Add a means of extracting active operations from SkPicture

tests/PictureTest.cpp

 /*
  * Copyright 2012 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include "SkBitmapDevice.h"
 #include "SkCanvas.h"
 #include "SkColorPriv.h"
 #include "SkData.h"
 #include "SkDecodingImageGenerator.h"
 #include "SkError.h"
 #include "SkImageEncoder.h"
 #include "SkImageGenerator.h"
 #include "SkPaint.h"
 #include "SkPicture.h"
 #include "SkPictureUtils.h"
+#include "SkQuadTreePicture.h"
 #include "SkRRect.h"
 #include "SkRandom.h"
 #include "SkShader.h"
 #include "SkStream.h"
+#include "SkTileGrid.h"
 #include "Test.h"
 
 static const int gColorScale = 30;
 static const int gColorOffset = 60;
 
 static void make_bm(SkBitmap* bm, int w, int h, SkColor color, bool immutable) {
     bm->allocN32Pixels(w, h);
     bm->eraseColor(color);
     if (immutable) {
         bm->setImmutable();
@@ skipping 847 matching lines @@
     {
         // Test without call to endRecording
         SkPicture picture;
         picture.beginRecording(1, 1);
         SkPicture* destPicture = picture.clone();
         REPORTER_ASSERT(reporter, NULL != destPicture);
         destPicture->unref();
     }
 }
 
+static void test_draw_empty(skiatest::Reporter* reporter) {
+    SkBitmap result;
+    make_bm(&result, 2, 2, SK_ColorBLACK, false);
+
+    SkCanvas canvas(result);
+
+    {
+        // stock SkPicture
+        SkPicture picture;
+        picture.beginRecording(1, 1);
+        picture.endRecording();
+
+        canvas.drawPicture(picture);
+    }
+
+    {
+        // tile grid
+        SkTileGridPicture::TileGridInfo gridInfo;
+        gridInfo.fMargin.setEmpty();
+        gridInfo.fOffset.setZero();
+        gridInfo.fTileInterval.set(1, 1);
+
+        SkTileGridPicture picture(1, 1, gridInfo);
+        picture.beginRecording(1, 1, SkPicture::kOptimizeForClippedPlayback_RecordingFlag);
+        picture.endRecording();
+
+        canvas.drawPicture(picture);
+    }
+
+    {
+        // RTree
+        SkPicture picture;
+        picture.beginRecording(1, 1, SkPicture::kOptimizeForClippedPlayback_RecordingFlag);
+        picture.endRecording();
+
+        canvas.drawPicture(picture);
+    }
+
+    {
+        // quad tree
+        SkQuadTreePicture picture(SkIRect::MakeWH(1, 1));
+        picture.beginRecording(1, 1, SkPicture::kOptimizeForClippedPlayback_RecordingFlag);
+        picture.endRecording();
+
+        canvas.drawPicture(picture);
+    }
+}
+
 static void test_clip_bound_opt(skiatest::Reporter* reporter) {
     // Test for crbug.com/229011
     SkRect rect1 = SkRect::MakeXYWH(SkIntToScalar(4), SkIntToScalar(4),
                                     SkIntToScalar(2), SkIntToScalar(2));
     SkRect rect2 = SkRect::MakeXYWH(SkIntToScalar(7), SkIntToScalar(7),
                                     SkIntToScalar(1), SkIntToScalar(1));
     SkRect rect3 = SkRect::MakeXYWH(SkIntToScalar(6), SkIntToScalar(6),
                                     SkIntToScalar(1), SkIntToScalar(1));
 
     SkPath invPath;
@@ skipping 198 matching lines @@
     test_serializing_empty_picture();
 #else
     test_bad_bitmap();
 #endif
     test_unbalanced_save_restores(reporter);
     test_peephole();
     test_gatherpixelrefs(reporter);
     test_gatherpixelrefsandrects(reporter);
     test_bitmap_with_encoded_data(reporter);
     test_clone_empty(reporter);
+    test_draw_empty(reporter);
     test_clip_bound_opt(reporter);
     test_clip_expansion(reporter);
     test_hierarchical(reporter);
 }
 
 static void draw_bitmaps(const SkBitmap bitmap, SkCanvas* canvas) {
     const SkPaint paint;
     const SkRect rect = { 5.0f, 5.0f, 8.0f, 8.0f };
     const SkIRect irect =  { 2, 2, 3, 3 };
 
@@ skipping 18 matching lines @@
     picture.endRecording();
 }
 
 DEF_TEST(Canvas_EmptyBitmap, r) {
     SkBitmap dst;
     dst.allocN32Pixels(10, 10);
     SkCanvas canvas(dst);
 
     test_draw_bitmaps(&canvas);
 }