LibWeb: Migrate CSS filter application to new ApplyFilters command

This helps reuse this code in other areas, such as for filters for SVGs

Libraries/LibWeb/Painting/Command.h

@@ -27,6 +27,7 @@
 #include <LibGfx/Size.h>
 #include <LibGfx/TextAlignment.h>
 #include <LibGfx/TextLayout.h>
+#include <LibWeb/CSS/ComputedValues.h>
 #include <LibWeb/CSS/Enums.h>
 #include <LibWeb/Painting/BorderRadiiData.h>
 #include <LibWeb/Painting/BorderRadiusCornerClipper.h>
@@ -118,7 +119,6 @@ struct StackingContextTransform {
 
 struct PushStackingContext {
     float opacity;
-    CSS::ResolvedFilter filter;
     // The bounding box of the source paintable (pre-transform).
     Gfx::IntRect source_paintable_rect;
     // A translation to be applied after the stacking context has been transformed.
@@ -408,6 +408,11 @@ struct ApplyOpacity {
     float opacity;
 };
 
+struct ApplyFilters {
+    float opacity;
+    CSS::ResolvedFilter filter;
+};
+
 struct ApplyTransform {
     Gfx::FloatPoint origin;
     Gfx::FloatMatrix4x4 matrix;
@@ -463,6 +468,7 @@ using Command = Variant<
     PaintNestedDisplayList,
     PaintScrollBar,
     ApplyOpacity,
+    ApplyFilters,
     ApplyTransform,
     ApplyMaskBitmap>;
 

Libraries/LibWeb/Painting/DisplayList.cpp

@@ -122,6 +122,7 @@ void DisplayListPlayer::execute(DisplayList& display_list)
         else HANDLE_COMMAND(PaintScrollBar, paint_scrollbar)
         else HANDLE_COMMAND(PaintNestedDisplayList, paint_nested_display_list)
         else HANDLE_COMMAND(ApplyOpacity, apply_opacity)
+        else HANDLE_COMMAND(ApplyFilters, apply_filters)
         else HANDLE_COMMAND(ApplyTransform, apply_transform)
         else HANDLE_COMMAND(ApplyMaskBitmap, apply_mask_bitmap)
         else VERIFY_NOT_REACHED();

Libraries/LibWeb/Painting/DisplayList.h

@@ -76,6 +76,7 @@ private:
     virtual void paint_nested_display_list(PaintNestedDisplayList const&) = 0;
     virtual void paint_scrollbar(PaintScrollBar const&) = 0;
     virtual void apply_opacity(ApplyOpacity const&) = 0;
+    virtual void apply_filters(ApplyFilters const&) = 0;
     virtual void apply_transform(ApplyTransform const&) = 0;
     virtual void apply_mask_bitmap(ApplyMaskBitmap const&) = 0;
     virtual bool would_be_fully_clipped_by_painter(Gfx::IntRect) const = 0;

Libraries/LibWeb/Painting/DisplayListPlayerSkia.cpp

@@ -396,33 +396,7 @@ void DisplayListPlayerSkia::push_stacking_context(PushStackingContext const& com
                              .translate(-command.transform.origin);
     auto matrix = to_skia_matrix(new_transform);
 
-    if (!command.filter.is_none()) {
-        sk_sp<SkImageFilter> image_filter;
-        auto append_filter = [&image_filter](auto new_filter) {
-            if (image_filter)
-                image_filter = SkImageFilters::Compose(new_filter, image_filter);
-            else
-                image_filter = new_filter;
-        };
-
-        // Apply filters in order
-        for (auto const& filter_function : command.filter.filters)
-            append_filter(to_skia_image_filter(filter_function));
-
-        // We apply opacity as a color filter here so we only need to save and restore a single layer.
-        if (command.opacity < 1) {
-            append_filter(to_skia_image_filter(CSS::ResolvedFilter::FilterFunction {
-                CSS::ResolvedFilter::Color {
-                    CSS::FilterOperation::Color::Type::Opacity,
-                    command.opacity,
-                },
-            }));
-        }
-
-        SkPaint paint;
-        paint.setImageFilter(image_filter);
-        canvas.saveLayer(nullptr, &paint);
-    } else if (command.opacity < 1) {
+    if (command.opacity < 1) {
         auto source_paintable_rect = to_skia_rect(command.source_paintable_rect);
         SkRect dest;
         matrix.mapRect(&dest, source_paintable_rect);
@@ -1105,6 +1079,41 @@ void DisplayListPlayerSkia::apply_opacity(ApplyOpacity const& command)
     canvas.saveLayer(nullptr, &paint);
 }
 
+void DisplayListPlayerSkia::apply_filters(ApplyFilters const& command)
+{
+    if (command.filter.is_none()) {
+        return;
+    }
+    sk_sp<SkImageFilter> image_filter;
+    auto append_filter = [&image_filter](auto new_filter) {
+        if (image_filter)
+            image_filter = SkImageFilters::Compose(new_filter, image_filter);
+        else
+            image_filter = new_filter;
+    };
+
+    // Apply filters in order
+    for (auto filter : command.filter.filters) {
+        append_filter(to_skia_image_filter(filter));
+    }
+
+    // We apply opacity as a color filter here so we only need to save and restore a single layer.
+    if (command.opacity < 1) {
+        append_filter(to_skia_image_filter(CSS::ResolvedFilter::FilterFunction {
+            CSS::ResolvedFilter::Color {
+                CSS::FilterOperation::Color::Type::Opacity,
+                command.opacity,
+            },
+        }));
+    }
+
+    SkPaint paint;
+    paint.setImageFilter(image_filter);
+    auto& canvas = surface().canvas();
+    canvas.saveLayer(nullptr, &paint);
+    return;
+}
+
 void DisplayListPlayerSkia::apply_transform(ApplyTransform const& command)
 {
     auto affine_transform = Gfx::extract_2d_affine_transform(command.matrix);

Libraries/LibWeb/Painting/DisplayListPlayerSkia.h

@@ -63,6 +63,7 @@ private:
     void paint_scrollbar(PaintScrollBar const&) override;
     void paint_nested_display_list(PaintNestedDisplayList const&) override;
     void apply_opacity(ApplyOpacity const&) override;
+    void apply_filters(ApplyFilters const&) override;
     void apply_transform(ApplyTransform const&) override;
     void apply_mask_bitmap(ApplyMaskBitmap const&) override;
 

Libraries/LibWeb/Painting/DisplayListRecorder.cpp

@@ -295,7 +295,6 @@ void DisplayListRecorder::push_stacking_context(PushStackingContextParams params
 {
     append(PushStackingContext {
         .opacity = params.opacity,
-        .filter = params.filter,
         .source_paintable_rect = params.source_paintable_rect,
         .transform = {
             .origin = params.transform.origin,
@@ -408,6 +407,11 @@ void DisplayListRecorder::apply_opacity(float opacity)
     append(ApplyOpacity { .opacity = opacity });
 }
 
+void DisplayListRecorder::apply_filters(float opacity, CSS::ResolvedFilter filter)
+{
+    append(ApplyFilters { .opacity = opacity, .filter = filter });
+}
+
 void DisplayListRecorder::apply_transform(Gfx::FloatPoint origin, Gfx::FloatMatrix4x4 matrix)
 {
     append(ApplyTransform {

Libraries/LibWeb/Painting/DisplayListRecorder.h

@@ -121,7 +121,6 @@ public:
 
     struct PushStackingContextParams {
         float opacity;
-        CSS::ResolvedFilter filter;
         bool is_fixed_position;
         Gfx::IntRect source_paintable_rect;
         StackingContextTransform transform;
@@ -150,6 +149,7 @@ public:
     void paint_scrollbar(int scroll_frame_id, Gfx::IntRect, CSSPixelFraction scroll_size, bool vertical);
 
     void apply_opacity(float opacity);
+    void apply_filters(float opacity, CSS::ResolvedFilter filter);
     void apply_transform(Gfx::FloatPoint origin, Gfx::FloatMatrix4x4);
     void apply_mask_bitmap(Gfx::IntPoint origin, Gfx::ImmutableBitmap const&, Gfx::Bitmap::MaskKind);
 

Libraries/LibWeb/Painting/StackingContext.cpp

@@ -301,7 +301,6 @@ void StackingContext::paint(PaintContext& context) const
 
     DisplayListRecorder::PushStackingContextParams push_stacking_context_params {
         .opacity = opacity,
-        .filter = paintable_box().computed_values().filter(),
         .is_fixed_position = paintable_box().is_fixed_position(),
         .source_paintable_rect = source_paintable_rect,
         .transform = {
@@ -328,6 +327,7 @@ void StackingContext::paint(PaintContext& context) const
         context.display_list_recorder().push_scroll_frame_id(*paintable_box().scroll_frame_id());
     }
     context.display_list_recorder().push_stacking_context(push_stacking_context_params);
+    context.display_list_recorder().apply_filters(opacity, paintable_box().computed_values().filter());
 
     if (auto mask_image = computed_values.mask_image()) {
         auto mask_display_list = DisplayList::create();