change old picture serialization to really handle images

BUG=skia:3965

Review URL: https://codereview.chromium.org/1199473002
diff --git a/tests/ImageTest.cpp b/tests/ImageTest.cpp
new file mode 100644
index 0000000..b196ca8
--- /dev/null
+++ b/tests/ImageTest.cpp
@@ -0,0 +1,105 @@
+/*
+ * Copyright 2015 Google Inc.
+ *
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+
+#include "SkCanvas.h"
+#include "SkData.h"
+#include "SkDevice.h"
+#include "SkImageEncoder.h"
+#include "SkImage_Base.h"
+#include "SkRRect.h"
+#include "SkSurface.h"
+#include "SkUtils.h"
+#include "Test.h"
+
+#if SK_SUPPORT_GPU
+#include "GrContextFactory.h"
+#include "GrTest.h"
+#include "gl/GrGLInterface.h"
+#include "gl/GrGLUtil.h"
+#else
+class GrContextFactory;
+class GrContext;
+#endif
+
+static void assert_equal(skiatest::Reporter* reporter, SkImage* a, const SkIRect* subsetA,
+                         SkImage* b) {
+    const int widthA = subsetA ? subsetA->width() : a->width();
+    const int heightA = subsetA ? subsetA->height() : a->height();
+
+    REPORTER_ASSERT(reporter, widthA == b->width());
+    REPORTER_ASSERT(reporter, heightA == b->height());
+#if 0
+    // see skbug.com/3965
+    bool AO = a->isOpaque();
+    bool BO = b->isOpaque();
+    REPORTER_ASSERT(reporter, AO == BO);
+#endif
+
+    SkImageInfo info = SkImageInfo::MakeN32(widthA, heightA,
+                                        a->isOpaque() ? kOpaque_SkAlphaType : kPremul_SkAlphaType);
+    SkAutoPixmapStorage pmapA, pmapB;
+    pmapA.alloc(info);
+    pmapB.alloc(info);
+
+    const int srcX = subsetA ? subsetA->x() : 0;
+    const int srcY = subsetA ? subsetA->y() : 0;
+
+    REPORTER_ASSERT(reporter, a->readPixels(pmapA, srcX, srcY));
+    REPORTER_ASSERT(reporter, b->readPixels(pmapB, 0, 0));
+
+    const size_t widthBytes = widthA * info.bytesPerPixel();
+    for (int y = 0; y < heightA; ++y) {
+        REPORTER_ASSERT(reporter, !memcmp(pmapA.addr32(0, y), pmapB.addr32(0, y), widthBytes));
+    }
+}
+
+static SkImage* make_image(GrContext* ctx, int w, int h, const SkIRect& ir) {
+    const SkImageInfo info = SkImageInfo::MakeN32(w, h, kOpaque_SkAlphaType);
+    SkAutoTUnref<SkSurface> surface(ctx ?
+                                    SkSurface::NewRenderTarget(ctx, SkSurface::kNo_Budgeted, info) :
+                                    SkSurface::NewRaster(info));
+    SkCanvas* canvas = surface->getCanvas();
+    canvas->clear(SK_ColorWHITE);
+
+    SkPaint paint;
+    paint.setColor(SK_ColorBLACK);
+    canvas->drawRect(SkRect::Make(ir), paint);
+    return surface->newImageSnapshot();
+}
+
+static void test_encode(skiatest::Reporter* reporter, GrContext* ctx) {
+    const SkIRect ir = SkIRect::MakeXYWH(5, 5, 10, 10);
+    SkAutoTUnref<SkImage> orig(make_image(ctx, 20, 20, ir));
+    SkAutoTUnref<SkData> origEncoded(orig->encode());
+    REPORTER_ASSERT(reporter, origEncoded);
+    REPORTER_ASSERT(reporter, origEncoded->size() > 0);
+
+    SkAutoTUnref<SkImage> decoded(SkImage::NewFromEncoded(origEncoded));
+    REPORTER_ASSERT(reporter, decoded);
+    assert_equal(reporter, orig, NULL, decoded);
+
+    // Now see if we can instantiate an image from a subset of the surface/origEncoded
+    
+    decoded.reset(SkImage::NewFromEncoded(origEncoded, &ir));
+    REPORTER_ASSERT(reporter, decoded);
+    assert_equal(reporter, orig, &ir, decoded);
+}
+
+DEF_TEST(Image_Encode_Cpu, reporter) {
+    test_encode(reporter, NULL);
+}
+
+#if SK_SUPPORT_GPU
+DEF_GPUTEST(Image_Encode_Gpu, reporter, factory) {
+    GrContext* ctx = factory->get(GrContextFactory::kNative_GLContextType);
+    if (!ctx) {
+        REPORTER_ASSERT(reporter, false);
+        return;
+    }
+    test_encode(reporter, ctx);
+}
+#endif