Adding option in SkPicture to record device-space bounds of draw commands.

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 "Test.h"
 #include "SkCanvas.h"
 #include "SkColorPriv.h"
 #include "SkData.h"
+#include "SkDevice.h"
 #include "SkPaint.h"
 #include "SkPicture.h"
 #include "SkRandom.h"
 #include "SkRRect.h"
 #include "SkShader.h"
 #include "SkStream.h"
 
 #include "SkPictureUtils.h"
 
 static void make_bm(SkBitmap* bm, int w, int h, SkColor color, bool immutable) {
@@ skipping 391 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_subregion_playback(skiatest::Reporter* reporter) {

[reed1, 2013/03/12 16:05:04]

Can you simplify or document the complexity in this test?
- why is the picture 6x6, the rect 4,4,1,1, the target 3x3, and the translate
-3,-3
- do you need the clear() in the picture? is that better than initializing your
target?


How does this test the new (or old) code? Can you comment on that in some way?

+    SkPicture picture;
+    SkCanvas* recordingCanvas = picture.beginRecording(6, 6);
+    SkPaint paint;
+    paint.setColor(SK_ColorWHITE);
+    SkRect rect = SkRect::MakeXYWH(SkIntToScalar(4), SkIntToScalar(4), SK_Scalar1, SK_Scalar1);
+    recordingCanvas->clear(SK_ColorTRANSPARENT);
+    recordingCanvas->drawRect(rect, paint);
+    picture.endRecording();
+    SkBitmap store;
+    store.setConfig(SkBitmap::kARGB_8888_Config, 3, 3);
+    store.allocPixels();
+    SkDevice device(store);

[reed1, 2013/03/12 16:05:04]

minor, but can't you just pass store to the canvas' constructor, and not need to
include SkDevice.h? (as we're trying to make that less public)

+    SkCanvas playbackCanvas(&device);
+    playbackCanvas.translate(SkIntToScalar(-3), SkIntToScalar(-3));
+    playbackCanvas.drawPicture(picture);
+    for (int x = 0; x < 3; x++) {
+        for (int y = 0; y < 3; y++) {
+            if (1 == x && 1 == y) {
+                REPORTER_ASSERT(reporter, SK_ColorWHITE == store.getColor(x,y));
+            } else {
+                REPORTER_ASSERT(reporter, SK_ColorTRANSPARENT == store.getColor(x,y));
+            }
+        }
+    }
+}
+
 static void TestPicture(skiatest::Reporter* reporter) {
 #ifdef SK_DEBUG
     test_deleting_empty_playback();
     test_serializing_empty_picture();
 #else
     test_bad_bitmap();
 #endif
     test_peephole();
     test_gatherpixelrefs(reporter);
     test_bitmap_with_encoded_data(reporter);
     test_clone_empty(reporter);
+    test_subregion_playback(reporter);
 }
 
 #include "TestClassDef.h"
 DEFINE_TESTCLASS("Pictures", PictureTestClass, TestPicture)