skia::AnalysisCanvas: implementation for IsCheapInRect().

skia/ext/analysis_canvas.h

+// Copyright (c) 2013 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef SKIA_EXT_ANALYSIS_CANVAS_H_
+#define SKIA_EXT_ANALYSIS_CANVAS_H_
+
+#include "third_party/skia/include/core/SkCanvas.h"
+#include "third_party/skia/include/core/SkDevice.h"
+
+namespace skia {
+
+class SK_API AnalysisDevice : public SkDevice {
+ public:
+  AnalysisDevice(const SkBitmap& bm);
+};
+
+// Does not render anything, but gathers statistics about a region
+// (specified as a clip rectangle) of an SkPicture as the picture is
+// played back through it.
+class SK_API AnalysisCanvas : public SkCanvas {
+ public:
+  AnalysisCanvas(SkDevice*, SkRect clip);
+  virtual ~AnalysisCanvas();
+
+  virtual int save(SkCanvas::SaveFlags = kMatrixClip_SaveFlag) SK_OVERRIDE;
+  virtual int saveLayer(const SkRect*, const SkPaint*,
+                        SkCanvas::SaveFlags = kARGB_ClipLayer_SaveFlag)
+                        SK_OVERRIDE;
+  virtual void restore() SK_OVERRIDE;
+  virtual bool clipRect(const SkRect&, SkRegion::Op, bool) SK_OVERRIDE;
+  virtual bool clipRRect(const SkRRect&, SkRegion::Op, bool) SK_OVERRIDE;
+  virtual bool clipPath(const SkPath&, SkRegion::Op, bool) SK_OVERRIDE;
+  virtual bool clipRegion(const SkRegion&, SkRegion::Op) SK_OVERRIDE;
+  virtual void clear(SkColor) SK_OVERRIDE;
+  virtual void drawPaint(const SkPaint&) SK_OVERRIDE;
+  virtual void drawPoints(PointMode, size_t, const SkPoint [],
+                          const SkPaint&) SK_OVERRIDE;
+  virtual void drawRect(const SkRect&, const SkPaint&) SK_OVERRIDE;
+  virtual void drawOval(const SkRect&, const SkPaint&) SK_OVERRIDE;
+  virtual void drawRRect(const SkRRect&, const SkPaint&) SK_OVERRIDE;
+  virtual void drawPath(const SkPath&, const SkPaint&) SK_OVERRIDE;
+  virtual void drawBitmap(const SkBitmap&, SkScalar, SkScalar,
+                          const SkPaint&) SK_OVERRIDE;
+  virtual void drawBitmapRectToRect(const SkBitmap&, const SkRect*,
+                                    const SkRect&, const SkPaint* = NULL)
+                          SK_OVERRIDE;
+  virtual void drawBitmapMatrix(const SkBitmap&, const SkMatrix&,
+                                const SkPaint* = NULL) SK_OVERRIDE;
+  virtual void drawBitmapNine(const SkBitmap&, const SkIRect&, const SkRect&,
+                              const SkPaint* = NULL) SK_OVERRIDE;
+  virtual void drawSprite(const SkBitmap&, int left, int top,
+                          const SkPaint* = NULL) SK_OVERRIDE;
+  virtual void drawText(const void*, size_t, SkScalar, SkScalar,
+                        const SkPaint&) SK_OVERRIDE;
+  virtual void drawPosText(const void*, size_t, const SkPoint [],
+                           const SkPaint&) SK_OVERRIDE;
+  virtual void drawPosTextH(const void*, size_t, const SkScalar [], SkScalar,
+                            const SkPaint&) SK_OVERRIDE;
+  virtual void drawTextOnPath(const void*, size_t, const SkPath&,
+                              const SkMatrix*, const SkPaint&) SK_OVERRIDE;
+  virtual void drawVertices(VertexMode, int, const SkPoint [],
+                            const SkPoint [], const SkColor [], SkXfermode*,
+                            const uint16_t [], int, const SkPaint&) SK_OVERRIDE;
+  virtual void drawData(const void*, size_t) SK_OVERRIDE;
+
+  // Returns true if the estimated cost of drawing is below an
+  // arbitrary threshold.
+  bool isCheap() const;
+
+  // Returns the estimated cost of drawing, in arbitrary units.
+  int getEstimatedCost() const;
+
+  // Resets the clip and the cost estimate.
+  void reset(SkRect clip);
+
+ protected:
+
+  int estimatedCost_;
+  SkRect clip_;
+
+};
+
+}  // namespace skia
+
+#endif  // SKIA_EXT_ANALYSIS_CANVAS_H_
+