tests/ImageTest.cpp

/*
 * 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 <functional>
#include <initializer_list>
#include <vector>

#include "SkAutoPixmapStorage.h"
#include "SkBitmap.h"
#include "SkCanvas.h"
#include "SkData.h"
#include "SkImageEncoder.h"
#include "SkImageGenerator.h"
#include "SkImage_Base.h"
#include "SkImagePriv.h"
#include "SkPicture.h"
#include "SkPictureRecorder.h"
#include "SkPixelSerializer.h"
#include "SkRRect.h"
#include "SkStream.h"
#include "SkSurface.h"
#include "SkUtils.h"
#include "Test.h"

#include "sk_tool_utils.h"

#if SK_SUPPORT_GPU
#include "GrGpu.h"
#endif

using namespace sk_gpu_test;

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());

    // see https://bug.skia.org/3965
    //REPORTER_ASSERT(reporter, a->isOpaque() == b->isOpaque());

    // The codecs may have given us back F16, we can't read from F16 raster to N32, only S32.
    SkImageInfo info = SkImageInfo::MakeS32(widthA, heightA, a->alphaType());
    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 void draw_image_test_pattern(SkCanvas* canvas) {
    canvas->clear(SK_ColorWHITE);
    SkPaint paint;
    paint.setColor(SK_ColorBLACK);
    canvas->drawRect(SkRect::MakeXYWH(5, 5, 10, 10), paint);
}
static sk_sp<SkImage> create_image() {
    const SkImageInfo info = SkImageInfo::MakeN32(20, 20, kOpaque_SkAlphaType);
    auto surface(SkSurface::MakeRaster(info));
    draw_image_test_pattern(surface->getCanvas());
    return surface->makeImageSnapshot();
}
static sk_sp<SkData> create_image_data(SkImageInfo* info) {
    *info = SkImageInfo::MakeN32(20, 20, kOpaque_SkAlphaType);
    const size_t rowBytes = info->minRowBytes();
    sk_sp<SkData> data(SkData::MakeUninitialized(rowBytes * info->height()));
    {
        SkBitmap bm;
        bm.installPixels(*info, data->writable_data(), rowBytes);
        SkCanvas canvas(bm);
        draw_image_test_pattern(&canvas);
    }
    return data;
}
static sk_sp<SkImage> create_data_image() {
    SkImageInfo info;
    sk_sp<SkData> data(create_image_data(&info));
    return SkImage::MakeRasterData(info, std::move(data), info.minRowBytes());
}
#if SK_SUPPORT_GPU // not gpu-specific but currently only used in GPU tests
static sk_sp<SkImage> create_image_565() {
    const SkImageInfo info = SkImageInfo::Make(20, 20, kRGB_565_SkColorType, kOpaque_SkAlphaType);
    auto surface(SkSurface::MakeRaster(info));
    draw_image_test_pattern(surface->getCanvas());
    return surface->makeImageSnapshot();
}

static sk_sp<SkImage> create_image_large(int maxTextureSize) {
    const SkImageInfo info = SkImageInfo::MakeN32(maxTextureSize + 1, 32, kOpaque_SkAlphaType);
    auto surface(SkSurface::MakeRaster(info));
    surface->getCanvas()->clear(SK_ColorWHITE);
    SkPaint paint;
    paint.setColor(SK_ColorBLACK);
    surface->getCanvas()->drawRect(SkRect::MakeXYWH(4000, 2, 28000, 30), paint);
    return surface->makeImageSnapshot();
}
static sk_sp<SkImage> create_image_ct() {
    SkPMColor colors[] = {
        SkPreMultiplyARGB(0xFF, 0xFF, 0xFF, 0x00),
        SkPreMultiplyARGB(0x80, 0x00, 0xA0, 0xFF),
        SkPreMultiplyARGB(0xFF, 0xBB, 0x00, 0xBB)
    };
    sk_sp<SkColorTable> colorTable(new SkColorTable(colors, SK_ARRAY_COUNT(colors)));
    uint8_t data[] = {
        0, 0, 0, 0, 0,
        0, 1, 1, 1, 0,
        0, 1, 2, 1, 0,
        0, 1, 1, 1, 0,
        0, 0, 0, 0, 0
    };
    SkImageInfo info = SkImageInfo::Make(5, 5, kIndex_8_SkColorType, kPremul_SkAlphaType);
    return SkImage::MakeRasterCopy(SkPixmap(info, data, 5, colorTable.get()));
}
static sk_sp<SkImage> create_picture_image() {
    SkPictureRecorder recorder;
    SkCanvas* canvas = recorder.beginRecording(10, 10);
    canvas->clear(SK_ColorCYAN);
    return SkImage::MakeFromPicture(recorder.finishRecordingAsPicture(), SkISize::Make(10, 10),
                                    nullptr, nullptr, SkImage::BitDepth::kU8,
                                    SkColorSpace::MakeNamed(SkColorSpace::kSRGB_Named));
};
#endif
// Want to ensure that our Release is called when the owning image is destroyed
struct RasterDataHolder {
    RasterDataHolder() : fReleaseCount(0) {}
    sk_sp<SkData> fData;
    int fReleaseCount;
    static void Release(const void* pixels, void* context) {
        RasterDataHolder* self = static_cast<RasterDataHolder*>(context);
        self->fReleaseCount++;
        self->fData.reset();
    }
};
static sk_sp<SkImage> create_rasterproc_image(RasterDataHolder* dataHolder) {
    SkASSERT(dataHolder);
    SkImageInfo info;
    dataHolder->fData = create_image_data(&info);
    return SkImage::MakeFromRaster(SkPixmap(info, dataHolder->fData->data(), info.minRowBytes()),
                                   RasterDataHolder::Release, dataHolder);
}
static sk_sp<SkImage> create_codec_image() {
    SkImageInfo info;
    sk_sp<SkData> data(create_image_data(&info));
    SkBitmap bitmap;
    bitmap.installPixels(info, data->writable_data(), info.minRowBytes());
    sk_sp<SkData> src(sk_tool_utils::EncodeImageToData(bitmap, SkEncodedImageFormat::kPNG, 100));
    return SkImage::MakeFromEncoded(std::move(src));
}
#if SK_SUPPORT_GPU
static sk_sp<SkImage> create_gpu_image(GrContext* context) {
    const SkImageInfo info = SkImageInfo::MakeN32(20, 20, kOpaque_SkAlphaType);
    auto surface(SkSurface::MakeRenderTarget(context, SkBudgeted::kNo, info));
    draw_image_test_pattern(surface->getCanvas());
    return surface->makeImageSnapshot();
}
#endif

static void test_encode(skiatest::Reporter* reporter, SkImage* image) {
    const SkIRect ir = SkIRect::MakeXYWH(5, 5, 10, 10);
    sk_sp<SkData> origEncoded(image->encode());
    REPORTER_ASSERT(reporter, origEncoded);
    REPORTER_ASSERT(reporter, origEncoded->size() > 0);

    sk_sp<SkImage> decoded(SkImage::MakeFromEncoded(origEncoded));
    if (!decoded) {
        ERRORF(reporter, "failed to decode image!");
        return;
    }
    REPORTER_ASSERT(reporter, decoded);
    assert_equal(reporter, image, nullptr, decoded.get());

    // Now see if we can instantiate an image from a subset of the surface/origEncoded

    decoded = SkImage::MakeFromEncoded(origEncoded, &ir);
    REPORTER_ASSERT(reporter, decoded);
    assert_equal(reporter, image, &ir, decoded.get());
}

DEF_TEST(ImageEncode, reporter) {
    test_encode(reporter, create_image().get());
}

#if SK_SUPPORT_GPU
DEF_GPUTEST_FOR_RENDERING_CONTEXTS(ImageEncode_Gpu, reporter, ctxInfo) {
    test_encode(reporter, create_gpu_image(ctxInfo.grContext()).get());
}
#endif

DEF_TEST(Image_MakeFromRasterBitmap, reporter) {
    const struct {
        SkCopyPixelsMode fCPM;
        bool            fExpectSameAsMutable;
        bool            fExpectSameAsImmutable;
    } recs[] = {
        { kIfMutable_SkCopyPixelsMode,  false,  true },
        { kAlways_SkCopyPixelsMode,     false,  false },
        { kNever_SkCopyPixelsMode,      true,   true },
    };
    for (auto rec : recs) {
        SkPixmap pm;
        SkBitmap bm;
        bm.allocN32Pixels(100, 100);

        auto img = SkMakeImageFromRasterBitmap(bm, rec.fCPM);
        REPORTER_ASSERT(reporter, img->peekPixels(&pm));
        const bool sameMutable = pm.addr32(0, 0) == bm.getAddr32(0, 0);
        REPORTER_ASSERT(reporter, rec.fExpectSameAsMutable == sameMutable);
        REPORTER_ASSERT(reporter, (bm.getGenerationID() == img->uniqueID()) == sameMutable);

        bm.notifyPixelsChanged();   // force a new generation ID

        bm.setImmutable();
        img = SkMakeImageFromRasterBitmap(bm, rec.fCPM);
        REPORTER_ASSERT(reporter, img->peekPixels(&pm));
        const bool sameImmutable = pm.addr32(0, 0) == bm.getAddr32(0, 0);
        REPORTER_ASSERT(reporter, rec.fExpectSameAsImmutable == sameImmutable);
        REPORTER_ASSERT(reporter, (bm.getGenerationID() == img->uniqueID()) == sameImmutable);
    }
}

namespace {

const char* kSerializedData = "serialized";

class MockSerializer : public SkPixelSerializer {
public:
    MockSerializer(sk_sp<SkData> (*func)()) : fFunc(func), fDidEncode(false) { }

    bool didEncode() const { return fDidEncode; }

protected:
    bool onUseEncodedData(const void*, size_t) override {
        return false;
    }

    SkData* onEncode(const SkPixmap&) override {
        fDidEncode = true;
        return fFunc().release();
    }

private:
    sk_sp<SkData> (*fFunc)();
    bool fDidEncode;

    typedef SkPixelSerializer INHERITED;
};

} // anonymous namespace

// Test that SkImage encoding observes custom pixel serializers.
DEF_TEST(Image_Encode_Serializer, reporter) {
    MockSerializer serializer([]() -> sk_sp<SkData> {
        return SkData::MakeWithCString(kSerializedData);
    });
    sk_sp<SkImage> image(create_image());
    sk_sp<SkData> encoded(image->encode(&serializer));
    sk_sp<SkData> reference(SkData::MakeWithCString(kSerializedData));

    REPORTER_ASSERT(reporter, serializer.didEncode());
    REPORTER_ASSERT(reporter, encoded);
    REPORTER_ASSERT(reporter, encoded->size() > 0);
    REPORTER_ASSERT(reporter, encoded->equals(reference.get()));
}

// Test that image encoding failures do not break picture serialization/deserialization.
DEF_TEST(Image_Serialize_Encoding_Failure, reporter) {
    auto surface(SkSurface::MakeRasterN32Premul(100, 100));
    surface->getCanvas()->clear(SK_ColorGREEN);
    sk_sp<SkImage> image(surface->makeImageSnapshot());
    REPORTER_ASSERT(reporter, image);

    SkPictureRecorder recorder;
    SkCanvas* canvas = recorder.beginRecording(100, 100);
    canvas->drawImage(image, 0, 0);
    sk_sp<SkPicture> picture(recorder.finishRecordingAsPicture());
    REPORTER_ASSERT(reporter, picture);
    REPORTER_ASSERT(reporter, picture->approximateOpCount() > 0);

    MockSerializer emptySerializer([]() -> sk_sp<SkData> { return SkData::MakeEmpty(); });
    MockSerializer nullSerializer([]() -> sk_sp<SkData> { return nullptr; });
    MockSerializer* serializers[] = { &emptySerializer, &nullSerializer };

    for (size_t i = 0; i < SK_ARRAY_COUNT(serializers); ++i) {
        SkDynamicMemoryWStream wstream;
        REPORTER_ASSERT(reporter, !serializers[i]->didEncode());
        picture->serialize(&wstream, serializers[i]);
        REPORTER_ASSERT(reporter, serializers[i]->didEncode());

        std::unique_ptr<SkStream> rstream(wstream.detachAsStream());
        sk_sp<SkPicture> deserialized(SkPicture::MakeFromStream(rstream.get()));
        REPORTER_ASSERT(reporter, deserialized);
        REPORTER_ASSERT(reporter, deserialized->approximateOpCount() > 0);
    }
}

DEF_TEST(Image_NewRasterCopy, reporter) {
    const SkPMColor red =   SkPackARGB32(0xFF, 0xFF, 0, 0);
    const SkPMColor green = SkPackARGB32(0xFF, 0, 0xFF, 0);
    const SkPMColor blue =  SkPackARGB32(0xFF, 0, 0, 0xFF);
    SkPMColor colors[] = { red, green, blue, 0 };
    sk_sp<SkColorTable> ctable(new SkColorTable(colors, SK_ARRAY_COUNT(colors)));
    // The colortable made a copy, so we can trash the original colors
    memset(colors, 0xFF, sizeof(colors));

    const SkImageInfo srcInfo = SkImageInfo::Make(2, 2, kIndex_8_SkColorType, kPremul_SkAlphaType);
    const size_t srcRowBytes = 2 * sizeof(uint8_t);
    uint8_t indices[] = { 0, 1, 2, 3 };
    auto image = SkImage::MakeRasterCopy(SkPixmap(srcInfo, indices, srcRowBytes, ctable.get()));
    // The image made a copy, so we can trash the original indices
    memset(indices, 0xFF, sizeof(indices));

    const SkImageInfo dstInfo = SkImageInfo::MakeN32Premul(2, 2);
    const size_t dstRowBytes = 2 * sizeof(SkPMColor);
    SkPMColor pixels[4];
    memset(pixels, 0xFF, sizeof(pixels));   // init with values we don't expect
    image->readPixels(dstInfo, pixels, dstRowBytes, 0, 0);
    REPORTER_ASSERT(reporter, red == pixels[0]);
    REPORTER_ASSERT(reporter, green == pixels[1]);
    REPORTER_ASSERT(reporter, blue == pixels[2]);
    REPORTER_ASSERT(reporter, 0 == pixels[3]);
}

// Test that a draw that only partially covers the drawing surface isn't
// interpreted as covering the entire drawing surface (i.e., exercise one of the
// conditions of SkCanvas::wouldOverwriteEntireSurface()).
DEF_TEST(Image_RetainSnapshot, reporter) {
    const SkPMColor red   = SkPackARGB32(0xFF, 0xFF, 0, 0);
    const SkPMColor green = SkPackARGB32(0xFF, 0, 0xFF, 0);
    SkImageInfo info = SkImageInfo::MakeN32Premul(2, 2);
    auto surface(SkSurface::MakeRaster(info));
    surface->getCanvas()->clear(0xFF00FF00);

    SkPMColor pixels[4];
    memset(pixels, 0xFF, sizeof(pixels));   // init with values we don't expect
    const SkImageInfo dstInfo = SkImageInfo::MakeN32Premul(2, 2);
    const size_t dstRowBytes = 2 * sizeof(SkPMColor);

    sk_sp<SkImage> image1(surface->makeImageSnapshot());
    REPORTER_ASSERT(reporter, image1->readPixels(dstInfo, pixels, dstRowBytes, 0, 0));
    for (size_t i = 0; i < SK_ARRAY_COUNT(pixels); ++i) {
        REPORTER_ASSERT(reporter, pixels[i] == green);
    }

    SkPaint paint;
    paint.setBlendMode(SkBlendMode::kSrc);
    paint.setColor(SK_ColorRED);

    surface->getCanvas()->drawRect(SkRect::MakeXYWH(1, 1, 1, 1), paint);

    sk_sp<SkImage> image2(surface->makeImageSnapshot());
    REPORTER_ASSERT(reporter, image2->readPixels(dstInfo, pixels, dstRowBytes, 0, 0));
    REPORTER_ASSERT(reporter, pixels[0] == green);
    REPORTER_ASSERT(reporter, pixels[1] == green);
    REPORTER_ASSERT(reporter, pixels[2] == green);
    REPORTER_ASSERT(reporter, pixels[3] == red);
}

/////////////////////////////////////////////////////////////////////////////////////////////////

static void make_bitmap_mutable(SkBitmap* bm) {
    bm->allocN32Pixels(10, 10);
}

static void make_bitmap_immutable(SkBitmap* bm) {
    bm->allocN32Pixels(10, 10);
    bm->setImmutable();
}

DEF_TEST(image_newfrombitmap, reporter) {
    const struct {
        void (*fMakeProc)(SkBitmap*);
        bool fExpectPeekSuccess;
        bool fExpectSharedID;
        bool fExpectLazy;
    } rec[] = {
        { make_bitmap_mutable,      true,   false, false },
        { make_bitmap_immutable,    true,   true,  false },
    };

    for (size_t i = 0; i < SK_ARRAY_COUNT(rec); ++i) {
        SkBitmap bm;
        rec[i].fMakeProc(&bm);

        sk_sp<SkImage> image(SkImage::MakeFromBitmap(bm));
        SkPixmap pmap;

        const bool sharedID = (image->uniqueID() == bm.getGenerationID());
        REPORTER_ASSERT(reporter, sharedID == rec[i].fExpectSharedID);

        const bool peekSuccess = image->peekPixels(&pmap);
        REPORTER_ASSERT(reporter, peekSuccess == rec[i].fExpectPeekSuccess);

        const bool lazy = image->isLazyGenerated();
        REPORTER_ASSERT(reporter, lazy == rec[i].fExpectLazy);
    }
}

///////////////////////////////////////////////////////////////////////////////////////////////////
#if SK_SUPPORT_GPU

#include "SkBitmapCache.h"

/*
 *  This tests the caching (and preemptive purge) of the raster equivalent of a gpu-image.
 *  We cache it for performance when drawing into a raster surface.
 *
 *  A cleaner test would know if each drawImage call triggered a read-back from the gpu,
 *  but we don't have that facility (at the moment) so we use a little internal knowledge
 *  of *how* the raster version is cached, and look for that.
 */
DEF_GPUTEST_FOR_RENDERING_CONTEXTS(c, reporter, ctxInfo) {
    SkImageInfo info = SkImageInfo::MakeN32(20, 20, kOpaque_SkAlphaType);
    sk_sp<SkImage> image(create_gpu_image(ctxInfo.grContext()));
    const uint32_t uniqueID = image->uniqueID();

    auto surface(SkSurface::MakeRaster(info));

    // now we can test drawing a gpu-backed image into a cpu-backed surface

    {
        SkBitmap cachedBitmap;
        REPORTER_ASSERT(reporter, !SkBitmapCache::Find(uniqueID, &cachedBitmap));
    }

    surface->getCanvas()->drawImage(image, 0, 0);
    {
        SkBitmap cachedBitmap;
        if (SkBitmapCache::Find(uniqueID, &cachedBitmap)) {
            REPORTER_ASSERT(reporter, cachedBitmap.getGenerationID() == uniqueID);
            REPORTER_ASSERT(reporter, cachedBitmap.isImmutable());
            REPORTER_ASSERT(reporter, cachedBitmap.getPixels());
        } else {
            // unexpected, but not really a bug, since the cache is global and this test may be
            // run w/ other threads competing for its budget.
            SkDebugf("SkImage_Gpu2Cpu : cachedBitmap was already purged\n");
        }
    }

    image.reset(nullptr);
    {
        SkBitmap cachedBitmap;
        REPORTER_ASSERT(reporter, !SkBitmapCache::Find(uniqueID, &cachedBitmap));
    }
}

DEF_GPUTEST_FOR_RENDERING_CONTEXTS(SkImage_makeNonTextureImage, reporter, contextInfo) {
    GrContext* context = contextInfo.grContext();

    std::function<sk_sp<SkImage>()> imageFactories[] = {
        create_image,
        create_codec_image,
        create_data_image,
        create_picture_image,
        [context] { return create_gpu_image(context); },
    };
    for (auto factory : imageFactories) {
        sk_sp<SkImage> image = factory();
        if (!image->isTextureBacked()) {
            REPORTER_ASSERT(reporter, image->makeNonTextureImage().get() == image.get());
            continue;
        }
        auto rasterImage = image->makeNonTextureImage();
        if (!rasterImage) {
            ERRORF(reporter, "makeNonTextureImage failed for texture-backed image.");
        }
        REPORTER_ASSERT(reporter, !rasterImage->isTextureBacked());
        assert_equal(reporter, image.get(), nullptr, rasterImage.get());
    }
}

DEF_GPUTEST_FOR_GL_RENDERING_CONTEXTS(SkImage_drawAbandonedGpuImage, reporter, contextInfo) {
    auto context = contextInfo.grContext();
    auto image = create_gpu_image(context);
    auto info = SkImageInfo::MakeN32(20, 20, kOpaque_SkAlphaType);
    auto surface(SkSurface::MakeRenderTarget(context, SkBudgeted::kNo, info));
    as_IB(image)->peekTexture()->abandon();
    surface->getCanvas()->drawImage(image, 0, 0);
}

#endif

// https://bug.skia.org/4390
DEF_TEST(ImageFromIndex8Bitmap, r) {
    SkPMColor pmColors[1] = {SkPreMultiplyColor(SK_ColorWHITE)};
    SkBitmap bm;
    sk_sp<SkColorTable> ctable( new SkColorTable(pmColors, SK_ARRAY_COUNT(pmColors)));
    SkImageInfo info = SkImageInfo::Make(1, 1, kIndex_8_SkColorType, kPremul_SkAlphaType);
    bm.allocPixels(info, nullptr, ctable.get());
    SkAutoLockPixels autoLockPixels(bm);
    *bm.getAddr8(0, 0) = 0;
    sk_sp<SkImage> img(SkImage::MakeFromBitmap(bm));
    REPORTER_ASSERT(r, img != nullptr);
}

class EmptyGenerator : public SkImageGenerator {
public:
    EmptyGenerator() : SkImageGenerator(SkImageInfo::MakeN32Premul(0, 0)) {}
};

DEF_TEST(ImageEmpty, reporter) {
    const SkImageInfo info = SkImageInfo::Make(0, 0, kN32_SkColorType, kPremul_SkAlphaType);
    SkPixmap pmap(info, nullptr, 0);
    REPORTER_ASSERT(reporter, nullptr == SkImage::MakeRasterCopy(pmap));
    REPORTER_ASSERT(reporter, nullptr == SkImage::MakeRasterData(info, nullptr, 0));
    REPORTER_ASSERT(reporter, nullptr == SkImage::MakeFromRaster(pmap, nullptr, nullptr));
    REPORTER_ASSERT(reporter, nullptr == SkImage::MakeFromGenerator(new EmptyGenerator));
}

DEF_TEST(ImageDataRef, reporter) {
    SkImageInfo info = SkImageInfo::MakeN32Premul(1, 1);
    size_t rowBytes = info.minRowBytes();
    size_t size = info.getSafeSize(rowBytes);
    sk_sp<SkData> data = SkData::MakeUninitialized(size);
    REPORTER_ASSERT(reporter, data->unique());
    sk_sp<SkImage> image = SkImage::MakeRasterData(info, data, rowBytes);
    REPORTER_ASSERT(reporter, !data->unique());
    image.reset();
    REPORTER_ASSERT(reporter, data->unique());
}

static bool has_pixels(const SkPMColor pixels[], int count, SkPMColor expected) {
    for (int i = 0; i < count; ++i) {
        if (pixels[i] != expected) {
            return false;
        }
    }
    return true;
}

static void test_read_pixels(skiatest::Reporter* reporter, SkImage* image) {
    if (!image) {
        ERRORF(reporter, "Failed to create image!");
        return;
    }
    const SkPMColor expected = SkPreMultiplyColor(SK_ColorWHITE);
    const SkPMColor notExpected = ~expected;

    const int w = 2, h = 2;
    const size_t rowBytes = w * sizeof(SkPMColor);
    SkPMColor pixels[w*h];

    SkImageInfo info;

    info = SkImageInfo::MakeUnknown(w, h);
    REPORTER_ASSERT(reporter, !image->readPixels(info, pixels, rowBytes, 0, 0));

    // out-of-bounds should fail
    info = SkImageInfo::MakeN32Premul(w, h);
    REPORTER_ASSERT(reporter, !image->readPixels(info, pixels, rowBytes, -w, 0));
    REPORTER_ASSERT(reporter, !image->readPixels(info, pixels, rowBytes, 0, -h));
    REPORTER_ASSERT(reporter, !image->readPixels(info, pixels, rowBytes, image->width(), 0));
    REPORTER_ASSERT(reporter, !image->readPixels(info, pixels, rowBytes, 0, image->height()));

    // top-left should succeed
    sk_memset32(pixels, notExpected, w*h);
    REPORTER_ASSERT(reporter, image->readPixels(info, pixels, rowBytes, 0, 0));
    REPORTER_ASSERT(reporter, has_pixels(pixels, w*h, expected));

    // bottom-right should succeed
    sk_memset32(pixels, notExpected, w*h);
    REPORTER_ASSERT(reporter, image->readPixels(info, pixels, rowBytes,
                                                image->width() - w, image->height() - h));
    REPORTER_ASSERT(reporter, has_pixels(pixels, w*h, expected));

    // partial top-left should succeed
    sk_memset32(pixels, notExpected, w*h);
    REPORTER_ASSERT(reporter, image->readPixels(info, pixels, rowBytes, -1, -1));
    REPORTER_ASSERT(reporter, pixels[3] == expected);
    REPORTER_ASSERT(reporter, has_pixels(pixels, w*h - 1, notExpected));

    // partial bottom-right should succeed
    sk_memset32(pixels, notExpected, w*h);
    REPORTER_ASSERT(reporter, image->readPixels(info, pixels, rowBytes,
                                                image->width() - 1, image->height() - 1));
    REPORTER_ASSERT(reporter, pixels[0] == expected);
    REPORTER_ASSERT(reporter, has_pixels(&pixels[1], w*h - 1, notExpected));
}
DEF_TEST(ImageReadPixels, reporter) {
    sk_sp<SkImage> image(create_image());
    test_read_pixels(reporter, image.get());

    image = create_data_image();
    test_read_pixels(reporter, image.get());

    RasterDataHolder dataHolder;
    image = create_rasterproc_image(&dataHolder);
    test_read_pixels(reporter, image.get());
    image.reset();
    REPORTER_ASSERT(reporter, 1 == dataHolder.fReleaseCount);

    image = create_codec_image();
    test_read_pixels(reporter, image.get());
}
#if SK_SUPPORT_GPU
DEF_GPUTEST_FOR_RENDERING_CONTEXTS(ImageReadPixels_Gpu, reporter, ctxInfo) {
    test_read_pixels(reporter, create_gpu_image(ctxInfo.grContext()).get());
}
#endif

static void check_legacy_bitmap(skiatest::Reporter* reporter, const SkImage* image,
                                const SkBitmap& bitmap, SkImage::LegacyBitmapMode mode) {
    REPORTER_ASSERT(reporter, image->width() == bitmap.width());
    REPORTER_ASSERT(reporter, image->height() == bitmap.height());
    REPORTER_ASSERT(reporter, image->alphaType() == bitmap.alphaType());

    if (SkImage::kRO_LegacyBitmapMode == mode) {
        REPORTER_ASSERT(reporter, bitmap.isImmutable());
    }

    SkAutoLockPixels alp(bitmap);
    REPORTER_ASSERT(reporter, bitmap.getPixels());

    const SkImageInfo info = SkImageInfo::MakeN32(1, 1, bitmap.alphaType());
    SkPMColor imageColor;
    REPORTER_ASSERT(reporter, image->readPixels(info, &imageColor, sizeof(SkPMColor), 0, 0));
    REPORTER_ASSERT(reporter, imageColor == *bitmap.getAddr32(0, 0));
}

static void test_legacy_bitmap(skiatest::Reporter* reporter, const SkImage* image, SkImage::LegacyBitmapMode mode) {
    if (!image) {
        ERRORF(reporter, "Failed to create image.");
        return;
    }
    SkBitmap bitmap;
    REPORTER_ASSERT(reporter, image->asLegacyBitmap(&bitmap, mode));
    check_legacy_bitmap(reporter, image, bitmap, mode);

    // Test subsetting to exercise the rowBytes logic.
    SkBitmap tmp;
    REPORTER_ASSERT(reporter, bitmap.extractSubset(&tmp, SkIRect::MakeWH(image->width() / 2,
                                                                         image->height() / 2)));
    sk_sp<SkImage> subsetImage(SkImage::MakeFromBitmap(tmp));
    REPORTER_ASSERT(reporter, subsetImage.get());

    SkBitmap subsetBitmap;
    REPORTER_ASSERT(reporter, subsetImage->asLegacyBitmap(&subsetBitmap, mode));
    check_legacy_bitmap(reporter, subsetImage.get(), subsetBitmap, mode);
}
DEF_TEST(ImageLegacyBitmap, reporter) {
    const SkImage::LegacyBitmapMode modes[] = {
        SkImage::kRO_LegacyBitmapMode,
        SkImage::kRW_LegacyBitmapMode,
    };
    for (auto& mode : modes) {
        sk_sp<SkImage> image(create_image());
        test_legacy_bitmap(reporter, image.get(), mode);

        image = create_data_image();
        test_legacy_bitmap(reporter, image.get(), mode);

        RasterDataHolder dataHolder;
        image = create_rasterproc_image(&dataHolder);
        test_legacy_bitmap(reporter, image.get(), mode);
        image.reset();
        REPORTER_ASSERT(reporter, 1 == dataHolder.fReleaseCount);

        image = create_codec_image();
        test_legacy_bitmap(reporter, image.get(), mode);
    }
}
#if SK_SUPPORT_GPU
DEF_GPUTEST_FOR_RENDERING_CONTEXTS(ImageLegacyBitmap_Gpu, reporter, ctxInfo) {
    const SkImage::LegacyBitmapMode modes[] = {
        SkImage::kRO_LegacyBitmapMode,
        SkImage::kRW_LegacyBitmapMode,
    };
    for (auto& mode : modes) {
        sk_sp<SkImage> image(create_gpu_image(ctxInfo.grContext()));
        test_legacy_bitmap(reporter, image.get(), mode);
    }
}
#endif

static void test_peek(skiatest::Reporter* reporter, SkImage* image, bool expectPeekSuccess) {
    if (!image) {
        ERRORF(reporter, "Failed to create image!");
        return;
    }
    SkPixmap pm;
    bool success = image->peekPixels(&pm);
    REPORTER_ASSERT(reporter, expectPeekSuccess == success);
    if (success) {
        const SkImageInfo& info = pm.info();
        REPORTER_ASSERT(reporter, 20 == info.width());
        REPORTER_ASSERT(reporter, 20 == info.height());
        REPORTER_ASSERT(reporter, kN32_SkColorType == info.colorType());
        REPORTER_ASSERT(reporter, kPremul_SkAlphaType == info.alphaType() ||
                        kOpaque_SkAlphaType == info.alphaType());
        REPORTER_ASSERT(reporter, info.minRowBytes() <= pm.rowBytes());
        REPORTER_ASSERT(reporter, SkPreMultiplyColor(SK_ColorWHITE) == *pm.addr32(0, 0));
    }
}
DEF_TEST(ImagePeek, reporter) {
    sk_sp<SkImage> image(create_image());
    test_peek(reporter, image.get(), true);

    image = create_data_image();
    test_peek(reporter, image.get(), true);

    RasterDataHolder dataHolder;
    image = create_rasterproc_image(&dataHolder);
    test_peek(reporter, image.get(), true);
    image.reset();
    REPORTER_ASSERT(reporter, 1 == dataHolder.fReleaseCount);

    image = create_codec_image();
    test_peek(reporter, image.get(), false);
}
#if SK_SUPPORT_GPU
DEF_GPUTEST_FOR_RENDERING_CONTEXTS(ImagePeek_Gpu, reporter, ctxInfo) {
    sk_sp<SkImage> image(create_gpu_image(ctxInfo.grContext()));
    test_peek(reporter, image.get(), false);
}
#endif

#if SK_SUPPORT_GPU
struct TextureReleaseChecker {
    TextureReleaseChecker() : fReleaseCount(0) {}
    int fReleaseCount;
    static void Release(void* self) {
        static_cast<TextureReleaseChecker*>(self)->fReleaseCount++;
    }
};
DEF_GPUTEST_FOR_GL_RENDERING_CONTEXTS(SkImage_NewFromTextureRelease, reporter, ctxInfo) {
    const int kWidth = 10;
    const int kHeight = 10;
    std::unique_ptr<uint32_t[]> pixels(new uint32_t[kWidth * kHeight]);
    GrBackendTextureDesc backendDesc;
    backendDesc.fConfig = kRGBA_8888_GrPixelConfig;
    backendDesc.fFlags = kRenderTarget_GrBackendTextureFlag;
    backendDesc.fWidth = kWidth;
    backendDesc.fHeight = kHeight;
    backendDesc.fSampleCnt = 0;
    backendDesc.fTextureHandle = ctxInfo.grContext()->getGpu()->createTestingOnlyBackendTexture(
        pixels.get(), kWidth, kHeight, kRGBA_8888_GrPixelConfig, true);

    TextureReleaseChecker releaseChecker;
    sk_sp<SkImage> refImg(
        SkImage::MakeFromTexture(ctxInfo.grContext(), backendDesc, kPremul_SkAlphaType,
                                 TextureReleaseChecker::Release, &releaseChecker));

    // Now exercise the release proc
    REPORTER_ASSERT(reporter, 0 == releaseChecker.fReleaseCount);
    refImg.reset(nullptr); // force a release of the image
    REPORTER_ASSERT(reporter, 1 == releaseChecker.fReleaseCount);

    ctxInfo.grContext()->getGpu()->deleteTestingOnlyBackendTexture(backendDesc.fTextureHandle);
}

static void check_images_same(skiatest::Reporter* reporter, const SkImage* a, const SkImage* b) {
    if (a->width() != b->width() || a->height() != b->height()) {
        ERRORF(reporter, "Images must have the same size");
        return;
    }
    if (a->alphaType() != b->alphaType()) {
        ERRORF(reporter, "Images must have the same alpha type");
        return;
    }

    SkImageInfo info = SkImageInfo::MakeN32Premul(a->width(), a->height());
    SkAutoPixmapStorage apm;
    SkAutoPixmapStorage bpm;

    apm.alloc(info);
    bpm.alloc(info);

    if (!a->readPixels(apm, 0, 0)) {
        ERRORF(reporter, "Could not read image a's pixels");
        return;
    }
    if (!b->readPixels(bpm, 0, 0)) {
        ERRORF(reporter, "Could not read image b's pixels");
        return;
    }

    for (auto y = 0; y < info.height(); ++y) {
        for (auto x = 0; x < info.width(); ++x) {
            uint32_t pixelA = *apm.addr32(x, y);
            uint32_t pixelB = *bpm.addr32(x, y);
            if (pixelA != pixelB) {
                ERRORF(reporter, "Expected image pixels to be the same. At %d,%d 0x%08x != 0x%08x",
                       x, y, pixelA, pixelB);
                return;
            }
        }
    }
}

DEF_GPUTEST_FOR_RENDERING_CONTEXTS(NewTextureFromPixmap, reporter, ctxInfo) {
    for (auto create : {&create_image,
                        &create_image_565,
                        &create_image_ct}) {
        sk_sp<SkImage> image((*create)());
        if (!image) {
            ERRORF(reporter, "Could not create image");
            return;
        }

        SkPixmap pixmap;
        if (!image->peekPixels(&pixmap)) {
            ERRORF(reporter, "peek failed");
        } else {
            sk_sp<SkImage> texImage(SkImage::MakeTextureFromPixmap(ctxInfo.grContext(), pixmap,
                                                                   SkBudgeted::kNo));
            if (!texImage) {
                ERRORF(reporter, "NewTextureFromPixmap failed.");
            } else {
                check_images_same(reporter, image.get(), texImage.get());
            }
        }
    }
}

DEF_GPUTEST_FOR_RENDERING_CONTEXTS(DeferredTextureImage, reporter, ctxInfo) {
    GrContext* context = ctxInfo.grContext();
    sk_gpu_test::TestContext* testContext = ctxInfo.testContext();
    sk_sp<GrContextThreadSafeProxy> proxy = context->threadSafeProxy();

    GrContextFactory otherFactory;
    ContextInfo otherContextInfo =
        otherFactory.getContextInfo(GrContextFactory::kNativeGL_ContextType);

    testContext->makeCurrent();
    REPORTER_ASSERT(reporter, proxy);
    auto createLarge = [context] {
        return create_image_large(context->caps()->maxTextureSize());
    };
    struct {
        std::function<sk_sp<SkImage> ()>                      fImageFactory;
        std::vector<SkImage::DeferredTextureImageUsageParams> fParams;
        SkFilterQuality                                       fExpectedQuality;
        int                                                   fExpectedScaleFactor;
        bool                                                  fExpectation;
    } testCases[] = {
        { create_image,          {{SkMatrix::I(), kNone_SkFilterQuality, 0}},
          kNone_SkFilterQuality, 1, true },
        { create_codec_image,    {{SkMatrix::I(), kNone_SkFilterQuality, 0}},
          kNone_SkFilterQuality, 1, true },
        { create_data_image,     {{SkMatrix::I(), kNone_SkFilterQuality, 0}},
          kNone_SkFilterQuality, 1, true },
        { create_picture_image,  {{SkMatrix::I(), kNone_SkFilterQuality, 0}},
          kNone_SkFilterQuality, 1, false },
        { [context] { return create_gpu_image(context); },
          {{SkMatrix::I(), kNone_SkFilterQuality, 0}},
          kNone_SkFilterQuality, 1, false },
        // Create a texture image in a another GrContext.
        { [testContext, otherContextInfo] {
            otherContextInfo.testContext()->makeCurrent();
            sk_sp<SkImage> otherContextImage = create_gpu_image(otherContextInfo.grContext());
            testContext->makeCurrent();
            return otherContextImage;
          }, {{SkMatrix::I(), kNone_SkFilterQuality, 0}},
        kNone_SkFilterQuality, 1, false },
        // Create an image that is too large to upload.
        { createLarge, {{SkMatrix::I(), kNone_SkFilterQuality, 0}},
          kNone_SkFilterQuality, 1, false },
        // Create an image that is too large, but is scaled to an acceptable size.
        { createLarge, {{SkMatrix::I(), kMedium_SkFilterQuality, 4}},
          kMedium_SkFilterQuality, 16, true},
        // Create an image with multiple low filter qualities, make sure we round up.
        { createLarge, {{SkMatrix::I(), kNone_SkFilterQuality, 4},
                        {SkMatrix::I(), kMedium_SkFilterQuality, 4}},
          kMedium_SkFilterQuality, 16, true},
        // Create an image with multiple prescale levels, make sure we chose the minimum scale.
        { createLarge, {{SkMatrix::I(), kMedium_SkFilterQuality, 5},
                        {SkMatrix::I(), kMedium_SkFilterQuality, 4}},
          kMedium_SkFilterQuality, 16, true},
    };


    for (auto testCase : testCases) {
        sk_sp<SkImage> image(testCase.fImageFactory());
        if (!image) {
            ERRORF(reporter, "Failed to create image!");
            continue;
        }

        size_t size = image->getDeferredTextureImageData(*proxy, testCase.fParams.data(),
                                                         static_cast<int>(testCase.fParams.size()),
                                                         nullptr, nullptr);
        static const char *const kFS[] = { "fail", "succeed" };
        if (SkToBool(size) != testCase.fExpectation) {
            ERRORF(reporter,  "This image was expected to %s but did not.",
                   kFS[testCase.fExpectation]);
        }
        if (size) {
            void* buffer = sk_malloc_throw(size);
            void* misaligned = reinterpret_cast<void*>(reinterpret_cast<intptr_t>(buffer) + 3);
            if (image->getDeferredTextureImageData(*proxy, testCase.fParams.data(),
                                                   static_cast<int>(testCase.fParams.size()),
                                                   misaligned, nullptr)) {
                ERRORF(reporter, "Should fail when buffer is misaligned.");
            }
            if (!image->getDeferredTextureImageData(*proxy, testCase.fParams.data(),
                                                    static_cast<int>(testCase.fParams.size()),
                                                    buffer, nullptr)) {
                ERRORF(reporter, "deferred image size succeeded but creation failed.");
            } else {
                for (auto budgeted : { SkBudgeted::kNo, SkBudgeted::kYes }) {
                    sk_sp<SkImage> newImage(
                        SkImage::MakeFromDeferredTextureImageData(context, buffer, budgeted));
                    REPORTER_ASSERT(reporter, newImage != nullptr);
                    if (newImage) {
                        // Scale the image in software for comparison.
                        SkImageInfo scaled_info = SkImageInfo::MakeN32(
                                                    image->width() / testCase.fExpectedScaleFactor,
                                                    image->height() / testCase.fExpectedScaleFactor,
                                                    image->alphaType());
                        SkAutoPixmapStorage scaled;
                        scaled.alloc(scaled_info);
                        image->scalePixels(scaled, testCase.fExpectedQuality);
                        sk_sp<SkImage> scaledImage = SkImage::MakeRasterCopy(scaled);
                        check_images_same(reporter, scaledImage.get(), newImage.get());
                    }
                    // The other context should not be able to create images from texture data
                    // created by the original context.
                    sk_sp<SkImage> newImage2(SkImage::MakeFromDeferredTextureImageData(
                        otherContextInfo.grContext(), buffer, budgeted));
                    REPORTER_ASSERT(reporter, !newImage2);
                    testContext->makeCurrent();
                }
            }
            sk_free(buffer);
        }
    }
}
#endif

///////////////////////////////////////////////////////////////////////////////////////////////////

static void make_all_premul(SkBitmap* bm) {
    bm->allocPixels(SkImageInfo::MakeN32(256, 256, kPremul_SkAlphaType));
    for (int a = 0; a < 256; ++a) {
        for (int r = 0; r < 256; ++r) {
            // make all valid premul combinations
            int c = SkTMin(a, r);
            *bm->getAddr32(a, r) = SkPackARGB32(a, c, c, c);
        }
    }
}

static bool equal(const SkBitmap& a, const SkBitmap& b) {
    SkASSERT(a.width() == b.width());
    SkASSERT(a.height() == b.height());
    for (int y = 0; y < a.height(); ++y) {
        for (int x = 0; x < a.width(); ++x) {
            SkPMColor pa = *a.getAddr32(x, y);
            SkPMColor pb = *b.getAddr32(x, y);
            if (pa != pb) {
                return false;
            }
        }
    }
    return true;
}

DEF_TEST(image_roundtrip_encode, reporter) {
    SkBitmap bm0;
    make_all_premul(&bm0);

    auto img0 = SkImage::MakeFromBitmap(bm0);
    sk_sp<SkData> data(img0->encode(SkEncodedImageFormat::kPNG, 100));
    auto img1 = SkImage::MakeFromEncoded(data);

    SkBitmap bm1;
    bm1.allocPixels(SkImageInfo::MakeN32(256, 256, kPremul_SkAlphaType));
    img1->readPixels(bm1.info(), bm1.getPixels(), bm1.rowBytes(), 0, 0);

    REPORTER_ASSERT(reporter, equal(bm0, bm1));
}

DEF_TEST(image_roundtrip_premul, reporter) {
    SkBitmap bm0;
    make_all_premul(&bm0);

    SkBitmap bm1;
    bm1.allocPixels(SkImageInfo::MakeN32(256, 256, kUnpremul_SkAlphaType));
    bm0.readPixels(bm1.info(), bm1.getPixels(), bm1.rowBytes(), 0, 0);

    SkBitmap bm2;
    bm2.allocPixels(SkImageInfo::MakeN32(256, 256, kPremul_SkAlphaType));
    bm1.readPixels(bm2.info(), bm2.getPixels(), bm2.rowBytes(), 0, 0);

    REPORTER_ASSERT(reporter, equal(bm0, bm2));
}