C++ SkImageInfo::height方法代码示例

bool SkPixmap::readPixels(const SkImageInfo& requestedDstInfo, void* dstPixels, size_t dstRB,
                          int x, int y) const {
    if (kUnknown_SkColorType == requestedDstInfo.colorType()) {
        return false;
    }
    if (nullptr == dstPixels || dstRB < requestedDstInfo.minRowBytes()) {
        return false;
    }
    if (0 == requestedDstInfo.width() || 0 == requestedDstInfo.height()) {
        return false;
    }
    
    SkIRect srcR = SkIRect::MakeXYWH(x, y, requestedDstInfo.width(), requestedDstInfo.height());
    if (!srcR.intersect(0, 0, this->width(), this->height())) {
        return false;
    }
    
    // the intersect may have shrunk info's logical size
    const SkImageInfo dstInfo = requestedDstInfo.makeWH(srcR.width(), srcR.height());
    
    // if x or y are negative, then we have to adjust pixels
    if (x > 0) {
        x = 0;
    }
    if (y > 0) {
        y = 0;
    }
    // here x,y are either 0 or negative
    dstPixels = ((char*)dstPixels - y * dstRB - x * dstInfo.bytesPerPixel());

    const SkImageInfo srcInfo = this->info().makeWH(dstInfo.width(), dstInfo.height());
    const void* srcPixels = this->addr(srcR.x(), srcR.y());
    return SkPixelInfo::CopyPixels(dstInfo, dstPixels, dstRB,
                                   srcInfo, srcPixels, this->rowBytes(), this->ctable());
}

 bool onGetPixels(const SkImageInfo& info, void* pixels, size_t rowBytes,
                  const Options& options) override {
     REPORTER_ASSERT(fReporter, pixels != nullptr);
     REPORTER_ASSERT(fReporter, rowBytes >= info.minRowBytes());
     if (fType != kSucceedGetPixels_TestType) {
         return false;
     }
     if (info.colorType() != kN32_SkColorType && info.colorType() != getInfo().colorType()) {
         return false;
     }
     char* bytePtr = static_cast<char*>(pixels);
     switch (info.colorType()) {
         case kN32_SkColorType:
             for (int y = 0; y < info.height(); ++y) {
                 sk_memset32((uint32_t*)bytePtr,
                             TestImageGenerator::PMColor(), info.width());
                 bytePtr += rowBytes;
             }
             break;
         case kRGB_565_SkColorType:
             for (int y = 0; y < info.height(); ++y) {
                 sk_memset16((uint16_t*)bytePtr,
                     SkPixel32ToPixel16(TestImageGenerator::PMColor()), info.width());
                 bytePtr += rowBytes;
             }
             break;
         default:
             return false;
     }
     return true;
 }

/*
 * Performs the heif decode
 */
SkCodec::Result SkHeifCodec::onGetPixels(const SkImageInfo& dstInfo,
                                         void* dst, size_t dstRowBytes,
                                         const Options& options,
                                         int* rowsDecoded) {
    if (options.fSubset) {
        // Not supporting subsets on this path for now.
        // TODO: if the heif has tiles, we can support subset here, but
        // need to retrieve tile config from metadata retriever first.
        return kUnimplemented;
    }

    if (!fHeifDecoder->decode(&fFrameInfo)) {
        return kInvalidInput;
    }

    fSwizzler.reset(nullptr);
    this->allocateStorage(dstInfo);

    int rows = this->readRows(dstInfo, dst, dstRowBytes, dstInfo.height(), options);
    if (rows < dstInfo.height()) {
        *rowsDecoded = rows;
        return kIncompleteInput;
    }

    return kSuccess;
}

/*
 * Performs the heif decode
 */
SkCodec::Result SkHeifCodec::onGetPixels(const SkImageInfo& dstInfo,
                                         void* dst, size_t dstRowBytes,
                                         const Options& options,
                                         int* rowsDecoded) {
    if (options.fSubset) {
        // Not supporting subsets on this path for now.
        // TODO: if the heif has tiles, we can support subset here, but
        // need to retrieve tile config from metadata retriever first.
        return kUnimplemented;
    }

    if (!this->initializeColorXform(dstInfo, options.fPremulBehavior)) {
        return kInvalidConversion;
    }

    // Check if we can decode to the requested destination and set the output color space
    if (!this->setOutputColorFormat(dstInfo)) {
        return kInvalidConversion;
    }

    if (!fHeifDecoder->decode(&fFrameInfo)) {
        return kInvalidInput;
    }

    fSwizzler.reset(nullptr);
    this->allocateStorage(dstInfo);

    int rows = this->readRows(dstInfo, dst, dstRowBytes, dstInfo.height(), options);
    if (rows < dstInfo.height()) {
        *rowsDecoded = rows;
        return kIncompleteInput;
    }

    return kSuccess;
}

/*
 * Performs the decoding
 */
SkCodec::Result SkBmpMaskCodec::decode(const SkImageInfo& dstInfo,
                                       void* dst, size_t dstRowBytes,
                                       const Options& opts) {
    // Set constant values
    const int width = dstInfo.width();
    const int height = dstInfo.height();
    const size_t rowBytes = SkAlign4(compute_row_bytes(width, this->bitsPerPixel()));

    // Iterate over rows of the image
    uint8_t* srcRow = fSrcBuffer.get();
    for (int y = 0; y < height; y++) {
        // Read a row of the input
        if (this->stream()->read(srcRow, rowBytes) != rowBytes) {
            SkCodecPrintf("Warning: incomplete input stream.\n");
            // Fill the destination image on failure
            SkPMColor fillColor = dstInfo.alphaType() == kOpaque_SkAlphaType ?
                    SK_ColorBLACK : SK_ColorTRANSPARENT;
            if (kNo_ZeroInitialized == opts.fZeroInitialized || 0 != fillColor) {
                void* dstStart = this->getDstStartRow(dst, dstRowBytes, y);
                SkSwizzler::Fill(dstStart, dstInfo, dstRowBytes, dstInfo.height() - y, fillColor,
                        nullptr);
            }
            return kIncompleteInput;
        }

        // Decode the row in destination format
        int row = SkBmpCodec::kBottomUp_RowOrder == this->rowOrder() ? height - 1 - y : y;
        void* dstRow = SkTAddOffset<void>(dst, row * dstRowBytes);
        fMaskSwizzler->swizzle(dstRow, srcRow);
    }

    // Finished decoding the entire image
    return kSuccess;
}

bool ImageFrameGenerator::decodeAndScale(size_t index, const SkImageInfo& info, void* pixels, size_t rowBytes)
{
    // Prevent concurrent decode or scale operations on the same image data.
    MutexLocker lock(m_decodeMutex);

    if (m_decodeFailed)
        return false;

    TRACE_EVENT1("blink", "ImageFrameGenerator::decodeAndScale", "frame index", static_cast<int>(index));

    m_externalAllocator = adoptPtr(new ExternalMemoryAllocator(info, pixels, rowBytes));

    // This implementation does not support scaling so check the requested size.
    SkISize scaledSize = SkISize::Make(info.width(), info.height());
    ASSERT(m_fullSize == scaledSize);

    SkBitmap bitmap = tryToResumeDecode(index, scaledSize);
    if (bitmap.isNull())
        return false;

    // Don't keep the allocator because it contains a pointer to memory
    // that we do not own.
    m_externalAllocator.clear();

    // Check to see if the decoder has written directly to the pixel memory
    // provided. If not, make a copy.
    ASSERT(bitmap.width() == scaledSize.width());
    ASSERT(bitmap.height() == scaledSize.height());
    SkAutoLockPixels bitmapLock(bitmap);
    if (bitmap.getPixels() != pixels)
        return bitmap.copyPixelsTo(pixels, rowBytes * info.height(), rowBytes);
    return true;
}

/*
 * Performs the decoding
 */
int SkBmpMaskCodec::decodeRows(const SkImageInfo& dstInfo,
                                           void* dst, size_t dstRowBytes,
                                           const Options& opts) {
    // Iterate over rows of the image
    uint8_t* srcRow = fSrcBuffer.get();
    const int height = dstInfo.height();
    for (int y = 0; y < height; y++) {
        // Read a row of the input
        if (this->stream()->read(srcRow, this->srcRowBytes()) != this->srcRowBytes()) {
            SkCodecPrintf("Warning: incomplete input stream.\n");
            return y;
        }

        // Decode the row in destination format
        uint32_t row = this->getDstRow(y, height);
        void* dstRow = SkTAddOffset<void>(dst, row * dstRowBytes);

        if (this->colorXform()) {
            SkImageInfo xformInfo = dstInfo.makeWH(fMaskSwizzler->swizzleWidth(), dstInfo.height());
            fMaskSwizzler->swizzle(this->xformBuffer(), srcRow);
            this->applyColorXform(xformInfo, dstRow, this->xformBuffer());
        } else {
            fMaskSwizzler->swizzle(dstRow, srcRow);
        }
    }

    // Finished decoding the entire image
    return height;
}

// check if scaling to dstInfo size from srcInfo size using sampleSize is possible
static bool scaling_supported(const SkImageInfo& dstInfo, const SkImageInfo& srcInfo,
                              int* sampleX, int* sampleY) {
    SkScaledCodec::ComputeSampleSize(dstInfo, srcInfo, sampleX, sampleY);
    const int dstWidth = dstInfo.width();
    const int dstHeight = dstInfo.height();
    const int srcWidth = srcInfo.width();
    const int srcHeight = srcInfo.height();
     // only support down sampling, not up sampling
    if (dstWidth > srcWidth || dstHeight  > srcHeight) {
        return false;
    }
    // check that srcWidth is scaled down by an integer value
    if (get_scaled_dimension(srcWidth, *sampleX) != dstWidth) {
        return false;
    }
    // check that src height is scaled down by an integer value
    if (get_scaled_dimension(srcHeight, *sampleY) != dstHeight) {
        return false;
    }
    // sampleX and sampleY should be equal unless the original sampleSize requested was larger
    // than srcWidth or srcHeight. If so, the result of this is dstWidth or dstHeight = 1.
    // This functionality allows for tall thin images to still be scaled down by scaling factors.
    if (*sampleX != *sampleY){
        if (1 != dstWidth && 1 != dstHeight) {
            return false;
        }
    }
    return true;
}

SK_API bool SkCopyPixelsFromCGImage(const SkImageInfo& info, size_t rowBytes, void* pixels,
                                    CGImageRef image) {
    CGBitmapInfo cg_bitmap_info = 0;
    size_t bitsPerComponent = 0;
    switch (info.colorType()) {
        case kRGBA_8888_SkColorType:
            bitsPerComponent = 8;
            cg_bitmap_info = ComputeCGAlphaInfo_RGBA(info.alphaType());
            break;
        case kBGRA_8888_SkColorType:
            bitsPerComponent = 8;
            cg_bitmap_info = ComputeCGAlphaInfo_BGRA(info.alphaType());
            break;
        default:
            return false;   // no other colortypes are supported (for now)
    }

    CGColorSpaceRef cs = CGColorSpaceCreateDeviceRGB();
    CGContextRef cg = CGBitmapContextCreate(pixels, info.width(), info.height(), bitsPerComponent,
                                            rowBytes, cs, cg_bitmap_info);
    CFRelease(cs);
    if (NULL == cg) {
        return false;
    }

    // use this blend mode, to avoid having to erase the pixels first, and to avoid CG performing
    // any blending (which could introduce errors and be slower).
    CGContextSetBlendMode(cg, kCGBlendModeCopy);

    CGContextDrawImage(cg, CGRectMake(0, 0, info.width(), info.height()), image);
    CGContextRelease(cg);
    return true;
}

void SkDrawCommandGeometryWidget::paintEvent(QPaintEvent* event) {
    this->QFrame::paintEvent(event);

    if (!fSurface) {
        return;
    }

    QPainter painter(this);
    painter.setRenderHint(QPainter::Antialiasing);

    SkImageInfo info;
    size_t rowBytes;
    if (const void* pixels = fSurface->peekPixels(&info, &rowBytes)) {
        SkASSERT(info.width() > 0);
        SkASSERT(info.height() > 0);

        QRectF resultRect;
        if (this->width() < this->height()) {
            float ratio = this->width() / info.width();
            resultRect = QRectF(0, 0, this->width(), ratio * info.height());
        } else {
            float ratio = this->height() / info.height();
            resultRect = QRectF(0, 0, ratio * info.width(), this->height());
        }

        resultRect.moveCenter(this->contentsRect().center());

        QImage image(reinterpret_cast<const uchar*>(pixels),
                     info.width(),
                     info.height(),
                     rowBytes,
                     QImage::Format_ARGB32_Premultiplied);
        painter.drawImage(resultRect, image);
    }
}

/*
 * Initiates the bitmap decode
 */
SkCodec::Result SkBmpRLECodec::onGetPixels(const SkImageInfo& dstInfo,
                                           void* dst, size_t dstRowBytes,
                                           const Options& opts,
                                           SkPMColor* inputColorPtr,
                                           int* inputColorCount,
                                           int* rowsDecoded) {
    if (opts.fSubset) {
        // Subsets are not supported.
        return kUnimplemented;
    }
    if (!conversion_possible_ignore_color_space(dstInfo, this->getInfo())) {
        SkCodecPrintf("Error: cannot convert input type to output type.\n");
        return kInvalidConversion;
    }

    Result result = this->prepareToDecode(dstInfo, opts, inputColorPtr, inputColorCount);
    if (kSuccess != result) {
        return result;
    }

    // Perform the decode
    int rows = this->decodeRows(dstInfo, dst, dstRowBytes, opts);
    if (rows != dstInfo.height()) {
        // We set rowsDecoded equal to the height because the background has already
        // been filled.  RLE encodings sometimes skip pixels, so we always start by
        // filling the background.
        *rowsDecoded = dstInfo.height();
        return kIncompleteInput;
    }

    return kSuccess;
}

 bool allocPixelRef(SkBitmap* bm, SkColorTable* ctable) override {
     const SkImageInfo bmi = bm->info();
     if (bmi.width() != fInfo.width() || bmi.height() != fInfo.height() ||
         bmi.colorType() != fInfo.colorType())
     {
         return false;
     }
     return bm->installPixels(bmi, fMemory, fRowBytes, ctable, NULL, NULL);
 }

bool SkBaseDevice::readPixels(const SkImageInfo& info, void* dstP, size_t rowBytes, int x, int y) {
#ifdef SK_DEBUG
    SkASSERT(info.width() > 0 && info.height() > 0);
    SkASSERT(dstP);
    SkASSERT(rowBytes >= info.minRowBytes());
    SkASSERT(x >= 0 && y >= 0);

    const SkImageInfo& srcInfo = this->imageInfo();
    SkASSERT(x + info.width() <= srcInfo.width());
    SkASSERT(y + info.height() <= srcInfo.height());
#endif
    return this->onReadPixels(info, dstP, rowBytes, x, y);
}

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() != info.width() || info.height() != info.height() || info.colorType() != info.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;
    }

    return m_frameGenerator->decodeAndScale(info, m_frameIndex, pixels, rowBytes);
}

/*
 * Performs the jpeg decode
 */
SkCodec::Result SkJpegCodec::onGetPixels(const SkImageInfo& dstInfo,
                                         void* dst, size_t dstRowBytes,
                                         const Options& options, SkPMColor*, int*,
                                         int* rowsDecoded) {
    if (options.fSubset) {
        // Subsets are not supported.
        return kUnimplemented;
    }

    // Get a pointer to the decompress info since we will use it quite frequently
    jpeg_decompress_struct* dinfo = fDecoderMgr->dinfo();

    // Set the jump location for libjpeg errors
    if (setjmp(fDecoderMgr->getJmpBuf())) {
        return fDecoderMgr->returnFailure("setjmp", kInvalidInput);
    }

    // Check if we can decode to the requested destination and set the output color space
    bool needsColorXform = needs_color_xform(dstInfo, this->getInfo());
    if (!this->setOutputColorSpace(dstInfo, needsColorXform)) {
        return fDecoderMgr->returnFailure("setOutputColorSpace", kInvalidConversion);
    }

    if (!this->initializeColorXform(dstInfo, needsColorXform)) {
        return fDecoderMgr->returnFailure("initializeColorXform", kInvalidParameters);
    }

    if (!jpeg_start_decompress(dinfo)) {
        return fDecoderMgr->returnFailure("startDecompress", kInvalidInput);
    }

    // The recommended output buffer height should always be 1 in high quality modes.
    // If it's not, we want to know because it means our strategy is not optimal.
    SkASSERT(1 == dinfo->rec_outbuf_height);

    J_COLOR_SPACE colorSpace = dinfo->out_color_space;
    if (JCS_CMYK == colorSpace || JCS_RGB == colorSpace) {
        this->initializeSwizzler(dstInfo, options);
    }

    this->allocateStorage(dstInfo);

    int rows = this->readRows(dstInfo, dst, dstRowBytes, dstInfo.height());
    if (rows < dstInfo.height()) {
        *rowsDecoded = rows;
        return fDecoderMgr->returnFailure("Incomplete image data", kIncompleteInput);
    }

    return kSuccess;
}