C++ SkImageFilter::filterImage方法代码示例

bool SkDisplacementMapEffect::onFilterImage(Proxy* proxy,
                                            const SkBitmap& src,
                                            const SkMatrix& ctm,
                                            SkBitmap* dst,
                                            SkIPoint* offset) {
    SkBitmap displ, color = src;
    SkImageFilter* colorInput = getColorInput();
    SkImageFilter* displacementInput = getDisplacementInput();
    SkASSERT(NULL != displacementInput);
    if ((colorInput && !colorInput->filterImage(proxy, src, ctm, &color, offset)) ||
        !displacementInput->filterImage(proxy, src, ctm, &displ, offset)) {
        return false;
    }
    if ((displ.config() != SkBitmap::kARGB_8888_Config) ||
        (color.config() != SkBitmap::kARGB_8888_Config)) {
        return false;
    }

    SkAutoLockPixels alp_displacement(displ), alp_color(color);
    if (!displ.getPixels() || !color.getPixels()) {
        return false;
    }
    dst->setConfig(displ.config(), displ.width(), displ.height());
    dst->allocPixels();
    if (!dst->getPixels()) {
        return false;
    }

    computeDisplacement(fXChannelSelector, fYChannelSelector, fScale, dst, &displ, &color);

    return true;
}

bool SkXfermodeImageFilter::onFilterImage(Proxy* proxy,
                                            const SkBitmap& src,
                                            const Context& ctx,
                                            SkBitmap* dst,
                                            SkIPoint* offset) const {
    SkBitmap background = src, foreground = src;
    SkImageFilter* backgroundInput = getInput(0);
    SkImageFilter* foregroundInput = getInput(1);
    SkIPoint backgroundOffset = SkIPoint::Make(0, 0);
    if (backgroundInput &&
        !backgroundInput->filterImage(proxy, src, ctx, &background, &backgroundOffset)) {
        background.reset();
    }
    SkIPoint foregroundOffset = SkIPoint::Make(0, 0);
    if (foregroundInput &&
        !foregroundInput->filterImage(proxy, src, ctx, &foreground, &foregroundOffset)) {
        foreground.reset();
    }

    SkIRect bounds, foregroundBounds;
    if (!applyCropRect(ctx, foreground, foregroundOffset, &foregroundBounds)) {
        foregroundBounds.setEmpty();
        foreground.reset();
    }
    if (!applyCropRect(ctx, background, backgroundOffset, &bounds)) {
        bounds.setEmpty();
        background.reset();
    }
    bounds.join(foregroundBounds);
    if (bounds.isEmpty()) {
        return false;
    }

    SkAutoTUnref<SkBaseDevice> device(proxy->createDevice(bounds.width(), bounds.height()));
    if (NULL == device.get()) {
        return false;
    }
    SkCanvas canvas(device);
    canvas.translate(SkIntToScalar(-bounds.left()), SkIntToScalar(-bounds.top()));
    SkPaint paint;
    paint.setXfermodeMode(SkXfermode::kSrc_Mode);
    canvas.drawBitmap(background, SkIntToScalar(backgroundOffset.fX),
                      SkIntToScalar(backgroundOffset.fY), &paint);
    paint.setXfermode(fMode);
    canvas.drawBitmap(foreground, SkIntToScalar(foregroundOffset.fX),
                      SkIntToScalar(foregroundOffset.fY), &paint);
    canvas.clipRect(SkRect::Make(foregroundBounds), SkRegion::kDifference_Op);
    paint.setColor(SK_ColorTRANSPARENT);
    canvas.drawPaint(paint);
    *dst = device->accessBitmap(false);
    offset->fX = bounds.left();
    offset->fY = bounds.top();
    return true;
}

bool SkImageFilter::filterInputGPU(int index, SkImageFilter::Proxy* proxy,
                                   const SkBitmap& src, const Context& ctx,
                                   SkBitmap* result, SkIPoint* offset) 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();
    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;
    }
}

void SkBitmapDevice::drawSpecial(const SkDraw& draw, SkSpecialImage* srcImg, int x, int y,
                                 const SkPaint& paint) {
    SkASSERT(!srcImg->isTextureBacked());

    SkBitmap resultBM;

    SkImageFilter* filter = paint.getImageFilter();
    if (filter) {
        SkIPoint offset = SkIPoint::Make(0, 0);
        SkMatrix matrix = *draw.fMatrix;
        matrix.postTranslate(SkIntToScalar(-x), SkIntToScalar(-y));
        const SkIRect clipBounds = draw.fRC->getBounds().makeOffset(-x, -y);
        SkAutoTUnref<SkImageFilterCache> cache(this->getImageFilterCache());
        SkImageFilter::OutputProperties outputProperties(fBitmap.colorSpace());
        SkImageFilter::Context ctx(matrix, clipBounds, cache.get(), outputProperties);
        
        sk_sp<SkSpecialImage> resultImg(filter->filterImage(srcImg, ctx, &offset));
        if (resultImg) {
            SkPaint tmpUnfiltered(paint);
            tmpUnfiltered.setImageFilter(nullptr);
            if (resultImg->getROPixels(&resultBM)) {
                this->drawSprite(draw, resultBM, x + offset.x(), y + offset.y(), tmpUnfiltered);
            }
        }
    } else {
        if (srcImg->getROPixels(&resultBM)) {
            this->drawSprite(draw, resultBM, x, y, paint);
        }
    }
}

void SkBaseDevice::drawSpriteWithFilter(const SkDraw& draw, const SkBitmap& bitmap,
                                        int x, int y,
                                        const SkPaint& paint) {
    SkImageFilter* filter = paint.getImageFilter();
    SkASSERT(filter);

    SkIPoint offset = SkIPoint::Make(0, 0);
    SkMatrix matrix = *draw.fMatrix;
    matrix.postTranslate(SkIntToScalar(-x), SkIntToScalar(-y));
    const SkIRect clipBounds = draw.fRC->getBounds().makeOffset(-x, -y);
    SkAutoTUnref<SkImageFilterCache> cache(this->getImageFilterCache());
    SkImageFilter::Context ctx(matrix, clipBounds, cache.get());

    sk_sp<SkSpecialImage> srcImg(SkSpecialImage::internal_fromBM(bitmap, &this->surfaceProps()));
    if (!srcImg) {
        return; // something disastrous happened
    }

    sk_sp<SkSpecialImage> resultImg(filter->filterImage(srcImg.get(), ctx, &offset));
    if (resultImg) {
        SkPaint tmpUnfiltered(paint);
        tmpUnfiltered.setImageFilter(nullptr);
        SkBitmap resultBM;
        if (resultImg->internal_getBM(&resultBM)) {
            // TODO: add drawSprite(SkSpecialImage) to SkDevice? (see skbug.com/5073)
            this->drawSprite(draw, resultBM, x + offset.x(), y + offset.y(), tmpUnfiltered);
        }
    }
}

bool SkTileImageFilter::onFilterImage(Proxy* proxy, const SkBitmap& src,
                                      const Context& ctx,
                                      SkBitmap* dst, SkIPoint* offset) const {
    SkBitmap source = src;
    SkImageFilter* input = getInput(0);
    SkIPoint srcOffset = SkIPoint::Make(0, 0);
    if (input && !input->filterImage(proxy, src, ctx, &source, &srcOffset)) {
        return false;
    }

    SkRect dstRect;
    ctx.ctm().mapRect(&dstRect, fDstRect);
    const SkIRect dstIRect = dstRect.roundOut();
    int w = dstIRect.width();
    int h = dstIRect.height();
    if (!fSrcRect.width() || !fSrcRect.height() || !w || !h) {
        return false;
    }

    SkRect srcRect;
    ctx.ctm().mapRect(&srcRect, fSrcRect);
    SkIRect srcIRect;
    srcRect.roundOut(&srcIRect);
    srcIRect.offset(-srcOffset);
    SkBitmap subset;
    SkIRect bounds;
    source.getBounds(&bounds);

    if (!srcIRect.intersect(bounds)) {
        offset->fX = offset->fY = 0;
        return true;
    } else if (!source.extractSubset(&subset, srcIRect)) {
        return false;
    }

    SkAutoTUnref<SkBaseDevice> device(proxy->createDevice(w, h));
    if (NULL == device.get()) {
        return false;
    }
    SkCanvas canvas(device);
    SkPaint paint;
    paint.setXfermodeMode(SkXfermode::kSrc_Mode);

    SkMatrix shaderMatrix;
    shaderMatrix.setTranslate(SkIntToScalar(srcOffset.fX),
                              SkIntToScalar(srcOffset.fY));
    SkAutoTUnref<SkShader> shader(SkShader::CreateBitmapShader(subset,
                                  SkShader::kRepeat_TileMode, SkShader::kRepeat_TileMode,
                                  &shaderMatrix));
    paint.setShader(shader);
    canvas.translate(-dstRect.fLeft, -dstRect.fTop);
    canvas.drawRect(dstRect, paint);
    *dst = device->accessBitmap(false);
    offset->fX = dstIRect.fLeft;
    offset->fY = dstIRect.fTop;
    return true;
}

bool SkImageFilter::filterInput(int index, Proxy* proxy, const SkBitmap& src,
                                const Context& ctx,
                                SkBitmap* result, SkIPoint* offset) const {
    SkImageFilter* input = this->getInput(index);
    if (!input) {
        return true;
    }
    return input->filterImage(proxy, src, this->mapContext(ctx), result, offset);
}

bool SkMergeImageFilter::onFilterImage(Proxy* proxy, const SkBitmap& src,
                                       const Context& ctx,
                                       SkBitmap* result, SkIPoint* offset) const {
    if (countInputs() < 1) {
        return false;
    }

    SkIRect bounds;
    if (!this->applyCropRect(ctx, src, SkIPoint::Make(0, 0), &bounds)) {
        return false;
    }

    const int x0 = bounds.left();
    const int y0 = bounds.top();

    SkAutoTUnref<SkBaseDevice> dst(proxy->createDevice(bounds.width(), bounds.height()));
    if (nullptr == dst) {
        return false;
    }
    SkCanvas canvas(dst);
    SkPaint paint;

    bool didProduceResult = false;
    int inputCount = countInputs();
    for (int i = 0; i < inputCount; ++i) {
        SkBitmap tmp;
        const SkBitmap* srcPtr;
        SkIPoint pos = SkIPoint::Make(0, 0);
        SkImageFilter* filter = getInput(i);
        if (filter) {
            if (!filter->filterImage(proxy, src, ctx, &tmp, &pos)) {
                continue;
            }
            srcPtr = &tmp;
        } else {
            srcPtr = &src;
        }

        if (fModes) {
            paint.setXfermodeMode((SkXfermode::Mode)fModes[i]);
        } else {
            paint.setXfermode(nullptr);
        }
        canvas.drawSprite(*srcPtr, pos.x() - x0, pos.y() - y0, &paint);
        didProduceResult = true;
    }

    if (!didProduceResult)
        return false;

    offset->fX = bounds.left();
    offset->fY = bounds.top();
    *result = dst->accessBitmap(false);
    return true;
}

bool SkComposeImageFilter::onFilterImage(Proxy* proxy,
                                         const SkBitmap& src,
                                         const SkMatrix& ctm,
                                         SkBitmap* result,
                                         SkIPoint* offset) {
    SkImageFilter* outer = getInput(0);
    SkImageFilter* inner = getInput(1);

    if (!outer && !inner) {
        return false;
    }

    if (!outer || !inner) {
        return (outer ? outer : inner)->filterImage(proxy, src, ctm, result, offset);
    }

    SkBitmap tmp;
    return inner->filterImage(proxy, src, ctm, &tmp, offset) &&
           outer->filterImage(proxy, tmp, ctm, result, offset);
}

SkBitmap SkImageFilter::getInputResult(int index, Proxy* proxy,
                                       const SkBitmap& src, const SkMatrix& ctm,
                                       SkIPoint* loc) {
    SkASSERT(index < fInputCount);
    SkImageFilter* input = getInput(index);
    SkBitmap result;
    if (input && input->filterImage(proxy, src, ctm, &result, loc)) {
        return result;
    } else {
        return src;
    }
}

bool SkMergeImageFilter::onFilterImage(Proxy* proxy, const SkBitmap& src,
                                       const SkMatrix& ctm,
                                       SkBitmap* result, SkIPoint* loc) {
    if (countInputs() < 1) {
        return false;
    }

    const SkIRect srcBounds = SkIRect::MakeXYWH(loc->x(), loc->y(),
                                                src.width(), src.height());
    SkIRect bounds;
    if (!this->filterBounds(srcBounds, ctm, &bounds)) {
        return false;
    }

    const int x0 = bounds.left();
    const int y0 = bounds.top();

    SkAutoTUnref<SkDevice> dst(proxy->createDevice(bounds.width(), bounds.height()));
    if (NULL == dst) {
        return false;
    }
    SkCanvas canvas(dst);
    SkPaint paint;

    int inputCount = countInputs();
    for (int i = 0; i < inputCount; ++i) {
        SkBitmap tmp;
        const SkBitmap* srcPtr;
        SkIPoint pos = *loc;
        SkImageFilter* filter = getInput(i);
        if (filter) {
            if (!filter->filterImage(proxy, src, ctm, &tmp, &pos)) {
                return false;
            }
            srcPtr = &tmp;
        } else {
            srcPtr = &src;
        }

        if (fModes) {
            paint.setXfermodeMode((SkXfermode::Mode)fModes[i]);
        } else {
            paint.setXfermode(NULL);
        }
        canvas.drawSprite(*srcPtr, pos.x() - x0, pos.y() - y0, &paint);
    }

    loc->set(bounds.left(), bounds.top());
    *result = dst->accessBitmap(false);
    return true;
}

sk_sp<SkSpecialImage> SkImageFilter::filterInput(int index,
                                                 SkSpecialImage* src,
                                                 const Context& ctx,
                                                 SkIPoint* offset) const {
    SkImageFilter* input = this->getInput(index);
    if (!input) {
        return sk_sp<SkSpecialImage>(SkRef(src));
    }

    sk_sp<SkSpecialImage> result(input->filterImage(src, this->mapContext(ctx), offset));

    SkASSERT(!result || src->isTextureBacked() == result->isTextureBacked());

    return result;
}

bool SkBlendImageFilter::onFilterImage(Proxy* proxy,
                                       const SkBitmap& src,
                                       const SkMatrix& ctm,
                                       SkBitmap* dst,
                                       SkIPoint* offset) {
    SkBitmap background, foreground = src;
    SkImageFilter* backgroundInput = getBackgroundInput();
    SkImageFilter* foregroundInput = getForegroundInput();
    SkASSERT(NULL != backgroundInput);
    if (!backgroundInput->filterImage(proxy, src, ctm, &background, offset)) {
        return false;
    }
    if (foregroundInput && !foregroundInput->filterImage(proxy, src, ctm, &foreground, offset)) {
        return false;
    }
    SkAutoLockPixels alp_foreground(foreground), alp_background(background);
    if (!foreground.getPixels() || !background.getPixels()) {
        return false;
    }
    dst->setConfig(background.config(), background.width(), background.height());
    dst->allocPixels();
    SkCanvas canvas(*dst);
    SkPaint paint;
    paint.setXfermodeMode(SkXfermode::kSrc_Mode);
    canvas.drawBitmap(background, 0, 0, &paint);
    // FEBlend's multiply mode is (1 - Sa) * Da + (1 - Da) * Sc + Sc * Dc
    // Skia's is just Sc * Dc.  So we use a custom proc to implement FEBlend's
    // version.
    if (fMode == SkBlendImageFilter::kMultiply_Mode) {
        paint.setXfermode(new SkProcXfermode(multiply_proc))->unref();
    } else {
        paint.setXfermodeMode(modeToXfermode(fMode));
    }
    canvas.drawBitmap(foreground, 0, 0, &paint);
    return true;
}

bool SkComposeImageFilter::onFilterImage(Proxy* proxy,
                                         const SkBitmap& src,
                                         const Context& ctx,
                                         SkBitmap* result,
                                         SkIPoint* offset) const {
    SkImageFilter* outer = getInput(0);
    SkImageFilter* inner = getInput(1);

    SkBitmap tmp;
    SkIPoint innerOffset = SkIPoint::Make(0, 0);
    SkIPoint outerOffset = SkIPoint::Make(0, 0);
    if (!inner->filterImage(proxy, src, ctx, &tmp, &innerOffset))
        return false;

    SkMatrix outerMatrix(ctx.ctm());
    outerMatrix.postTranslate(SkIntToScalar(-innerOffset.x()), SkIntToScalar(-innerOffset.y()));
    Context outerContext(outerMatrix, ctx.clipBounds(), ctx.cache());
    if (!outer->filterImage(proxy, tmp, outerContext, result, &outerOffset)) {
        return false;
    }

    *offset = innerOffset + outerOffset;
    return true;
}

bool SkImageFilter::filterInput(int index, Proxy* proxy, const SkBitmap& src,
                                const Context& origCtx,
                                SkBitmap* result, SkIPoint* offset,
                                bool relaxSizeConstraint) const {
    SkImageFilter* input = this->getInput(index);
    if (!input) {
        return true;
    }

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

    return input->filterImage(proxy, src, this->mapContext(ctx), result, offset);
}