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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/dom/ElementTraversal.h"
     37 #include "core/fetch/DocumentResource.h"
     38 #include "core/rendering/svg/RenderSVGResourceFilter.h"
     39 #include "core/svg/SVGDocumentExtensions.h"
     40 #include "core/svg/SVGFilterPrimitiveStandardAttributes.h"
     41 #include "core/svg/graphics/filters/SVGFilterBuilder.h"
     42 #include "platform/graphics/filters/SourceAlpha.h"
     43 
     44 namespace blink {
     45 
     46 HashMap<const FilterOperation*, OwnPtr<DocumentResourceReference> >* ReferenceFilterBuilder::documentResourceReferences = 0;
     47 
     48 DocumentResourceReference* ReferenceFilterBuilder::documentResourceReference(const FilterOperation* filterOperation)
     49 {
     50     if (!documentResourceReferences)
     51         return 0;
     52 
     53     return documentResourceReferences->get(filterOperation);
     54 }
     55 
     56 void ReferenceFilterBuilder::setDocumentResourceReference(const FilterOperation* filterOperation, PassOwnPtr<DocumentResourceReference> documentResourceReference)
     57 {
     58     if (!documentResourceReferences)
     59         documentResourceReferences = new HashMap<const FilterOperation*, OwnPtr<DocumentResourceReference> >;
     60     documentResourceReferences->add(filterOperation, documentResourceReference);
     61 }
     62 
     63 void ReferenceFilterBuilder::clearDocumentResourceReference(const FilterOperation* filterOperation)
     64 {
     65     if (!documentResourceReferences)
     66         return;
     67 
     68     documentResourceReferences->remove(filterOperation);
     69 }
     70 
     71 // Returns whether or not the SVGElement object contains a valid color-interpolation-filters attribute
     72 static bool getSVGElementColorSpace(SVGElement* svgElement, ColorSpace& cs)
     73 {
     74     if (!svgElement)
     75         return false;
     76 
     77     const RenderObject* renderer = svgElement->renderer();
     78     const RenderStyle* style = renderer ? renderer->style() : 0;
     79     const SVGRenderStyle* svgStyle = style ? &style->svgStyle() : 0;
     80     EColorInterpolation eColorInterpolation = CI_AUTO;
     81     if (svgStyle) {
     82         // If a layout has been performed, then we can use the fast path to get this attribute
     83         eColorInterpolation = svgStyle->colorInterpolationFilters();
     84     } else if (!svgElement->presentationAttributeStyle()) {
     85         return false;
     86     } else {
     87         // Otherwise, use the slow path by using string comparison (used by external svg files)
     88         RefPtrWillBeRawPtr<CSSValue> cssValue = svgElement->presentationAttributeStyle()->getPropertyCSSValue(CSSPropertyColorInterpolationFilters);
     89         if (cssValue.get() && cssValue->isPrimitiveValue()) {
     90             const CSSPrimitiveValue& primitiveValue = *((CSSPrimitiveValue*)cssValue.get());
     91             eColorInterpolation = (EColorInterpolation)primitiveValue;
     92         } else {
     93             return false;
     94         }
     95     }
     96 
     97     switch (eColorInterpolation) {
     98     case CI_AUTO:
     99     case CI_SRGB:
    100         cs = ColorSpaceDeviceRGB;
    101         break;
    102     case CI_LINEARRGB:
    103         cs = ColorSpaceLinearRGB;
    104         break;
    105     default:
    106         return false;
    107     }
    108 
    109     return true;
    110 }
    111 
    112 PassRefPtr<FilterEffect> ReferenceFilterBuilder::build(Filter* parentFilter, RenderObject* renderer, FilterEffect* previousEffect, const ReferenceFilterOperation* filterOperation)
    113 {
    114     if (!renderer)
    115         return nullptr;
    116 
    117     TreeScope* treeScope = &renderer->node()->treeScope();
    118 
    119     if (DocumentResourceReference* documentResourceRef = documentResourceReference(filterOperation)) {
    120         DocumentResource* cachedSVGDocument = documentResourceRef->document();
    121 
    122         // If we have an SVG document, this is an external reference. Otherwise
    123         // we look up the referenced node in the current document.
    124         if (cachedSVGDocument)
    125             treeScope = cachedSVGDocument->document();
    126     }
    127 
    128     if (!treeScope)
    129         return nullptr;
    130 
    131     Element* filter = treeScope->getElementById(filterOperation->fragment());
    132 
    133     if (!filter) {
    134         // Although we did not find the referenced filter, it might exist later
    135         // in the document.
    136         treeScope->document().accessSVGExtensions().addPendingResource(filterOperation->fragment(), toElement(renderer->node()));
    137         return nullptr;
    138     }
    139 
    140     if (!isSVGFilterElement(*filter))
    141         return nullptr;
    142 
    143     SVGFilterElement& filterElement = toSVGFilterElement(*filter);
    144 
    145     // FIXME: Figure out what to do with SourceAlpha. Right now, we're
    146     // using the alpha of the original input layer, which is obviously
    147     // wrong. We should probably be extracting the alpha from the
    148     // previousEffect, but this requires some more processing.
    149     // This may need a spec clarification.
    150     RefPtr<SVGFilterBuilder> builder = SVGFilterBuilder::create(previousEffect, SourceAlpha::create(parentFilter));
    151 
    152     ColorSpace filterColorSpace = ColorSpaceDeviceRGB;
    153     bool useFilterColorSpace = getSVGElementColorSpace(&filterElement, filterColorSpace);
    154 
    155     for (SVGElement* element = Traversal<SVGElement>::firstChild(filterElement); element; element = Traversal<SVGElement>::nextSibling(*element)) {
    156         if (!element->isFilterEffect())
    157             continue;
    158 
    159         SVGFilterPrimitiveStandardAttributes* effectElement = static_cast<SVGFilterPrimitiveStandardAttributes*>(element);
    160 
    161         RefPtr<FilterEffect> effect = effectElement->build(builder.get(), parentFilter);
    162         if (!effect)
    163             continue;
    164 
    165         effectElement->setStandardAttributes(effect.get());
    166         effect->setEffectBoundaries(SVGLengthContext::resolveRectangle<SVGFilterPrimitiveStandardAttributes>(effectElement, filterElement.primitiveUnits()->currentValue()->enumValue(), parentFilter->sourceImageRect()));
    167         ColorSpace colorSpace = filterColorSpace;
    168         if (useFilterColorSpace || getSVGElementColorSpace(effectElement, colorSpace))
    169             effect->setOperatingColorSpace(colorSpace);
    170         builder->add(AtomicString(effectElement->result()->currentValue()->value()), effect);
    171     }
    172     return builder->lastEffect();
    173 }
    174 
    175 } // namespace blink
    176