text: /*
   * Copyright (C) 2008 Alex Mathews <possessedpenguinbob@gmail.com>
   * Copyright (C) 2009 Dirk Schulze <krit@webkit.org>
   *
   * This library is free software; you can redistribute it and/or
   * modify it under the terms of the GNU Library General Public
   * License as published by the Free Software Foundation; either
   * version 2 of the License, or (at your option) any later version.
   *
   * This library is distributed in the hope that it will be useful,
   * but WITHOUT ANY WARRANTY; without even the implied warranty of
   * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
   * Library General Public License for more details.
   *
   * You should have received a copy of the GNU Library General Public License
   * along with this library; see the file COPYING.LIB.  If not, write to
   * the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
   * Boston, MA 02110-1301, USA.
   */
  
  #ifndef THIRD_PARTY_BLINK_RENDERER_CORE_SVG_GRAPHICS_FILTERS_SVG_FILTER_BUILDER_H_
  #define THIRD_PARTY_BLINK_RENDERER_CORE_SVG_GRAPHICS_FILTERS_SVG_FILTER_BUILDER_H_
  
  #include "third_party/blink/renderer/core/style/computed_style_constants.h"
  #include "third_party/blink/renderer/platform/graphics/interpolation_space.h"
  #include "third_party/blink/renderer/platform/graphics/paint/paint_flags.h"
  #include "third_party/blink/renderer/platform/heap/collection_support/heap_hash_map.h"
  #include "third_party/blink/renderer/platform/heap/collection_support/heap_hash_set.h"
  #include "third_party/blink/renderer/platform/heap/handle.h"
  #include "third_party/blink/renderer/platform/wtf/hash_map.h"
  #include "third_party/blink/renderer/platform/wtf/hash_set.h"
  #include "third_party/blink/renderer/platform/wtf/text/atomic_string.h"
  #include "third_party/blink/renderer/platform/wtf/text/atomic_string_hash.h"
  
  namespace gfx {
  class RectF;
  }
  
  namespace blink {
  
  class Filter;
  class FilterEffect;
  class SVGFilterElement;
  class SVGFilterPrimitiveStandardAttributes;
  
  // A map from SVGFilterPrimitiveStandardAttributes -> FilterEffect and
  // FilterEffect -> dependent (downstream) FilterEffects ("reverse DAG"). Used
  // during invalidations for changes to the primitives (graph nodes).
  class SVGFilterGraphNodeMap final
      : public GarbageCollected<SVGFilterGraphNodeMap> {
   public:
    SVGFilterGraphNodeMap();
  
    typedef HeapHashSet<Member<FilterEffect>> FilterEffectSet;
  
    void AddBuiltinEffect(FilterEffect*);
    void AddPrimitive(SVGFilterPrimitiveStandardAttributes&, FilterEffect*);
  
    // Required to change the attributes of a filter during an
    // SvgAttributeChanged.
    FilterEffect* EffectForElement(
        SVGFilterPrimitiveStandardAttributes& primitive) {
      auto it = effect_element_.find(&primitive);
      return it != effect_element_.end() ? it->value : nullptr;
    }
  
    void InvalidateDependentEffects(FilterEffect*);
  
    void Trace(Visitor*) const;
  
   private:
    FilterEffectSet& EffectReferences(FilterEffect* effect) {
      // Only allowed for effects that are part of this node map.
      DCHECK(effect_references_.Contains(effect));
      return *effect_references_.find(effect)->value;
    }
  
    // The value is the set of filter effects that depend on the key
    // filter effect.
    HeapHashMap<Member<FilterEffect>, Member<FilterEffectSet>> effect_references_;
    HeapHashMap<WeakMember<SVGFilterPrimitiveStandardAttributes>,
                Member<FilterEffect>>
        effect_element_;
  };
  
  class SVGFilterBuilder {
    STACK_ALLOCATED();
  
   public:
    SVGFilterBuilder(FilterEffect* source_graphic,
                     SVGFilterGraphNodeMap* = nullptr,
                     const PaintFlags* fill_flags = nullptr,
                     const PaintFlags* stroke_flags = nullptr);
  
    void BuildGraph(Filter*, SVGFilterElement&, const gfx::RectF&);
  
    FilterEffect* GetEffectById(const AtomicString& id) const;
    FilterEffect* LastEffect() const { return last_effect_; }
  
    static InterpolationSpace ResolveInterpolationSpace(EColorInterpolation);
  
   private:
    void Add(const AtomicString& id, FilterEffect*);
    void AddBuiltinEffects();
  
    typedef HeapHashMap<AtomicString, Member<FilterEffect>> NamedFilterEffectMap;
  
    NamedFilterEffectMap builtin_effects_;
    NamedFilterEffectMap named_effects_;
  
    FilterEffect* last_effect_ = nullptr;
    SVGFilterGraphNodeMap* node_map_;
  };
  
  }  // namespace blink
  
  #endif  // THIRD_PARTY_BLINK_RENDERER_CORE_SVG_GRAPHICS_FILTERS_SVG_FILTER_BUILDER_H_
  