Add support for more complex strokes (#505)

1 files changed, 51 insertions, 3 deletions

diff --git a/src/export/render.rs b/src/export/render.rs
index 8cee3aa6..f3c72ba0 100644
--- a/src/export/render.rs
+++ b/src/export/render.rs
@@ -11,7 +11,8 @@ use usvg::{FitTo, NodeExt};
 
 use crate::doc::{Frame, FrameItem, GroupItem, Meta, TextItem};
 use crate::geom::{
-    self, Abs, Color, Geometry, Paint, PathItem, Shape, Size, Stroke, Transform,
+    self, Abs, Color, Geometry, LineCap, LineJoin, Paint, PathItem, Shape, Size, Stroke,
+    Transform,
 };
 use crate::image::{DecodedImage, Image};
 
@@ -392,9 +393,36 @@ fn render_shape(
         canvas.fill_path(&path, &paint, rule, ts, mask);
     }
 
-    if let Some(Stroke { paint, thickness }) = &shape.stroke {
+    if let Some(Stroke {
+        paint,
+        thickness,
+        line_cap,
+        line_join,
+        dash_pattern,
+        miter_limit,
+    }) = &shape.stroke
+    {
+        let dash = dash_pattern.as_ref().and_then(|pattern| {
+            // tiny-skia only allows dash patterns with an even number of elements,
+            // while pdf allows any number.
+            let len = if pattern.array.len() % 2 == 1 {
+                pattern.array.len() * 2
+            } else {
+                pattern.array.len()
+            };
+            let dash_array =
+                pattern.array.iter().map(|l| l.to_f32()).cycle().take(len).collect();
+
+            sk::StrokeDash::new(dash_array, pattern.phase.to_f32())
+        });
         let paint = paint.into();
-        let stroke = sk::Stroke { width: thickness.to_f32(), ..Default::default() };
+        let stroke = sk::Stroke {
+            width: thickness.to_f32(),
+            line_cap: line_cap.into(),
+            line_join: line_join.into(),
+            dash,
+            miter_limit: miter_limit.0 as f32,
+        };
         canvas.stroke_path(&path, &paint, &stroke, ts, mask);
     }
 
@@ -525,6 +553,26 @@ impl From<Color> for sk::Color {
     }
 }
 
+impl From<&LineCap> for sk::LineCap {
+    fn from(line_cap: &LineCap) -> Self {
+        match line_cap {
+            LineCap::Butt => sk::LineCap::Butt,
+            LineCap::Round => sk::LineCap::Round,
+            LineCap::Square => sk::LineCap::Square,
+        }
+    }
+}
+
+impl From<&LineJoin> for sk::LineJoin {
+    fn from(line_join: &LineJoin) -> Self {
+        match line_join {
+            LineJoin::Miter => sk::LineJoin::Miter,
+            LineJoin::Round => sk::LineJoin::Round,
+            LineJoin::Bevel => sk::LineJoin::Bevel,
+        }
+    }
+}
+
 /// Allows to build tiny-skia paths from glyph outlines.
 struct WrappedPathBuilder(sk::PathBuilder);