LibWeb: Use the new Gfx::Painter::draw_text_run() API for drawing text

This avoids a bunch of unnecessary work in Painter which not only took
time, but sometimes also led to alignment issues. draw_text_run() will
draw the text where we tell it, and that's it.

Userland/Libraries/LibWeb/Layout/LineBoxFragment.h

@@ -43,6 +43,10 @@ public:
     const Gfx::FloatPoint& offset() const { return m_offset; }
     void set_offset(const Gfx::FloatPoint& offset) { m_offset = offset; }
 
+    // The baseline of a fragment is the number of pixels from the top to the text baseline.
+    void set_baseline(float y) { m_baseline = y; }
+    float baseline() const { return m_baseline; }
+
     const Gfx::FloatSize& size() const { return m_size; }
     void set_width(float width) { m_size.set_width(width); }
     void set_height(float height) { m_size.set_height(height); }
@@ -75,6 +79,7 @@ private:
     Gfx::FloatSize m_size;
     float m_border_box_top { 0 };
     float m_border_box_bottom { 0 };
+    float m_baseline { 0 };
     Type m_type { Type::Normal };
 };
 

Userland/Libraries/LibWeb/Layout/LineBuilder.cpp

@@ -159,7 +159,7 @@ void LineBuilder::update_last_line()
 
     auto line_box_baseline = [&] {
         float line_box_baseline = 0;
-        for (auto const& fragment : line_box.fragments()) {
+        for (auto& fragment : line_box.fragments()) {
             auto baseline = fragment_baseline(fragment);
             if (fragment.height() < m_context.containing_block().line_height())
                 baseline += (m_context.containing_block().line_height() - fragment.height()) / 2;
@@ -168,6 +168,9 @@ void LineBuilder::update_last_line()
             if (auto length_percentage = fragment.layout_node().computed_values().vertical_align().template get_pointer<CSS::LengthPercentage>(); length_percentage && length_percentage->is_length())
                 baseline += length_percentage->length().to_px(fragment.layout_node());
 
+            // Store the baseline on the fragment. This is used when painting.
+            fragment.set_baseline(baseline);
+
             line_box_baseline = max(line_box_baseline, baseline);
         }
         return line_box_baseline;

Userland/Libraries/LibWeb/Painting/PaintableBox.cpp

@@ -369,8 +369,6 @@ static void paint_text_fragment(PaintContext& context, Layout::TextNode const& t
     if (phase == Painting::PaintPhase::Foreground) {
         auto fragment_absolute_rect = fragment.absolute_rect();
 
-        painter.set_font(text_node.font());
-
         if (text_node.document().inspected_node() == &text_node.dom_node())
             context.painter().draw_rect(enclosing_int_rect(fragment_absolute_rect), Color::Magenta);
 
@@ -382,17 +380,17 @@ static void paint_text_fragment(PaintContext& context, Layout::TextNode const& t
         if (text_transform == CSS::TextTransform::Lowercase)
             text = text_node.text_for_rendering().to_lowercase();
 
-        // FIXME: This is a hack to prevent text clipping when painting a bitmap font into a too-small box.
+        Gfx::FloatPoint baseline_start { fragment_absolute_rect.x(), fragment_absolute_rect.y() + fragment.baseline() };
-        auto draw_rect = enclosing_int_rect(fragment_absolute_rect);
+        Utf8View view { text.substring_view(fragment.start(), fragment.length()) };
-        draw_rect.set_height(max(draw_rect.height(), text_node.font().pixel_size()));
+
-        painter.draw_text(draw_rect, text.substring_view(fragment.start(), fragment.length()), Gfx::TextAlignment::CenterLeft, text_node.computed_values().color());
+        painter.draw_text_run(baseline_start, view, fragment.layout_node().font(), text_node.computed_values().color());
 
         auto selection_rect = fragment.selection_rect(text_node.font());
         if (!selection_rect.is_empty()) {
             painter.fill_rect(enclosing_int_rect(selection_rect), context.palette().selection());
             Gfx::PainterStateSaver saver(painter);
             painter.add_clip_rect(enclosing_int_rect(selection_rect));
-            painter.draw_text(enclosing_int_rect(fragment_absolute_rect), text.substring_view(fragment.start(), fragment.length()), Gfx::TextAlignment::CenterLeft, context.palette().selection_text());
+            painter.draw_text_run(baseline_start, view, fragment.layout_node().font(), context.palette().selection_text());
         }
 
         paint_text_decoration(painter, text_node, fragment);

Userland/Libraries/LibWeb/Painting/ShadowPainting.cpp

@@ -159,7 +159,8 @@ void paint_text_shadow(PaintContext& context, Layout::LineBoxFragment const& fra
         Gfx::Painter shadow_painter { *shadow_bitmap };
         shadow_painter.set_font(context.painter().font());
         // FIXME: "Spread" the shadow somehow.
-        shadow_painter.draw_text(text_rect, fragment.text(), Gfx::TextAlignment::CenterLeft, layer.color);
+        Gfx::FloatPoint baseline_start(text_rect.x(), text_rect.y() + fragment.baseline());
+        shadow_painter.draw_text_run(baseline_start, Utf8View(fragment.text()), context.painter().font(), layer.color);
 
         // Blur
         Gfx::FastBoxBlurFilter filter(*shadow_bitmap);