Start work on emoji

WIP

piet-gpu/src/lib.rs

@@ -192,7 +192,7 @@ fn render_text_test(rc: &mut impl RenderContext) {
     //rc.transform(Affine::new([0.2, 0.0, 0.0, -0.2, 200.0, 800.0]));
     let layout = rc
         .text()
-        .new_text_layout("hello piet-gpu text!")
+        .new_text_layout("\u{1f600}hello piet-gpu text!")
         .default_attribute(TextAttribute::FontSize(100.0))
         .build()
         .unwrap();

piet-gpu/src/render_ctx.rs

@@ -492,7 +492,7 @@ impl PietGpuRenderContext {
     pub(crate) fn append_path_encoder(&mut self, path: &PathEncoder) {
         let elements = path.elements();
         self.elements.extend(elements.iter().cloned());
-        self.pathseg_count += elements.len();
+        self.pathseg_count += path.n_segs();
     }
 
     pub(crate) fn fill_glyph(&mut self, rgba_color: u32) {

piet-gpu/src/text.rs

@@ -16,7 +16,7 @@ use crate::render_ctx::{self, FillMode};
 use crate::PietGpuRenderContext;
 
 // This is very much a hack to get things working.
-const FONT_DATA: &[u8] = include_bytes!("../third-party/Roboto-Regular.ttf");
+const FONT_DATA: &[u8] = include_bytes!("c:\\Windows\\Fonts\\seguiemj.ttf");
 
 #[derive(Clone)]
 pub struct Font {
@@ -53,6 +53,9 @@ struct Glyph {
 #[derive(Default)]
 pub struct PathEncoder {
     elements: Vec<Element>,
+    n_segs: usize,
+    // If this is zero, then it's a text glyph and should be followed by a fill
+    n_colr_layers: usize,
 }
 
 impl PietGpuText {
@@ -128,6 +131,7 @@ impl Font {
         let mut scale_context = ScaleContext::new();
         let mut scaler = scale_context.builder(self.font_ref).size(2048.).build();
         let mut encoder = PathEncoder::default();
+        println!("glyph {} has_color_outlines {}", glyph_id, scaler.has_color_outlines());
         if let Some(outline) = scaler.scale_outline(glyph_id) {
             let verbs = outline.verbs();
             let points = outline.points();
@@ -186,6 +190,7 @@ impl Font {
                 }
             }
         }
+        encoder.n_segs = encoder.elements.len();
         encoder
     }
 }
@@ -307,6 +312,10 @@ impl PathEncoder {
     pub(crate) fn elements(&self) -> &[Element] {
         &self.elements
     }
+
+    pub(crate) fn n_segs(&self) -> usize {
+        self.n_segs
+    }
 }
 
 fn convert_swash_point(v: Vector) -> [f32; 2] {