C++ SkBitmap::info方法代码示例

unsigned MaxComponentDifference(const SkBitmap& a, const SkBitmap& b) {
    if (a.info() != b.info()) {
        SkFAIL("Can't compare bitmaps of different shapes.");
    }

    unsigned max = 0;

    const SkAutoLockPixels lockA(a), lockB(b);
    if (a.info().colorType() == kRGB_565_SkColorType) {
        // 565 is special/annoying because its 3 components straddle 2 bytes.
        const uint16_t* aPixels = (const uint16_t*)a.getPixels();
        const uint16_t* bPixels = (const uint16_t*)b.getPixels();
        for (size_t i = 0; i < a.getSize() / 2; i++) {
            unsigned ar, ag, ab,
                     br, bg, bb;
            unpack_565(aPixels[i], &ar, &ag, &ab);
            unpack_565(bPixels[i], &br, &bg, &bb);
            max = SkTMax(max, abs_diff(ar, br));
            max = SkTMax(max, abs_diff(ag, bg));
            max = SkTMax(max, abs_diff(ab, bb));
        }
    } else {
        // Everything else we produce is byte aligned, so max component diff == max byte diff.
        const uint8_t* aBytes = (const uint8_t*)a.getPixels();
        const uint8_t* bBytes = (const uint8_t*)b.getPixels();
        for (size_t i = 0; i < a.getSize(); i++) {
            max = SkTMax(max, abs_diff(aBytes[i], bBytes[i]));
        }
    }

    return max;
}

SkBitmapDevice::SkBitmapDevice(const SkBitmap& bitmap)
    : INHERITED(bitmap.info(), SkSurfaceProps(SkSurfaceProps::kLegacyFontHost_InitType))
    , fBitmap(bitmap)
{
    SkASSERT(valid_for_bitmap_device(bitmap.info(), nullptr));
    fBitmap.lockPixels();
}

sk_sp<SkSpecialSurface> SkSpecialSurface::MakeFromBitmap(const SkIRect& subset, SkBitmap& bm,
                                                         const SkSurfaceProps* props) {
    if (subset.isEmpty() || !SkSurfaceValidateRasterInfo(bm.info(), bm.rowBytes())) {
        return nullptr;
    }
    return sk_make_sp<SkSpecialSurface_Raster>(bm.info(), sk_ref_sp(bm.pixelRef()), subset, props);
}

bool BitmapsEqual(const SkBitmap& a, const SkBitmap& b) {
    if (a.info() != b.info()) {
        return false;
    }
    const SkAutoLockPixels lockA(a), lockB(b);
    return 0 == memcmp(a.getPixels(), b.getPixels(), a.getSize());
}

// Check to see that the size of the bitmap that would be produced by
// scaling by the given inverted matrix is less than the maximum allowed.
static inline bool cache_size_okay(const SkBitmap& bm, const SkMatrix& invMat) {
    size_t maximumAllocation = SkResourceCache::GetSingleAllocationByteLimit();
    if (0 == maximumAllocation) {
        return true;
    }
    // float matrixScaleFactor = 1.0 / (invMat.scaleX * invMat.scaleY);
    // return ((origBitmapSize * matrixScaleFactor) < maximumAllocationSize);
    // Skip the division step:
    return bm.info().getSafeSize(bm.info().minRowBytes())
        < (maximumAllocation * invMat.getScaleX() * invMat.getScaleY());
}

void copy_to_g8(SkBitmap* dst, const SkBitmap& src) {
    SkASSERT(kBGRA_8888_SkColorType == src.colorType() ||
             kRGBA_8888_SkColorType == src.colorType());

    SkImageInfo grayInfo = src.info().makeColorType(kGray_8_SkColorType);
    dst->allocPixels(grayInfo);
    uint8_t* dst8 = (uint8_t*)dst->getPixels();
    const uint32_t* src32 = (const uint32_t*)src.getPixels();

    const int w = src.width();
    const int h = src.height();
    const bool isBGRA = (kBGRA_8888_SkColorType == src.colorType());
    for (int y = 0; y < h; ++y) {
        if (isBGRA) {
            // BGRA
            for (int x = 0; x < w; ++x) {
                uint32_t s = src32[x];
                dst8[x] = SkComputeLuminance((s >> 16) & 0xFF, (s >> 8) & 0xFF, s & 0xFF);
            }
        } else {
            // RGBA
            for (int x = 0; x < w; ++x) {
                uint32_t s = src32[x];
                dst8[x] = SkComputeLuminance(s & 0xFF, (s >> 8) & 0xFF, (s >> 16) & 0xFF);
            }
        }
        src32 = (const uint32_t*)((const char*)src32 + src.rowBytes());
        dst8 += dst->rowBytes();
    }

bool SkCreateBitmapFromCGImage(SkBitmap* dst, CGImageRef image, SkISize* scaleToFit) {
    const int width = scaleToFit ? scaleToFit->width() : SkToInt(CGImageGetWidth(image));
    const int height = scaleToFit ? scaleToFit->height() : SkToInt(CGImageGetHeight(image));
    SkImageInfo info = SkImageInfo::MakeN32Premul(width, height);

    SkBitmap tmp;
    if (!tmp.allocPixels(info)) {
        return false;
    }

    if (!SkCopyPixelsFromCGImage(tmp.info(), tmp.rowBytes(), tmp.getPixels(), image)) {
        return false;
    }

    CGImageAlphaInfo cgInfo = CGImageGetAlphaInfo(image);
    switch (cgInfo) {
        case kCGImageAlphaNone:
        case kCGImageAlphaNoneSkipLast:
        case kCGImageAlphaNoneSkipFirst:
            SkASSERT(SkBitmap::ComputeIsOpaque(tmp));
            tmp.setAlphaType(kOpaque_SkAlphaType);
            break;
        default:
            // we don't know if we're opaque or not, so compute it.
            if (SkBitmap::ComputeIsOpaque(tmp)) {
                tmp.setAlphaType(kOpaque_SkAlphaType);
            }
    }

    *dst = tmp;
    return true;
}

sk_sp<SkImage> SkImage::MakeFromBitmap(const SkBitmap& bm) {
    SkPixelRef* pr = bm.pixelRef();
    if (nullptr == pr) {
        return nullptr;
    }

#if SK_SUPPORT_GPU
    if (GrTexture* tex = pr->getTexture()) {
        SkAutoTUnref<GrTexture> unrefCopy;
        if (!bm.isImmutable()) {
            tex = GrDeepCopyTexture(tex, SkBudgeted::kNo);
            if (nullptr == tex) {
                return nullptr;
            }
            unrefCopy.reset(tex);
        }
        const SkImageInfo info = bm.info();
        return sk_make_sp<SkImage_Gpu>(info.width(), info.height(), bm.getGenerationID(),
                                       info.alphaType(), tex, sk_ref_sp(info.colorSpace()),
                                       SkBudgeted::kNo);
    }
#endif

    // This will check for immutable (share or copy)
    return SkMakeImageFromRasterBitmap(bm);
}

void SkSurface_Raster::onCopyOnWrite(ContentChangeMode mode) {
    // are we sharing pixelrefs with the image?
    sk_sp<SkImage> cached(this->refCachedImage(SkBudgeted::kNo, kNo_ForceUnique));
    SkASSERT(cached);
    if (SkBitmapImageGetPixelRef(cached.get()) == fBitmap.pixelRef()) {
        SkASSERT(fWeOwnThePixels);
        if (kDiscard_ContentChangeMode == mode) {
            fBitmap.allocPixels();
        } else {
            SkBitmap prev(fBitmap);
            fBitmap.allocPixels();
            prev.lockPixels();
            SkASSERT(prev.info() == fBitmap.info());
            SkASSERT(prev.rowBytes() == fBitmap.rowBytes());
            memcpy(fBitmap.getPixels(), prev.getPixels(), fBitmap.getSafeSize());
        }
        SkASSERT(fBitmap.rowBytes() == fRowBytes);  // be sure we always use the same value

        // Now fBitmap is a deep copy of itself (and therefore different from
        // what is being used by the image. Next we update the canvas to use
        // this as its backend, so we can't modify the image's pixels anymore.
        SkASSERT(this->getCachedCanvas());
        this->getCachedCanvas()->getDevice()->replaceBitmapBackendForRasterSurface(fBitmap);
    }
}

DEF_GPUTEST_FOR_RENDERING_CONTEXTS(SpecialImage_Gpu, reporter, ctxInfo) {
    GrContext* context = ctxInfo.grContext();
    SkBitmap bm = create_bm();

    const GrSurfaceDesc desc = GrImageInfoToSurfaceDesc(bm.info(), *context->caps());

    sk_sp<GrTextureProxy> proxy(GrSurfaceProxy::MakeDeferred(context->resourceProvider(),
                                                             desc, SkBudgeted::kNo,
                                                             bm.getPixels(), bm.rowBytes()));
    if (!proxy) {
        return;
    }

    sk_sp<SkSpecialImage> fullSImg(SkSpecialImage::MakeDeferredFromGpu(
                                                            context,
                                                            SkIRect::MakeWH(kFullSize, kFullSize),
                                                            kNeedNewImageUniqueID_SpecialImage,
                                                            proxy, nullptr));

    const SkIRect& subset = SkIRect::MakeXYWH(kPad, kPad, kSmallerSize, kSmallerSize);

    {
        sk_sp<SkSpecialImage> subSImg1(SkSpecialImage::MakeDeferredFromGpu(
                                                               context, subset,
                                                               kNeedNewImageUniqueID_SpecialImage,
                                                               std::move(proxy), nullptr));
        test_image(subSImg1, reporter, context, true, kPad, kFullSize);
    }

    {
        sk_sp<SkSpecialImage> subSImg2(fullSImg->makeSubset(subset));
        test_image(subSImg2, reporter, context, true, kPad, kFullSize);
    }
}

sk_sp<GrTextureProxy> GrUploadBitmapToTextureProxy(GrProxyProvider* proxyProvider,
                                                   const SkBitmap& bitmap,
                                                   SkColorSpace* dstColorSpace) {
    if (!bitmap.peekPixels(nullptr)) {
        return nullptr;
    }

    SkDestinationSurfaceColorMode colorMode = dstColorSpace
        ? SkDestinationSurfaceColorMode::kGammaAndColorSpaceAware
        : SkDestinationSurfaceColorMode::kLegacy;

    if (!SkImageInfoIsValid(bitmap.info(), colorMode)) {
        return nullptr;
    }

    // In non-ddl we will always instantiate right away. Thus we never want to copy the SkBitmap
    // even if it's mutable. In ddl, if the bitmap is mutable then we must make a copy since the
    // upload of the data to the gpu can happen at anytime and the bitmap may change by then.
    SkCopyPixelsMode cpyMode = proxyProvider->mutableBitmapsNeedCopy() ? kIfMutable_SkCopyPixelsMode
                                                                       : kNever_SkCopyPixelsMode;
    sk_sp<SkImage> image = SkMakeImageFromRasterBitmap(bitmap, cpyMode);

    return proxyProvider->createTextureProxy(std::move(image), kNone_GrSurfaceFlags,
                                             kTopLeft_GrSurfaceOrigin, 1, SkBudgeted::kYes,
                                             SkBackingFit::kExact);
}

    virtual Result onGetPixels(const SkImageInfo& info, void* pixels, size_t rowBytes,
                               const Options&,
                               SkPMColor ctableEntries[], int* ctableCount) override {
        SkMemoryStream stream(fData->data(), fData->size(), false);
        SkAutoTUnref<BareMemoryAllocator> allocator(SkNEW_ARGS(BareMemoryAllocator,
                                                               (info, pixels, rowBytes)));
        fDecoder->setAllocator(allocator);
        fDecoder->setRequireUnpremultipliedColors(kUnpremul_SkAlphaType == info.alphaType());

        SkBitmap bm;
        const SkImageDecoder::Result result = fDecoder->decode(&stream, &bm, info.colorType(),
                                                               SkImageDecoder::kDecodePixels_Mode);
        if (SkImageDecoder::kFailure == result) {
            return kInvalidInput;
        }

        SkASSERT(info.colorType() == bm.info().colorType());

        if (kIndex_8_SkColorType == info.colorType()) {
            SkASSERT(ctableEntries);

            SkColorTable* ctable = bm.getColorTable();
            if (NULL == ctable) {
                return kInvalidConversion;
            }
            const int count = ctable->count();
            memcpy(ctableEntries, ctable->readColors(), count * sizeof(SkPMColor));
            *ctableCount = count;
        }
        if (SkImageDecoder::kPartialSuccess == result) {
            return kIncompleteInput;
        }
        return kSuccess;
    }

SkBitmapDevice* SkBitmapDevice::Create(const SkImageInfo& origInfo,
                                       const SkSurfaceProps& surfaceProps) {
    SkAlphaType newAT = origInfo.alphaType();
    if (!valid_for_bitmap_device(origInfo, &newAT)) {
        return NULL;
    }

    const SkImageInfo info = origInfo.makeAlphaType(newAT);
    SkBitmap bitmap;

    if (kUnknown_SkColorType == info.colorType()) {
        if (!bitmap.setInfo(info)) {
            return NULL;
        }
    } else {
        if (!bitmap.tryAllocPixels(info)) {
            return NULL;
        }
        if (!bitmap.info().isOpaque()) {
            bitmap.eraseColor(SK_ColorTRANSPARENT);
        }
    }

    return SkNEW_ARGS(SkBitmapDevice, (bitmap, surfaceProps));
}

SkBitmapDevice* SkBitmapDevice::Create(const SkImageInfo& origInfo,
                                       const SkDeviceProperties* props) {
    SkImageInfo info = origInfo;
    if (!valid_for_bitmap_device(info, &info.fAlphaType)) {
        return NULL;
    }

    SkBitmap bitmap;

    if (kUnknown_SkColorType == info.colorType()) {
        if (!bitmap.setInfo(info)) {
            return NULL;
        }
    } else {
        if (!bitmap.allocPixels(info)) {
            return NULL;
        }
        if (!bitmap.info().isOpaque()) {
            bitmap.eraseColor(SK_ColorTRANSPARENT);
        }
    }

    if (props) {
        return SkNEW_ARGS(SkBitmapDevice, (bitmap, *props));
    } else {
        return SkNEW_ARGS(SkBitmapDevice, (bitmap));
    }
}

static void generate_bitmap_texture_desc(const SkBitmap& bitmap, GrSurfaceDesc* desc) {
    desc->fFlags = kNone_GrSurfaceFlags;
    desc->fWidth = bitmap.width();
    desc->fHeight = bitmap.height();
    desc->fConfig = SkImageInfo2GrPixelConfig(bitmap.info());
    desc->fSampleCnt = 0;
}