add pipecanvas

tests/PipeTest.cpp

+/*
+ * Copyright 2016 Google Inc.
+ *
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+
+#include "Resources.h"
+#include "SkCanvas.h"
+#include "SkPipe.h"
+#include "SkPaint.h"
+#include "SkStream.h"
+#include "SkSurface.h"
+#include "Test.h"
+
+#include "SkNullCanvas.h"
+#include "SkAutoPixmapStorage.h"
+
+static void drain(SkPipeDeserializer* deserial, SkDynamicMemoryWStream* stream) {
+    std::unique_ptr<SkCanvas> canvas(SkCreateNullCanvas());
+    sk_sp<SkData> data = stream->detachAsData();
+    deserial->playback(data->data(), data->size(), canvas.get());
+}
+
+static sk_sp<SkImage> drain_as_image(SkPipeDeserializer* deserial, SkDynamicMemoryWStream* stream) {
+    sk_sp<SkData> data = stream->detachAsData();
+    return deserial->readImage(data->data(), data->size());
+}
+
+static bool deep_equal(SkImage* a, SkImage* b) {
+    if (a->width() != b->width() || a->height() != b->height()) {
+        return false;
+    }
+
+    const SkImageInfo info = SkImageInfo::MakeN32Premul(a->width(), a->height());
+    SkAutoPixmapStorage pmapA, pmapB;
+    pmapA.alloc(info);
+    pmapB.alloc(info);
+
+    if (!a->readPixels(pmapA, 0, 0) || !b->readPixels(pmapB, 0, 0)) {
+        return false;
+    }
+
+    for (int y = 0; y < info.height(); ++y) {
+        if (memcmp(pmapA.addr32(0, y), pmapB.addr32(0, y), info.width() * sizeof(SkPMColor))) {
+            return false;
+        }
+    }
+    return true;
+}
+
+DEF_TEST(Pipe_image, reporter) {
+    sk_sp<SkImage> img = GetResourceAsImage("mandrill_128.png");
+    SkASSERT(img.get());
+
+    SkPipeSerializer serializer;
+    SkPipeDeserializer deserializer;
+
+    SkDynamicMemoryWStream stream;
+    SkCanvas* wc = serializer.beginWrite(SkRect::MakeWH(100, 100), &stream);
+    wc->drawImage(img, 0, 0, nullptr);
+    serializer.endWrite();
+    size_t offset0 = stream.bytesWritten();
+    REPORTER_ASSERT(reporter, offset0 > 100);   // the raw image must be sorta big
+    drain(&deserializer, &stream);
+
+    // try drawing the same image again -- it should be much smaller
+    wc = serializer.beginWrite(SkRect::MakeWH(100, 100), &stream);
+    wc->drawImage(img, 0, 0, nullptr);
+    size_t offset1 = stream.bytesWritten();
+    serializer.endWrite();
+    REPORTER_ASSERT(reporter, offset1 <= 32);
+    drain(&deserializer, &stream);
+
+    // try serializing the same image directly, again it should be small
+    serializer.write(img.get(), &stream);
+    size_t offset2 = stream.bytesWritten();
+    REPORTER_ASSERT(reporter, offset2 <= 32);
+    auto img1 = drain_as_image(&deserializer, &stream);
+    REPORTER_ASSERT(reporter, deep_equal(img.get(), img1.get()));
+
+    // try serializing the same image directly (again), check that it is the same!
+    serializer.write(img.get(), &stream);
+    size_t offset3 = stream.bytesWritten();
+    REPORTER_ASSERT(reporter, offset3 <= 32);
+    auto img2 = drain_as_image(&deserializer, &stream);
+    REPORTER_ASSERT(reporter, img1.get() == img2.get());
+}