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
43namespace WebCore {
44
45HashMap<const FilterOperation*, OwnPtr<DocumentResourceReference> >* ReferenceFilterBuilder::documentResourceReferences = 0;
46
47DocumentResourceReference* ReferenceFilterBuilder::documentResourceReference(const FilterOperation* filterOperation)
48{
49    if (!documentResourceReferences)
50        return 0;
51
52    return documentResourceReferences->get(filterOperation);
53}
54
55void 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
62void 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
71static 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
111PassRefPtr<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