LibWeb: Implement <feComposite> SVG filter

Author: https://github.com/tcl3 Commit: a00e7cb20b Pull-request: https://github.com/LadybirdBrowser/ladybird/pull/5744 Reviewed-by: https://github.com/gmta ✅ Reviewed-by: https://github.com/konradekk
2025-12-08 06:09:58 +00:00 · 2025-08-06 13:27:50 +01:00 · 2025-08-06 13:27:50 +01:00 · a00e7cb20b · 2025-09-30 21:34:29 +00:00
commit a00e7cb20b
parent bbfc3a0f5e
15 changed files with 303 additions and 0 deletions
--- a/Libraries/LibWeb/SVG/SVGFECompositeElement.cpp
+++ b/Libraries/LibWeb/SVG/SVGFECompositeElement.cpp
@ -0,0 +1,133 @@
+/*
+ * Copyright (c) 2025, Tim Ledbetter <tim.ledbetter@ladybird.org>
+ *
+ * SPDX-License-Identifier: BSD-2-Clause
+ */
+
+#include <LibWeb/Bindings/SVGFECompositeElementPrototype.h>
+#include <LibWeb/SVG/SVGAnimatedEnumeration.h>
+#include <LibWeb/SVG/SVGFECompositeElement.h>
+
+namespace Web::SVG {
+
+GC_DEFINE_ALLOCATOR(SVGFECompositeElement);
+
+SVGFECompositeElement::SVGFECompositeElement(DOM::Document& document, DOM::QualifiedName qualified_name)
+    : SVGElement(document, qualified_name)
+{
+}
+
+void SVGFECompositeElement::initialize(JS::Realm& realm)
+{
+    WEB_SET_PROTOTYPE_FOR_INTERFACE(SVGFECompositeElement);
+    Base::initialize(realm);
+}
+
+void SVGFECompositeElement::visit_edges(Cell::Visitor& visitor)
+{
+    Base::visit_edges(visitor);
+    SVGFilterPrimitiveStandardAttributes::visit_edges(visitor);
+    visitor.visit(m_in1);
+    visitor.visit(m_in2);
+    visitor.visit(m_k1);
+    visitor.visit(m_k2);
+    visitor.visit(m_k3);
+    visitor.visit(m_k4);
+}
+
+static SVGFECompositeElement::CompositingOperator string_to_compositing_operator(StringView string)
+{
+    if (string == "over"sv)
+        return SVGFECompositeElement::CompositingOperator::Over;
+    if (string == "in"sv)
+        return SVGFECompositeElement::CompositingOperator::In;
+    if (string == "out"sv)
+        return SVGFECompositeElement::CompositingOperator::Out;
+    if (string == "atop"sv)
+        return SVGFECompositeElement::CompositingOperator::Atop;
+    if (string == "xor"sv)
+        return SVGFECompositeElement::CompositingOperator::Xor;
+    if (string == "arithmetic"sv)
+        return SVGFECompositeElement::CompositingOperator::Arithmetic;
+    return SVGFECompositeElement::CompositingOperator::Unknown;
+}
+
+void SVGFECompositeElement::attribute_changed(FlyString const& name, Optional<String> const& old_value, Optional<String> const& new_value, Optional<FlyString> const& namespace_)
+{
+    Base::attribute_changed(name, old_value, new_value, namespace_);
+
+    if (name == SVG::AttributeNames::operator_) {
+        auto parse_compositing_operator = [](Optional<String> const& value) -> Optional<CompositingOperator> {
+            if (!value.has_value())
+                return {};
+            return string_to_compositing_operator(*value);
+        };
+
+        m_operator = parse_compositing_operator(new_value);
+    }
+}
+
+GC::Ref<SVGAnimatedString> SVGFECompositeElement::in1()
+{
+    if (!m_in1)
+        m_in1 = SVGAnimatedString::create(realm(), *this, AttributeNames::in);
+
+    return *m_in1;
+}
+
+GC::Ref<SVGAnimatedString> SVGFECompositeElement::in2()
+{
+    if (!m_in2)
+        m_in2 = SVGAnimatedString::create(realm(), *this, AttributeNames::in2);
+
+    return *m_in2;
+}
+
+// https://drafts.fxtf.org/filter-effects/#element-attrdef-fecomposite-k1
+GC::Ref<SVGAnimatedNumber> SVGFECompositeElement::k1()
+{
+    if (!m_k1)
+        m_k1 = SVGAnimatedNumber::create(realm(), *this, AttributeNames::k1, 0.f);
+
+    return *m_k1;
+}
+
+// https://drafts.fxtf.org/filter-effects/#element-attrdef-fecomposite-k2
+GC::Ref<SVGAnimatedNumber> SVGFECompositeElement::k2()
+{
+    if (!m_k2)
+        m_k2 = SVGAnimatedNumber::create(realm(), *this, AttributeNames::k2, 0.f);
+
+    return *m_k2;
+}
+
+// https://drafts.fxtf.org/filter-effects/#element-attrdef-fecomposite-k3
+GC::Ref<SVGAnimatedNumber> SVGFECompositeElement::k3()
+{
+    if (!m_k3)
+        m_k3 = SVGAnimatedNumber::create(realm(), *this, AttributeNames::k3, 0.f);
+
+    return *m_k3;
+}
+
+// https://drafts.fxtf.org/filter-effects/#element-attrdef-fecomposite-k4
+GC::Ref<SVGAnimatedNumber> SVGFECompositeElement::k4()
+{
+    if (!m_k4)
+        m_k4 = SVGAnimatedNumber::create(realm(), *this, AttributeNames::k4, 0.f);
+
+    return *m_k4;
+}
+
+SVGFECompositeElement::CompositingOperator SVGFECompositeElement::operator_() const
+{
+    return m_operator.value_or(CompositingOperator::Over);
+}
+
+// https://drafts.fxtf.org/filter-effects/#element-attrdef-fecomposite-operator
+GC::Ref<SVGAnimatedEnumeration> SVGFECompositeElement::operator_for_bindings() const
+{
+    return SVGAnimatedEnumeration::create(realm(), to_underlying(m_operator.value_or(CompositingOperator::Over)));
+}
+
+}