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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 "core/css/CSSPrimitiveValue.h"
     33 #include "core/css/CSSPrimitiveValueMappings.h"
     34 #include "core/css/StylePropertySet.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 if (!svgElement->presentationAttributeStyle()) {
     84         return false;
     85     } else {
     86         // Otherwise, use the slow path by using string comparison (used by external svg files)
     87         RefPtrWillBeRawPtr<CSSValue> cssValue = svgElement->presentationAttributeStyle()->getPropertyCSSValue(CSSPropertyColorInterpolationFilters);
     88         if (cssValue.get() && cssValue->isPrimitiveValue()) {
     89             const CSSPrimitiveValue& primitiveValue = *((CSSPrimitiveValue*)cssValue.get());
     90             eColorInterpolation = (EColorInterpolation)primitiveValue;
     91         } else {
     92             return false;
     93         }
     94     }
     95 
     96     switch (eColorInterpolation) {
     97     case CI_AUTO:
     98     case CI_SRGB:
     99         cs = ColorSpaceDeviceRGB;
    100         break;
    101     case CI_LINEARRGB:
    102         cs = ColorSpaceLinearRGB;
    103         break;
    104     default:
    105         return false;
    106     }
    107 
    108     return true;
    109 }
    110 
    111 PassRefPtr<FilterEffect> ReferenceFilterBuilder::build(Filter* parentFilter, RenderObject* renderer, FilterEffect* previousEffect, const ReferenceFilterOperation* filterOperation)
    112 {
    113     if (!renderer)
    114         return nullptr;
    115 
    116     TreeScope* treeScope = &renderer->node()->treeScope();
    117 
    118     if (DocumentResourceReference* documentResourceRef = documentResourceReference(filterOperation)) {
    119         DocumentResource* cachedSVGDocument = documentResourceRef->document();
    120 
    121         // If we have an SVG document, this is an external reference. Otherwise
    122         // we look up the referenced node in the current document.
    123         if (cachedSVGDocument)
    124             treeScope = cachedSVGDocument->document();
    125     }
    126 
    127     if (!treeScope)
    128         return nullptr;
    129 
    130     Element* filter = treeScope->getElementById(filterOperation->fragment());
    131 
    132     if (!filter) {
    133         // Although we did not find the referenced filter, it might exist later
    134         // in the document.
    135         treeScope->document().accessSVGExtensions().addPendingResource(filterOperation->fragment(), toElement(renderer->node()));
    136         return nullptr;
    137     }
    138 
    139     if (!isSVGFilterElement(*filter))
    140         return nullptr;
    141 
    142     SVGFilterElement& filterElement = toSVGFilterElement(*filter);
    143 
    144     // FIXME: Figure out what to do with SourceAlpha. Right now, we're
    145     // using the alpha of the original input layer, which is obviously
    146     // wrong. We should probably be extracting the alpha from the
    147     // previousEffect, but this requires some more processing.
    148     // This may need a spec clarification.
    149     RefPtr<SVGFilterBuilder> builder = SVGFilterBuilder::create(previousEffect, SourceAlpha::create(parentFilter));
    150 
    151     ColorSpace filterColorSpace = ColorSpaceDeviceRGB;
    152     bool useFilterColorSpace = getSVGElementColorSpace(&filterElement, filterColorSpace);
    153 
    154     for (SVGElement* element = Traversal<SVGElement>::firstChild(filterElement); element; element = Traversal<SVGElement>::nextSibling(*element)) {
    155         if (!element->isFilterEffect())
    156             continue;
    157 
    158         SVGFilterPrimitiveStandardAttributes* effectElement = static_cast<SVGFilterPrimitiveStandardAttributes*>(element);
    159 
    160         RefPtr<FilterEffect> effect = effectElement->build(builder.get(), parentFilter);
    161         if (!effect)
    162             continue;
    163 
    164         effectElement->setStandardAttributes(effect.get());
    165         effect->setEffectBoundaries(SVGLengthContext::resolveRectangle<SVGFilterPrimitiveStandardAttributes>(effectElement, filterElement.primitiveUnits()->currentValue()->enumValue(), parentFilter->sourceImageRect()));
    166         ColorSpace colorSpace = filterColorSpace;
    167         if (useFilterColorSpace || getSVGElementColorSpace(effectElement, colorSpace))
    168             effect->setOperatingColorSpace(colorSpace);
    169         builder->add(AtomicString(effectElement->result()->currentValue()->value()), effect);
    170     }
    171     return builder->lastEffect();
    172 }
    173 
    174 } // namespace WebCore
    175