar dx, SkScalar dy) {
-                fMatrixID = -1;
-                fMatrix.preTranslate(dx, dy);
-            }
-
-            void preScale(SkScalar sx, SkScalar sy) {
-                fMatrixID = -1;
-                fMatrix.preScale(sx, sy);
-            }
-
-            void preRotate(SkScalar degrees) {
-                fMatrixID = -1;
-                fMatrix.preRotate(degrees);
-            }
-
-            void preSkew(SkScalar sx, SkScalar sy) {
-                fMatrixID = -1;
-                fMatrix.preSkew(sx, sy);
-            }
-
-            void preConcat(const SkMatrix& matrix) {
-                fMatrixID = -1;
-                fMatrix.preConcat(matrix);
-            }
-
-            void setMatrix(const SkMatrix& matrix) {
-                fMatrixID = -1;
-                fMatrix = matrix;
-            }
-
-            int getID(SkMatrixClipStateMgr* mgr) {
-                if (fMatrixID >= 0) {
-                    return fMatrixID;
-                }
-
-                fMatrixID = mgr->addMatToDict(fMatrix);
-                return fMatrixID;
-            }
-
-        private:
-            SkMatrix fMatrix;
-            int      fMatrixID;
-
-            typedef SkNoncopyable INHERITED;
-        };
-
-        class ClipInfo : SkNoncopyable {
-        public:
-            ClipInfo() {}
-
-            bool clipRect(const SkRect& rect,
-                          SkRegion::Op op,
-                          bool doAA,
-                          int matrixID) {
-                ClipOp* newClip = fClips.append();
-                newClip->fClipType = kRect_ClipType;
-                newClip->fGeom.fRRect.setRect(rect);   // storing the clipRect in the RRect
-                newClip->fOp = op;
-                newClip->fDoAA = doAA;
-                newClip->fMatrixID = matrixID;
-                return false;
-            }
-
-            bool clipRRect(const SkRRect& rrect,
-                           SkRegion::Op op,
-                           bool doAA,
-                           int matrixID) {
-                ClipOp* newClip = fClips.append();
-                newClip->fClipType = kRRect_ClipType;
-                newClip->fGeom.fRRect = rrect;
-                newClip->fOp = op;
-                newClip->fDoAA = doAA;
-                newClip->fMatrixID = matrixID;
-                return false;
-            }
-
-            bool clipPath(SkPictureRecord* picRecord,
-                          const SkPath& path,
-                          SkRegion::Op op,
-                          bool doAA,
-                          int matrixID);
-            bool clipRegion(SkPictureRecord* picRecord,
-                            int regionID,
-                            SkRegion::Op op,
-                            int matrixID);
-            void writeClip(int* curMatID, SkMatrixClipStateMgr* mgr);
-
-            SkDEBUGCODE(int numClips() const { return fClips.count(); })
-
-        private:
-            enum ClipType {
-                kRect_ClipType,
-                kRRect_ClipType,
-                kPath_ClipType,
-                kRegion_ClipType
-            };
-
-            class ClipOp {
-            public:
-                ClipType     fClipType;
-
-                union {
-                    SkRRect fRRect;        // also stores clip rect
-                    int     fPathID;
-                    int     fRegionID;
-                } fGeom;
-
-                bool         fDoAA;
-                SkRegion::Op fOp;
-
-                // The CTM in effect when this clip call was issued
-                int          fMatrixID;
-            };
-
-            SkTDArray<ClipOp> fClips;
-
-            typedef SkNoncopyable INHERITED;
-        };
-
-        MatrixClipState(MatrixClipState* prev)
-            : fPrev(prev)
-        {
-            fHasOpen = false;
-
-            if (NULL == prev) {
-                fLayerID = 0;
-
-                fMatrixInfoStorage.reset();
-                fMatrixInfo = &fMatrixInfoStorage;
-                fClipInfo = &fClipInfoStorage;  // ctor handles init of fClipInfoStorage
-
-                // The identity/wide-open-clip state is current by default
-                fMCStateID = kIdentityWideOpenStateID;
-#ifdef SK_DEBUG
-                fExpectedDepth = 1;
-#endif
-            }
-            else {
-                fLayerID = prev->fLayerID;
-
-                fMatrixInfoStorage = *prev->fMatrixInfo;
-                fMatrixInfo = &fMatrixInfoStorage;
-
-                // We don't copy the ClipOps of the previous clip states
-                fClipInfo = &fClipInfoStorage;
-
-                // Initially a new save/saveLayer represents the same MC state
-                // as its predecessor.
-                fMCStateID = prev->fMCStateID;
-#ifdef SK_DEBUG
-                fExpectedDepth = prev->fExpectedDepth;
-#endif
-            }
-
-            fIsSaveLayer = false;
-        }
-
-        MatrixInfo*  fMatrixInfo;
-        MatrixInfo   fMatrixInfoStorage;
-
-        ClipInfo*    fClipInfo;
-        ClipInfo     fClipInfoStorage;
-
-        // Tracks the current depth of saveLayers to support the isDrawingToLayer call
-        int          fLayerID;
-        // Does this MC state represent a saveLayer call?
-        bool         fIsSaveLayer;
-
-        // The next field is only valid when fIsSaveLayer is set.
-        SkTDArray<int>* fSavedSkipOffsets;
-
-        // Does the MC state have an open block in the skp?
-        bool         fHasOpen;
-
-        MatrixClipState* fPrev;
-
-#ifdef SK_DEBUG
-        int              fExpectedDepth;    // debugging aid
-#endif
-
-        int32_t     fMCStateID;
-    };
-
-    enum CallType {
-        kMatrix_CallType,
-        kClip_CallType,
-        kOther_CallType
-    };
-
-    SkMatrixClipStateMgr();
-    ~SkMatrixClipStateMgr();
-
-    void init(SkPictureRecord* picRecord) {
-        // Note: we're not taking a ref here. It is expected that the SkMatrixClipStateMgr
-        // is owned by the SkPictureRecord object
-        fPicRecord = picRecord;
-    }
-
-    SkPictureRecord* getPicRecord() { return fPicRecord; }
-
-    // TODO: need to override canvas' getSaveCount. Right now we pass the
-    // save* and restore calls on to the base SkCanvas in SkPictureRecord but
-    // this duplicates effort.
-    int getSaveCount() const { return fMatrixClipStack.count(); }
-
-    int save();
-
-    int saveLayer(const SkRect* bounds, const SkPaint* paint, SkCanvas::SaveFlags flags);
-
-    bool isDrawingToLayer() const {
-        return fCurMCState->fLayerID > 0;
-    }
-
-    void restore();
-
-    void translate(SkScalar dx, SkScalar dy) {
-        this->call(kMatrix_CallType);
-        fCurMCState->fMatrixInfo->preTranslate(dx, dy);
-    }
-
-    void scale(SkScalar sx, SkScalar sy) {
-        this->call(kMatrix_CallType);
-        fCurMCState->fMatrixInfo->preScale(sx, sy);
-    }
-
-    void rotate(SkScalar degrees) {
-        this->call(kMatrix_CallType);
-        fCurMCState->fMatrixInfo->preRotate(degrees);
-    }
-
-    void skew(SkScalar sx, SkScalar sy) {
-        this->call(kMatrix_CallType);
-        fCurMCState->fMatrixInfo->preSkew(sx, sy);
-    }
-
-    void concat(const SkMatrix& matrix) {
-        this->call(kMatrix_CallType);
-        fCurMCState->fMatrixInfo->preConcat(matrix);
-    }
-
-    void setMatrix(const SkMatrix& matrix) {
-        this->call(kMatrix_CallType);
-        fCurMCState->fMatrixInfo->setMatrix(matrix);
-    }
-
-    bool clipRect(const SkRect& rect, SkRegion::Op op, bool doAA) {
-        this->call(SkMatrixClipStateMgr::kClip_CallType);
-        return fCurMCState->fClipInfo->clipRect(rect, op, doAA,
-                                                fCurMCState->fMatrixInfo->getID(this));
-    }
-
-    bool clipRRect(const SkRRect& rrect, SkRegion::Op op, bool doAA) {
-        this->call(SkMatrixClipStateMgr::kClip_CallType);
-        return fCurMCState->fClipInfo->clipRRect(rrect, op, doAA,
-                                                 fCurMCState->fMatrixInfo->getID(this));
-    }
-
-    bool clipPath(const SkPath& path, SkRegion::Op op, bool doAA) {
-        this->call(SkMatrixClipStateMgr::kClip_CallType);
-        return fCurMCState->fClipInfo->clipPath(fPicRecord, path, op, doAA,
-                                                fCurMCState->fMatrixInfo->getID(this));
-    }
-
-    bool clipRegion(const SkRegion& region, SkRegion::Op op) {
-        this->call(SkMatrixClipStateMgr::kClip_CallType);
-        int regionID = this->addRegionToDict(region);
-        return fCurMCState->fClipInfo->clipRegion(fPicRecord, regionID, op,
-                                                  fCurMCState->fMatrixInfo->getID(this));
-    }
-
-    bool call(CallType callType);
-
-    void fillInSkips(SkWriter32* writer, int32_t restoreOffset);
-
-    void finish();
-
-protected:
-    SkPictureRecord* fPicRecord;
-
-    uint32_t         fMatrixClipStackStorage[43]; // sized to fit 2 clip states
-    SkDeque          fMatrixClipStack;
-    MatrixClipState* fCurMCState;
-
-    // This dictionary doesn't actually de-duplicate the matrices (except for the
-    // identity matrix). It merely stores the matrices and allows them to be looked
-    // up by ID later. The de-duplication mainly falls upon the matrix/clip stack
-    // which stores the ID so a revisited clip/matrix (via popping the stack) will
-    // use the same ID.
-    SkTDArray<SkMatrix> fMatrixDict;
-
-    SkTDArray<SkRegion*> fRegionDict;
-
-    // The MCStateID of the state currently in effect in the byte stream. 0 if none.
-    int32_t          fCurOpenStateID;
-    // The skip offsets for the current open state. These are the locations in the
-    // skp that must be filled in when the current open state is closed. These are
-    // here rather then distributed across the MatrixClipState's because saveLayers
-    // can cause MC states to be nested.
-    SkTDArray<int32_t>  *fSkipOffsets;  // TODO: should we store u32 or size_t instead?
-
-    SkDEBUGCODE(void validate();)
-
-    int MCStackPush();
-
-    void addClipOffset(size_t offset) {
-        SkASSERT(NULL != fSkipOffsets);
-        SkASSERT(kIdentityWideOpenStateID != fCurOpenStateID);
-        SkASSERT(fCurMCState->fHasOpen);
-        SkASSERT(!fCurMCState->fIsSaveLayer);
-
-        *fSkipOffsets->append() = SkToS32(offset);
-    }
-
-    void writeDeltaMat(int currentMatID, int desiredMatID);
-    static int32_t   NewMCStateID();
-
-    int addRegionToDict(const SkRegion& region);
-    const SkRegion* lookupRegion(int index) {
-        SkASSERT(index >= 0 && index < fRegionDict.count());
-        return fRegionDict[index];
-    }
-
-    // TODO: add stats to check if the dictionary really does
-    // reduce the size of the SkPicture.
-    int addMatToDict(const SkMatrix& mat);
-    const SkMatrix& lookupMat(int index) {
-        SkASSERT(index >= 0 && index < fMatrixDict.count());
-        return fMatrixDict[index];
-    }
-
-    bool isNestingMCState(int stateID);
-
-#ifdef SK_DEBUG
-    int fActualDepth;
-#endif
-
-    // save layers are nested within a specific MC state. This stack tracks
-    // the nesting MC state's ID as save layers are pushed and popped.
-    SkTDArray<int> fStateIDStack;
-};
-
-#endif