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

tests/PictureTest.cpp

Index: tests/PictureTest.cpp
===================================================================
--- tests/PictureTest.cpp	(revision 8043)
+++ tests/PictureTest.cpp	(working copy)
@@ -8,6 +8,7 @@
 #include "SkCanvas.h"
 #include "SkColorPriv.h"
 #include "SkData.h"
+#include "SkDevice.h"
 #include "SkPaint.h"
 #include "SkPicture.h"
 #include "SkRandom.h"
@@ -419,6 +420,33 @@
     }
 }
 
+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();
@@ -430,6 +458,7 @@
     test_gatherpixelrefs(reporter);
     test_bitmap_with_encoded_data(reporter);
     test_clone_empty(reporter);
+    test_subregion_playback(reporter);
 }
 
 #include "TestClassDef.h"