core: Always enable kerning for device fonts

The kerning setting works only for embedded fonts, and it does not
affect device fonts at all. Kerning is always enabled for device fonts.

Flash documentation also mentions that the kerning setting only affects
embedded fonts.

Author: kjarosh

core/src/font.rs

@@ -411,6 +411,10 @@ pub enum FontType {
 }
 
 impl FontType {
+    pub fn is_device(self) -> bool {
+        self == Self::Device
+    }
+
     pub fn is_embedded(self) -> bool {
         self != Self::Device
     }
@@ -744,15 +748,16 @@ pub trait FontLike<'gc> {
         // TODO [KJ] I'm not sure whether we should iterate over characters here or over code units.
         //   I suspect Flash Player does not support full UTF-16 when displaying and laying out text.
         let mut char_indices = text.char_indices().peekable();
-        let has_kerning_info = self.has_kerning_info();
+        let kerning_enabled =
+            self.has_kerning_info() && (self.font_type().is_device() || params.kerning);
         let mut x = Twips::ZERO;
         while let Some((pos, c)) = char_indices.next() {
             let c = c.unwrap_or(char::REPLACEMENT_CHARACTER);
             if let Some(render_data) = self.get_glyph_render_data(c) {
                 let glyph = render_data.glyph;
                 let scale = params.height.get() as f32 / render_data.font.scale();
                 let mut advance = glyph.advance();
-                if has_kerning_info && params.kerning {
+                if kerning_enabled {
                     let next_char = char_indices.peek().cloned().unwrap_or((0, Ok('\0'))).1;
                     let next_char = next_char.unwrap_or(char::REPLACEMENT_CHARACTER);
                     advance += self.get_kerning_offset(c, next_char);