Add a means of extracting active operations from SkPicture

src/core/SkPicturePlayback.cpp

Index: src/core/SkPicturePlayback.cpp
===================================================================
--- src/core/SkPicturePlayback.cpp	(revision 13850)
+++ src/core/SkPicturePlayback.cpp	(working copy)
@@ -1,4 +1,3 @@
-
 /*
  * Copyright 2011 Google Inc.
  *
@@ -69,7 +68,7 @@
 
     record.validate(record.writeStream().bytesWritten(), 0);
     const SkWriter32& writer = record.writeStream();
-    init();
+    this->init();
     SkASSERT(!fOpData);
     if (writer.bytesWritten() == 0) {
         fOpData = SkData::NewEmpty();
@@ -261,6 +260,7 @@
     fFactoryPlayback = NULL;
     fBoundingHierarchy = NULL;
     fStateTree = NULL;
+    fCachedActiveOps = NULL;
 }
 
 SkPicturePlayback::~SkPicturePlayback() {
@@ -271,6 +271,8 @@
     SkSafeUnref(fBoundingHierarchy);
     SkSafeUnref(fStateTree);
 
+    SkDELETE(fCachedActiveOps);
+
     for (int i = 0; i < fPictureCount; i++) {
         fPictureRefs[i]->unref();
     }
@@ -754,11 +756,16 @@
 // The activeOps parameter is actually "const SkTDArray<SkPictureStateTree::Draw*>&".
 // It represents the operations about to be drawn, as generated by some spatial
 // subdivision helper class. It should already be in 'fOffset' sorted order.
-void SkPicturePlayback::preLoadBitmaps(const SkTDArray<void*>& activeOps) {
-    if (0 == activeOps.count() || NULL == fBitmapUseOffsets) {
+void SkPicturePlayback::preLoadBitmaps(const SkTDArray<void*>* activeOps) {
+    if ((NULL != activeOps && 0 == activeOps->count()) || NULL == fBitmapUseOffsets) {
         return;
     }
 
+    if (NULL == activeOps) {
+        // going to need everything
+        return;
+    }
+
     SkTDArray<int> active;
 
     SkAutoTDeleteArray<bool> needToCheck(new bool[fBitmapUseOffsets->numIDs()]);
@@ -766,10 +773,10 @@
         needToCheck.get()[i] = true;
     }
 
-    uint32_t max = ((SkPictureStateTree::Draw*)activeOps[activeOps.count()-1])->fOffset;
+    uint32_t max = ((SkPictureStateTree::Draw*)(*activeOps)[(*activeOps).count()-1])->fOffset;
 
-    for (int i = 0; i < activeOps.count(); ++i) {
-        SkPictureStateTree::Draw* draw = (SkPictureStateTree::Draw*) activeOps[i];
+    for (int i = 0; i < activeOps->count(); ++i) {
+        SkPictureStateTree::Draw* draw = (SkPictureStateTree::Draw*) (*activeOps)[i];
 
         for (int j = 0; j < fBitmapUseOffsets->numIDs(); ++j) {
             if (!needToCheck.get()[j]) {
@@ -795,6 +802,42 @@
     }
 }
 
+uint32_t SkPicturePlayback::CachedOperationList::offset(int index) const {
+    SkASSERT(index < fOps.count());
+    return ((SkPictureStateTree::Draw*)fOps[index])->fOffset;
+}
+
+const SkMatrix& SkPicturePlayback::CachedOperationList::matrix(int index) const {
+    SkASSERT(index < fOps.count());
+    return *((SkPictureStateTree::Draw*)fOps[index])->fMatrix;
+}
+
+const SkPicture::OperationList& SkPicturePlayback::getActiveOps(const SkIRect& query) {
+    if (NULL == fStateTree || NULL == fBoundingHierarchy) {
+        return SkPicture::OperationList::InvalidList();
+    }
+
+    if (NULL == fCachedActiveOps) {
+        fCachedActiveOps = SkNEW(CachedOperationList);
+    }
+
+    if (query == fCachedActiveOps->fCacheQueryRect) {
+        return *fCachedActiveOps;
+    }
+
+    fCachedActiveOps->fOps.rewind();
+
+    fBoundingHierarchy->search(query, &(fCachedActiveOps->fOps));
+    if (0 != fCachedActiveOps->fOps.count()) {
+        SkTQSort<SkPictureStateTree::Draw>(
+            reinterpret_cast<SkPictureStateTree::Draw**>(fCachedActiveOps->fOps.begin()),
+            reinterpret_cast<SkPictureStateTree::Draw**>(fCachedActiveOps->fOps.end()-1));
+    }
+
+    fCachedActiveOps->fCacheQueryRect = query;
+    return *fCachedActiveOps;
+}
+
 void SkPicturePlayback::draw(SkCanvas& canvas, SkDrawPictureCallback* callback) {
 #ifdef ENABLE_TIME_DRAW
     SkAutoTime  at("SkPicture::draw", 50);
@@ -815,26 +858,29 @@
 
     SkReader32 reader(fOpData->bytes(), fOpData->size());
     TextContainer text;
-    SkTDArray<void*> activeOps;
+    const SkTDArray<void*>* activeOps = NULL;
 
     if (NULL != fStateTree && NULL != fBoundingHierarchy) {
         SkRect clipBounds;
         if (canvas.getClipBounds(&clipBounds)) {
             SkIRect query;
             clipBounds.roundOut(&query);
-            fBoundingHierarchy->search(query, &activeOps);
-            if (activeOps.count() == 0) {
-                return;
+
+            const SkPicture::OperationList& activeOpsList = this->getActiveOps(query);
+            if (activeOpsList.valid()) {
+                if (0 == activeOpsList.numOps()) {
+                    return;     // nothing to draw
+                }
+                
+                // Since the opList is valid we know it is our derived class
+                activeOps = &((const CachedOperationList&)activeOpsList).fOps;
             }
-            SkTQSort<SkPictureStateTree::Draw>(
-                reinterpret_cast<SkPictureStateTree::Draw**>(activeOps.begin()),
-                reinterpret_cast<SkPictureStateTree::Draw**>(activeOps.end()-1));
         }
     }
 
-    SkPictureStateTree::Iterator it = (NULL == fStateTree) ?
+    SkPictureStateTree::Iterator it = (NULL == activeOps) ?
         SkPictureStateTree::Iterator() :
-        fStateTree->getIterator(activeOps, &canvas);
+        fStateTree->getIterator(*activeOps, &canvas);
 
     if (it.isValid()) {
         uint32_t skipTo = it.draw();