C++ SkImageInfo::colorType方法代码示例

static void check_fill(skiatest::Reporter* r,
                       const SkImageInfo& imageInfo,
                       uint32_t startRow,
                       uint32_t endRow,
                       size_t rowBytes,
                       uint32_t offset,
                       uint32_t colorOrIndex,
                       SkPMColor* colorTable) {

    // Calculate the total size of the image in bytes.  Use the smallest possible size.
    // The offset value tells us to adjust the pointer from the memory we allocate in order
    // to test on different memory alignments.  If offset is nonzero, we need to increase the
    // size of the memory we allocate in order to make sure that we have enough.  We are
    // still allocating the smallest possible size.
    const size_t totalBytes = imageInfo.getSafeSize(rowBytes) + offset;

    // Create fake image data where every byte has a value of 0
    SkAutoTDeleteArray<uint8_t> storage(SkNEW_ARRAY(uint8_t, totalBytes));
    memset(storage.get(), 0, totalBytes);
    // Adjust the pointer in order to test on different memory alignments
    uint8_t* imageData = storage.get() + offset;
    uint8_t* imageStart = imageData + rowBytes * startRow;

    // Fill image with the fill value starting at the indicated row
    SkSwizzler::Fill(imageStart, imageInfo, rowBytes, endRow - startRow + 1, colorOrIndex,
            colorTable);

    // Ensure that the pixels are filled properly
    // The bots should catch any memory corruption
    uint8_t* indexPtr = imageData + startRow * rowBytes;
    uint32_t* colorPtr = (uint32_t*) indexPtr;
    for (uint32_t y = startRow; y <= endRow; y++) {
        for (int32_t x = 0; x < imageInfo.width(); x++) {
            if (kIndex_8_SkColorType == imageInfo.colorType()) {
                REPORTER_ASSERT(r, kFillIndex == indexPtr[x]);
            } else {
                REPORTER_ASSERT(r, kFillColor == colorPtr[x]);
            }
        }
        indexPtr += rowBytes;
        colorPtr = (uint32_t*) indexPtr;
    }
}

static void apply_premul(const SkImageInfo& info, void* pixels, size_t rowBytes) {
    switch (info.colorType()) {
        case kRGBA_8888_SkColorType:
        case kBGRA_8888_SkColorType:
            break;
        default:
            return; // nothing to do
    }

    // SkColor is not necesarily RGBA or BGRA, but it is one of them on little-endian,
    // and in either case, the alpha-byte is always in the same place, so we can safely call
    // SkPreMultiplyColor()
    //
    SkColor* row = (SkColor*)pixels;
    for (int y = 0; y < info.height(); ++y) {
        for (int x = 0; x < info.width(); ++x) {
            row[x] = SkPreMultiplyColor(row[x]);
        }
    }
}

bool SkImageGeneratorCG::onGetPixels(const SkImageInfo& info, void* pixels, size_t rowBytes,
        SkPMColor ctable[], int* ctableCount) {
    if (kN32_SkColorType != info.colorType()) {
        // FIXME: Support other colorTypes.
        return false;
    }
    
    switch (info.alphaType()) {
        case kOpaque_SkAlphaType:
            if (kOpaque_SkAlphaType != this->getInfo().alphaType()) {
                return false;
            }
            break;
        case kPremul_SkAlphaType:
            break;
        default:
            return false;
    }
    
    CGImageRef image = CGImageSourceCreateImageAtIndex((CGImageSourceRef) fImageSrc.get(), 0,
            nullptr);
    if (!image) {
        return false;
    }
    SkAutoTCallVProc<CGImage, CGImageRelease> autoImage(image);

    // FIXME: Using this function (as opposed to swizzling ourselves) greatly
    //        restricts the color and alpha types that we support.  If we
    //        swizzle ourselves, we can add support for:
    //            kUnpremul_SkAlphaType
    //            16-bit per component RGBA
    //            kGray_8_SkColorType
    //            kIndex_8_SkColorType
    //        Additionally, it would be interesting to compare the performance
    //        of SkSwizzler with CG's built in swizzler.
    if (!SkCopyPixelsFromCGImage(info, rowBytes, pixels, image)) {
        return false;
    }

    return true;
}

SkMallocPixelRef::SkMallocPixelRef(const SkImageInfo& info, void* storage,
                                   size_t rowBytes, SkColorTable* ctable,
                                   bool ownsPixels)
    : INHERITED(info)
    , fReleaseProc(ownsPixels ? sk_free_releaseproc : NULL)
    , fReleaseProcContext(NULL) {
    // This constructor is now DEPRICATED.
    SkASSERT(is_valid(info, ctable));
    SkASSERT(rowBytes >= info.minRowBytes());

    if (kIndex_8_SkColorType != info.colorType()) {
        ctable = NULL;
    }

    fStorage = storage;
    fCTable = ctable;
    fRB = rowBytes;
    SkSafeRef(ctable);

    this->setPreLocked(fStorage, rowBytes, fCTable);
}

static bool is_valid(const SkImageInfo& info, SkColorTable* ctable) {
    if (info.width() < 0 || info.height() < 0 ||
        (unsigned)info.colorType() > (unsigned)kLastEnum_SkColorType ||
        (unsigned)info.alphaType() > (unsigned)kLastEnum_SkAlphaType)
    {
        return false;
    }

    // these seem like good checks, but currently we have (at least) tests
    // that expect the pixelref to succeed even when there is a mismatch
    // with colortables. fix?
#if 0
    if (kIndex8_SkColorType == info.fColorType && nullptr == ctable) {
        return false;
    }
    if (kIndex8_SkColorType != info.fColorType && ctable) {
        return false;
    }
#endif
    return true;
}

bool DecodingImageGenerator::onGetPixels(const SkImageInfo& info, void* pixels, size_t rowBytes,
    SkPMColor ctable[], int* ctableCount)
{
    TRACE_EVENT1("blink", "DecodingImageGenerator::getPixels", "index", static_cast<int>(m_frameIndex));

    // Implementation doesn't support scaling yet so make sure we're not given a different size.
    if (info.width() != getInfo().width() || info.height() != getInfo().height())
        return false;

    if (info.colorType() != getInfo().colorType()) {
        // ImageFrame may have changed the owning SkBitmap to kOpaque_SkAlphaType after sniffing the encoded data, so if we see a request
        // for opaque, that is ok even if our initial alphatype was not opaque.
        return false;
    }

    PlatformInstrumentation::willDecodeLazyPixelRef(m_generationId);
    bool decoded = m_frameGenerator->decodeAndScale(getInfo(), m_frameIndex, pixels, rowBytes);
    PlatformInstrumentation::didDecodeLazyPixelRef();

    return decoded;
}

void SkJpegCodec::allocateStorage(const SkImageInfo& dstInfo) {
    size_t swizzleBytes = 0;
    if (fSwizzler) {
        swizzleBytes = get_row_bytes(fDecoderMgr->dinfo());
        SkASSERT(!fColorXform || SkIsAlign4(swizzleBytes));
    }

    size_t xformBytes = 0;
    if (kRGBA_F16_SkColorType == dstInfo.colorType()) {
        SkASSERT(fColorXform);
        xformBytes = dstInfo.width() * sizeof(uint32_t);
    }

    size_t totalBytes = swizzleBytes + xformBytes;
    if (totalBytes > 0) {
        fStorage.reset(totalBytes);
        fSwizzleSrcRow = (swizzleBytes > 0) ? fStorage.get() : nullptr;
        fColorXformSrcRow = (xformBytes > 0) ?
                SkTAddOffset<uint32_t>(fStorage.get(), swizzleBytes) : nullptr;
    }
}

bool SkInstallDiscardablePixelRef(SkImageGenerator* generator, SkBitmap* dst,
                                  SkDiscardableMemory::Factory* factory) {
    SkImageInfo info;
    SkAutoTDelete<SkImageGenerator> autoGenerator(generator);
    if ((NULL == autoGenerator.get())
        || (!autoGenerator->getInfo(&info))
        || (!dst->setInfo(info))) {
        return false;
    }
    // Since dst->setInfo() may have changed/fixed-up info, we copy it back from that bitmap
    info = dst->info();

    SkASSERT(info.colorType() != kUnknown_SkColorType);
    if (dst->empty()) {  // Use a normal pixelref.
        return dst->tryAllocPixels();
    }
    SkAutoTUnref<SkDiscardablePixelRef> ref(
        SkNEW_ARGS(SkDiscardablePixelRef,
                   (info, autoGenerator.detach(), dst->rowBytes(), factory)));
    dst->setPixelRef(ref);
    return true;
}

static void clamp_if_necessary(const SkImageInfo& info, void* pixels) {
    if (kRGBA_F16_SkColorType != info.colorType()) {
        return;
    }

    for (int y = 0; y < info.height(); y++) {
        for (int x = 0; x < info.width(); x++) {
            uint64_t pixel = ((uint64_t*) pixels)[y * info.width() + x];

            Sk4f rgba = SkHalfToFloat_finite_ftz(pixel);
            if (kUnpremul_SkAlphaType == info.alphaType()) {
                rgba = Sk4f::Max(0.0f, Sk4f::Min(rgba, 1.0f));
            } else {
                SkASSERT(kPremul_SkAlphaType == info.alphaType());
                rgba = Sk4f::Max(0.0f, Sk4f::Min(rgba, rgba[3]));
            }
            SkFloatToHalf_finite_ftz(rgba).store(&pixel);

            ((uint64_t*) pixels)[y * info.width() + x] = pixel;
        }
    }
}

void SkCodec::fillIncompleteImage(const SkImageInfo& info, void* dst, size_t rowBytes,
        ZeroInitialized zeroInit, int linesRequested, int linesDecoded) {

    void* fillDst;
    const uint32_t fillValue = this->getFillValue(info.colorType());
    const int linesRemaining = linesRequested - linesDecoded;
    SkSampler* sampler = this->getSampler(false);

    int fillWidth = info.width();
    if (fOptions.fSubset) {
        fillWidth = fOptions.fSubset->width();
    }

    switch (this->getScanlineOrder()) {
        case kTopDown_SkScanlineOrder:
        case kNone_SkScanlineOrder: {
            const SkImageInfo fillInfo = info.makeWH(fillWidth, linesRemaining);
            fillDst = SkTAddOffset<void>(dst, linesDecoded * rowBytes);
            fill_proc(fillInfo, fillDst, rowBytes, fillValue, zeroInit, sampler);
            break;
        }
        case kBottomUp_SkScanlineOrder: {
            fillDst = dst;
            const SkImageInfo fillInfo = info.makeWH(fillWidth, linesRemaining);
            fill_proc(fillInfo, fillDst, rowBytes, fillValue, zeroInit, sampler);
            break;
        }
        case kOutOfOrder_SkScanlineOrder: {
            SkASSERT(1 == linesRequested || this->getInfo().height() == linesRequested);
            const SkImageInfo fillInfo = info.makeWH(fillWidth, 1);
            for (int srcY = linesDecoded; srcY < linesRequested; srcY++) {
                fillDst = SkTAddOffset<void>(dst, this->outputScanline(srcY) * rowBytes);
                fill_proc(fillInfo, fillDst, rowBytes, fillValue, zeroInit, sampler);
            }
            break;
        }
    }
}

bool SkLinearGradient::LinearGradient4fContext::onChooseBlitProcs(const SkImageInfo& info,
                                                                  BlitState* state) {
    SkXfermode::Mode mode;
    if (!SkXfermode::AsMode(state->fXfer, &mode)) {
        return false;
    }

    if (mode != SkXfermode::kSrc_Mode &&
        !(mode == SkXfermode::kSrcOver_Mode && (fFlags & kOpaqueAlpha_Flag))) {
        return false;
    }

    switch (info.colorType()) {
        case kN32_SkColorType:
            state->fBlitBW = D32_BlitBW;
            return true;
        case kRGBA_F16_SkColorType:
            state->fBlitBW = D64_BlitBW;
            return true;
        default:
            return false;
    }
}

bool SkImageGeneratorWIC::onGetPixels(const SkImageInfo& info, void* pixels, size_t rowBytes,
        SkPMColor ctable[], int* ctableCount) {
    if (kN32_SkColorType != info.colorType()) {
        return false;
    }

    // Create a format converter.
    SkTScopedComPtr<IWICFormatConverter> formatConverter;
    HRESULT hr = fImagingFactory->CreateFormatConverter(&formatConverter);
    if (FAILED(hr)) {
        return false;
    }

    GUID format = GUID_WICPixelFormat32bppPBGRA;
    if (kUnpremul_SkAlphaType == info.alphaType()) {
        format = GUID_WICPixelFormat32bppBGRA;
    }

    hr = formatConverter->Initialize(fImageSource.get(), format, WICBitmapDitherTypeNone, nullptr,
            0.0, WICBitmapPaletteTypeCustom);
    if (FAILED(hr)) {
        return false;
    }

    // Treat the format converter as an image source.
    SkTScopedComPtr<IWICBitmapSource> formatConverterSrc;
    hr = formatConverter->QueryInterface(IID_PPV_ARGS(&formatConverterSrc));
    if (FAILED(hr)) {
        return false;
    }

    // Set the destination pixels.
    hr = formatConverterSrc->CopyPixels(nullptr, (UINT) rowBytes, (UINT) rowBytes * info.height(),
            (BYTE*) pixels);

    return SUCCEEDED(hr);
}

bool SkImageFilter::filterInputGPU(int index, SkImageFilter::Proxy* proxy,
                                   const SkBitmap& src, const Context& origCtx,
                                   SkBitmap* result, SkIPoint* offset,
                                   bool relaxSizeConstraint) const {
    SkImageFilter* input = this->getInput(index);
    if (!input) {
        return true;
    }
    // Ensure that GrContext calls under filterImage and filterImageGPU below will see an identity
    // matrix with no clip and that the matrix, clip, and render target set before this function was
    // called are restored before we return to the caller.
    GrContext* context = src.getTexture()->getContext();

    SizeConstraint constraint = origCtx.sizeConstraint();
    if (relaxSizeConstraint && (kExact_SizeConstraint == constraint)) {
        constraint = kApprox_SizeConstraint;
    }
    Context ctx(origCtx.ctm(), origCtx.clipBounds(), origCtx.cache(), constraint);

    if (input->filterImage(proxy, src, this->mapContext(ctx), result, offset)) {
        if (!result->getTexture()) {
            const SkImageInfo info = result->info();
            if (kUnknown_SkColorType == info.colorType()) {
                return false;
            }
            SkAutoTUnref<GrTexture> resultTex(
                GrRefCachedBitmapTexture(context, *result, GrTextureParams::ClampNoFilter()));
            if (!resultTex) {
                return false;
            }
            result->setPixelRef(new SkGrPixelRef(info, resultTex))->unref();
        }
        return true;
    } else {
        return false;
    }
}

/*
 * Checks if the conversion between the input image and the requested output
 * image has been implemented
 * Sets the output color format
 */
bool SkHeifCodec::setOutputColorFormat(const SkImageInfo& dstInfo) {
    if (kUnknown_SkAlphaType == dstInfo.alphaType()) {
        return false;
    }

    if (kOpaque_SkAlphaType != dstInfo.alphaType()) {
        SkCodecPrintf("Warning: an opaque image should be decoded as opaque "
                "- it is being decoded as non-opaque, which will draw slower\n");
    }

    switch (dstInfo.colorType()) {
        case kRGBA_8888_SkColorType:
            return fHeifDecoder->setOutputColor(kHeifColorFormat_RGBA_8888);

        case kBGRA_8888_SkColorType:
            return fHeifDecoder->setOutputColor(kHeifColorFormat_BGRA_8888);

        case kRGB_565_SkColorType:
            if (this->colorXform()) {
                return fHeifDecoder->setOutputColor(kHeifColorFormat_RGBA_8888);
            } else {
                return fHeifDecoder->setOutputColor(kHeifColorFormat_RGB565);
            }

        case kRGBA_F16_SkColorType:
            SkASSERT(this->colorXform());

            if (!dstInfo.colorSpace()->gammaIsLinear()) {
                return false;
            }
            return fHeifDecoder->setOutputColor(kHeifColorFormat_RGBA_8888);

        default:
            return false;
    }
}

bool SkLinearGradient::LinearGradient4fContext::onChooseBlitProcs(const SkImageInfo& info,
                                                                  BlitState* state) {
    SkXfermode::Mode mode;
    if (!SkXfermode::AsMode(state->fXfer, &mode)) {
        return false;
    }

    const SkGradientShaderBase& shader = static_cast<const SkGradientShaderBase&>(fShader);
    if (mode != SkXfermode::kSrc_Mode &&
        !(mode == SkXfermode::kSrcOver_Mode && shader.colorsAreOpaque())) {
        return false;
    }

    switch (info.colorType()) {
        case kN32_SkColorType:
            state->fBlitBW = D32_BlitBW;
            return true;
        case kRGBA_F16_SkColorType:
            state->fBlitBW = D64_BlitBW;
            return true;
        default:
            return false;
    }
}