Always store pixels of mutable bitmaps when recording a SkPicture.

Prior to this CL mutable bitmaps only saved a copy of their pixels
if a flag was set at recording time.  That flag has been removed
and the default behavior when recording a mutable bitmap is to
make a copy of it's pixels. This is the only way to ensure that
the pixels are not manipulated before we playback their contents.

However, enabling this behavior breaks the recording of extracted
bitmaps in SkPicture. This is because we currently cache bitmaps
within a picture based only on their pixelRef. This results in
false positive cache hit when drawing an extracted bitmap as it
shares a pixelRef with its orginating bitmap.  Therefore we must
update the index of the bitmap cache to be both the pixelRef AND
the size and offset of the bitmap using those pixels.

BUG=
TEST=extractbitmap.cpp

Review URL: https://codereview.appspot.com/6439043

git-svn-id: http://skia.googlecode.com/svn/trunk@4809 2bbb7eff-a529-9590-31e7-b0007b416f81

6 files changed, 34 insertions, 48 deletions

diff --git a/include/core/SkPicture.h b/include/core/SkPicture.h
index 976c594cad..dae7ed7829 100644
--- a/include/core/SkPicture.h
+++ b/include/core/SkPicture.h
@@ -58,16 +58,7 @@ public:
             clip-query calls will reflect the path's bounds, not the actual
             path.
          */
-        kUsePathBoundsForClip_RecordingFlag = 0x01,
-
-        /*  When a draw operation is recorded that has a bitmap parameter, it
-            may be unsafe to defer rendering if source bitmap may be written to
-            between the time of recording and the time of executing the draw 
-            operation. This flag specifies that SkPicture should serialize a
-            snapshot of any source bitmaps that reside in RAM and are not
-            marked as immutable, making the draw operation safe for deferral.
-         */
-        kFlattenMutableNonTexturePixelRefs_RecordingFlag = 0x02
+        kUsePathBoundsForClip_RecordingFlag = 0x01
     };
 
     /** Returns the canvas that records the drawing commands.
@@ -96,11 +87,6 @@ public:
     */
     bool hasRecorded() const;
 
-    /** Returns true if a snapshot of the specified bitmap will be flattened
-        whaen a draw operation using the bitmap is recorded.
-    */
-    bool willFlattenPixelsOnRecord(const SkBitmap&) const;
-    
     /** Replays the drawing commands on the specified canvas. This internally
         calls endRecording() if that has not already been called.
         @param surface the canvas receiving the drawing commands.
diff --git a/src/core/SkPicture.cpp b/src/core/SkPicture.cpp
index 58098e7bfc..9f606f736d 100644
--- a/src/core/SkPicture.cpp
+++ b/src/core/SkPicture.cpp
@@ -168,10 +168,6 @@ bool SkPicture::hasRecorded() const {
     return NULL != fRecord && fRecord->writeStream().size() > 0;
 }
 
-bool SkPicture::willFlattenPixelsOnRecord(const SkBitmap& bitmap) const {
-    return NULL != fRecord && fRecord->shouldFlattenPixels(bitmap);
-}
-
 SkCanvas* SkPicture::getRecordingCanvas() const {
     // will be null if we are not recording
     return fRecord;
diff --git a/src/core/SkPictureRecord.cpp b/src/core/SkPictureRecord.cpp
index 9f5a1c22dc..8b3e9fdab6 100644
--- a/src/core/SkPictureRecord.cpp
+++ b/src/core/SkPictureRecord.cpp
@@ -523,7 +523,7 @@ void SkPictureRecord::reset() {
     fPathHeap = NULL;
 
     fBitmaps.reset();
-    fPixelRefDictionary.reset();
+    fBitmapIndexCache.reset();
     fMatrices.reset();
     fPaints.reset();
     fPictureRefs.unrefAll();
@@ -640,27 +640,23 @@ void SkPictureRecord::addText(const void* text, size_t byteLength) {
 
 ///////////////////////////////////////////////////////////////////////////////
 
-bool SkPictureRecord::shouldFlattenPixels(const SkBitmap& bitmap) const {
-    return (fRecordFlags &
-        SkPicture::kFlattenMutableNonTexturePixelRefs_RecordingFlag)
-        && !bitmap.isImmutable() && bitmap.pixelRef()
-        && NULL == bitmap.getTexture();
-}
-
 int SkPictureRecord::find(const SkBitmap& bitmap) {
     int dictionaryIndex = 0;
-    PixelRefDictionaryEntry entry;
-    bool flattenPixels = shouldFlattenPixels(bitmap);
+    BitmapIndexCacheEntry entry;
+    const bool flattenPixels = !bitmap.isImmutable();
     if (flattenPixels) {
         // Flattened bitmap may be very large. First attempt a fast lookup
         // based on generation ID to avoid unnecessary flattening in
         // fBitmaps.find()
-        entry.fKey = bitmap.pixelRef()->getGenerationID();
+        entry.fGenerationId = bitmap.getGenerationID();
+        entry.fPixelOffset = bitmap.pixelRefOffset();
+        entry.fWidth = bitmap.width();
+        entry.fHeight = bitmap.height();
         dictionaryIndex = 
-            SkTSearch<const PixelRefDictionaryEntry>(fPixelRefDictionary.begin(),
-            fPixelRefDictionary.count(), entry, sizeof(entry));
+            SkTSearch<const BitmapIndexCacheEntry>(fBitmapIndexCache.begin(),
+                    fBitmapIndexCache.count(), entry, sizeof(entry));
         if (dictionaryIndex >= 0) {
-            return fPixelRefDictionary[dictionaryIndex].fIndex;
+            return fBitmapIndexCache[dictionaryIndex].fIndex;
         }
     }
     
@@ -671,7 +667,7 @@ int SkPictureRecord::find(const SkBitmap& bitmap) {
     if (flattenPixels) {
         entry.fIndex = index;
         dictionaryIndex = ~dictionaryIndex;
-        *fPixelRefDictionary.insert(dictionaryIndex) = entry;
+        *fBitmapIndexCache.insert(dictionaryIndex) = entry;
     }
     return index;
 }
diff --git a/src/core/SkPictureRecord.h b/src/core/SkPictureRecord.h
index 23d0828b97..3dda39bfa9 100644
--- a/src/core/SkPictureRecord.h
+++ b/src/core/SkPictureRecord.h
@@ -96,18 +96,30 @@ public:
         return fWriter;
     }
 
-    bool shouldFlattenPixels(const SkBitmap&) const;
-
     void endRecording();
 private:
-    struct PixelRefDictionaryEntry {
-        uint32_t fKey; // SkPixelRef GenerationID.
+    struct BitmapIndexCacheEntry {
+        uint32_t fGenerationId; // SkPixelRef GenerationID.
+        size_t fPixelOffset;
+        uint32_t fWidth;
+        uint32_t fHeight;
         uint32_t fIndex; // Index of corresponding flattened bitmap in fBitmaps.
-        bool operator < (const PixelRefDictionaryEntry& other) const {
-            return this->fKey < other.fKey;
+        bool operator < (const BitmapIndexCacheEntry& other) const {
+            if (this->fGenerationId != other.fGenerationId) {
+                return this->fGenerationId < other.fGenerationId;
+            } else if(this->fPixelOffset != other.fPixelOffset) {
+                return this->fPixelOffset < other.fPixelOffset;
+            } else if(this->fWidth != other.fWidth) {
+                return this->fWidth < other.fWidth;
+            } else {
+                return this->fHeight < other.fHeight;
+            }
         } 
-        bool operator != (const PixelRefDictionaryEntry& other) const {
-            return this->fKey != other.fKey;
+        bool operator != (const BitmapIndexCacheEntry& other) const {
+            return this->fGenerationId != other.fGenerationId
+                || this->fPixelOffset != other.fPixelOffset
+                || this->fWidth != other.fWidth
+                || this->fHeight != other.fHeight;
         } 
     };
 
@@ -192,7 +204,7 @@ private:
     SkRefCntSet fRCSet;
     SkRefCntSet fTFSet;
     
-    SkTDArray<PixelRefDictionaryEntry> fPixelRefDictionary;
+    SkTDArray<BitmapIndexCacheEntry> fBitmapIndexCache;
     SkBitmapDictionary fBitmaps;
     SkMatrixDictionary fMatrices;
     SkPaintDictionary fPaints;
diff --git a/src/utils/SkDeferredCanvas.cpp b/src/utils/SkDeferredCanvas.cpp
index c5a21831d4..47e551ef5d 100644
--- a/src/utils/SkDeferredCanvas.cpp
+++ b/src/utils/SkDeferredCanvas.cpp
@@ -576,8 +576,7 @@ void SkDeferredCanvas::DeferredDevice::beginRecording() {
     fRecordingCanvas = fPipeWriter.startRecording(&fPipeController, 0);
 #else
     fRecordingCanvas = fPicture.beginRecording(fImmediateDevice->width(),
-        fImmediateDevice->height(),
-        SkPicture::kFlattenMutableNonTexturePixelRefs_RecordingFlag);
+        fImmediateDevice->height());
 #endif
 }
     
diff --git a/tests/CanvasTest.cpp b/tests/CanvasTest.cpp
index cf70f433aa..5401026792 100644
--- a/tests/CanvasTest.cpp
+++ b/tests/CanvasTest.cpp
@@ -884,9 +884,6 @@ static void TestCanvas(skiatest::Reporter* reporter) {
         TestOverrideStateConsistency(reporter, testStepArray()[testStep]);
         SkPictureTester::TestPictureFlattenedObjectReuse(reporter,
             testStepArray()[testStep], 0);
-        SkPictureTester::TestPictureFlattenedObjectReuse(reporter,
-            testStepArray()[testStep],
-            SkPicture::kFlattenMutableNonTexturePixelRefs_RecordingFlag);
     }
 }