C++ NativeImageSkia::bitmap方法代码示例

static void paintSkBitmap(PlatformContextSkia* platformContext, const NativeImageSkia& bitmap, const SkIRect& srcRect, const SkRect& destRect, const SkXfermode::Mode& compOp)
{
#if PLATFORM(CHROMIUM)
    TRACE_EVENT("paintSkBitmap", platformContext, 0);
#endif
    SkPaint paint;
    paint.setXfermodeMode(compOp);
    paint.setFilterBitmap(true);
    paint.setAlpha(platformContext->getNormalizedAlpha());
    paint.setLooper(platformContext->getDrawLooper());
    // only antialias if we're rotated or skewed
    paint.setAntiAlias(hasNon90rotation(platformContext));

    SkCanvas* canvas = platformContext->canvas();

    ResamplingMode resampling;
    if (platformContext->isAccelerated())
        resampling = RESAMPLE_LINEAR;
    else
        resampling = platformContext->printing() ? RESAMPLE_NONE :
            computeResamplingMode(platformContext, bitmap, srcRect.width(), srcRect.height(), SkScalarToFloat(destRect.width()), SkScalarToFloat(destRect.height()));
    if (resampling == RESAMPLE_AWESOME) {
        drawResampledBitmap(*canvas, paint, bitmap, srcRect, destRect);
    } else {
        // No resampling necessary, we can just draw the bitmap. We want to
        // filter it if we decided to do linear interpolation above, or if there
        // is something interesting going on with the matrix (like a rotation).
        // Note: for serialization, we will want to subset the bitmap first so
        // we don't send extra pixels.
        canvas->drawBitmapRect(bitmap.bitmap(), &srcRect, destRect, &paint);
    }
    platformContext->didDrawRect(destRect, paint, &bitmap.bitmap());
}

void BitmapImage::draw(GraphicsContext* ctxt, const FloatRect& dstRect, const FloatRect& srcRect, ColorSpace colorSpace, CompositeOperator compositeOp, RespectImageOrientationEnum shouldRespectImageOrientation)
{
    if (!m_source.initialized())
        return;

    // Spin the animation to the correct frame before we try to draw it, so we
    // don't draw an old frame and then immediately need to draw a newer one,
    // causing flicker and wasting CPU.
    startAnimation();

    NativeImageSkia* bm = nativeImageForCurrentFrame();
    if (!bm)
        return; // It's too early and we don't have an image yet.

    FloatRect normDstRect = normalizeRect(dstRect);
    FloatRect normSrcRect = normalizeRect(srcRect);
    normSrcRect.intersect(FloatRect(0, 0, bm->bitmap().width(), bm->bitmap().height()));

    if (normSrcRect.isEmpty() || normDstRect.isEmpty())
        return; // Nothing to draw.

    ImageOrientation orientation = DefaultImageOrientation;
    if (shouldRespectImageOrientation == RespectImageOrientation)
        orientation = frameOrientationAtIndex(m_currentFrame);

    GraphicsContextStateSaver saveContext(*ctxt, false);
    if (orientation != DefaultImageOrientation) {
        saveContext.save();

        // ImageOrientation expects the origin to be at (0, 0)
        ctxt->translate(normDstRect.x(), normDstRect.y());
        normDstRect.setLocation(FloatPoint());

        ctxt->concatCTM(orientation.transformFromDefault(normDstRect.size()));

        if (orientation.usesWidthAsHeight()) {
            // The destination rect will have it's width and height already reversed for the orientation of
            // the image, as it was needed for page layout, so we need to reverse it back here.
            normDstRect = FloatRect(normDstRect.x(), normDstRect.y(), normDstRect.height(), normDstRect.width());
        }
    }

    paintSkBitmap(ctxt->platformContext(),
        *bm,
        normSrcRect,
        normDstRect,
        WebCoreCompositeToSkiaComposite(compositeOp));

    if (ImageObserver* observer = imageObserver())
        observer->didDraw(this);
}

static void loadBufferingImageData()
{
    static bool loaded = false;
    if (!loaded) {
        static Image* bufferingIcon = Image::loadPlatformResource("vidbuffer").leakRef();
        NativeImageSkia* nativeImage = bufferingIcon->nativeImageForCurrentFrame();
        if (!nativeImage)
            return;

        if (!nativeImage->isDataComplete())
            return;

        loaded = true;
        nativeImage->bitmap().lockPixels();

        int bufSize = nativeImage->bitmap().width() * nativeImage->bitmap().height() * 4;
        s_bufferingImageWidth = nativeImage->bitmap().width();
        s_bufferingImageHeight = nativeImage->bitmap().height();
        s_bufferingImageData = static_cast<char*>(malloc(bufSize));
        memcpy(s_bufferingImageData, nativeImage->bitmap().getPixels(), bufSize);

        nativeImage->bitmap().unlockPixels();
        bufferingIcon->deref();
    }
}

DragImageRef createDragImageFromImage(Image* image, RespectImageOrientationEnum shouldRespectImageOrientation)
{
    if (!image)
        return 0;

    NativeImageSkia* bitmap = image->nativeImageForCurrentFrame();
    if (!bitmap)
        return 0;

    DragImageChromium* dragImageChromium = new DragImageChromium;
    dragImageChromium->bitmap = new SkBitmap();
    dragImageChromium->resolutionScale = bitmap->resolutionScale();

    if (image->isBitmapImage()) {
        ImageOrientation orientation = DefaultImageOrientation;
        BitmapImage* bitmapImage = static_cast<BitmapImage*>(image);
        IntSize sizeRespectingOrientation = bitmapImage->sizeRespectingOrientation();

        if (shouldRespectImageOrientation == RespectImageOrientation)
            orientation = bitmapImage->currentFrameOrientation();

        if (orientation != DefaultImageOrientation) {
            // Construct a correctly-rotated copy of the image to use as the drag image.
            dragImageChromium->bitmap->setConfig(
                SkBitmap::kARGB_8888_Config, sizeRespectingOrientation.width(), sizeRespectingOrientation.height());
            dragImageChromium->bitmap->allocPixels();

            FloatRect destRect(FloatPoint(), sizeRespectingOrientation);
            SkCanvas canvas(*dragImageChromium->bitmap);

            canvas.concat(orientation.transformFromDefault(sizeRespectingOrientation));

            if (orientation.usesWidthAsHeight())
                destRect = FloatRect(destRect.x(), destRect.y(), destRect.height(), destRect.width());

            canvas.drawBitmapRect(bitmap->bitmap(), 0, destRect);
            return dragImageChromium;
        }
    }

    bitmap->bitmap().copyTo(dragImageChromium->bitmap, SkBitmap::kARGB_8888_Config);
    return dragImageChromium;
}

// This function is used to scale an image and extract a scaled fragment.
//
// ALGORITHM
//
// Because the scaled image size has to be integers, we approximate the real
// scale with the following formula (only X direction is shown):
//
// scaledImageWidth = round(scaleX * imageRect.width())
// approximateScaleX = scaledImageWidth / imageRect.width()
//
// With this method we maintain a constant scale factor among fragments in
// the scaled image. This allows fragments to stitch together to form the
// full scaled image. The downside is there will be a small difference
// between |scaleX| and |approximateScaleX|.
//
// A scaled image fragment is identified by:
//
// - Scaled image size
// - Scaled image fragment rectangle (IntRect)
//
// Scaled image size has been determined and the next step is to compute the
// rectangle for the scaled image fragment which needs to be an IntRect.
//
// scaledSrcRect = srcRect * (approximateScaleX, approximateScaleY)
// enclosingScaledSrcRect = enclosingIntRect(scaledSrcRect)
//
// Finally we extract the scaled image fragment using
// (scaledImageSize, enclosingScaledSrcRect).
//
static SkBitmap extractScaledImageFragment(const NativeImageSkia& bitmap, const SkRect& srcRect, float scaleX, float scaleY, SkRect* scaledSrcRect, SkIRect* enclosingScaledSrcRect)
{
    SkISize imageSize = SkISize::Make(bitmap.bitmap().width(), bitmap.bitmap().height());
    SkISize scaledImageSize = SkISize::Make(clampToInteger(roundf(imageSize.width() * scaleX)),
        clampToInteger(roundf(imageSize.height() * scaleY)));

    SkRect imageRect = SkRect::MakeWH(imageSize.width(), imageSize.height());
    SkRect scaledImageRect = SkRect::MakeWH(scaledImageSize.width(), scaledImageSize.height());

    SkMatrix scaleTransform;
    scaleTransform.setRectToRect(imageRect, scaledImageRect, SkMatrix::kFill_ScaleToFit);
    scaleTransform.mapRect(scaledSrcRect, srcRect);

    scaledSrcRect->intersect(scaledImageRect);
    *enclosingScaledSrcRect = enclosingIntRect(*scaledSrcRect);

    // |enclosingScaledSrcRect| can be larger than |scaledImageSize| because
    // of float inaccuracy so clip to get inside.
    enclosingScaledSrcRect->intersect(SkIRect::MakeSize(scaledImageSize));
    return bitmap.resizedBitmap(scaledImageSize, *enclosingScaledSrcRect);
}

DragImageRef createDragImageFromImage(Image* image)
{
    if (!image)
        return 0;

    NativeImageSkia* bitmap = image->nativeImageForCurrentFrame();
    if (!bitmap)
        return 0;

    SkBitmap* dragImage = new SkBitmap();
    bitmap->bitmap().copyTo(dragImage, SkBitmap::kARGB_8888_Config);
    return dragImage;
}

bool FEComponentTransfer::platformApplySkia()
{
    FilterEffect* in = inputEffect(0);
    ImageBuffer* resultImage = createImageBufferResult();
    if (!resultImage)
        return false;

    RefPtr<Image> image = in->asImageBuffer()->copyImage(DontCopyBackingStore);
    NativeImageSkia* nativeImage = image->nativeImageForCurrentFrame();
    if (!nativeImage)
        return false;

    unsigned char rValues[256], gValues[256], bValues[256], aValues[256];
    getValues(rValues, gValues, bValues, aValues);

    SkPaint paint;
    paint.setColorFilter(SkTableColorFilter::CreateARGB(aValues, rValues, gValues, bValues))->unref();
    paint.setXfermodeMode(SkXfermode::kSrc_Mode);
    resultImage->context()->platformContext()->drawBitmap(nativeImage->bitmap(), 0, 0, &paint);

    return true;
}

void Image::drawPattern(GraphicsContext* context,
                        const FloatRect& floatSrcRect,
                        const AffineTransform& patternTransform,
                        const FloatPoint& phase,
                        ColorSpace styleColorSpace,
                        CompositeOperator compositeOp,
                        const FloatRect& destRect)
{
#if PLATFORM(CHROMIUM)
    TRACE_EVENT0("skia", "Image::drawPattern");
#endif
    FloatRect normSrcRect = normalizeRect(floatSrcRect);
    if (destRect.isEmpty() || normSrcRect.isEmpty())
        return; // nothing to draw

    NativeImageSkia* bitmap = nativeImageForCurrentFrame();
    if (!bitmap)
        return;

    SkMatrix ctm = context->platformContext()->canvas()->getTotalMatrix();
    SkMatrix totalMatrix;
    totalMatrix.setConcat(ctm, patternTransform);

    // Figure out what size the bitmap will be in the destination. The
    // destination rect is the bounds of the pattern, we need to use the
    // matrix to see how big it will be.
    SkRect destRectTarget;
    totalMatrix.mapRect(&destRectTarget, normSrcRect);

    float destBitmapWidth = SkScalarToFloat(destRectTarget.width());
    float destBitmapHeight = SkScalarToFloat(destRectTarget.height());

    // Compute the resampling mode.
    ResamplingMode resampling;
    if (context->platformContext()->isAccelerated() || context->platformContext()->printing())
        resampling = RESAMPLE_LINEAR;
    else
        resampling = computeResamplingMode(totalMatrix, *bitmap, normSrcRect.width(), normSrcRect.height(), destBitmapWidth, destBitmapHeight);
    resampling = limitResamplingMode(context->platformContext(), resampling);

    // Load the transform WebKit requested.
    SkMatrix matrix(patternTransform);

    SkShader* shader;
    if (resampling == RESAMPLE_AWESOME) {
        // Do nice resampling.
        float scaleX = destBitmapWidth / normSrcRect.width();
        float scaleY = destBitmapHeight / normSrcRect.height();
        SkRect scaledSrcRect;
        SkIRect enclosingScaledSrcRect;

        // The image fragment generated here is not exactly what is
        // requested. The scale factor used is approximated and image
        // fragment is slightly larger to align to integer
        // boundaries.
        SkBitmap resampled = extractScaledImageFragment(*bitmap, normSrcRect, scaleX, scaleY, &scaledSrcRect, &enclosingScaledSrcRect);
        shader = SkShader::CreateBitmapShader(resampled, SkShader::kRepeat_TileMode, SkShader::kRepeat_TileMode);

        // Since we just resized the bitmap, we need to remove the scale
        // applied to the pixels in the bitmap shader. This means we need
        // CTM * patternTransform to have identity scale. Since we
        // can't modify CTM (or the rectangle will be drawn in the wrong
        // place), we must set patternTransform's scale to the inverse of
        // CTM scale.
        matrix.setScaleX(ctm.getScaleX() ? 1 / ctm.getScaleX() : 1);
        matrix.setScaleY(ctm.getScaleY() ? 1 / ctm.getScaleY() : 1);
    } else {
        // No need to do nice resampling.
        SkBitmap srcSubset;
        bitmap->bitmap().extractSubset(&srcSubset, enclosingIntRect(normSrcRect));
        shader = SkShader::CreateBitmapShader(srcSubset, SkShader::kRepeat_TileMode, SkShader::kRepeat_TileMode);
    }

    // We also need to translate it such that the origin of the pattern is the
    // origin of the destination rect, which is what WebKit expects. Skia uses
    // the coordinate system origin as the base for the patter. If WebKit wants
    // a shifted image, it will shift it from there using the patternTransform.
    float adjustedX = phase.x() + normSrcRect.x() *
                      narrowPrecisionToFloat(patternTransform.a());
    float adjustedY = phase.y() + normSrcRect.y() *
                      narrowPrecisionToFloat(patternTransform.d());
    matrix.postTranslate(SkFloatToScalar(adjustedX),
                         SkFloatToScalar(adjustedY));
    shader->setLocalMatrix(matrix);

    SkPaint paint;
    paint.setShader(shader)->unref();
    paint.setXfermodeMode(WebCoreCompositeToSkiaComposite(compositeOp));
    paint.setFilterBitmap(resampling == RESAMPLE_LINEAR);

    context->platformContext()->paintSkPaint(destRect, paint);
}

static void paintSkBitmap(PlatformContextSkia* platformContext, const NativeImageSkia& bitmap, const SkRect& srcRect, const SkRect& destRect, const SkXfermode::Mode& compOp)
{
#if PLATFORM(CHROMIUM)
    TRACE_EVENT0("skia", "paintSkBitmap");
#endif
    SkPaint paint;
    paint.setXfermodeMode(compOp);
    paint.setAlpha(platformContext->getNormalizedAlpha());
    paint.setLooper(platformContext->getDrawLooper());
    // only antialias if we're rotated or skewed
    paint.setAntiAlias(hasNon90rotation(platformContext));

    ResamplingMode resampling;
    if (platformContext->isAccelerated())
        resampling = RESAMPLE_LINEAR;
    else if (platformContext->printing())
        resampling = RESAMPLE_NONE;
    else {
        // Take into account scale applied to the canvas when computing sampling mode (e.g. CSS scale or page scale).
        SkRect destRectTarget = destRect;
        if (!(platformContext->getTotalMatrix().getType() & (SkMatrix::kAffine_Mask | SkMatrix::kPerspective_Mask)))
            platformContext->getTotalMatrix().mapRect(&destRectTarget, destRect);

        resampling = computeResamplingMode(platformContext->getTotalMatrix(), bitmap,
            SkScalarToFloat(srcRect.width()), SkScalarToFloat(srcRect.height()),
            SkScalarToFloat(destRectTarget.width()), SkScalarToFloat(destRectTarget.height()));
    }

    if (resampling == RESAMPLE_NONE) {
        // FIXME: This is to not break tests (it results in the filter bitmap flag
        // being set to true). We need to decide if we respect RESAMPLE_NONE
        // being returned from computeResamplingMode.
        resampling = RESAMPLE_LINEAR;
    }
    resampling = limitResamplingMode(platformContext, resampling);
    paint.setFilterBitmap(resampling == RESAMPLE_LINEAR);
    if (resampling == RESAMPLE_AWESOME)
        drawResampledBitmap(platformContext, paint, bitmap, srcRect, destRect);
    else {
        // No resampling necessary, we can just draw the bitmap. We want to
        // filter it if we decided to do linear interpolation above, or if there
        // is something interesting going on with the matrix (like a rotation).
        // Note: for serialization, we will want to subset the bitmap first so
        // we don't send extra pixels.
        SkIRect enclosingSrcRect;
        SkRect enclosingDestRect;
        SkISize bitmapSize = SkISize::Make(bitmap.bitmap().width(), bitmap.bitmap().height());
        bool needsClipping = computeBitmapDrawRects(bitmapSize, srcRect, destRect, &enclosingSrcRect, &enclosingDestRect);

        if (enclosingSrcRect.isEmpty() || enclosingDestRect.isEmpty())
            return;

        // If destination is enlarged because source rectangle didn't align to
        // integer boundaries then we draw a slightly larger rectangle and clip
        // to the original destination rectangle.
        // See http://crbug.com/145540.
        if (needsClipping) {
            platformContext->save();
            platformContext->clipRect(destRect);
        }

        platformContext->drawBitmapRect(bitmap.bitmap(), &enclosingSrcRect, enclosingDestRect, &paint);

        if (needsClipping)
            platformContext->restore();
    }
    platformContext->didDrawRect(destRect, paint, &bitmap.bitmap());
}

void Image::drawPattern(GraphicsContext* context,
                        const FloatRect& floatSrcRect,
                        const AffineTransform& patternTransform,
                        const FloatPoint& phase,
                        ColorSpace styleColorSpace,
                        CompositeOperator compositeOp,
                        const FloatRect& destRect)
{
    FloatRect normSrcRect = normalizeRect(floatSrcRect);
    if (destRect.isEmpty() || normSrcRect.isEmpty())
        return; // nothing to draw

    NativeImageSkia* bitmap = nativeImageForCurrentFrame();
    if (!bitmap)
        return;

    SkIRect srcRect = enclosingIntRect(normSrcRect);

    // Figure out what size the bitmap will be in the destination. The
    // destination rect is the bounds of the pattern, we need to use the
    // matrix to see how big it will be.
    float destBitmapWidth, destBitmapHeight;
    TransformDimensions(patternTransform, srcRect.width(), srcRect.height(),
                        &destBitmapWidth, &destBitmapHeight);

    // Compute the resampling mode.
    ResamplingMode resampling;
    if (context->platformContext()->isAccelerated() || context->platformContext()->printing())
        resampling = RESAMPLE_LINEAR;
    else
        resampling = computeResamplingMode(context->platformContext(), *bitmap, srcRect.width(), srcRect.height(), destBitmapWidth, destBitmapHeight);

    // Load the transform WebKit requested.
    SkMatrix matrix(patternTransform);

    SkShader* shader;
    if (resampling == RESAMPLE_AWESOME) {
        // Do nice resampling.
        int width = static_cast<int>(destBitmapWidth);
        int height = static_cast<int>(destBitmapHeight);
        SkBitmap resampled = bitmap->resizedBitmap(srcRect, width, height);
        shader = SkShader::CreateBitmapShader(resampled, SkShader::kRepeat_TileMode, SkShader::kRepeat_TileMode);

        // Since we just resized the bitmap, we need to undo the scale set in
        // the image transform.
        matrix.setScaleX(SkIntToScalar(1));
        matrix.setScaleY(SkIntToScalar(1));
    } else {
        // No need to do nice resampling.
        SkBitmap srcSubset;
        bitmap->bitmap().extractSubset(&srcSubset, srcRect);
        shader = SkShader::CreateBitmapShader(srcSubset, SkShader::kRepeat_TileMode, SkShader::kRepeat_TileMode);
    }

    // We also need to translate it such that the origin of the pattern is the
    // origin of the destination rect, which is what WebKit expects. Skia uses
    // the coordinate system origin as the base for the patter. If WebKit wants
    // a shifted image, it will shift it from there using the patternTransform.
    float adjustedX = phase.x() + normSrcRect.x() *
                      narrowPrecisionToFloat(patternTransform.a());
    float adjustedY = phase.y() + normSrcRect.y() *
                      narrowPrecisionToFloat(patternTransform.d());
    matrix.postTranslate(SkFloatToScalar(adjustedX),
                         SkFloatToScalar(adjustedY));
    shader->setLocalMatrix(matrix);

    SkPaint paint;
    paint.setShader(shader)->unref();
    paint.setXfermodeMode(WebCoreCompositeToSkiaComposite(compositeOp));
    paint.setFilterBitmap(resampling == RESAMPLE_LINEAR);

    context->platformContext()->paintSkPaint(destRect, paint);
}