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      1 /*
      2  * Copyright (C) 2013 Adobe Systems Inc. All rights reserved.
      3  * Copyright (C) 2013 Google Inc.  All rights reserved.
      4  * Copyright (C) 2011 Apple Inc. All rights reserved.
      5  *
      6  * Redistribution and use in source and binary forms, with or without
      7  * modification, are permitted provided that the following conditions
      8  * are met:
      9  * 1. Redistributions of source code must retain the above copyright
     10  *    notice, this list of conditions and the following disclaimer.
     11  * 2. Redistributions in binary form must reproduce the above copyright
     12  *    notice, this list of conditions and the following disclaimer in the
     13  *    documentation and/or other materials provided with the distribution.
     14  *
     15  * THIS SOFTWARE IS PROVIDED BY APPLE INC. ``AS IS'' AND ANY
     16  * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     17  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
     18  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL APPLE COMPUTER, INC. OR
     19  * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
     20  * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
     21  * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
     22  * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
     23  * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
     24  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
     25  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
     26  */
     27 
     28 #include "config.h"
     29 
     30 #include "core/rendering/svg/ReferenceFilterBuilder.h"
     31 
     32 #include "SVGNames.h"
     33 #include "core/css/CSSPrimitiveValue.h"
     34 #include "core/css/CSSPrimitiveValueMappings.h"
     35 #include "core/dom/Element.h"
     36 #include "core/fetch/DocumentResource.h"
     37 #include "core/rendering/svg/RenderSVGResourceFilter.h"
     38 #include "core/svg/SVGDocumentExtensions.h"
     39 #include "core/svg/SVGFilterPrimitiveStandardAttributes.h"
     40 #include "core/svg/graphics/filters/SVGFilterBuilder.h"
     41 #include "platform/graphics/filters/SourceAlpha.h"
     42 
     43 namespace WebCore {
     44 
     45 HashMap<const FilterOperation*, OwnPtr<DocumentResourceReference> >* ReferenceFilterBuilder::documentResourceReferences = 0;
     46 
     47 DocumentResourceReference* ReferenceFilterBuilder::documentResourceReference(const FilterOperation* filterOperation)
     48 {
     49     if (!documentResourceReferences)
     50         return 0;
     51 
     52     return documentResourceReferences->get(filterOperation);
     53 }
     54 
     55 void ReferenceFilterBuilder::setDocumentResourceReference(const FilterOperation* filterOperation, PassOwnPtr<DocumentResourceReference> documentResourceReference)
     56 {
     57     if (!documentResourceReferences)
     58         documentResourceReferences = new HashMap<const FilterOperation*, OwnPtr<DocumentResourceReference> >;
     59     documentResourceReferences->add(filterOperation, documentResourceReference);
     60 }
     61 
     62 void ReferenceFilterBuilder::clearDocumentResourceReference(const FilterOperation* filterOperation)
     63 {
     64     if (!documentResourceReferences)
     65         return;
     66 
     67     documentResourceReferences->remove(filterOperation);
     68 }
     69 
     70 // Returns whether or not the SVGElement object contains a valid color-interpolation-filters attribute
     71 static bool getSVGElementColorSpace(SVGElement* svgElement, ColorSpace& cs)
     72 {
     73     if (!svgElement)
     74         return false;
     75 
     76     const RenderObject* renderer = svgElement->renderer();
     77     const RenderStyle* style = renderer ? renderer->style() : 0;
     78     const SVGRenderStyle* svgStyle = style ? style->svgStyle() : 0;
     79     EColorInterpolation eColorInterpolation = CI_AUTO;
     80     if (svgStyle) {
     81         // If a layout has been performed, then we can use the fast path to get this attribute
     82         eColorInterpolation = svgStyle->colorInterpolationFilters();
     83     } else {
     84         // Otherwise, use the slow path by using string comparison (used by external svg files)
     85         RefPtr<CSSValue> cssValue = svgElement->getPresentationAttribute(
     86             SVGNames::color_interpolation_filtersAttr.toString());
     87         if (cssValue.get() && cssValue->isPrimitiveValue()) {
     88             const CSSPrimitiveValue& primitiveValue = *((CSSPrimitiveValue*)cssValue.get());
     89             eColorInterpolation = (EColorInterpolation)primitiveValue;
     90         } else {
     91             return false;
     92         }
     93     }
     94 
     95     switch (eColorInterpolation) {
     96     case CI_AUTO:
     97     case CI_SRGB:
     98         cs = ColorSpaceDeviceRGB;
     99         break;
    100     case CI_LINEARRGB:
    101         cs = ColorSpaceLinearRGB;
    102         break;
    103     default:
    104         return false;
    105     }
    106 
    107     return true;
    108 }
    109 
    110 PassRefPtr<FilterEffect> ReferenceFilterBuilder::build(Filter* parentFilter, RenderObject* renderer, FilterEffect* previousEffect, const ReferenceFilterOperation* filterOperation)
    111 {
    112     if (!renderer)
    113         return 0;
    114 
    115     Document* document = &renderer->document();
    116 
    117     if (DocumentResourceReference* documentResourceRef = documentResourceReference(filterOperation)) {
    118         DocumentResource* cachedSVGDocument = documentResourceRef->document();
    119 
    120         // If we have an SVG document, this is an external reference. Otherwise
    121         // we look up the referenced node in the current document.
    122         if (cachedSVGDocument)
    123             document = cachedSVGDocument->document();
    124     }
    125 
    126     if (!document)
    127         return 0;
    128 
    129     Element* filter = document->getElementById(filterOperation->fragment());
    130 
    131     if (!filter) {
    132         // Although we did not find the referenced filter, it might exist later
    133         // in the document
    134         document->accessSVGExtensions()->addPendingResource(filterOperation->fragment(), toElement(renderer->node()));
    135         return 0;
    136     }
    137 
    138     if (!filter->isSVGElement() || !filter->hasTagName(SVGNames::filterTag))
    139         return 0;
    140 
    141     SVGFilterElement* filterElement = toSVGFilterElement(toSVGElement(filter));
    142 
    143     // FIXME: Figure out what to do with SourceAlpha. Right now, we're
    144     // using the alpha of the original input layer, which is obviously
    145     // wrong. We should probably be extracting the alpha from the
    146     // previousEffect, but this requires some more processing.
    147     // This may need a spec clarification.
    148     RefPtr<SVGFilterBuilder> builder = SVGFilterBuilder::create(previousEffect, SourceAlpha::create(parentFilter));
    149 
    150     ColorSpace filterColorSpace = ColorSpaceDeviceRGB;
    151     bool useFilterColorSpace = getSVGElementColorSpace(filterElement, filterColorSpace);
    152 
    153     for (Node* node = filterElement->firstChild(); node; node = node->nextSibling()) {
    154         if (!node->isSVGElement())
    155             continue;
    156 
    157         SVGElement* element = toSVGElement(node);
    158         if (!element->isFilterEffect())
    159             continue;
    160 
    161         SVGFilterPrimitiveStandardAttributes* effectElement = static_cast<SVGFilterPrimitiveStandardAttributes*>(element);
    162 
    163         RefPtr<FilterEffect> effect = effectElement->build(builder.get(), parentFilter);
    164         if (!effect)
    165             continue;
    166 
    167         effectElement->setStandardAttributes(effect.get());
    168         effect->setEffectBoundaries(SVGLengthContext::resolveRectangle<SVGFilterPrimitiveStandardAttributes>(effectElement, filterElement->primitiveUnitsCurrentValue(), parentFilter->sourceImageRect()));
    169         ColorSpace colorSpace = filterColorSpace;
    170         if (useFilterColorSpace || getSVGElementColorSpace(effectElement, colorSpace))
    171             effect->setOperatingColorSpace(colorSpace);
    172         builder->add(effectElement->resultCurrentValue(), effect);
    173     }
    174     return builder->lastEffect();
    175 }
    176 
    177 } // namespace WebCore
    178