Create SkLayerRasterizer w/o destroying Builder.

tests/LayerRasterizerTest.cpp

+/*
+ * Copyright 2014 Google Inc.
+ *
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+
+#include "SkDeque.h"
+#include "SkLayerRasterizer.h"
+#include "SkPaint.h"
+#include "SkRasterizer.h"
+#include "Test.h"
+
+class SkReadBuffer;
+
+// Dummy class to place on a paint just to ensure the paint's destructor
+// is called.
+// ONLY to be used by LayerRasterizer_destructor, since other tests may
+// be run in a separate thread, and this class is not threadsafe.
+class DummyRasterizer : public SkRasterizer {
+public:
+    DummyRasterizer()
+        : INHERITED()
+    {
+        // Not threadsafe. Only used in one thread.
+        gCount++;
+    }
+
+    ~DummyRasterizer() {
+        // Not threadsafe. Only used in one thread.
+        gCount--;
+    }
+
+    static int GetCount() { return gCount; }
+
+    SK_DECLARE_PUBLIC_FLATTENABLE_DESERIALIZATION_PROCS(DummyRasterizer)
+
+private:
+    DummyRasterizer(SkReadBuffer&) {}
+
+    static int gCount;
+
+    typedef SkRasterizer INHERITED;
+};
+
+int DummyRasterizer::gCount;
+
+// Check to make sure that the SkPaint in the layer has its destructor called.
+DEF_TEST(LayerRasterizer_destructor, reporter) {
+    {
+        SkPaint paint;
+        paint.setRasterizer(SkNEW(DummyRasterizer))->unref();
+        REPORTER_ASSERT(reporter, DummyRasterizer::GetCount() == 1);
+
+        SkLayerRasterizer::Builder builder;
+        builder.addLayer(paint);
+    }
+    REPORTER_ASSERT(reporter, DummyRasterizer::GetCount() == 0);
+}
+
+class LayerRasterizerTester {
+public:
+    static int CountLayers(const SkLayerRasterizer& layerRasterizer) {
+        return layerRasterizer.fLayers->count();
+    }
+
+    static const SkDeque& GetLayers(const SkLayerRasterizer& layerRasterizer) {
+        return *layerRasterizer.fLayers;
+    }
+};
+
+// MUST stay in sync with definition of SkLayerRasterizer_Rec in SkLayerRasterizer.cpp.
+struct SkLayerRasterizer_Rec {
+    SkPaint     fPaint;
+    SkVector    fOffset;
+};
+
+static bool equals(const SkLayerRasterizer_Rec& rec1, const SkLayerRasterizer_Rec& rec2) {
+    return rec1.fPaint == rec2.fPaint && rec1.fOffset == rec2.fOffset;
+}
+
+DEF_TEST(LayerRasterizer_copy, reporter) {
+    SkLayerRasterizer::Builder builder;
+    SkPaint paint;
+    // Create a bunch of paints with different flags.
+    for (uint32_t flags = 0x01; flags < SkPaint::kAllFlags; flags <<= 1) {
+        paint.setFlags(flags);
+        builder.addLayer(paint, flags, flags);
+    }
+
+    // Create a layer rasterizer with all the existing layers.
+    SkAutoTUnref<SkLayerRasterizer> firstCopy(builder.snapshotRasterizer());
+
+    // Add one more layer.
+    paint.setFlags(SkPaint::kAllFlags);
+    builder.addLayer(paint);
+
+    SkAutoTUnref<SkLayerRasterizer> oneLarger(builder.snapshotRasterizer());
+    SkAutoTUnref<SkLayerRasterizer> detached(builder.detachRasterizer());
+
+    // Check the counts for consistency.
+    const int largerCount = LayerRasterizerTester::CountLayers(*oneLarger.get());
+    const int smallerCount = LayerRasterizerTester::CountLayers(*firstCopy.get());
+    REPORTER_ASSERT(reporter, largerCount == LayerRasterizerTester::CountLayers(*detached.get()));
+    REPORTER_ASSERT(reporter, smallerCount == largerCount - 1);
+
+    const SkLayerRasterizer_Rec* recFirstCopy = NULL;
+    const SkLayerRasterizer_Rec* recOneLarger = NULL;
+    const SkLayerRasterizer_Rec* recDetached = NULL;
+
+    const SkDeque& layersFirstCopy = LayerRasterizerTester::GetLayers(*firstCopy.get());
+    const SkDeque& layersOneLarger = LayerRasterizerTester::GetLayers(*oneLarger.get());
+    const SkDeque& layersDetached = LayerRasterizerTester::GetLayers(*detached.get());
+
+    // Ensure that our version of SkLayerRasterizer_Rec is the same as the one in
+    // SkLayerRasterizer.cpp - or at least the same size. If the order were switched, we
+    // would fail the test elsewhere.
+    REPORTER_ASSERT(reporter, layersFirstCopy.elemSize() == sizeof(SkLayerRasterizer_Rec));
+    REPORTER_ASSERT(reporter, layersOneLarger.elemSize() == sizeof(SkLayerRasterizer_Rec));
+    REPORTER_ASSERT(reporter, layersDetached.elemSize() == sizeof(SkLayerRasterizer_Rec));
+
+    SkDeque::F2BIter iterFirstCopy(layersFirstCopy);
+    SkDeque::F2BIter iterOneLarger(layersOneLarger);
+    SkDeque::F2BIter iterDetached(layersDetached);
+
+    for (int i = 0; i < largerCount; ++i) {
+        recFirstCopy = static_cast<const SkLayerRasterizer_Rec*>(iterFirstCopy.next());
+        recOneLarger = static_cast<const SkLayerRasterizer_Rec*>(iterOneLarger.next());
+        recDetached  = static_cast<const SkLayerRasterizer_Rec*>(iterDetached.next());
+
+        REPORTER_ASSERT(reporter, equals(*recOneLarger, *recDetached));
+        if (smallerCount == i) {
+            REPORTER_ASSERT(reporter, recFirstCopy == NULL);
+        } else {
+            REPORTER_ASSERT(reporter, equals(*recFirstCopy, *recOneLarger));
+        }
+    }
+}