Feature: Add support for interior polygons

README.md

@@ -14,13 +14,12 @@ For now, see the [tests](tests/test_extrusion.rs). More examples coming soon!
 
 ## Limitations
 
-* Currently supports only stencil fonts
-  * Right now all regions returned are exterior regions. Any glyphs with interiors will fail to extrude. Since stencil fonts have no interiors, they work well.
-* Rendering using Fornjot is slow - try exporting to an STL and viewing in another viewer.
+* Unlikely to support fonts with nested features (like a zero with a dot in the center).
+* Rendering using Fornjot is slow - try exporting to an STL/OBJ/3MF and viewing in another viewer.
+* All glyphs are individually normalized to a height of 1 - this should be changed, but I need to learn more about fonts first.
 
 ## Future
 
-* Support for interior polygons
 * Support string generation (currently only single glyph at a time)
 * Reduce number of vertices used
 

src/lib.rs

@@ -1,6 +1,13 @@
 use anyhow::{anyhow, Result};
 use bezier_rs::{Bezier, TValueType};
-use fj::core::{objects::Region, operations::build::BuildRegion, services::Services};
+use fj::{
+    core::{
+        objects::Region,
+        operations::{build::BuildRegion, update::UpdateRegion},
+        services::Services,
+    },
+    math::Winding,
+};
 use font::{glyph::Segment, Font, Glyph, Offset};
 
 const DEFAULT_RESOLUTION: usize = 5;
@@ -82,10 +89,17 @@ impl GlyphRegionBuilder {
                     .collect()
             })
             .collect();
-        let mut polygons = vec![];
+        let mut polygons: Vec<Region> = vec![];
         for mut region_points in point_lists {
             region_points.reverse();
-            polygons.push(Region::polygon(region_points, services));
+            let region = Region::polygon(region_points, services);
+            if region.exterior().winding() == Winding::Cw {
+                let last_polygon = polygons.remove(0);
+                let new_region = last_polygon.add_interiors([region.exterior().clone()]);
+                polygons.insert(0, new_region);
+            } else {
+                polygons.push(region);
+            }
         }
         polygons
     }