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
44namespace blink {
45
46HashMap<const FilterOperation*, OwnPtr<DocumentResourceReference> >* ReferenceFilterBuilder::documentResourceReferences = 0;
47
48DocumentResourceReference* ReferenceFilterBuilder::documentResourceReference(const FilterOperation* filterOperation)
49{
50    if (!documentResourceReferences)
51        return 0;
52
53    return documentResourceReferences->get(filterOperation);
54}
55
56void 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
63void 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
72static 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
112PassRefPtr<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