1 files changed, 169 insertions, 0 deletions
diff --git a/third_party/rust/aa-stroke/src/c_bindings.rs b/third_party/rust/aa-stroke/src/c_bindings.rs
new file mode 100644
index 0000000000..fb21791fda
--- /dev/null
+++ b/third_party/rust/aa-stroke/src/c_bindings.rs
@@ -0,0 +1,169 @@
+use crate::{filled_circle_with_path_builder, PathBuilder, Point, StrokeStyle, Stroker};
+
+type OutputVertex = crate::Vertex;
+
+#[repr(C)]
+pub struct VertexBuffer {
+    data: *const OutputVertex,
+    len: usize
+}
+
+#[no_mangle]
+pub extern "C" fn aa_stroke_new(
+    style: &StrokeStyle,
+    output_ptr: *mut OutputVertex,
+    output_capacity: usize,
+) -> *mut Stroker {
+    let mut s = Stroker::new(style);
+    if output_ptr != std::ptr::null_mut() {
+        let slice = unsafe { std::slice::from_raw_parts_mut(output_ptr, output_capacity) };
+        s.set_output_buffer(slice);
+    }
+    Box::into_raw(Box::new(s))
+}
+
+#[no_mangle]
+pub extern "C" fn aa_stroke_move_to(s: &mut Stroker, x: f32, y: f32, closed: bool) {
+    s.move_to(Point::new(x, y), closed);
+}
+
+#[no_mangle]
+pub extern "C" fn aa_stroke_line_to(s: &mut Stroker, x: f32, y: f32, end: bool) {
+    if end {
+        s.line_to_capped(Point::new(x, y))
+    } else {
+        s.line_to(Point::new(x, y));
+    }
+}
+
+#[no_mangle]
+pub extern "C" fn aa_stroke_curve_to(s: &mut Stroker, c1x: f32, c1y: f32, c2x: f32, c2y: f32, x: f32, y: f32, end: bool) {
+    if end {
+        s.curve_to_capped(Point::new(c1x, c1y), Point::new(c2x, c2y), Point::new(x, y));
+    } else {
+        s.curve_to(Point::new(c1x, c1y), Point::new(c2x, c2y), Point::new(x, y));
+    }
+}
+
+/* 
+#[no_mangle]
+pub extern "C" fn aa_stroke_quad_to(s: &mut Stroker, cx: f32, cy: f32, x: f32, y: f32) {
+    s.quad_to(cx, cy, x, y);
+}*/
+
+#[no_mangle]
+pub extern "C" fn aa_stroke_close(s: &mut Stroker) {
+    s.close();
+}
+
+#[no_mangle]
+pub extern "C" fn aa_stroke_finish(s: &mut Stroker) -> VertexBuffer {
+    let stroked_path = s.get_stroked_path();
+    if let Some(output_buffer_size) = stroked_path.get_output_buffer_size() {
+        // if let Some(output_buffer) = stroked_path.output_buffer {
+        //     dbg!(&output_buffer[0..output_buffer_size]);
+        // }
+        VertexBuffer {
+            data: std::ptr::null(),
+            len: output_buffer_size,
+        }
+    } else {
+        let result = s.finish();
+        let len = result.len();
+        let vb = VertexBuffer { data: Box::leak(result).as_ptr(), len };
+        vb
+    }
+}
+
+#[no_mangle]
+pub extern "C" fn aa_stroke_vertex_buffer_release(vb: VertexBuffer)
+{
+    if vb.data != std::ptr::null() {
+        unsafe {
+            drop(Box::from_raw(std::slice::from_raw_parts_mut(vb.data as *mut OutputVertex, vb.len)));
+        }
+    }
+}
+
+#[no_mangle]
+pub unsafe extern "C" fn aa_stroke_release(s: *mut Stroker) {
+    drop(Box::from_raw(s));
+}
+
+#[no_mangle]
+pub extern "C" fn aa_stroke_filled_circle(
+    cx: f32, cy: f32, radius: f32, output_ptr: *mut OutputVertex, output_capacity: usize
+) -> VertexBuffer {
+    let mut path_builder = PathBuilder::new(1.);
+    if output_ptr != std::ptr::null_mut() {
+        let slice = unsafe { std::slice::from_raw_parts_mut(output_ptr, output_capacity) };
+        path_builder.set_output_buffer(slice);
+    }
+
+    filled_circle_with_path_builder(&mut path_builder, Point::new(cx, cy), radius);
+
+    if let Some(output_buffer_size) = path_builder.get_output_buffer_size() {
+        VertexBuffer {
+            data: std::ptr::null(),
+            len: output_buffer_size,
+        }
+    } else {
+        let result = path_builder.finish();
+        let len = result.len();
+        let vb = VertexBuffer { data: Box::leak(result).as_ptr(), len };
+        vb
+    }
+}
+
+
+#[test]
+fn simple() {
+    let style = StrokeStyle::default();
+    let s = unsafe { &mut *aa_stroke_new(&style, std::ptr::null_mut(), 0) } ;
+    aa_stroke_move_to(s, 10., 10., false);
+    aa_stroke_line_to(s, 100., 100., false);
+    aa_stroke_line_to(s, 100., 10., true);
+    let vb = aa_stroke_finish(s);
+    aa_stroke_vertex_buffer_release(vb);
+    unsafe { aa_stroke_release(s) } ;
+}
+
+#[test]
+fn output_buffer() {
+    let style = StrokeStyle::default();
+    let mut output = Vec::new();
+    output.resize_with(1000, || OutputVertex{x: 0., y: 0., coverage: 0.});
+    let s = unsafe { &mut *aa_stroke_new(&style, output.as_mut_ptr(), output.len()) } ;
+    aa_stroke_move_to(s, 10., 10., false);
+    aa_stroke_line_to(s, 100., 100., false);
+    aa_stroke_line_to(s, 100., 10., true);
+
+    let vb = aa_stroke_finish(s);
+    assert_ne!(vb.len, 0);
+    assert_eq!(vb.data, std::ptr::null());
+    aa_stroke_vertex_buffer_release(vb);
+    unsafe { aa_stroke_release(s) } ;
+}
+
+#[test]
+fn filled_circle_output_buffer() {
+    use crate::Vertex;
+    let mut output = Vec::new();
+    output.resize_with(1000, || OutputVertex{x: 0., y: 0., coverage: 0.});
+    let center = Point::new(100., 100.);
+    let radius = 33.;
+
+    let vb = aa_stroke_filled_circle(center.x, center.y, radius, output.as_mut_ptr(), output.len());
+    assert_ne!(vb.len, 0);
+    assert_eq!(vb.data, std::ptr::null());
+    let result = &output[0..vb.len];
+    let min_x  = result.iter().map(|v: &Vertex| v.x).reduce(|a, b| a.min(b)).unwrap();
+    let max_x  = result.iter().map(|v: &Vertex| v.x).reduce(|a, b| a.max(b)).unwrap();
+    let min_y  = result.iter().map(|v: &Vertex| v.y).reduce(|a, b| a.min(b)).unwrap();
+    let max_y  = result.iter().map(|v: &Vertex| v.y).reduce(|a, b| a.max(b)).unwrap();
+    assert_eq!(min_x, center.x - (radius + 0.5));
+    assert_eq!(max_x, center.x + (radius + 0.5));
+    assert_eq!(min_y, center.y - (radius + 0.5));
+    assert_eq!(max_y, center.y + (radius + 0.5));
+}
+