Add DISABLE_HINTING cache flag

examples/rich-text/src/main.rs

@@ -94,6 +94,7 @@ fn set_buffer_text(buffer: &mut BorrowedWithFontSystem<'_, Buffer>) {
                 .weight(Weight::BOLD)
                 .style(Style::Italic),
         ),
+        ("🌈", attrs.clone()),
         ("R", attrs.clone().color(Color::rgb(0xFF, 0x00, 0x00))),
         ("A", attrs.clone().color(Color::rgb(0xFF, 0x7F, 0x00))),
         ("I", attrs.clone().color(Color::rgb(0xFF, 0xFF, 0x00))),
@@ -114,11 +115,20 @@ fn set_buffer_text(buffer: &mut BorrowedWithFontSystem<'_, Buffer>) {
         ("C", attrs.clone().color(Color::rgb(0x00, 0xFF, 0x00))),
         ("O", attrs.clone().color(Color::rgb(0xFF, 0xFF, 0x00))),
         ("R", attrs.clone().color(Color::rgb(0xFF, 0x7F, 0x00))),
-        ("N\n", attrs.clone().color(Color::rgb(0xFF, 0x00, 0x00))),
+        ("N", attrs.clone().color(Color::rgb(0xFF, 0x00, 0x00))),
+        ("🦄\n", attrs.clone()),
         (
-            "生活,삶,जिंदगी 😀 FPS\n",
+            "生活,삶,जिंदगी 😀\n",
             attrs.clone().color(Color::rgb(0xFF, 0x00, 0x00)),
         ),
+        (
+            "Hinting enabled, ",
+            attrs.clone()
+        ),
+        (
+            "Hinting disabled\n",
+            attrs.clone().cache_key_flags(CacheKeyFlags::DISABLE_HINTING),
+        ),
     ];
 
     buffer.set_rich_text(

src/glyph_cache.rs

@@ -7,6 +7,8 @@ bitflags::bitflags! {
     pub struct CacheKeyFlags: u32 {
         /// Skew by 14 degrees to synthesize italic
         const FAKE_ITALIC = 1;
+        // Disable hinting
+        const DISABLE_HINTING = 2;
     }
 }
 

src/swash.rs

@@ -29,7 +29,7 @@ fn swash_image(
     let mut scaler = context
         .builder(font.as_swash())
         .size(f32::from_bits(cache_key.font_size_bits))
-        .hint(true)
+        .hint(!cache_key.flags.contains(CacheKeyFlags::DISABLE_HINTING))
         .build();
 
     // Compute the fractional offset-- you'll likely want to quantize this
@@ -80,7 +80,7 @@ fn swash_outline_commands(
     let mut scaler = context
         .builder(font.as_swash())
         .size(f32::from_bits(cache_key.font_size_bits))
-        .hint(true)
+        .hint(!cache_key.flags.contains(CacheKeyFlags::DISABLE_HINTING))
         .build();
 
     // Scale the outline