Replace SkPictureReplacementPlayback with GrRecordReplaceDraw

src/gpu/GrRecordReplaceDraw.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 GrRecordReplaceDraw_DEFINED
+#define GrRecordReplaceDraw_DEFINED
+
+#include "SkDrawPictureCallback.h"
+#include "SkRect.h"
+#include "SkTDArray.h"
+
+class SkBBoxHierarchy;
+class SkBitmap;
+class SkCanvas;
+class SkPaint;
+class SkRecord;
+
+// GrReplacements collects op ranges that can be replaced with
+// a single drawBitmap call (using a precomputed bitmap).
+class GrReplacements {
+public:
+    // All the operations between fStart and fStop (inclusive) will be replaced with
+    // a single drawBitmap call using fPos, fBM and fPaint.
+    struct ReplacementInfo {
+        unsigned        fStart;
+        unsigned        fStop;
+        SkIPoint        fPos;
+        SkBitmap*       fBM;     // fBM is allocated so ReplacementInfo can remain POD

[bsalomon, 2014/09/03 15:43:50]

Does it have to be an SkBitmap? Could it be an SkImage?

[mtklein, 2014/09/03 15:46:12]

Is this an alternative to SkTArray<ReplacementInfo>, or something more
complicated?

[robertphillips, 2014/09/03 17:36:24]

The former.

[robertphillips, 2014/09/03 17:36:24]

Done.

+        const SkPaint*  fPaint;  // Note: this object doesn't own the paint
+
+        SkIRect         fSrcRect;
+    };
+
+    ~GrReplacements() { 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();
+
+    // look up a replacement range by its start offset
+    const ReplacementInfo* lookupByStart(size_t start, int* lastLookedUp) const;

[mtklein, 2014/09/03 15:46:12]

Not clear here that lastLookedUp is both input and output.

[robertphillips, 2014/09/03 17:36:24]

I've added a comment. Other then that I'm open to suggestions.

+
+private:
+    SkTDArray<ReplacementInfo> fReplacements;
+
+    void freeAll();
+
+#ifdef SK_DEBUG
+    void validate() const;
+#endif
+};
+
+// Draw an SkRecord into an SkCanvas replacing saveLayer/restore blocks with
+// drawBitmap calls.  A convenience wrapper around SkRecords::Draw.
+void GrRecordReplaceDraw(const SkRecord&, 
+                         SkCanvas*,
+                         const SkBBoxHierarchy*,
+                         const GrReplacements*,
+                         SkDrawPictureCallback*);
+
+#endif // GrRecordReplaceDraw_DEFINED