From 5c469013c78c8d01d9ef9005109c4ab319b34091 Mon Sep 17 00:00:00 2001
From: Raph Levien <raph@google.com>
Date: Thu, 12 Jan 2023 21:07:29 -0800
Subject: [PATCH] Fix even-odd rule

This works with winding numbers even larger than 2.
---
 shader/fine.wgsl | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/shader/fine.wgsl b/shader/fine.wgsl
index cd40e18..46f180e 100644
--- a/shader/fine.wgsl
+++ b/shader/fine.wgsl
@@ -139,8 +139,8 @@ fn fill_path(tile: Tile, xy: vec2<f32>, even_odd: bool) -> array<f32, PIXELS_PER
     if even_odd {
         // even-odd winding rule
         for (var i = 0u; i < PIXELS_PER_THREAD; i += 1u) {
-            let a = abs(area[i]);
-            area[i] = select(a, 2.0 - min(a, 2.0), a > 1.0);
+            let a = area[i];
+            area[i] = abs(a - 2.0 * round(0.5 * a));
         }
     } else {
         // non-zero winding rule