LibWeb: Add SVG <rect> element and test case :^)

Userland/Libraries/LibWeb/SVG/AttributeNames.h

@@ -54,6 +54,8 @@ namespace Web::SVG::AttributeNames {
     E(repeatCount)                  \
     E(repeatDur)                    \
     E(requiredExtensions)           \
+    E(rx)                           \
+    E(ry)                           \
     E(requiredFeatures)             \
     E(specularConstant)             \
     E(specularExponent)             \

Userland/Libraries/LibWeb/SVG/SVGRectElement.cpp

@@ -0,0 +1,153 @@
+/*
+ * Copyright (c) 2022, Sam Atkins <atkinssj@serenityos.org>
+ *
+ * SPDX-License-Identifier: BSD-2-Clause
+ */
+
+#include "SVGRectElement.h"
+#include <LibWeb/SVG/AttributeNames.h>
+#include <LibWeb/SVG/AttributeParser.h>
+
+namespace Web::SVG {
+
+SVGRectElement::SVGRectElement(DOM::Document& document, QualifiedName qualified_name)
+    : SVGGeometryElement(document, qualified_name)
+{
+}
+
+void SVGRectElement::parse_attribute(FlyString const& name, String const& value)
+{
+    SVGGeometryElement::parse_attribute(name, value);
+
+    if (name == SVG::AttributeNames::x) {
+        m_x = AttributeParser::parse_coordinate(value);
+        m_path.clear();
+    } else if (name == SVG::AttributeNames::y) {
+        m_y = AttributeParser::parse_coordinate(value);
+        m_path.clear();
+    } else if (name == SVG::AttributeNames::width) {
+        m_width = AttributeParser::parse_positive_length(value);
+        m_path.clear();
+    } else if (name == SVG::AttributeNames::height) {
+        m_height = AttributeParser::parse_positive_length(value);
+        m_path.clear();
+    } else if (name == SVG::AttributeNames::rx) {
+        m_radius_x = AttributeParser::parse_length(value);
+        m_path.clear();
+    } else if (name == SVG::AttributeNames::ry) {
+        m_radius_y = AttributeParser::parse_length(value);
+        m_path.clear();
+    }
+}
+
+Gfx::Path& SVGRectElement::get_path()
+{
+    if (m_path.has_value())
+        return m_path.value();
+
+    float width = m_width.value_or(0);
+    float height = m_height.value_or(0);
+    float x = m_x.value_or(0);
+    float y = m_y.value_or(0);
+
+    Gfx::Path path;
+    // If width or height is zero, rendering is disabled.
+    if (width == 0 && height == 0) {
+        m_path = move(path);
+        return m_path.value();
+    }
+
+    auto corner_radii = calculate_used_corner_radius_values();
+    float rx = corner_radii.x();
+    float ry = corner_radii.y();
+
+    // 1. perform an absolute moveto operation to location (x+rx,y);
+    path.move_to({ x + rx, y });
+
+    // 2, perform an absolute horizontal lineto with parameter x+width-rx;
+    path.horizontal_line_to(x + width - rx);
+
+    // 3. if both rx and ry are greater than zero,
+    //    perform an absolute elliptical arc operation to coordinate (x+width,y+ry),
+    //    where rx and ry are used as the equivalent parameters to the elliptical arc command,
+    //    the x-axis-rotation and large-arc-flag are set to zero,
+    //    the sweep-flag is set to one;
+    double x_axis_rotation = 0;
+    bool large_arc_flag = false;
+    bool sweep_flag = true;
+    if (rx > 0 && ry > 0)
+        path.elliptical_arc_to({ x + width, y + ry }, corner_radii, x_axis_rotation, large_arc_flag, sweep_flag);
+
+    // 4. perform an absolute vertical lineto parameter y+height-ry;
+    path.vertical_line_to(y + height - ry);
+
+    // 5. if both rx and ry are greater than zero,
+    //    perform an absolute elliptical arc operation to coordinate (x+width-rx,y+height),
+    //    using the same parameters as previously;
+    if (rx > 0 && ry > 0)
+        path.elliptical_arc_to({ x + width - rx, y + height }, corner_radii, x_axis_rotation, large_arc_flag, sweep_flag);
+
+    // 6. perform an absolute horizontal lineto parameter x+rx;
+    path.horizontal_line_to(x + rx);
+
+    // 7. if both rx and ry are greater than zero,
+    //    perform an absolute elliptical arc operation to coordinate (x,y+height-ry),
+    //    using the same parameters as previously;
+    if (rx > 0 && ry > 0)
+        path.elliptical_arc_to({ x, y + height - ry }, corner_radii, x_axis_rotation, large_arc_flag, sweep_flag);
+
+    // 8. perform an absolute vertical lineto parameter y+ry
+    path.vertical_line_to(y + ry);
+
+    // 9. if both rx and ry are greater than zero,
+    //    perform an absolute elliptical arc operation with a segment-completing close path operation,
+    //    using the same parameters as previously.
+    if (rx > 0 && ry > 0)
+        path.elliptical_arc_to({ x + rx, y }, corner_radii, x_axis_rotation, large_arc_flag, sweep_flag);
+
+    m_path = move(path);
+    return m_path.value();
+}
+
+Gfx::FloatPoint SVGRectElement::calculate_used_corner_radius_values()
+{
+    // 1. Let rx and ry be length values.
+    float rx = 0;
+    float ry = 0;
+
+    // 2. If neither ‘rx’ nor ‘ry’ are properly specified, then set both rx and ry to 0. (This will result in square corners.)
+    if (!m_radius_x.has_value() && !m_radius_y.has_value()) {
+        rx = 0;
+        ry = 0;
+    }
+    // 3. Otherwise, if a properly specified value is provided for ‘rx’, but not for ‘ry’, then set both rx and ry to the value of ‘rx’.
+    else if (m_radius_x.has_value()) {
+        rx = m_radius_x.value();
+        ry = m_radius_x.value();
+    }
+    // 4. Otherwise, if a properly specified value is provided for ‘ry’, but not for ‘rx’, then set both rx and ry to the value of ‘ry’.
+    else if (m_radius_y.has_value()) {
+        rx = m_radius_y.value();
+        ry = m_radius_y.value();
+    }
+    // 5. Otherwise, both ‘rx’ and ‘ry’ were specified properly. Set rx to the value of ‘rx’ and ry to the value of ‘ry’.
+    else {
+        rx = m_radius_x.value();
+        ry = m_radius_y.value();
+    }
+
+    // 6. If rx is greater than half of ‘width’, then set rx to half of ‘width’.
+    auto half_width = m_width.value_or(0) / 2;
+    if (rx > half_width)
+        rx = half_width;
+
+    // 7. If ry is greater than half of ‘height’, then set ry to half of ‘height’.
+    auto half_height = m_height.value_or(0) / 2;
+    if (ry > half_height)
+        ry = half_height;
+
+    // 8. The effective values of ‘rx’ and ‘ry’ are rx and ry, respectively.
+    return Gfx::FloatPoint { rx, ry };
+}
+
+}

Userland/Libraries/LibWeb/SVG/SVGRectElement.h

@@ -0,0 +1,38 @@
+/*
+ * Copyright (c) 2022, Sam Atkins <atkinssj@serenityos.org>
+ *
+ * SPDX-License-Identifier: BSD-2-Clause
+ */
+
+#pragma once
+
+#include <LibWeb/SVG/SVGGeometryElement.h>
+
+namespace Web::SVG {
+
+// https://www.w3.org/TR/SVG11/shapes.html#RectElement
+class SVGRectElement final : public SVGGeometryElement {
+public:
+    using WrapperType = Bindings::SVGRectElementWrapper;
+
+    SVGRectElement(DOM::Document&, QualifiedName);
+    virtual ~SVGRectElement() override = default;
+
+    virtual void parse_attribute(FlyString const& name, String const& value) override;
+
+    virtual Gfx::Path& get_path() override;
+
+private:
+    Gfx::FloatPoint calculate_used_corner_radius_values();
+
+    Optional<Gfx::Path> m_path;
+
+    Optional<float> m_x;
+    Optional<float> m_y;
+    Optional<float> m_width;
+    Optional<float> m_height;
+    Optional<float> m_radius_x;
+    Optional<float> m_radius_y;
+};
+
+}

Userland/Libraries/LibWeb/SVG/SVGRectElement.idl

@@ -0,0 +1,9 @@
+[Exposed=Window]
+interface SVGRectElement : SVGGeometryElement {
+    // [SameObject] readonly attribute SVGAnimatedLength x;
+    // [SameObject] readonly attribute SVGAnimatedLength y;
+    // [SameObject] readonly attribute SVGAnimatedLength width;
+    // [SameObject] readonly attribute SVGAnimatedLength height;
+    // [SameObject] readonly attribute SVGAnimatedLength rx;
+    // [SameObject] readonly attribute SVGAnimatedLength ry;
+};

Userland/Libraries/LibWeb/SVG/TagNames.h

@@ -13,6 +13,7 @@ namespace Web::SVG::TagNames {
 #define ENUMERATE_SVG_GRAPHICS_TAGS \
     __ENUMERATE_SVG_TAG(g)          \
     __ENUMERATE_SVG_TAG(path)       \
+    __ENUMERATE_SVG_TAG(rect)       \
     __ENUMERATE_SVG_TAG(svg)
 
 #define ENUMERATE_SVG_TAGS             \