LibWeb: Fix passing size/position to paint_radial_gradient()

This was wrong twice making it right... But let's fix that.

The center was being passed as a DevicePixelPoint, but was in fact in
CSS pixels, the size was passed as a Gfx::FloatSize but was in
CSS pixels again. Then we were scaling from device pixels to CSS pixels
when painting which does not need to be done if everything is passed
which the correct scale factors already applied.

Author: MacDue

Userland/Libraries/LibWeb/CSS/StyleValue.cpp

@@ -2178,7 +2178,9 @@ bool RadialGradientStyleValue::equals(StyleValue const& other) const
 void RadialGradientStyleValue::paint(PaintContext& context, Gfx::IntRect const& dest_rect, CSS::ImageRendering) const
 {
     VERIFY(m_resolved.has_value());
-    Painting::paint_radial_gradient(context, dest_rect.to_type<DevicePixels>(), m_resolved->data, m_resolved->center.to_rounded<DevicePixels>(), m_resolved->gradient_size);
+    Painting::paint_radial_gradient(context, dest_rect.to_type<DevicePixels>(), m_resolved->data,
+        context.rounded_device_point(m_resolved->center.to_type<CSSPixels>()),
+        context.rounded_device_size(m_resolved->gradient_size.to_type<CSSPixels>()));
 }
 
 DeprecatedString ConicGradientStyleValue::to_deprecated_string() const

Userland/Libraries/LibWeb/Painting/GradientPainting.cpp

@@ -304,18 +304,18 @@ void paint_conic_gradient(PaintContext& context, DevicePixelRect const& gradient
     });
 }
 
-void paint_radial_gradient(PaintContext& context, DevicePixelRect const& gradient_rect, RadialGradientData const& data, DevicePixelPoint center, Gfx::FloatSize size)
+void paint_radial_gradient(PaintContext& context, DevicePixelRect const& gradient_rect, RadialGradientData const& data, DevicePixelPoint center, DevicePixelSize size)
 {
     // A conservative guesstimate on how many colors we need to generate:
     auto max_dimension = max(gradient_rect.width(), gradient_rect.height());
-    int max_visible_gradient = max(max_dimension.value() / 2, min(size.width(), max_dimension.value()));
+    auto max_visible_gradient = max(max_dimension / 2, min(size.width(), max_dimension.value())).value();
     GradientLine gradient_line(max_visible_gradient, data.color_stops);
     auto center_point = Gfx::FloatPoint { center.to_type<int>() }.translated(0.5, 0.5);
     gradient_line.paint_into_rect(context.painter(), gradient_rect, [&](DevicePixels x, DevicePixels y) {
         // FIXME: See if there's a more efficient calculation we do there :^)
-        auto point = context.scale_to_css_point({ x, y }).to_type<float>() - center_point;
-        auto gradient_x = point.x() / size.width();
-        auto gradient_y = point.y() / size.height();
+        auto point = Gfx::FloatPoint(x.value(), y.value()) - center_point;
+        auto gradient_x = point.x() / size.width().value();
+        auto gradient_y = point.y() / size.height().value();
         return AK::sqrt(gradient_x * gradient_x + gradient_y * gradient_y) * max_visible_gradient;
     });
 }

Userland/Libraries/LibWeb/Painting/GradientPainting.h

@@ -47,6 +47,6 @@ RadialGradientData resolve_radial_gradient_data(Layout::Node const&, CSSPixelSiz
 
 void paint_linear_gradient(PaintContext&, DevicePixelRect const&, LinearGradientData const&);
 void paint_conic_gradient(PaintContext&, DevicePixelRect const&, ConicGradientData const&, DevicePixelPoint position);
-void paint_radial_gradient(PaintContext&, DevicePixelRect const&, RadialGradientData const&, DevicePixelPoint position, Gfx::FloatSize size);
+void paint_radial_gradient(PaintContext&, DevicePixelRect const&, RadialGradientData const&, DevicePixelPoint position, DevicePixelSize size);
 
 }