Make basic text shaping the default shaping strategy

wgpu/src/backend.rs

@@ -354,8 +354,10 @@ impl backend::Text for Backend {
         size: f32,
         font: Font,
         bounds: Size,
+        advanced_shape: bool,
     ) -> (f32, f32) {
-        self.text_pipeline.measure(contents, size, font, bounds)
+        self.text_pipeline
+            .measure(contents, size, font, bounds, advanced_shape)
     }
 
     fn hit_test(
@@ -366,6 +368,7 @@ impl backend::Text for Backend {
         bounds: Size,
         point: Point,
         nearest_only: bool,
+        advanced_shape: bool,
     ) -> Option<core::text::Hit> {
         self.text_pipeline.hit_test(
             contents,
@@ -374,6 +377,7 @@ impl backend::Text for Backend {
             bounds,
             point,
             nearest_only,
+            advanced_shape,
         )
     }
 

wgpu/src/geometry.rs

@@ -334,6 +334,7 @@ impl Frame {
             font: text.font,
             horizontal_alignment: text.horizontal_alignment,
             vertical_alignment: text.vertical_alignment,
+            advanced_shape: text.advanced_shape,
         });
     }
 

wgpu/src/layer.rs

@@ -64,6 +64,7 @@ impl<'a> Layer<'a> {
                 font: Font::MONOSPACE,
                 horizontal_alignment: alignment::Horizontal::Left,
                 vertical_alignment: alignment::Vertical::Top,
+                advanced_shape: false,
             };
 
             overlay.text.push(text);
@@ -116,6 +117,7 @@ impl<'a> Layer<'a> {
                 font,
                 horizontal_alignment,
                 vertical_alignment,
+                advanced_shape,
             } => {
                 let layer = &mut layers[current_layer];
 
@@ -127,6 +129,7 @@ impl<'a> Layer<'a> {
                     font: *font,
                     horizontal_alignment: *horizontal_alignment,
                     vertical_alignment: *vertical_alignment,
+                    advanced_shape: *advanced_shape,
                 });
             }
             Primitive::Quad {

wgpu/src/layer/text.rs

@@ -24,4 +24,14 @@ pub struct Text<'a> {
 
     /// The vertical alignment of the [`Text`].
     pub vertical_alignment: alignment::Vertical,
+
+    /// Whether the text needs advanced shaping and font fallback.
+    ///
+    /// You will need to enable this flag if the text contains a complex
+    /// script, the font used needs it, and/or multiple fonts in your system
+    /// may be needed to display all of the glyphs.
+    ///
+    /// Advanced shaping is expensive! You should only enable it when
+    /// necessary.
+    pub advanced_shape: bool,
 }

wgpu/src/text.rs

@@ -83,6 +83,7 @@ impl Pipeline {
                             height: (section.bounds.height * scale_factor)
                                 .ceil(),
                         },
+                        advanced_shape: section.advanced_shape,
                     },
                 );
 
@@ -213,6 +214,7 @@ impl Pipeline {
         size: f32,
         font: Font,
         bounds: Size,
+        advanced_shape: bool,
     ) -> (f32, f32) {
         let mut measurement_cache = self.measurement_cache.borrow_mut();
 
@@ -223,6 +225,7 @@ impl Pipeline {
                 size,
                 font,
                 bounds,
+                advanced_shape,
             },
         );
 
@@ -244,6 +247,7 @@ impl Pipeline {
         bounds: Size,
         point: Point,
         _nearest_only: bool,
+        advanced_shape: bool,
     ) -> Option<Hit> {
         let mut measurement_cache = self.measurement_cache.borrow_mut();
 
@@ -254,6 +258,7 @@ impl Pipeline {
                 size,
                 font,
                 bounds,
+                advanced_shape,
             },
         );
 
@@ -364,6 +369,7 @@ impl Cache {
                     .family(to_family(key.font.family))
                     .weight(to_weight(key.font.weight))
                     .stretch(to_stretch(key.font.stretch)),
+                !key.advanced_shape,
             );
 
             let _ = entry.insert(buffer);
@@ -388,6 +394,7 @@ struct Key<'a> {
     size: f32,
     font: Font,
     bounds: Size,
+    advanced_shape: bool,
 }
 
 type KeyHash = u64;