Split SkPicturePlayback out of SkPictureData

src/core/SkPicturePlayback.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 SkPicturePlayback_DEFINED
+#define SkPicturePlayback_DEFINED
+
+#include "SkTypes.h"
+
+class SkBitmap;
+class SkCanvas;
+class SkDrawPictureCallback;
+class SkPaint;
+class SkPictureData;
+
+class SkPicturePlayback : SkNoncopyable {
+public:
+    SkPicturePlayback(const SkPicture* picture)
+        : fPictureData(picture->fData.get())
+        , fCurOffset(0)
+        , fUseBBH(true)
+        , fStart(0)
+        , fStop(0)
+        , fReplacements(NULL) {
+    }
+
+    void draw(SkCanvas* canvas, SkDrawPictureCallback*);
+
+    // Return the ID of the operation currently being executed when playing
+    // back. 0 indicates no call is active.
+    size_t curOpID() const { return fCurOffset; }
+    void resetOpID() { fCurOffset = 0; }
+
+    void setUseBBH(bool useBBH) { fUseBBH = useBBH; }
+
+    // Limit the opcode playback to be between the offsets 'start' and 'stop'.
+    // The opcode at 'start' should be a saveLayer while the opcode at
+    // 'stop' should be a restore. Neither of those commands will be issued.
+    // Set both start & stop to 0 to disable draw limiting
+    // Draw limiting cannot be enabled at the same time as draw replacing
+    void setDrawLimits(size_t start, size_t stop) {
+        SkASSERT(NULL == fReplacements);
+        fStart = start;
+        fStop = stop;
+    }
+
+    // PlaybackReplacements collects op ranges that can be replaced with
+    // a single drawBitmap call (using a precomputed bitmap).
+    class PlaybackReplacements {
+    public:
+        // All the operations between fStart and fStop (inclusive) will be replaced with
+        // a single drawBitmap call using fPos, fBM and fPaint.
+        // fPaint will be NULL if the picture's paint wasn't copyable
+        struct ReplacementInfo {
+            size_t          fStart;
+            size_t          fStop;
+            SkIPoint        fPos;
+            SkBitmap*       fBM;     // fBM is allocated so ReplacementInfo can remain POD
+            const SkPaint*  fPaint;  // Note: this object doesn't own the paint
+
+            SkIRect         fSrcRect;
+        };
+
+        ~PlaybackReplacements() { this->freeAll(); }
+
+        // Add a new replacement range. The replacement ranges should be
+        // sorted in increasing order and non-overlapping (esp. no nested
+        // saveLayers).
+        ReplacementInfo* push();
+
+    private:
+        friend class SkPicturePlayback; // for access to lookupByStart
+
+        // look up a replacement range by its start offset
+        ReplacementInfo* lookupByStart(size_t start);
+
+        void freeAll();
+
+#ifdef SK_DEBUG
+        void validate() const;
+#endif
+
+        SkTDArray<ReplacementInfo> fReplacements;
+    };
+
+    // Replace all the draw ops in the replacement ranges in 'replacements' with
+    // the associated drawBitmap call
+    // Draw replacing cannot be enabled at the same time as draw limiting
+    void setReplacements(PlaybackReplacements* replacements) {
+        SkASSERT(fStart == 0 && fStop == 0);
+        fReplacements = replacements;
+    }
+
+protected:
+    const SkPictureData* fPictureData;
+
+    // The offset of the current operation when within the draw method
+    size_t fCurOffset;
+
+    bool   fUseBBH;
+    size_t fStart;
+    size_t fStop;
+    PlaybackReplacements* fReplacements;
+
+#ifdef SK_DEVELOPER
+    virtual bool preDraw(int opIndex, int type) { return false; }
+    virtual void postDraw(int opIndex) { }
+#endif
+
+private:
+    typedef SkNoncopyable INHERITED;
+};
+
+#endif